State of Toxic Substances in Maine 2008
This chapter of the report examines how toxic contamination affects Mainers. We focus specifically on three heavy metals: lead, arsenic and mercury; contaminants that pose serious risks to human health. In our analysis, we summarize the sources of contamination, rates of exposure, and known and predicted human health effects for lead, arsenic and mercury.
The threat of lead exposure is most prevalent for children under the age of two; and today they are exposed primarily through lead-based paint on houses built before 1950. In Maine, childhood lead poisoning is concentrated particularly in urban areas with a high percentage of older housing units and a high percentage of rental housing. Mainers are exposed to arsenic primarily through drinking water from private wells that have been contaminated through the natural degradation of arsenical bedrock. The burden of arsenic contamination is disproportionately focused on the rural poor who do not have the means to pay for expensive filtration systems. This demographic also lacks access to education about well water testing and the human health effects caused by elevated levels of arsenic. Mercury levels in the Maine environment remain high, putting 10-20% of women of child-bearing age at risk for having babies with birth defects (MDEP 2005). Maine reduced its in-state mercury releases by 99% between 1994 and 2008 and has maintained emissions near zero since 2000. EPA has failed to apply the immediate and stringent controls of the Clean Air Act to electric utilities, however, and coal-fired power plants in the Midwest and other industrial centers continue to emit high amounts of mercury air emissions which travel on prevailing winds to Maine.
To facilitate a healthier environment in Maine, we recommend increased federal funding to be given to the state government to allow for wider testing for toxics and better toxics education. More strict federal regulation would speed chemical hazard abatement and comprehensive national emission reductions. Maine also needs to continue health studies to further understand the scope and severity of the potential health effects of toxic exposure, and to support better public education about toxic chemicals.
The average person in the US is exposed to thousands of hazardous chemicals throughout their lifetime. An estimated 85% of the 3,000 most commonly used industrial chemicals lack publicly-available data on their health and environmental impacts (McCally 2002). In the US, after World War II, there was a surplus of hazardous chemicals. Although originally intended for chemical warfare, US industries began to market them for public use despite their proven and suspected hazards to the environment and human health Industries were not required to demonstrate the safety of these chemicals before using them in their products (Aroian 2008). Rachel Carson's publishing of Silent Spring, in 1962 brought knowledge about toxic contamination to the general public (Rolle 2007). In the 1970s, a series of environmental catastrophes, including the burning of the Cuyahoga River in Ohio and the toxic waste disaster at Love Canal in New York, increased awareness of environmental and human health risks of toxic chemicals. These events contributed to increased demand for a public right-to-know about chemicals in consumer products and their human health risks and for increased government regulation. As a result of this increased public environmental awareness, the first major environmental regulations of toxic chemicals were instituted in the 1970's.
Heavy metals are chemicals of particular concern; five out of the top 20 chemicals on the priority list of the most hazardous chemicals at Superfund sites are heavy metals (Scorecard 2005). Anthropogenic activities have increased the natural flux of metals in the environment to levels hazardous to human health, and humans now bear the brunt of this pollution. Heavy metals tend to bioaccumulate in human tissues and can lead to increased cancer rates, blood disorders, and neurological dysfunction (INLES 2008).
Toxic chemicals from industrial, agricultural, and naturally occurring sources end up in our food, water, and household products (WTC 2008). Recently, there has been renewed concern about the health threats posed by toxic chemicals through the media and new scientific studies. Current environmental activism focuses on the replacement of hazardous chemicals with environmentally safe alternatives, and increasing federal, state, and local regulations are aimed at limiting human exposure.
Numerous heavy metals affect human health, but the focus of this report is on three heavy metals which are a particular threat to Mainers: lead, arsenic, and mercury. Maine's location and history cause the state to suffer from a disproportionately large amount of toxic contamination. The toxic levels evident in Maine are comparable to bigger states with much larger agricultural and industrial sectors that contribute to increased contamination. High levels of lead, arsenic, and mercury contamination result because of Maine's particular sizable older urban housing stock, geologic structure, and geographic placement. Approximately 40% of housing units in Maine were constructed before 1959 (MSPO 2000), and structures built prior to 1950 are more likely to contain hazardous lead-based paint. The primary health concern for lead is that low levels of chronic lead exposure have toxic effects on children's brains (EWG 2008). As a result, in Maine, there has been strong activism to promote research to better understand specific health issues associated with elevated blood lead levels (EBLLs) and to drastically decrease the number of cases of childhood lead poisoning.
Maine is located above a geologic band of arsenic which contaminates many of its water supplies with high levels of arsenic. Maine's agricultural industry contributes a small amount of arsenic into the groundwater tables from the run-off of arsenical pesticides, but the primary safety concern in Maine is drinking water from private wells that may be contaminated with high levels of arsenic (Schmitt 2005). Federal law protects those receiving water from municipal water sources from high levels of arsenic, but private well water remains largely untested for arsenic and completely unregulated (EPA 2007a). Those who rely on private well water may inadvertently ingest dangerous levels of arsenic without knowing.
A large percentage of Maine's mercury contamination comes from sources outside of the state. Maine's position on the East Coast makes it the recipient of large amounts of contaminated air. The jet stream carries mercury emissions from factories in the Midwest and southern New England industrial centers that release emissions containing mercury (Prindiville 2006).
The Alliance for a Clean and Healthy Maine conducted a unique study to determine what toxics affect the health of Mainers. This study, entitled Body of Evidence, found that the 13 volunteers had 46 different toxics (of the 71 tested) contaminating their bodies, including: lead, mercury and arsenic (ACHM 2007b). These heavy metals can persist in Maine's environment for many years making successful management and clean-up of these three contaminants difficult. Maine is a leader in awareness and activism in the toxics field, and Mainers have advocated for important laws in their legislature to protect citizens from exposure to lead, arsenic, and mercury. Agencies in Maine, like the Department of Health and Human Service and the Department of Environmental Protection are focusing on identifying "hot spots" for naturally-occurring arsenic, protecting children from lead consumption, and decreasing Mainers exposure mercury through education and awareness programs.
Focus of the Chapter
In this chapter we summarize the most important state laws and polices that regulate heavy metal contamination in Maine; identify the sources of lead, arsenic, and mercury contamination in Maine's environment; and evaluate how these toxic chemicals affect the health of Mainers. Additionally, we compare how Maine's toxics legislation, education, and remediation compares to other states. Finally, we offer recommendations to help Maine further reduce its levels of toxic contamination.
Laws and Institutions
To fully understand the scope of the toxic contamination problem in the US and Maine, it is important to identify how toxics currently are regulated. Toxics are controlled by both the US government and by state governments. The following sections detail the laws relating to lead, arsenic and mercury.
Federal Laws Relating to Two or More of the Chemicals Lead, Arsenic, and Mercury
Table 2.1 Federal laws relating to two or more of the specified toxic substances. The Clean Air Act applies to both lead and mercury, the Clean Water Act applies to arsenic and mercury, and the Safe Drinking Water Act applies to lead, arsenic, and mercury.
Clean Air Act (1970)
In 1970, when Congress enacted the Clean Air Act (CAA), it established the National Ambient Air Quality Standards (NAAQS) for six criteria pollutants, including lead. CAA also requires that EPA control the air emissions of hazardous air pollutants which pose a threat to human health. CAA mandated the phase-out of leaded gasoline by the mid-1980s and the regulation of smokestack emissions from smelters. EPA was slow to apply CAA to hazardous chemicals (Borgford-Parnell 2008), however, so in 1990 Congress amended CAA , requiring EPA to regulate 189 specific hazardous air pollutants (HAPs) (EPA 2008a), including mercury. EPA must regulate all existing sources of these HAPs with the maximum achievable control technology (MACT) (EPA 2008a). EPA may not remove a source from the regulated list unless EPA can prove that emissions from this source do not pose a threat to human health or to the environment (Borgford-Parnell 2008).
Clean Water Act (1974)
The Clean Water Act endeavors to "restore and maintain the chemical, physical, and biological integrity of the nation's waters by preventing point and non-point pollution sources, providing assistance to publicly owned treatment works for the improvement of wastewater treatment, and maintaining the integrity of wetlands" (EPA 2008c). CWA sets allowable contamination levels for both arsenic and mercury. One of the goals of this law is to make all waters in the US "fishable" and "swimmable". Water bodies that do not meet these criteria use Total Maximum Daily Load (TMDL) guidelines to establish a baseline "amount of a pollutant that a water body can receive and still safely meet water quality standards" (EPA 2008c). Waters in agricultural areas that use pesticides, industrial sectors, and in locations with high levels of naturally occurring arsenic often do not meet TMDL standards. CWA also requires that all point sources must obtain permits to emit mercury in order to limit mercury contamination in water.
Safe Drinking Water Act (1974)
The Safe Drinking Water Act (SDWA) establishes national health-based standards for drinking water to protect against both naturally-occurring and man-made contaminants" (EPA 2004a). In Maine, regulations established by the SDWA apply mostly to controlling arsenic and lead contamination in drinking water, because consumption of mercury-contaminated water is not a major threat to human health in Maine. SDWA establishes maximum contaminant levels (MCLs), which are the highest levels of lead, arsenic, and mercury in drinking water "below which there is no known or expected risk to health" (EPA 2004a). SDWA enforces guidelines for all public drinking water systems in the US, but not for private well water. In 1991, EPA passed the Lead and Copper Rule, an amendment to SDWA, which set a maximum contaminant level goal (MCLG) of 0 parts per billion (ppb) for lead in drinking water and an MCL of 15 ppb in drinking water. In addition, SDWA prevents the use or sale of any pipe, plumbing fitting or fixture, solder, or flux that contains lead. The 1996 amendments to SDWA reduced the MCL for arsenic from 50 parts per billion (ppb) to 10 ppb, because the former MCL was deemed too high to protect human health.
Laws Relating to Lead
Two recently enacted federal laws, listed in Table 2.2, have the specific objective of decreasing childhood lead poisoning.
Table 2.2 Federal laws relating to lead.
Renovation, Repair, and Painting Rule
House renovation and demolition disturb lead-based paint and create hazardous lead dust, which leads to elevated blood lead levels (EBLLs) primarily in children. To protect against this risk, EPA issued this rule requiring the use of lead-safe renovation practices. Beginning in 2010, contractors performing renovation, repair and painting projects that disturb lead-based paint in homes, child care facilities, and schools, built before 1978, must be certified and must follow specific work practices to prevent lead contamination (EPA 2008i).
Consumer Product Safety Improvement Act
The US Congress focuses upon the prevention of lead poisoning in children and the regulation of lead in children's toys. In July, Congress passed the Consumer Product Safety Improvement Act, increasing the budget of the Consumer Product Safety Commission (CPSC), and providing funds to ban lead in children's toys to trace amounts and to lower lead safety standards. This act requires CPSC to set a lead standard of 0.01% within three years and to tighten the federal standard on lead paint to 0.009%. The act also requires CPSC to create and to maintain a publicly accessible database containing reports from consumers, state and local health officials and health care providers about harm relating to the use of consumer products.
Recently, the Maine Legislature enacted important laws regulating toxic lead exposure in Maine. The following laws, listed in Table 2.3 were enacted from December 2000 to April 2008.
Table 2.3 State laws relating to lead.
An Act To Amend The Maine Lead Poisoning Control Act
This amendment extends the lead poisoning surveillance program mandated by the Lead Poisoning Control Act. The original act required screening for lead poisoning for Maine children ages one and two and enrolled in the MaineCare (Medicaid) program. This amendment adds that all children ages one and two not covered by Maine Care also must now be screened, as increases in the levels of blood lead screening in the states benefit Maine's children. A 2000 study by the Maine Medical Assessment Foundation estimated that 6,410 lead poisoned children in Maine go unidentified and untreated annually (DHHS 2003a).
Lead Poisoning Control Act
A section of this act mandates a Lead Poisoning Prevention Fee, which requires that paint manufacturers pay a tax to sell their products that may contain trace amounts of lead. Beginning July 1, 2006, the state identified which manufactures of paint sold in Maine were responsible for paying the fee, and the taxes collected will benefit the Lead Poisoning Prevention Fund. This fee is expected to generate $800,000 a year to benefit this fund, which will be directed to primary prevention efforts, including outreach, education, and funding for community lead hazard testing and abatement.
An Act to Protect Children from Hazardous Lead-based Paint
This act mandates that the state analyze and summarize health care providers' lead screening information, and convey this information to state and local agencies and the general public. The act also specifies that the Department of Environmental Protection (DEP), the Maine State Housing Authority (MSHA), the Department of Health and Human Services (DHHS), and Maine Center for Disease Control and Prevention will recommend how the state should enforce lead poisoning prevention programs and achieve lead-safe housing to eliminate lead-poisoning.
An Act to Ensure that Children's Toys and Products are Free of Lead
This act has the purpose of measuring the lead level in children's toys. Beginning July 1, 2009, a person may not manufacture, knowingly sell, or distribute lead-containing children's products, excluding electronic products. This act may be enforced by the Attorney General, under the Maine Unfair Trade Practices Act, and any penalties collected will be paid to the Lead Poisoning Prevention Fund. The act also mandates that the DHHS continues to collect data about lead poisoning from children's toys and researches methods of protection against lead poisoning.
Laws Relating to Arsenic
Maine currently has a few laws in place regulating arsenic contamination. The following laws, listed in Table 2.4, were enacted over a time period from 1975 to 2006.
Table 2.4 State laws relating to arsenic.
Maine Pesticide Control Act (1975)
This act set a baseline for the first regulations on pesticide use in Maine. It clarifies when, how and who can use pesticides on agricultural crops in Maine and establishes penalties for non-compliance. Specifically, it targets mislabeling, unlawful distribution, the conditions of review and registration of pesticides, and how to apply for experimental use permits regarding their application. It pledges to comply with the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) and enforce all federally mandated pesticide regulation (MRS Title 7 Chapter 103 §3 1975).
Maine Board of Pesticides Control Law (1989)
This act established the body of control for the regulation of pesticide use in Maine. It clarifies who enforces and mandates policy regarding pesticide usage. The objective of this act is to "assure to the public the benefits derived from the safe, scientific and proper use of chemical pesticides while safeguarding the public health, safety and welfare, and for the further purpose of protecting natural resources of the State... and regulating the sale and application of chemical insecticides, fungicides, herbicides and other chemical pesticides, and to regulating the return and disposal of limited and restricted use pesticide containers" (MRS Title 22 Subtitle 2 Chapter 258-A §11 1989). Seven members, each appointed by the governor of Maine, compose this board which operates under the Department of Agriculture, Food and Rural Resources (MBPC 2008).
Arsenic Treated Wood Products Act (2003)
This act mirrors the establishment of a national voluntary ban on arsenic-treated wood products, defined as "wood or other forest products intended for outdoor use that have been pressure treated to reduce decay with a wood preservative containing inorganic arsenic or inorganic arsenic compounds including, but not limited to, chromated copper arsenate, more commonly referred to as CCA or similar-based arsenic-containing chemical compounds (MRS Title 38 Chapter 16-C §2 2003)". In this act, the state of Maineattempts to phase out arsenic treated lumber at a faster rate, because of awareness about the large host of ill health effects that come from exposure to arsenic. This act established that Maine retailers could not buy arsenic treated wood after April 9th, 2003 and that by 2004 it would be illegal to sell any arsenic treated wood products (Goad 2003).
Maine's Household Television and Computer Monitor Recycling Law (2006)
The establishment of this legislation aims to reduce the amount of pollution caused by heavy metals and other toxics (including arsenic) that leach out of improperly disposed of electronic equipment. It mandates that municipalities are fully responsible for the safe recycling of all computer monitors and televisions in Maine, requiring municipalities to make sure that all monitors are taken to consolidation facilities that count and ship all electronic equipment to the appropriate recycling center. Recycling centers must abide by the environmentally sound management practices, as established by Maine DEP (MDEP 2005a). The manufacturers of the items share some of the responsibility by defraying the cost of consolidation facility processes, such as the handling, transportation and recycling of these products. Manufacturers must also provide DEP with an annual report on how "recycling of its products generated as waste in Maine(MRS Title 38 Chapter 16 §1610 2006)."
Laws Relating to Mercury
Table 2.5 Federal laws relating to mercury.
Resource Conservation and Recovery Act (RCRA) (1976)
Under RCRA, EPA must monitor mercury wastes through production, transportation, and disposal. RCRA also limits emissions of incinerated mercury-containing toxic waste. States are responsible for most of the implementation of RCRA and may adopt stricter standards than those included in the federal law (EPA 2008g). With its recent restrictions or bans on the production, sale and disposal of many mercury-containing products, Maine is a forerunner among states in its application of RCRA.
Mercury-Containing and Rechargeable Battery Management Act (1996)
This act requires the phase-out of the use of mercury in batteries, and facilitates "the efficient and cost-effective disposal" of certain types of batteries (EPA 2007). It is directed towards battery producers and waste managers (EPA 2007b) but includes provisions to inform the public about proper battery disposal and to label certain types of batteries.
Table 2.6 State laws relating to mercury.
An Act to Reduce the Release of Mercury into the Environment from Consumer Products (1999)
This act limits the release of mercury from products into Maine's environment by limiting the sale and use of mercury-containing products and by informing the public about mercury used in products. Perhaps most importantly, it bans on the disposal of mercury-added products in solid waste facilities. Other sections of the act require product labeling, reductions in the use of mercury in dental offices, and the development of alternatives to mercury devices in automobiles. The act also establishes the Mercury Products Advisory Committee to limit the releases of mercury to the environment from consumer products.
An Act to Further Reduce Mercury Emissions from Consumer Products (2001)
This act further limits discharges of mercury into Maine's environment from manufactured goods. Under the act, manufacturers must notify DEP about mercury in their products before selling these items. The act includes additional restrictions on the sale and use of mercury-containing products in hospitals and in schools.
Stakeholders and Institutions for Lead, Arsenic and Mercury
EPA regulates sources of contamination and establishes national health-based limits for lead, arsenic, and mercury in air and waters in the US. EPA is also responsible for enforcing state compliance with its regulations. It sets standards for lead-safe renovation practices, limits agricultural operations' use of arsenical pesticides, and mandates that industrial sources restrict their mercury air emissions to ensure that mercury levels in the air and water do not exceed legal standards.
Other federal agencies also help to reduce human exposure to toxic chemicals. Centers for Disease Control and Prevention (CDC) monitor levels of toxics in the human body and identify health effects of these hazardous chemicals. CDC also provides people with services to help mitigate exposure to toxic chemicals, including information on health risks for particular segments of the population.
The Maine Department of Health and Human Services (DHHS) remains responsible for the majority of the regulation and the promotion of education and awareness regarding lead, mercury, and arsenic within the state. In 1992, DHHS created the Maine Childhood Lead Poisoning Prevention Program (MCLPPP), which monitors the incidence of childhood lead poisoning and assesses exposure risks in young children (DHHS 2003b). DHHS is responsible for testing samples from private well water for arsenic and frequently promotes vigilant testing to avoid health risks associated with elevated levels of arsenic in drinking water. DHHS also investigates the health risks posed by mercury-contaminated fish.
The Maine Department of Environmental Protection (DEP) protects the Maine air, water, and land from toxic contamination from household, industrial, and agricultural sources. DEP is particularly important in mercury regulation due to mercury's cycle through the air and water and the continued marketing of many mercury-containing products. Within DEP, the Bureau of Land and Water Quality (BLWQ) and the Bureau of Air Quality (BAQ) issue licenses for water and air and monitor discharges of hazardous chemicals from stationary and mobile sources (BAQ 2005, BLWQ 2005). BLWQ also oversees the Maine Board of Pesticide Control, which is responsible for regulating arsenical pesticides that are most commonly applied to blueberry, apple, and potato crops in Maine. The Bureau of Remediation and Waste Management (BRWM), also within DEP, regulates the generation, use, and disposal of household hazardous waste containing lead, arsenic, and mercury (BRWM 2005).
Several non-governmental organizations on the national and state level conduct scientific studies on toxic chemicals and work to reduce toxics contamination in Maine. The Environmental Working Group (EWG) creates national databases containing information available to the general public about levels of lead, arsenic, and mercury in regular human consumption and advocates for stricter regulation of health-based standards. More specifically, in Maine, Environmental Health Strategy Center (EHSC) is on the forefront of toxics awareness; the organization currently promotes increased education about the hazards of chemicals that humans are exposed to on a daily basis and supports new toxics legislation in Maine.
For this chapter, we conducted a literature and data review about regulatory policies, sources of contamination, and human exposure rates for lead, arsenic, and mercury in the US and in Maine. Internet resources from select national and state agencies and environmental non-profit organizations, including EPA, MDEP, EWG, and EHSC provided us with valuable information about Maine's current activities to reduce human health risks to these chemicals. We constructed tables and graphs in Microsoft Excel and maps in Geographic Imaging Systems (GIS) to illustrate the sources of contamination and the distribution of chemical exposure in Maine. We also determined how Maine differs from other states in terms of toxics contamination, and whether Maine has been successful in reducing citizen's exposure to these chemicals.
We interviewed the State Toxicologist at Maine DHHS, Andrew Smith, who provided us with data regarding town counts of EBLLs of children from 2003 to 2007. We hypothesized that percent of houses built before 1950, median value of housing unit, percent of total housing units that are rented, and median household income would all be variables that would be associated with EBLLs and that would best explain the distribution of EBLL counts. Lead paint is most commonly found in housing units built before 1950, but the data we collected from the Maine State Planning Office had already grouped housing age into ranges of years. As a result, percent of housing units built before 1959 was the closest estimate we had to percent of houses built before 1950. We used the SPSS statistical program to determine which variables were significant in determining the distribution of EBLL counts throughout the state of Maine. Non-parametric tests were more appropriate for our analysis because we could not assume a normal distribution for our small sample size. We used the Mann-Whitney U tests for two independent samples, because we had split each of our four variables into a separate low and a high group using the median value as a cutoff. We ran four tests and analyzed the EBLLs grouped by the low and high values of one of our variables for each test. Andrew Smith also provided us with data regarding arsenic contamination testing results of private well water in Maine, which were mapped using GIS to understand the location of the arsenic contamination hot-spots in Maine. Additionally, we used data from Toxic Release Inventory (TRI) to compare graphs to establish state and national mercury emissions and to analyze the distribution of mercury emissions by geographic area and by industry (EPA 2004b).
State of the Topic: Lead
Background of Lead
Lead chemically competes with and replaces calcium throughout the body, particularly in the bones, brain, blood and nervous system, which all depend on calcium to function properly (Davis 2002). According to the National Health and Nutrition Examination Survey, children between the ages of one and two are the most vulnerable to lead poisoning. In 1991, the CDC mandated that 10 micrograms per deciliter (µg/dL) was the allowable amount of lead in children age six and under, and it recommended universal blood lead screening of all children between the ages of six months and five years (McCally 2002).
The dominant source of lead dispersion into the environment for the past 50 years has been the use of lead organic compounds as anti-knock motor vehicle fuel additives. The phase-out of leaded gasoline, beginning in 1970, resulted in an enormous health achievement that successfully reduced childhood lead poisoning. Historically, another major contributor to lead in the environment was use of lead in paint. Lead was a major ingredient in most interior and exterior oil house paint until 1950 when acrylic and latex-based paints began to be produced. From the late 19th century to 1978, the US used 6.6 million tons of white lead in paint to make paint last longer and cling to surfaces better (Mielke 2005). In 1978, the CPSC completely removed leaded paint from markets.
In 1978, 13.5 million children in the US had EBLLs (EPA 2008f). On average, from 1976 to 1980, the median blood lead level for children was 15µg/dL, a blood lead concentration that currently is considered lead poisoning. Figure 2.1 depicts the effect that major public health policy actions, including the concurrent reduction of lead in automotive emissions, paint, and drinking water, had on blood lead levels in children; since 1978, children's average blood lead levels decreased by approximately 80% (AAP 2005). The American Academy of Pediatrics declared in 2005 that it no longer considers airborne lead as a major source of community exposure in the US.
Figure 2.1 Average median blood lead concentrations (µg/dL) of US children age one to five from 1976 to 1999. Line represents the current CDC health threshold of 10µg/dL for elevated blood lead levels (AAP 2005).
Today, lead is still used in a wide-variety of electronics, paint pigments, plastics, and ceramics. Studies suggest the primary sources of lead exposure for children include contaminated dust and contaminated residential soil from deteriorating older paint. Before lead was removed from paint, household paints contained as much as 50% lead by weight, and as a result, even limited exposure to older paint can result in the lead poisoning of a child (DHHS 2000). CDC estimates that 1 of every 20 children in the US suffers from sub-clinical lead poisoning (Markowitz and Rosner 2000).
Children are highly vulnerable to chemical toxins, including lead, because pound-for-pound of body weight, children drink more water, eat more food, and breathe more air than adults, resulting in disproportionate exposure. In addition, children undergo rapid growth and development and are therefore less able to process chemical toxins because their metabolic pathways are not yet mature (McCally 2002). Blood lead concentrations peak in children exposed to lead at approximately two years of age. But, cognitive damage due to lead poisoning does not become apparent until approximately five years of age when IQ becomes reliably testable (AAP 2005). In studies of the effects of lead exposure on elementary school children, those with high lead levels consistently under performed on a variety of tests of intelligence and behavior when compared to their classmates with low lead levels. On average, those children with higher levels also had lower IQ's at the age of ten and higher rates of criminal and delinquent behavior in adolescence (Davis 2002). These effects of lead poisoning remain significant even while controlling for these childrens neighborhood crime rates, mother's education, race, and family income (Mielke 2005).
Maine DHHS reports that 550 children in Maine are officially lead-poisoned each year. A compilation of six years of surveillance data from 1994 to 1999 revealed that one in nine Maine children screened was found to have EBLLs (DHHS 2000). The Maine Childhood Lead Poisoning Prevention Program (MCLPPP) has identified that the main contributor to children's EBLLs is dust from lead paint in housing built before 1950 with lead risks that have not been abated. When MCLPPP examined National Health and Nutrition Examination Survey data, collected for lead poisoned children in the US between 2000 and 2002, it found that 87% of lead poisoned children lived in homes constructed prior to 1950, and that 65% of these children's homes had reported recent or ongoing renovations or remodeling activity that lead to more releases of lead contaminated dust into the air (DHHS 2003b). The Maine State Housing Authority (MSHA) reports that about 80% of all Maine homes and apartments built before 1978 contain some lead-based paint, and that the likelihood, extent, and concentration of lead-based paint increase with the building's age (MSHA 2008).
Current State of Lead
The percent of children under six with EBLLs at or above the threshold level of 10µg/dL has been decreasing in Maine, New England, and the US over the past 10 years (Figure 2.2). Maine historically has lower EBLLs rates than the rest of the US. However, in recent years, the percent of Maine children with EBLL's measured slightly higher than the percentages in New England and the US. Maine currently has multiple childhood lead poisoning prevention initiatives, but DHHS calls lead poisoning "Maine's number one childhood environmental health hazard" in terms of known risk, prevalence, and consequences (DHHS 2000). Despite the hard work of these prevention programs, Maine has not been successful in reducing the percentage of children with EBLLs to a level below the current US average.
Figure 2.2 Percent of children with elevated blood lead levels (>10µg/dL) from 1997 to 2006 for Maine, New England, and US (CDC 2007).
Higher EBLL counts are concentrated in Maine's southern urban areas with the towns of Portland, Lewiston, Bangor, and Auburn recording the highest counts, respectively (Figure 2.3). For privacy reasons, counts of fewer than six are reported as one to five. Scientific literature suggests that factors such as low income and old housing unit age, low home value, and rental of a house all positively contribute to elevated blood lead levels in children. Our analysis determined that towns with a higher percentage of housing units built before 1959 are significantly more likely to have children with EBLLs (p-value 0.000), as the highest percentages of old houses occur in the same towns that had more lead poisoned children. We also determined that towns with a higher percentage of rental units were significantly more likely to have children with EBLLs (p-value 0.000), as the highest percentages of rental housing also occur in the same towns that had more children with lead poisoning.
Figure 2.3 The distribution of the total number of children under the age of six with blood lead levels exceeding 10µg/dL (EBLL) by township from 2003 to 2007. Percent of housing units built before 1959 by township (A). Percent of housing units that are rented by township (B) (MSPO 2000b, Smith 2008b).
The towns with the highest EBLL counts in southern Maine contain older houses because these areas were among the first population and industrial centers in Maine. Today, Portland, Lewiston, Bangor, and Auburn are all large urban areas with more than 20,000 residents living within their city limits (US Census Bureau 2000). Also, people living in rental housing also are more at risk for lead exposure. Lead hazards in rental housing units are less often abated because there are no incentives for landlords to clean up lead hazards. The US Department of Housing and Urban Development (HUD) mandates that owners of any home built before 1978 inform potential buyers and renters about known lead hazards, but the owners are not required to test for lead nor clean up existing lead hazards (HUD 2008).
However, township level maps mask important variations within Maine towns. For a more detailed analysis, we observe one of the significant variables, percent of housing units built before 1959 on the level of census block group (Figure 2.4). Old housing units are most concentrated in the centers of larger urban areas in southern Maine. When we focus in on the four towns that had the highest counts of EBLLs from 2003 to 2007, Portland, Lewiston, Bangor, and Auburn, we realize that that the smaller urban census block groups in these towns have the highest percentages of housing units built before 1959. Children living in these areas are at a high risk of lead poisoning. Additionally, high lead levels in soil are found around urban houses with exterior lead paint and where there was heavy vehicle traffic before leaded gasoline was phased out. Therefore, old houses in urban areas are at a high risk for contaminated soils, as the lead emitted for over 50 years in car exhaust still remains in the soil (Mieke 2005). However, no federal programs exist to remediate lead-contaminated soil, except in Superfund sites. According to CDC and EPA, insufficient information is available on which to base such a program (Ryan 2004).
Figure 2.4 Percent of housing units built before 1959 by census block group. A focus on the percent of housing units built before 1959 in the urban areas of Bangor (A), Lewiston/Auburn (B), and Portland (C) (U.S. Census Bureau 2000).
DHHS has determined that housing stock areas where more than 26% of the housing is built before 1950 qualify as high risk areas for lead poisoning, and health-providers in these areas must achieve universal blood screening of all one and two-year-olds (DHHS 2000). This qualification reveals the great extent of the lead poisoning problem in Maine, because the majority of census block groups in Maine have more than 26% of their housing units built before 1959.
The prevalence of an older housing stock with remaining lead paint hazards contributes to children's widespread lead exposure in Maine. Childhood lead prevention programs work hard to increase testing rates and to ultimately eliminate childhood lead poisoning. One of the main goals of Maine's Childhood Lead Poisoning Prevention Program (MCLPPP) is to identify areas in Maine where children are at a high risk of lead poisoning in order to better focus prevention efforts (DHHS 2003b). Under the current system, health providers discover children with lead poisoning to identify hazardous housing units, and then aid in the abatement of these lead hazards. MCLPPP is working to prevent childhood lead poisoning before it occurs. The new lead poisoning prevention fee, as mandated by the lead poisoning control act in 2005, will provide funding for primary prevention efforts. The first prevention fees will be collected in April 2007, based upon the paint sales of the previous year (MRS Title 22 Chapter 252 § 1322 - F). DHHS has developed multifaceted plans to use this fee money for community outreach and education in high-risk communities with targeted mailings to families with one and two year old children and education of landlords and contractors about lead hazards and lead-safe renovation practices.
EBLLs pose not only a health problem for Maine but also an economic problem. Therefore, Maine's health-care providers and environmental health organizations are justified in their high energy focus on the problem of childhood lead poisoning because EBLLs affect children's intellectual development, social function, school performance, employment, and lifetime earnings and achievements (CDC 2008). Cost-benefit analyses comparing housing remediation costs against the value of increased IQs from the removal of lead paint determine that the removal of lead paint is cost-effective and that economic gains result from the reduction of children's blood lead levels (Grosse et. al. 2002). Each one point rise in IQ raises a worker's productivity by 1.76% - 2.38%, resulting in an economic benefit of $US 110-319 billion for a generation of children (AAP 2005).
Additionally, Maine has a growing immigrant and refugee population, particularly in larger cities, including Portland, Lewiston, Bangor, and Auburn. In our analysis, median household income was not significantly associated with EBLLs. However, if immigrants and refugees have low incomes, and are moving into large urban areas, they may not have the option to move into newer housing or well-maintained housing in which lead hazards have been abated properly. Therefore, an increasing number of these immigrants and refugees will likely move into communities with older housing units in lower income neighborhoods, and their children might have an increased risk of lead exposure and lead poisoning. The MCLPPP has not been collecting race nor ethnicity data on the children screened for lead exposure, because Maine hospitals, laboratories and physicians do not report race and ethnicity. As a result, policy-makers lack the resources to determine whether there is a need for the regulation of EBLLs in immigrant and refugee communities in Maine (DHHS 2003b).
Furthermore, the current US standard of 10µg/dL arguably does not represent the actual threshold level for lead poisoning. Blood lead levels below 10µg/dL have been associated with neurocognitive deficits in children (Surkan 2007). A recent study specifically designed to assess whether blood lead levels within the health standard were associated with health impacts found that children with blood lead levels of 5-10µg/dL had significantly lower scores on IQ, achievement, attention, and working memory tests than did children in the reference group, who had levels of 1-2 µg/dL. The study deemed it inappropriate to regard 10µg/dL as the lowest observed adverse effect threshold and reported that blood lead levels of 5-10µg/dL in school-age children are associated with deficits in intelligence, visual-spatial skills, executive function, and IQ adjusted achievement (Surkan 2007). Further studies are needed to confirm that 10µg/dL is a level with no biological threshold significance. If we have not identified a true threshold for lead induced cognitive dysfunction in children, then a higher number of children in Maine could be, unbeknownst to health officials, suffering from the effects of toxic lead exposure.
After analyzing the current state and implications of lead poisoning in Maine, we now examine two possible scenarios for the future. The first scenario presents the possibility that the problem of lead poisoning in Maine worsens considerably, while the second scenario explores how continued effective actions of lead prevention programs could lead to the successful control of lead poisoning in Maine.
Scenario 1: Leaded Mainers
One possible scenario is that lead poisoning remains a large problem in Maine, because in the next few years, further scientific studies may confirm that 10µg/dL is not an adequate threshold for preventing health effects of lead exposure. The scientific evidence that justifies the need to decrease the federal standard for lead poisoning raises concerns for Mainers in particular. The average blood lead level for Maine children is more than twice as high as the national average (EHSC 2001). In 2002, the average blood lead level for children in the US was 1.9µg/dL (AAP 2005). This level is well below the lead poisoning threshold of 10µg/dL, and scientific studies have found no observed health effects in children with blood lead levels below 2µg/dL (Surkan 2007). If the lead poisoning threshold is lowered to this concentration, then this change will disproportionately affect Maine. A larger percentage of children in Maine than in the US would suddenly be recognized as lead poisoned. Maine health providers and environmental health organizations would have to refurbish their lead poisoning prevention programs to account for the large increase in the population requiring treatment and lead hazard abatement.
Scenario 2: Lead-free Mainers
Another possible scenario is that in the next few years, Maine may succeed in eliminating its childhood lead poisoning problem. In 2001, the Act To Amend The Maine Lead Poisoning Control Act mandated lead testing of all Maine children age one and two. As a result, MCLPPP greatly increased testing of children's blood lead levels, in some cases by more than 20%, and now constructs a more accurate picture of the health state of Maine's children. Overall EBLL's of Maine children are decreasing; in 1994 the DHHS recorded 400 cases of EBLLs, and in 2008 so far they have only recorded 170 cases (Smith 2008b). However, this decrease can still be attributed to the decreasing lead in the environment due to the removal of lead from gasoline and from paint, and also general landlord and homeowner housing upkeep, which is moderately effective in covering up or removing lead hazards. As a result of the mandatory testing law, DHHS acquires increasing amounts of blood lead level data for children. DHHS predicts that health-providers will need to further increase testing rates to 40% of all Maine's children to control the lead poisoning problem (DHHS 2000). Hopefully, an increase in available data will allow DHHS to identify more definite high risk communities for childhood lead poisoning and to distribute the funds generated from the lead poisoning prevention fee to these communities, which can then support lead hazard education and abatement. This primary prevention will result in the achievement of the goal of the MCLPPP's Strategic Plan to eliminate childhood lead poisoning in Maine.
In order for Maine to reach its goals of eliminating childhood lead poisoning, we have a few key recommendations. The MCLPPP needs to continue to expand their surveillance program of testing the blood lead levels of one and two year-olds. Overall, the average blood lead level among children has decreased, but the problem of lead poisoning remains concentrated on a more local level, as the risk for EBLLs varies greatly within the state. Increased information from surveillance needs to be used to target blood screening, education, and outreach efforts towards high risk communities. We recommend a focus on larger urban areas with a high percentage of old houses and rental units. There is also a need for increased education about lead-safe renovation practices, as homeowners or contractors who attempt renovations without a lead-safe certification are jeopardizing their children's health.
The Federal or State government must assume more of the burden of cost for lead abatement. When the identification of lead hazards and the cost of abatement is solely the responsibility of the homeowner or renter then lead poisoning disproportionately affects lower income families. HUD regulates some processes for removing lead-based paint and provides grants to state and local housing programs for lead hazard control, but there is a need for increased federal assistance in Maine (HUD 2008). Finally, eliminating childhood lead poisoning in Maine requires continued research about whether 10µg/dL should continue as the standard for the allowable amount of lead in children.
State of the Topic: Arsenic
Background of Arsenic
Arsenic is a naturally occurring metalloid released into groundwater through the weathering and breakdown of bedrock. Some bedrock contains higher levels of arsenic and, when arsenic is released into the water consumed by humans, poses a significant risk to human health. The inorganic salts of arsenic are odorless and therefore impossible for humans to detect without advanced scientific tests. Elevated arsenic levels occur on a random geologic basis, making the identification of "hotspots" hard to accomplish (Schmitt 2005).
Regulations have been put in place to establish a limit for how much arsenic is permitted in water without causing a risk to human health. The global and American health standards are the same; they set the allowable level of arsenic in water at 10ppb. These limits were established by the World Health Organization (WHO 2008) and US EPA (EPA 2007a). In the US, only municipal water supplies are regulated and monitored for arsenic contamination. All municipal water systems are mandated by federal law under SDWA to consistently check the levels of arsenic in water to make sure it is in accordance with mandated EPA limits. Municipal systems are also responsible for the amelioration of arsenic excesses, if arsenic levels exceed 10ppb (EPA 2004a). Maine has a problem with arsenic regulation because over half of the population in Maine relies on unmonitored private well water for their drinking water (Smith 2008a).
Arsenic contamination cases in countries in Southeast Asia are the most well known (SFIAST 2008). Groundwater samples from wells in many of these countries have been found to frequently be five to ten times over the 10ppb health limit (WHO 2008). Some tests have shown samples with arsenic levels exceeding 3,000ppb, over 300 times the worldwide health limit. It is estimated that over 70 million people are affected by arsenic exposure in this region (Sambu 2007). Some estimates calculate that 1 in 100 people here are near death because of severe arsenic poisoning and that 5 in 100 will be experiencing symptoms linked to arsenic poisoning (Queens University 2008). While this is clearly a significant public health problem in this region of the world, it is important to know, as some of the water samples tested in Maine have shown arsenic levels comparable to those found in these Southeastern Asian countries.
Many states in the US are currently dealing battling arsenic contamination in their drinking water supplies. Some of these states are trying to institute legislation and clean-up programs to deal with the elevated arsenic levels caused by pollution from pesticides, manufacturing waste and the improper disposal of electronic trash (GreenFacts 2008). Other states have the misfortune of being located on top of geologic "hotspots" of arsenic (Ryker 2001). These states have the challenging task of figuring out how to best handle the problems associated with naturally occurring, persistent arsenic contamination in water in private wells, without financial support from the US government (Varney 2005). Maine is one such state that lies over arsenical bedrock. Much of Maine's groundwater exceeds the 10ppb limit and many consumers of private well water are not aware they are consuming contaminated water (Schmitt 2005). While it is well known that there is an arsenic contamination problem in the state, there is still a large population drinking water from untested, private wells that are likely exposed to high levels of arsenic and this report seeks to answer which population is most affected by arsenic contamination.
Current State of Arsenic
Some places in the US have elevated levels of arsenic solely due to natural contamination, but many others have arsenic contamination caused by industrial pollution. As shown in the following map (Figure 2.5) the regions that tend to be most heavily affected are the coastal northeast, the deep west and some portions of the Midwest. These regions exhibit the highest arsenic contamination levels in the US, the contamination problems in the northeast are caused by naturally occurring arsenic, the Midwest is plagued by contamination coming from industry and the deep west has a combination of naturally occurring arsenic and industrial arsenical pollution.
Figure 2.5 Arsenic concentrations in municipal water supplies in the US. Green values represent places with the lowest levels of arsenic contamination (1-3 µg/L) and red values represent the highest levels of arsenic contamination (at least 50 µg/L) ( (Ryker 2007).
The majority of the data available for arsenic contamination in water supplies is for water supplied by municipal systems. The following figure shows the top ten states with the highest levels of arsenic contamination, in comparison to Maine. Although it appears that many states have higher levels of contamination, it is hard to estimate which states are the most deeply affected by arsenic contamination, because states with large rural populations, like Maine, do not know how many people relying on private well water are affected by contamination. Even in municipal systems, however, high levels of arsenic are sometimes found. According to a study done by the Environmental Working Group (EWG), almost 100% of the population in California is exposed to arsenic levels exceeding the health limit established by EPA (EWG 2008, US Census Bureau 2008) (Figure 2.6)!
Figure 2.6 States with the highest populations exposed to arsenic over health based limits (>10ppb). This is in comparison to Maine and measured per capita (EWG 2008, US Census Bureau 2008).
In an effort to reduce the number of people affected by arsenic contamination, numerous groups in the US monitor the contributors of industrial and agricultural arsenic contamination. The Toxics Release Inventory records the environmental releases of arsenic in the US through information provided by manufacturers who monitor how and where their waste is disposed. Their data are measured in pounds of arsenic released into US soils, and the following graph shows the top ten states that have the highest levels of arsenical wastes released into their soils. They evaluate this by including "all reported on-site releases to air, water, and land (including underground injection). This total does not include any waste that is transferred off-site, so it does not include any environmental releases that may occur as a result of off-site disposal or treatment" (Scorecard 2005). This information is important, because it helps target where arsenic contamination is most prevalent. The following table (Table 2.7) shows which states have the highest amount of non-naturally occurring arsenic contamination.
Table 2.7 Top ten states with reported total environmental releases of arsenic (EPA 2004b).
Many of the states that had high percentages of their populations exposed to elevated levels of arsenic (Figure 2.5), are also states that have had a significant amount of arsenic released into their soils (Table 2.7). These states are: California,Idaho, Arizona,Illinois and Nevada. The United States Geological Survey (USGS) has done studies in all 50 states and offers three reasons these states all have elevated levels of arsenic. First, these five states used to or currently still have functioning industry, including mining (which is a high contributor of arsenical waste) (USGS 2007). Second, they all used to have electronics industries that are now defunct, but have left their arsenical pollution as their legacy. All of these states have agricultural sectors where arsenical pesticides were once used (Ryker 2001).
Overall, in the US, arsenic contamination is a prevalent problem. According to EWG, arsenic ranks eighth on the list of toxic contaminants affecting people in the US. It is estimated that about 90 million people in the US are exposed to levels above 10ppb, which exceeds the health standard (>10ppb) (EWG 2008).
While there is a sizeable amount of the population in the US affected by arsenic contamination, there have been some promising regulatory mechanisms put in place to try and protect as many people as possible. The EPA finally changed the allowable level of arsenic from 50ppb to 10ppb in 2001 and the 10ppb limit was fully enacted in 2006. Another contributor to arsenic contamination, the use of CCA treated lumber was addressed on a national level and CCA treated lumber was banned in 2003. CCA treated lumber cannot be disposed in public waste facilities or by incineration (EPA 2008b).
Federal regulations have gotten tougher on arsenic levels allowed in municipal water supplies, but some groups are pushing for tighter regulation to better protect human health. Some states are trying to create their own regulations for arsenic. California's state government, for example, has advocated for a statewide arsenic level of 4ppb, as opposed to the federal level of 10ppb. Proponents hope that this lower level will protect more people from the health problems associated with long term arsenic exposure (Sambu 2007). Maine is also taking important steps to reduce the number of Mainers exposed to unhealthy levels of arsenic.
In Maine, arsenic is a contaminant recognized to be very dangerous, second only to trihalomethanes (Table 2.8). It is estimated that almost 300,000 or about 17% of the population, of Mainers are affected by arsenic contamination (EWG 2008). This is a concern as long-term arsenic exposure can lead to a host of health problems like bladder and skin cancer, cognitive dysfunction and adverse reproductive effects (WHO 2008).
Table 2.8 Toxic contaminants of the most concern in Maine (EWG 2008).
Concern over arsenic contamination in Maine's water supplies emerged in 2000, after a school in the Buxton/Hollis was found to have elevated levels of arsenic in its water supply. Further testing of nearby homes and businesses also found high levels of arsenic. Since there had been no reason before, to test the water, residents had no idea their water was seriously contaminated (Smith 2008a). The Buxton/Hollis case was considered an isolated incident until later that year when Governor Angus King commissioned studies on the levels of Methyl Tertiary Butyl Ether (MTBE) in Maine's groundwater. MTBE is an additive to gasoline that easily leaches into groundwater when gasoline is improperly stored and contaminates the water and poses a risk to human health (EPA 2007c). Many of the samples from the MTBE study also contained high levels of arsenic. Studies were subsequently commissioned to examine how widespread and severe arsenic contamination is in the state (Smith 2008a).
USGS and DHHS have been the two agencies responsible for these studies. USGS has been continually mapping "hotspots" of arsenic contamination in the state to identify trends in geologic bands of arsenic. USGS found that these arsenic bands appear at random. In some testing sites, water samples from one side of a street have tested very high for arsenic in the water, while the water of neighbors across the street meet health standards (Paulu 2007). DHHS has been responsible for testing private wells for arsenic, but on a very limited budget. The small amount of funding available for these studies is problematic because it is estimated that 660,787 Mainers rely on private well systems for their drinking water though only about a third of Maine's private wells have been tested for arsenic (Smith 2008a).
The majority of water samples tested from municipal supplies and private well water in Maine that exceeded health based limits were close to the 10ppb limit, but some cases exhibited unusually high levels of arsenic, on par with extreme levels found in Sri Lanka, Bangladesh and other South Asian countries. In the following table, Table 2.9, municipal systems in locations in Palmyra and Orland exhibit arsenic levels nine or ten times over health limits. Additionally, as seen in Table 2.10, private well water supplies in Standish and Hollis Center have had arsenic levels that exceed health limits by a factor of 30 and 20!
Table 2.9 Municipal water systems in Maine with the highest levels of arsenic contamination (EWG 2008).
Table 2.10 Private well water systems in Maine with the highest levels of arsenic contamination (Smith 2008a).
In order to protect more people from arsenic contamination, the DHHS has been trying to test as many private wells in Maine as possible. As indicated by the following map, Figure 2.7, DHHS's limited testing has revealed some of the "hotspots" of arsenic in the state, but there are still large portions of the state where private well water supplies remain untested. Locations in southern Maine, in the Buxton/Hollis area and in the Newport, or mid-Maine area, exhibit some of the highest levels of contamination.
Figure 2.7 Average levels of arsenic (ppb) in private well water in towns in Maine (Smith 2008a).
When prominent arsenic "hotspots" are identified, the DHHS sends free testing kits to homes in areas, in the hopes that it will people will be more willing to test their water with a known risk. As a national leader in studies on arsenic contamination, DHHS is presently doing a study on toenail and urine samples of those consuming water from private well water. This study aims to measure whether or not arsenic can be accumulated in the body through dermal absorption. While the final results have not been released to the public, it is likely that the results will show there is a significant amount of the population in Maine that carries residual arsenic in their bodies from their drinking water and will be at risk for long term health effects from this exposure (Paulu 2007).
Beyond testing, the DHHS also gives regular education sessions on the importance of homeowners to test their private wells to protect themselves from adverse health effects caused by arsenic contamination. They have also tried media campaigns in newspaper and the radio to reach as many people as possible with their message on the importance of testing private well water. DHHS has frequently lobbied in the Legislature in favor of federal regulation of private well water and for better assistance for private well owners to fix high levels of arsenic, though not one of these bills has ever been passed (Smith 2008a).
These measures are important because there is a large population in Maine that relies on untested private well water. Since testing for private wells is initiated and paid for by the homeowner, there is less data on water from private wells than from municipal systems. This is problematic for a state in which 10% of private wells have levels of arsenic far over 10ppb. While values as high as 5,000ppb have been found in Maine, the majority of tested samples show levels around 100ppb, which is still more than ten times the EPA health standard for arsenic (Smith 2008a)! Other risks dangerous to these homeowners are that many remain uninformed of the dangers of arsenic contamination and that some might not have any idea that they are drinking contaminated water.
Homeowners relying on private well water who are aware of high levels of arsenic in their drinking water, however, are still inhibited from taking action because of the high cost of arsenic remediation. The current status quo is that many of these homeowners choose not to install any filtration systems because of the high cost. They are aware of high levels of arsenic in their water and associated health risks, but simply cannot install the filtration systems because they are too expensive.
The other options available to those affected by high levels of arsenic in their drinking water that choose to install a filtration system are a Point-of-Use (POU) system and a Point-of-Entry (POE) system. A POU filtration system, where the filter is installed on only one tap in the house, usually on the kitchen sink, is the cheaper option. Point-of-use systems cost between $300 and $1,700. A POE filtration system treats all of the water coming into a house and is the most expensive, costing between $3,000 and $8,000 to install (Paulu 2007). Currently, since there have been no definitive studies that show that significant arsenic contamination arises from dermal absorption, a POU system is the most attractive to homeowners because of its more affordable cost. Ideally, POE systems should be installed, as users would be best protected because all water in the home, used for cooking, drinking and bathing would be treated (Smith 2008a).
Because these filtration systems are expensive, lower-income populations cannot afford them and they are left more at risk for health problems associated with high levels of arsenic in their drinking water. This population tends to reside in more rural areas, also leaving them unexposed to the information available on arsenic contamination better available in more populous, urban areas. Maine has done an admirable job controlling arsenic levels in its municipal water supplies, but needs to take action to fully protect the people who rely on private well water systems for their drinking water. The burden of arsenic contamination in Maine is falling unfairly on the shoulders of the rural poor (Smith 2008a).
While the future of arsenic's effect on the health of Mainers remains unclear, a few items that indicate that further studies are important. There are many sites in Maine where the arsenic levels in the drinking water greatly exceed the 10ppb limit set by EPA as the level of arsenic safe to be consumed, and this means Maine could potentially be facing a serious public health problem. Additionally, there are also large numbers of Mainers experiencing long term, low-level arsenic contamination. Although no definitive studies have been done, it is plausible these people will be at risk for elevated cancer rates, dermal problems and decreased cognitive function.
Since the elevated arsenic levels in Maine are caused by high levels of naturally occurring arsenic in the bedrock, arsenic contamination is not easily rectified. While regulation and clean-ups can ameliorate industrial waste, pesticide run-off and exposure to CCA treated wood there is nothing that can change the composition of the bedrock. The only way that Maine can deal with this issue is through installing water treatment systems in homes to reduce arsenic exposure. Due to the high costs and lack of aid for the installation of these systems, some cannot afford to install these systems and continue to drink the untreated water. This puts another population at serious risk for future health problems.
On the other hand, Maine is actively raising awareness on how important it is to deal with arsenic contamination. If the majority of people in Maine had their water tested and had one of the less expensive, POU water treatment systems installed, it may help to reduce the number of people facing health risks because of arsenic contamination. The problem with this is that DHHS is one of the few agencies that have the capability to identify and test the water of at risk homes but DHHS does not have nearly enough funding or support to test all private wells for arsenic (Smith 2008a).
Based on the current state of arsenic contamination in Maine, there are a few scenarios possible for how Mainers might be affected in the future. The first scenario describes what might happen if the current regulations and trends associated with arsenic contamination remained the norm. The second scenario details what could happen if the Maine government took initiative to change the health standards for arsenic in water to be stricter than the ones currently set by EPA. The third scenario describes what could be possible if better federal regulation on arsenic contamination was enacted and more money was allocated to state agencies to better monitor arsenic contamination.
Scenario 1: The Standstill
One of the possibilities is that little could change in toxics regulation. This would mean there would still be a huge number of people in the state drinking private well water that has not been tested and therefore could potentially have high levels of arsenic. Many Mainers would still have little or no knowledge of what arsenic contamination is, or how it affects the human body. Little funding would be available for further testing of arsenic and questions would remain on how serious and widespread this problem is in Maine. This would be a "nightmare" scenario, leaving large amounts of people vulnerable to arsenic contamination. The burden of exposure, again, would be on the rural poor, because of their reliance on private wells, their lack of access to the education available about arsenic contamination, and their lack of resources available to procure arsenic filtration systems.
Scenario 2: Setting a Stricter Standard
Maine could adopt a stricter health based limit for arsenic. Lowering this limit would protect many more people from the health problems associated with long term exposure to arsenic and send the message that Maine is very serious about their dedication to protecting human health. There is already some skepticism that the 10ppb limit set by EPA and WHO is insufficient for protecting human health (ACS 2005). This would mean that huge numbers of private wells would be out of attainment of these new standards. If the arsenic limits were lowered, more people would have to be paying for expensive filtration systems, which might be impossible due to the high cost of instillation of filters. Municipal water providers would also be forced to revamp their systems to further lower the allowable amount of arsenic in the water supplies. This would come at a high cost, but would be possible as municipal water quality is a federal responsibility and the funding would have to be made available.
Scenario 3: Tightening the Reigns of Regulation and Doling out some Dough
The last scenario is that regulatory processes dealing with drinking water safety could change; this would be very beneficial to Mainers. Currently, FDA safe drinking water regulations only apply to municipal water sources, so only about half of Maine's population is protected from elevated arsenic levels in their drinking water (EPA 2004a) (Smith 2008a). All others (those with private well water systems) are responsible for testing for and rectifying arsenic contamination. Two changes would help the current state of arsenic contamination in Maine. The federal government could take regulatory responsibility for private well water, necessitating that all private well water be in accordance with the same limits set for municipal systems. It would be beneficial if federal funds could be allocated to test all private well systems in Maine and allow further study of the health effects of long term, low-level arsenic contamination. First, if these two changes occurred, homeowners would not be responsible for the costs of the testing. Second, if private wells were found to exceed EPA arsenic MCLs, the US government would be responsible for fixing this problem. This would necessitate the government paying for the cost of installing the filtration systems, or subsidizing the treatment systems. Alternatively, the federal government could allocate money to the Maine government and give them the responsibility of lowering the number of people affected by arsenic contamination. Although this would require more work for the over-taxed DHHS, there would be funding available; which right now is absent. If additional funding was given to DHHS they could conduct extensive research on future effects of arsenic contamination in Maine. This would enable them to better target the arsenic contamination "hotspots" in the state and help those affected; perhaps by defraying the costs of treatment systems.
Arsenic contamination is a problem facing millions across the globe. Since arsenic is a naturally occurring toxin, its geologic distribution is random and hard to identify. This creates a tough scenario for rectification. An effort needs to be made worldwide to reduce the amount of arsenic released into waters and soils from industrial and agricultural sources. Arsenic contamination is still a relatively new area of study, and much more research needs to be done to determine the eventual health effects of long-term, low level exposure to arsenic, in the United States and in Maine. In the US, federal funds should be given to the state to test all private water systems and offer aid to those with arsenic contamination in their water supplies. While Maine is a leader in arsenic advocacy, it still has a significant problem because of its large population which relies on private well water and has far go until its problems with arsenic contamination can be fully identified and fixed. More cost-effective filtration systems need to be made available and more funding is needed for identification and education about arsenic contamination.
State of the Topic: Mercury
Background of Mercury
Mercury is a heavy metal which occurs naturally in oceans, rocks, and soils (MDEP 2005b). Mercury is also released into the environment from human activities, including waste incineration, the combustion of coal, oil, wood, or natural gas as fuel, and the production and use of certain consumer goods, such as mercury thermometers and some dental fillings (MDEP 2005b). Mercury is discharged into the water and air. Air emissions of mercury have a greater potential to cause impacts over a wider geographical range because these emissions often travel long distances before settling in lakes and rivers. The mercury deposition is particularly high in Maine due to the state's location east of major emissions sources.
Once in the water, mercury converts to the more toxic form of methyl mercury and bio-accumulates up the food chain, increasing in concentration as a succession of organisms consume other biota containing mercury. Mercury levels in some fish are 10,000 to 1 million times mercury levels in water (USDEP 2005). The most common route of human exposure to mercury is through the consumption of fish contaminated with methyl mercury (EPA 2008f). Humans may also ingest mercury vapors from the breakage of products containing mercury, the use of dental amalgams, and mercury in the workplace (BAQ 2005b). Mercury exposure increases the risk of neurological problems for young children and birth defects in the fetuses of pregnant women (EPA 2008f).
Current State of Mercury
Despite regional and state reductions in mercury releases, mercury has persisted in the Maine environment, posing a particular health threat to women of child-bearing age, to babies, and to young children. A study on mercury deposition in northeastern North America, (Evers et al. 2007) identified areas along the Kennebec River among areas in the Northeast with especially high levels of mercury deposition. Fish and other wildlife in Maine continue to contain high levels of mercury relative to their counterparts in most of the nation (MDEP 2005). The state has maintained fish advisories warning high-risk groups (children and pregnant women, especially) of the risks of consuming mercury-contaminated fish. Ten to twenty percent of Maine women of child-bearing age have concentrations of mercury in their blood which put them at risk for having babies with developmental abnormalities (USDEP 2005). In addition, about 46,000 newborns in the northeastern US have levels of mercury in their blood which put them at risk for brain and cardiovascular abnormalities (USDEP 2005).
Maine is a national leader in mercury legislation and reductions in mercury. The State has initiated controls on mercury releases to the air and water and has restricted the use of mercury in consumer products. Maine reduced its total releases of mercury by over 99% from 1994 to 2006, as indicated in Figure 2.8. Emissions dropped rapidly in 1998, the same year in which the Land and Water Resources Council formulated the Mercury Reduction Strategy for Maine. Maine reduced its mercury air emissions by over 75% between 1991 and 2008, outdoing goals set by the Northeast region in the New England Governors and Eastern Canadian Premiers Mercury Action Plan (BAQ 2005). Since 2000, mercury emissions in Maine have remained close to zero, as shown in Figure 2.8.
Figure 2.8 Total mercury releases and total air emissions of mercury in Maine (pounds), 1988-2006 (EPA 2006c). Mercury releases include air emissions, discharges to water, waste treatment, and mercury disposal to landfills or other locations.
Maine accomplished the bulk of its recent reductions in mercury emissions through DEP's limits on discharges from municipal waste combustors and medical waste incinerators and through the closure in 2000 of the Holtra Chem chlor-alkali manufacturing plant in Orrington (BAQ 2005). Since these facilities controlled their emissions, industrial and commercial boilers for energy and heat generation have taken their place as Maine's largest sources of mercury air emissions (USDEP 2005). To further curb Maine's releases of mercury to the environment, DEP has recently prohibited the production, sale and disposal of many mercury-added products in Maine (BAQ 2005).
Since human and wildlife health impacts continue despite reductions in Maine's in-state mercury releases, out of state sources are most likely largely responsible for current mercury accumulation in Maine. Regional, national, and global sources each emit about 25% of the total mercury which enters the Maine environment (USDEP 2005). The Midwest region has high total air emissions of mercury in comparison to most of the US, as indicated in Figure 2.9. Prevailing winds from the west transport these emissions to Maine.
Figure 2.9 Total US air emissions of mercury (pounds), by state, 2004 (EPA 2004b).
The bulk of US mercury emissions originate from electric utilities, as shown in Figure 2.10. Many of these electric utilities are in the Midwest.
Figure 2.10 Total US air emissions of mercury (pounds) by industry, five industries with highest emissions, 2004 (EPA 2004b).
Maine has consistently exceeded national goals for the control of mercury contamination and advocated for stronger national mercury regulation. In the past 10 years, EPA has been relatively ineffective in controlling mercury releases on a national scale. In 2000, after an EPA study connected anthropogenic mercury discharges with mercury levels in fish, EPA advised Congress to list coal- and oil-fired power plants as sources of hazardous air pollutants under CAA regulation (Borgford-Parnell 2008). In 2004, however, EPA attempted to revoke this decision and to replace CAA control of mercury with the much weaker Clean Air Mercury Rule (CAMR). This rule would have achieved reductions in mercury emissions on a national scale by allocating a mercury limit to each state and establishing a national cap-and-trade program for mercury emissions from coal- and oil-fired power plants. It would have achieved emissions reductions partly through the controls on emissions achieved through the Clean Air Interstate Rule (CAIR). CAIR controls mercury pollution across state boundaries in the eastern half of the US (including the Midwest). Maine and several other states objected to CAMR because it would have delayed emissions reductions by 10 years and resulted in little short-term reductions in emissions (Borgford-Parnell 2008). Fourteen states, including Maine, pursued a lawsuit against EPA in February 2008, charging it with failure to adhere to the requirements of CAA (Borgford-Parnell 2008). The court ruled that EPA was in violation of CAA, and subsequently, the court vacated CAMR. The controversy over CAMR and CAIR, however, has continued.
Maine has substantially reduced its emissions of mercury over the past 15 years through the implementation of regional and state regulations. The State has been motivated to pursue strong mercury legislation likely due to Maine's vulnerability to mercury pollution, to its lack of major industrial sources of mercury, and to the absence of strong federal controls on mercury releases. However, levels of mercury in the Maine environment remain high, as indicated by human and wildlife studies. Mercury has continued to accumulate in Maine largely due to the continued entrance of emissions from outside the state. Maine has, however, recently been effective in pressuring the federal government to adopt more stringent mercury regulation. Maine has opposed EPA's CAMR and CAIR, which would delay emissions reductions and hence be likely to harm Maine in the short term. The cap-and-trade program associated with CAMR could result in disproportionate accumulation of mercury in certain areas even in the long-term. CAMR does not achieve the immediate and substantial decreases in mercury emissions that would result from application of CAA to coal- and oil-fired power plants. Maine and other states have also objected to CAIR for its allowance of 75% more pollution than CAA, an allowance which does not provide sufficient protection of human health (Parry 2005). Effective federal mercury regulations must protect human health throughout the US in the short-term and in the long-term.
If EPA adopted CAMR or CAIR, total US mercury emissions could decrease in the long term, but they would be likely to increase in the short term. Industrial sources and states with high mercury emissions might also pressure EPA to adopt less stringent mercury regulation, due to the potentially high costs of mercury reductions for these industries and states. This scenario would likely result in continued accumulation of mercury in Maine and continued health impacts from mercury. Even if Maine continued on its present trend of in-state reductions in mercury emissions, the state would be unable to eliminate the threats of mercury pollution without reductions in out-of-state sources.
If EPA further delayed the application of CAA to coal- and oil-fired power plants, states which are emitting high quantities of mercury would likely continue to emit at levels equal to or greater than current levels. Mercury deposition in Maine would remain high, as would health impacts. Mainers would be unlikely to experience reductions in health problems from mercury pollution until emissions decreased on the national level.
If Maine and other states continued to exert pressure on EPA to apply the CAA to coal- and oil-fired power plants, EPA could accomplish this action in the near future. This scenario would be more likely to occur if Maine pursued research on the specific health effects of mercury in Maine and on the expected outcomes of CAA as compared to CAMR and CAIR. CAA application to coal- and oil-fired power plants would ideally result in immediate and stringent controls on power plant emissions of mercury throughout the US. Individual facility emissions would decrease the concentration of mercury deposition in certain areas, and would benefit sensitive areas like Maine. In the best scenario, Maine and other northeastern states would also continue to reduce emissions. Government, industry, and citizens would combine to reduce national mercury emissions. The incidence of mercury-related health problems among Mainers would be likely to decrease in this scenario.
Maine has been a leader in the control of mercury releases to the environment, with its recent measures to limit emissions from waste combustion facilities and to eliminate commerce in mercury-containing products in Maine. Mainers would benefit from expanded restrictions on mercury-added products in Maine and continued rigorous legislation and monitoring of impacts. On the regional scale, Maine and other northeastern states should cooperate to reduce the impacts of mercury throughout the Northeast and to restrict the movement of mercury across state boundaries. Maine should pressure states in the Midwest and in other areas with high mercury releases to reduce their emissions through state policies. As Maine remains vulnerable to emissions from outside the Northeast, we also recommend that MDEP, MDHHS, concerned NGOs, and citizens urge EPA to adopt stricter federal regulations on mercury. Specifically, Maine should continue to urge EPA to apply CAA controls to mercury emissions from coal- and oil-fired power plants.
In 2000, the Maine DHHS established the initiative for "Healthy Maine 2010: Longer and Healthier Lives and Opportunities for All," an on-going health project outlining specific goals and strategies to combat problems of lead, arsenic, and mercury exposure, among other toxic chemicals. A specific strategy for reducing lead exposure for children is to track the proportion of tested Maine homes that are subsequently made lead-free. Other strategies to reduce arsenic and mercury exposure include testing and remediating private well drinking water for arsenic contamination and reducing local, regional, and national mercury emissions (DHHS 2000). The 2010 deadline for these goals is fast approaching. The promotion of a healthier Maine environment and the realization of these goals require Maine to execute the following actions. The elimination of childhood lead poisoning in Maine necessitates increased blood level surveillance of children and targeted lead hazard education and abatement programs for high risk communities. Decreasing the health effects associated with arsenic contamination in private well water requires more federal funds. This additional funding would allow for the testing of all private wells in Maine and the implementation of conclusive studies to measure the health effects of long term, low level (closer to the 10ppm limit) arsenic levels in drinking water. In order to reduce mercury levels in its rivers, lakes, and streams, Maine needs to urge the federal government to further limit the mercury air emissions of major industrial polluters to complement the current national cap-and-trade program for mercury emissions from utilities.
In relation to other states in the US, Maine is on the forefront of toxics regulation and is recognized for its strong effort to protect its citizens from the health effects of toxic chemicals. However, Maine has not taken strong actions to promote the abatement of these chemical hazards. Maine law mandates testing of toxic hazards, but the burden of cost for hazard remediation typically falls on the individual. A shift in the burden of cost to the state government with more comprehensive regulation and funding would improve the health of low income families in Maine. Healthy Maine 2010 recognizes that people with low socioeconomic status are more likely to be exposed to environmental toxicants, and they also may not have the resources to pay for the cost of abatement (DHHS 2000). Recently, Maine has increased the effort to attain their health goals. In December 2008, the Maine DHHS will release an environmental public health tracking system that will report data on environmental hazards, human exposure, and health effects from a single comprehensive database. This Maine Tracking Network will be a Maine-specific version of the new federal initiative by the CDC making toxics data more available to the public. The publicly available database will contain specific data, graphs, and maps concerning lead, arsenic, and mercury contamination, along with other hazardous chemicals, and will educate people on how to limit their exposure to these toxic chemicals.
In the past year, because of the initiative of the EHSC, the Maine Legislature enacted a new toxics law, which will radically change how toxics chemicals are regulated in this state. The Act to Protect Children's Health and the Environment from Toxic Chemicals in Toys and Children's Products mandates that the state adopt a list of priority chemicals. Maine will require manufacturers to disclose information on products containing these priority chemicals and to replace them with safer alternatives where possible. If a manufacturer fails to comply, the state can prohibit the sale or distribution of that product (Pub. L. Chapter 643 123rd Legislature Second Regular Session). Though this act does not specifically reference lead, arsenic, or mercury, it is important because it changes the way that chemicals are regulated; it requires manufactures to prove their product is safe before sale, rather than requiring consumers to prove harm after exposure. Maine is currently struggling to gather enough funding to begin the first steps of implementing this law, but it has the potential to be very powerful and a real impetus for reducing the exposure of Mainers to hazardous chemicals.
On a more national scale, the 2008 Presidential Election opened new possibilities for the future regulation of lead, arsenic, and mercury. The new president elect, Barack Obama, may propose new hazardous chemical regulations to replace the lack of toxics regulation from the previous administration. His administration plans to promote a healthy environment and healthier communities; they have committed to protecting children from health hazards caused by environmental toxins. As a state senator, Obama supported reduced lead exposure regulations in Illinois, and he proposes new EPA rules mandating lead-safe renovation and remodeling of structures with lead hazards. He also plans to encourage organic and sustainable agriculture which will decrease the use of arsenical pesticides. This new administration has also pledged to restore the strength of the Superfund (lead, arsenic and mercury are all contaminants commonly found at Superfund sites) program and to require polluters to pay for the clean-up of contaminated sites. Furthermore, Obama stated his plans to strengthen federal environmental justice programs to ensure that low income and minority communities do not suffer disproportionately from toxic contamination (Obama 2008). These proposed federal actions have important implications for the health of Maine's environment. A federally comprehensive chemical regulation policy would reduce the pressure on Maine's resources and transfer responsibility for regulation and enforcement from the state to the federal government.
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