PUBLIC HEALTH ASSESSMENT
BRICK TOWNSHIP INVESTIGATION
(a/k/a BRICK TOWNSHIP AUTISM INVESTIGATION)
BRICK TOWNSHIP, OCEAN COUNTY, NEW JERSEY
This public health assessment (PHA) was developed to address specific concerns brought to the attention of the Agency for Toxic Substances and Disease Registry (ATSDR) by a local parents group, Senator Torricelli and Representative Smith regarding concerns about a possible excess of children with autism spectrum disorders (ASD) in Brick Township, New Jersey. ATSDR was asked to assess hazardous chemical exposure in the environment from three areas: (1) the municipal drinking water supply, (2) swimming in the Metedeconk River, and (3) the Brick Township Landfill. This public health assessment evaluates possible exposures from these areas.
ATSDR collected data from the Environmental Protection Agency (EPA), New Jersey Department of Environmental Protection (NJDEP), Ocean County Health Department (OCHD) and the Brick Township Municipal Utilities Authority (BTMUA) to assess past and current possible exposures related to the three exposure pathways.
ATSDR evaluated the information collected on the Brick Township municipal drinking water supply and found that either well water or municipal drinking water contained tetrachloroethylene (PCE), trichloroethylene (TCE) or trihalomethanes (THMs) at various times during the study period. ATSDR discusses these contaminants at length in this report, but concluded the following: (1) TCE was never found in the distribution system for the municipal drinking water supply and therefore would not cause adverse health effects to children or pregnant mothers. (2) PCE was detected at low levels in the municipal drinking water supply several times between 1987 and 1994, but the observed levels were not sufficient to cause adverse health effects to children or pregnant mothers. (3) Total THM levels in the municipal drinking water supply exceeded 80 parts per billion (ppb), the EPA maximum contaminant level goal, several times during the study period. However, the locations in the water system where total THM levels were high do not match the locations and timing of the pregnancies of the majority of the autism cases plotted. Since there is no clear pattern linking the residences of the cases, during mothers' pregnancies, with location and timing of the high THM levels, it appears unlikely that THMs in the municipal drinking water supply were associated with ASD in Brick Township.
ATSDR evaluated information on the Metedeconk River and does not believe that levels of chemicals in the river would have been sufficient to cause adverse health effects to children or pregnant mothers who swam in the river in the past, because the continual current and tidal fluctuation of the Metedeconk River would dilute any past chemical releases to the river to trace amounts. Exposure to trace amounts through occasional swimming in the river (even more frequent swimming in summer months) would be unlikely to cause adverse health effects.
ATSDR evaluated information on the Brick Township Landfill and found that the groundwater beneath the landfill is contaminated with a variety of VOC's and metals. The contaminated groundwater beneath the landfill is not used for drinking water, thus preventing exposures which could result in adverse health effects. Residents in the area are supplied water by the municipal drinking water system provided by the Brick Township Municipal Utilities Authority. ATSDR believes that any exposure to contaminated groundwater through the use of irrigation wells near the site would not have been at high enough levels or frequent enough to adversely affect the health of pregnant mothers or children.
In February 1998, ATSDR and the Centers for Disease Control and Prevention were contacted by a local parents group, U.S. Senator Robert Torricelli, and U.S. Representative Christopher Smith with a request to investigate concerns about a possible excess of children with autism and other pervasive developmental disorders in Brick Township, New Jersey. They also asked that ATSDR assess whether community members may have been exposed to hazardous chemicals in the environment. ATSDR requested assistance from the Centers for Disease Control and Prevention (CDC), because of CDC's experience related to autism research. With assistance from CDC, ATSDR developed a draft Public Health Action Plan (PHAP) for the Brick Township autism investigation. On April 1, 1998 Senator Torricelli, Representative Smith, and the parents were briefed on the draft PHAP and their comments were solicited. In addition, comments were received from a representative of the National Alliance for Autism Research (NAAR), who was advising the Brick parents. Based on the comments received, ATSDR and CDC developed a final draft of the PHAP.
The final PHAP outlined four main tasks: (1) Prepare a literature review of associations between autism and environmental contaminants, (2) Determine the prevalence of children with autism spectrum disorders among the residents of Brick Township during 1998, (3) Investigate environmental pathways for human exposure, with emphasis on the Metedeconk River, and (4) Inform the community through involvement and health education.
ATSDR and CDC began working on the four main tasks outlined in the final draft PHAP. The PHAP was subsequently revised after comments were received during a public meeting in Brick Township in September 1998, but the four main tasks remained the same. An outline of the four main tasks and their status is provided in this section.
In January, 1999 ATSDR completed and released to the public a consultation, entitled Chemical Specific Consultation: Hazardous Substance Exposures and Autism. The consultation is a review of the available scientific literature pertaining to hazardous substance exposures and autism. The literature review found that very few studies have investigated associations between exposure to hazardous substances and autism. For this reason the scope of the consultation was broadened to consider other exposure scenarios or chemical agents that might play a role in the etiology of autism. The available data suggest possible involvement of chemical exposure, along with strong evidence of genetic and suggestive evidence of immunological factors, in the development of autism spectrum disorders. Evidence that exposure to hazardous substances in the environment prior to conception or during pregnancy or infancy is related to the development of autism may be suggestive, but not conclusive.
CDC's Developmental Disabilities Branch (DDB) was tasked with taking the lead on the prevalence investigation to determine the rate of ASD in Brick Township. This section summarizes the prevalence report.
The objective of this investigation was to determine the prevalence of autism in children age 3-10 years old who were residents of Brick Township in 1998. To do this, a two-phased approach was used. Phase I involved identifying all children who might meet the case definition for autism. This was done by reviewing records at schools, service providers (physicians or programs for children with autism), and from names provided by the citizen's group. Phase II was to verify case status from an examination by developmental clinicians. In addition to standard evaluation procedures, the Autism Diagnostic Observation Schedule was administered. Autism Spectrum Disorder was defined to include: autistic disorder, Asperger's disorder, and pervasive developmental disorder- not otherwise specified (PDD-NOS) as defined by the American Psychiatric Associations's Diagnostic and Statistical Manual - Fourth Revision (DSM-IV). The denominator was the estimated number of children ages 3-10 years in Brick Township in 1998.
Phase I of the investigation identified 75 children with possible autism. In Phase II, 60 children were found to meet the DSM-IV criteria for an autism spectrum disorder (ASD). The prevalence of ASD was found to be 6.7 cases per 1,000 children (95% CI- 5.1-8.7). For the subset of 36 children who met the diagnosis for autistic disorder, the prevalence rate was 4.0 cases per 1,000 children (95% CI = 2.8-5.6). The male to female ratios ranged from 2.2-3.7 for autistic disorder and PDD-NOS, respectively. About half of the children were found to have an IQ score of less than or equal to 70. Of those children with a known town of birth residence, 66% were born in Brick Township. Seven children were reported to have a brother or sister who also had an ASD. Specific medical conditions were found in 5 of the 60 children.
The rates of ASD and autistic disorder in Brick Township are high compared with prevalence rates from previously published studies. The intense case finding of this study may have contributed, to some extent, to the high rate of autism found in Brick Township. For example, recent studies that have employed intense case finding methods to study populations of comparable size or larger than the Brick Township population have found prevalences for autistic disorder as high as 3.1 cases per 1,000 children. However, these prevalences are still lower than the prevalence for autistic disorder found in Brick Township (i.e. 4 cases per 1,000 children). The epidemiologic characteristics of children with ASD in Brick Township, the predominance in males and the high proportion of children with IQ of 70 or less, are comparable to those found in previous studies. In addition, most of the children with autism in Brick Township were born in town, so migration cannot explain the high prevalence found.
During discussions initiated while developing the PHAP parents expressed concern that hazardous substances might be present in the environment of Brick Township and that an increase in the number of children with autism may be attributable to exposure to these substances. There were three areas of concern regarding possible environmental contamination and exposure: (1) the municipal drinking water supply, (2) swimming in the Metedeconk River, and (3) the Brick Township Landfill. ATSDR has investigated each of these concerns and has summarized them in this report.
In addition, information on residence during pregnancy and birth, for the children who participated in Phase II of the prevalence study and were diagnosed with ASD, was obtained from families by ATSDR. The information collected indicated that 68%(1) of the children diagnosed with autism or PDD by CDC were born or conceived in Brick Township, 29% were born or conceived elsewhere, and for 3% the place of birth or conception could not be identified (see Appendix E, Figure 1). ATSDR also reviewed date of birth information for children in the study and calculated the beginning of the first trimester for each child.
Community involvement plays a vital role in all public health activities carried out by ATSDR. ATSDR met with community members, local parents groups, as well as with town and federal officials on several occasions throughout the investigation. In addition, information regarding the investigation has been provided to local and national media upon request.
Brick Township is located in the northeast corner of Ocean County, New Jersey, approximately 50 miles south of Newark and approximately 60 miles north of Atlantic City. The Township has an estimated total population of 77,202 based on projections from 1990 census data. The population is mostly white (75,333) with some Hispanic (3352), Asian (1102), Black (628), and American Indian (139) populations. According to the 1990 census, 7,117 children between the ages of 3 to 10 years resided in Brick Township. [Demographic Statistics Source: 1999 Claritas Inc.]
ATSDR identifies human exposure pathways by examining environmental and human factors which may lead to contact with contaminants of concern. A pathways analysis considers five principal elements: (1) a source of contamination, (2) transport through an environmental medium, (3) a point of exposure, (4) a route of human exposure, and (5) a receptor population. Completed exposure pathways are those for which the five elements are evident, and indicate that exposure to a contaminant has occurred in the past, is currently occurring, or will occur in the future. ATSDR regards people who come into contact with contamination as exposed; for example, people who reside in an area with contaminants in air, or who drink water known to be contaminated, or who work or play in contaminated soil are considered to be exposed. Potential exposure pathways are those for which exposure seems possible, but one or more of the elements is not clearly defined. Potential pathways indicate that exposure to a contaminant could have occurred in the past, could be occurring currently, or could occur in the future. Identification of an exposure pathway does not imply that health effects will occur. Exposures may be, or may not be, substantive. Thus, exposures may or may not cause adverse health effects.
ATSDR staff developed a list of contaminants of concern (see Appendix A) and then reviewed data and information from the Environmental Protection Agency (EPA), New Jersey Department of Environmental Protection (NJDEP), Ocean County Health Department (OCHD) and the Brick Township Municipal Utilities Authority (BTMUA) to assess past and current possible exposures.
The contaminants of concern identified have the potential to cause adverse health effects. However, for adverse health effects to occur, the pathway for exposure must be completed. A release does not always result in exposure. A person can only be exposed to a contaminant if they come into contact with the contaminant. Health effects resulting from the interaction of an individual with a hazardous substance in the environment depend on several factors. One is route of exposure; that is whether the chemical is inhaled; consumed with food, soil, or water (ingestion); or whether it contacts the skin (dermal). Another factor is the dose level to which a person is exposed, and the amount of the exposure dose that is actually absorbed. Mechanisms by which chemicals are changed in the environment or inside the body, as well as the combination (types) of the chemicals also is important. Once exposure occurs, characteristics such as age, sex, nutritional status, genetics, lifestyle, and health status of the exposed individual influence how the contaminants are absorbed, distributed, metabolized, and excreted. Together those factors and characteristics determine the health effects that may occur as a result of exposure to a contaminant. Substantial variation in those mechanisms exists among individuals.
1. Completed Exposure Pathways
Virtually all residents of Brick Township obtain their drinking water from the BTMUA, with the exception of residents of Brick Beach who are served by the New Jersey American Water Company. The BTMUA's water supply comes from both groundwater wells and surface water (the Metedeconk River). Prior to 1994 the BTMUA used primarily groundwater for distribution, but by 1994 the amount of surface water had increased gradually to about two-thirds of the supply. Today about 70% of the water supply is from surface water. The groundwater and surface water supplies are mixed at the treatment plant prior to being distributed to residences. At the treatment plant, the water goes through a disinfection process that includes the addition of chlorine. In 1995 the BTMUA began adding chlorine to the drinking water distribution system at two locations in addition to the water treatment facility (during the summer months only) to ensure continued disinfection of the drinking water throughout the system.
During the study period (1987-1995) two types of contaminants in the municipal drinking water supply were evaluated: solvents (i.e. TCE and PCE) and disinfection byproducts (i.e. trihalomethanes (THMs) such as chloroform and bromoform). Bromoform, chloroform and tetrachloroethylene (PCE) were found in the drinking water supply above ATSDR comparison values (see Appendix C) at various times during the study period. These chemicals are discussed in more detail below.
The primary method of disinfection of drinking water used in the U.S. involves the addition of chlorine to drinking water. THM's and other disinfection byproducts are formed by the interaction of chlorine with organic matter in the water. Naturally occurring organic matter in the water is the result of the decomposition of plant matter (e.g., leaves) and the metabolism of aquatic biota (e.g., algae). The longer the chlorine has a chance to react with the organic matter in the water, the higher the amount of THMs produced. This means that areas furthest from the treatment plant are more likely to have higher THMs in the drinking water than areas closer to the treatment plant. In addition, in areas where there is a low use of water or where there is a "dead-end" in the system, or where the system consists of small diameter pipes, the water tends to move very slowly and the chlorine has more time to react with any organic matter in the water to produce more THMs. As a result, residences in different areas can have very different levels of THMs in their drinking water. In addition, a sample taken in one location may have THM levels that are very different from homes that are less than 1 mile away. For example, homes located at a dead-end or low volume area of the system may have THM levels that differ substantially from levels found at nearby homes that are not at a low volume point in the system.
THMs will also vary in levels by season. In the summer and fall, there tends to be more organic matter in surface water (e.g., leaves and other vegetation), so there also tends to be more residual organic matter in the drinking water that can react with chlorine. (Ground water has very little organic matter so the chlorination of ground water produces very low or undetectable amounts of THMs.)
THMs include chloroform, bromoform, dibromochloromethane and bromodichloromethane. Other disinfection byproducts include MX (3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone) and the haloacetic acids (e.g., trichloroacetic acid). Teratogenicity, mutagenicity, and carcinogenicity have been suspected as being associated with the ingestion of several of the disinfection byproducts including THMs (Mills 1998, Boorman 1999).
THMs in drinking water have been linked to adult cancers in a few studies (Cantor 1997, Mills 1998). The strongest association is with bladder cancer. Associations have also been found for rectal and colon cancers. Recently, a study found an association between duration of residence with a chlorinated surface water source and brain cancer, but the association was found only for males (Cantor 1999). It is not known whether the cancers in these studies were caused by one or more of the THMs, by some other disinfection byproduct in the drinking water, or some combination of THMs and other disinfection byproducts.
THMs in drinking water have also been linked to adverse birth outcomes such as spontaneous abortion, small for gestational age, neural tube defects (NTD), oral cleft defects, and heart defects (Bove 1995, Waller 1998, Klotz 1999).
Of particular interest is the association between THMs and NTD. In two NJ studies, levels of THMs within the range found in some samples taken in Brick Township were associated with at least a two-fold increased risk of NTD (Bove 1995, Klotz 1999). On the other hand, a study conducted in Nova Scotia found a smaller increased risk of NTD with levels of THMs within the range found at Brick (Dodds 1999). An NTD is a defect of the spinal cord that occurs when the neural tube fails to close properly during the period between day 21 and day 26 of pregnancy. Recently, the drug thalidomide, which caused severe limb defects during an epidemic in Europe in the late 1950s and early 1960s, has been linked to an increased risk of autism (Stromland 1994, Rodier 1997). Among those exposed in utero to thalidomide, a high percentage developed autism. However, all the cases of autism were exposed to thalidomide between day 20 and day 24 of the pregnancy. Those exposed to thalidomide at other periods during pregnancy did not develop autism. This evidence suggests an hypothesis that the period when the neural tube closes may also be a period when exposures to certain chemicals might lead to the development of an ASD. It also suggests an hypothesis that chemicals that cause NTD, since they act during this period of gestation, might also cause ASD. However, research on these hypotheses is at a very early stage. Therefore, it is currently unknown whether in utero exposure to environmental chemicals such as the disinfection byproducts of chlorination are associated with ASD.
THM's were found in the municipal drinking water supply approximately 356 times in samples taken between 1987 and 1995. Total THM's were detected at levels between 1 to 251 parts per billion (ppb)(2). The highest THM level (251 ppb) was found at the Crab Shack. The next highest levels were also at the Crab Shack in August 1994 and ranged from 123 ppb to 142 ppb. During the study period, other sites which had at least one sample above 100 ppb but below 140 ppb were Crossroads Realty, Baywood Hardware, Greenbriar Clubhouse, Lionshead Clubhouse, and Shore Acre Plaza. Total Trihalomethanes exceeded 80 ppb approximately sixteen times in sampling data during the study period, but did not exceed the EPA Maximum Contaminant Level (MCL). The MCL was 100 ppb based on an annual rolling average during the study period. It should be noted however that the EPA revised the MCL for THMs in the Federal Register on December 16, 1998. The MCL was lowered from 100 ppb to 80 ppb, but community water systems serving 10,000 or more persons have been given until December 2001 to comply with this change. ATSDR used the MCL goal of 80 ppb for some of its analysis in this report to be conservative from a public health perspective. The primary THM detected in Brick Township water supplies was chloroform with a range of <1 ppb to 240 ppb. No data were available on the levels of disinfection byproducts other than THMs during this period.
ATSDR attempted to contact the families of the 43 children who participated in the clinical exams and who were diagnosed with ASD to obtain residence during pregnancy and date of birth information. Two families declined to be contacted by ATSDR and one family could not be contacted after repeated attempts to obtain residence during pregnancy. ATSDR was able to obtain date of birth information for 41 children and residence during pregnancy for 40 children. Therefore ATSDR used 41 children as the denominator for its calculations. Twenty eight (28) of the children who participated in the clinical exams and were diagnosed with ASD were born in Brick Township, 12 were born outside of Brick Township, and the place of birth for one child was unknown. The residence during pregnancy for children born in Brick Township was plotted through Geographic Information Systems (GIS) and indicated no apparent grouping or pattern (see Figure 4). Residence during pregnancy also was plotted and compared to the top 15 and top 50 THM levels found in the municipal drinking water system. This pattern also was random and did not indicate a relationship between residence and THM levels.
ATSDR calculated the month and year of the first trimester for children who participated in the clinical exams and were diagnosed with ASD. For approximately 40% of the children who participated in the clinical exams, the first trimester was in 1991 or 1992. ATSDR reviewed THM data for the years prior to 1991 and 1992. The peak THM level (251 ppb) was in March 1988 and there were several THM samples that exceeded 100 ppb in September 1990 and September 1992. These levels do not correspond with the birth or conception periods of children with autism or PDD. In 1988 when the peak THM level occurred in March one child in the study was in the first trimester. In 1990 several THM levels exceeded 100 ppb in September and there were four children in the study in their first trimester. In 1992 several THM levels exceeded 100 ppb in September and there were five children in the study in their first trimester at or about this time. In 1991 the year with the highest number of children in the study with ASD total THM levels did not exceed 100 ppb.
ATSDR plotted residence during pregnancy and distance to the nearest sampling locations with THM samples greater than 80 ppb and greater than 60 ppb. There were 14 participants within approximately one mile of a sampling point location where THM levels exceeded 80 ppb at least once between 1987 and 1995. Five of these 14 study participants lived within approximately one mile of a sampling point location where THM levels exceeded 80 ppb during the pregnancy period. Thus, about 18% (5/28) of the participants who lived in Brick Township resided within one mile of a sampling point that exceeded 80 ppb during their pregnancies. All of the 28 participants lived within approximately one mile of a sampling point location where THM levels exceeded 60 ppb at least once between 1987 and 1995. Eight of these 28 study participants (about 29%) lived within approximately one mile of a sampling point location where THM levels exceeded 60 ppb during the pregnancy period.
Based on these analysis, ATSDR is not able to show a clear pattern between elevated THM levels and the pregnancy period for children in the prevalence study.
THM data from other NJ water systems was compared to THM data in Brick Township. Out of 198 water companies with THM data available for review, between 1988 and 1993, the Brick Township water system ranked 30th for average THMs. This means that there were 29 systems in the state during this time period with higher average THM levels. About 45 out of these 198 systems have similar surface water systems to the one in Brick Township. However, out of the data reviewed for the 198 NJ water systems Brick Township had the 2nd highest reported THM level (251 ppb) which was obtained at the Crab Shack. Based on this THM data review, Brick Township's THM levels could be considered typical or average for similar surface water systems in NJ with the exception of the 251 ppb sample.
Bromoform is one of the THMs. It was found in samples from the Brick Township drinking water supply fourteen times between 1987 and 1995. The concentration of bromoform was detected at levels from 0.6 to 5 ppb. Bromoform exceeded the ATSDR comparison value of 4 ppb (see Appendix C) only once during the study period. In general, the range of bromoform found in the Brick Township water supply are similar to levels found in other areas of NJ as well as areas in the U.S. where the bromine content in water is very low. In areas of the U.S. where bromine levels in water are high, bromoform levels are ten to thirty times higher than the highest level found in the Brick Township supply.
Studies in animals indicate that long-term intake of bromoform can cause cancer. However, the levels found in the Brick Township water supply are very low and are not expected to increase a person's risk of developing cancer. Evidence from animal studies is sparse but has not indicated that bromoform is a teratogen. Other than the studies of THMs in drinking water, there have been no studies of exposure to bromoform and cancers or adverse birth outcomes in humans. ATSDR did perform a cancer risk analysis for bromoform found in the Brick Township drinking water supply (see Appendix D) and there appears to be no significant increased risk of cancer.
Chloroform is another of the THMs. It was found in drinking water supply samples approximately 356 times between 1987 and 1995. The concentration of chloroform was detected at levels from 0.6 to 240 ppb(3). Chloroform exceeded the ATSDR comparison value of 6 ppb in 320 of the samples in the study period.
Based on animal studies, chloroform may be anticipated to be a carcinogen and a teratogen. In one study, the offspring of mice exposed to chloroform by inhalation had increased incidences of cleft palate and growth retardation. The observed defects and growth retardation occurred among fetuses exposed during organogenesis (days 8-15 of gestation). ATSDR performed a cancer risk analysis for chloroform found in the Brick Township drinking water supply (see Appendix D) and there appears to be no significant increased risk of cancer.
During 1987, two small municipal wells were found to be contaminated with the solvents PCE and TCE. These wells were shut down in early 1988. Water from these wells was sent (along with water from other ground water and surface water sources) to the treatment plant were it was mixed prior to disinfection. Because the water was mixed at the treatment plant, the PCE and TCE from the two contaminated wells were diluted by the rest of the water that was not contaminated with TCE and PCE prior to reaching Brick residences. In addition, because of the mixing of water prior to delivery, all residences served by the BTMUA received approximately the same amount of TCE and PCE. The amount of TCE and PCE in the drinking water reaching every home in Brick depended on the percentage of the total water that was supplied by the two contaminated wells. On average, these two wells supplied about 2%each to the total supply during 1987, but the percentage of total water supplied by these two wells varied depending on the demand on the system (e.g., more water is usually consumed in the summer months) and the pumping rates of each well in the system as well as the amount of water provided by surface water sources.
PCE was found in distribution system 12 times between 1987 and 1994 at levels between 0.13 to 6 ppb. PCE was not detected after 1994. PCE exceeded the ATSDR comparison values of 0.7 ppb in five of these samples. The EPA MCL for PCE is 5 ppb and was exceeded once during the study period.
Data reported by the NJDEP and reviewed by ATSDR indicated higher values for PCE in well #2 (170 ppb - 360 ppb) and well #8 (6 ppb - 29 ppb). These wells provided approximately 2% each to the total water supply and were mixed with water not contaminated with PCE at the treatment plant prior to distribution to homes, so high levels found at the well were substantially diluted by the time they reached homes. This is the reason why the well samples are high, but the distribution samples are no higher than 6 ppb.
PCE is a synthetic chemical that is widely used for dry cleaning fabrics and for metal-degreasing operations. It also is used as a starter material for making other chemicals and is used in some consumer products. Other names for tetrachloroethylene include perchloroethylene, PCE, perc, tetrachloroethene, perclene, and perchlor.
There have been a few studies linking PCE in drinking water to cancers in humans. In one study, exposure to high levels of PCE in drinking water (i.e., from about 500 ppb to over 1 ppm) was associated with increased risk of leukemia and bladder cancer. A second study of this same population found that similar levels of PCE in drinking water was associated with breast cancer. A study in NJ found an association between PCE levels greater than 5 ppb and increased risk of leukemia and non-Hodgkins lymphoma, but the increase was only among females. In Woburn, MA, a 1979 drinking water sample from two contaminated wells detected trichloroethylene (TCE) at 267 ppb and PCE at 21 ppb. A cluster of childhood leukemia was linked to these drinking water contaminants (Lagakos, 1986). It is not clear whether the causative agent was TCE, PCE or the mixture, but since TCE was the predominant contaminant, the focus has been on TCE.
Based on human and animal studies, the International Agency for Cancer Research has determined PCE to be a probable human carcinogen. The U.S. EPA considers PCE to be on a continuum between probably and possibly carcinogenic to humans. ATSDR performed a cancer risk analysis for PCE found in the Brick Township drinking water supply (see Appendix D) and there appears to be no significant increased risk of cancer.
It is unknown whether PCE is a human teratogen. There is animal data indicating PCE at high doses can cause reduced fetal weight. A few studies have linked occupational exposure to PCE among dry cleaning workers and spontaneous abortions, but these findings have been contradicted by other studies that found no increased risk among dry cleaning workers. In a study conducted in NJ, PCE levels in drinking water above 10 ppb were associated with an increased risk of oral clefts. At U.S. Marine Corp Base, Camp LeJeune, NC, PCE levels in drinking water ranging from 76 ppb to 215 ppb were associated with a slight increase in small for gestational age among base residents. However, among the subgroup of Camp LeJeune mothers aged 35 years and older, the association between PCE exposure in drinking water and the risk of small for gestational age infants was nearly fourfold. In Woburn, MA, a 1979 drinking water sample from two contaminated wells detected trichloroethylene (TCE) at 267 ppb and PCE at 21 ppb. A study of birth outcomes parallel to the childhood cancer study found increased risks for several birth defects including NTD and an increased risk of small for gestational age. However, it is unclear whether the increased risks are due to the TCE, PCE or the mixture. Given that TCE was the predominant contaminant, the focus has been on TCE.
ATSDR also reviewed PCE data and compared it with the month and year of the first trimester for children who participated in the clinical exams and who were diagnosed with ASDin the prevalence study. Based on the data reviewed seven of the samples indicating PCE in the municipal drinking water were in either 1987 or 1988 and there was one positive sample for PCE in 1994. In 1987 the year with the most hits of PCE there was one child in the first trimester from the study. In 1988 there were three children in the first trimester from the study. In 1994 all children were through the first trimester before the positive PCE sample. Again the data are limited and the number of children in our study is small, but based on this information PCE levels and children diagnosed with autism or PDD in the prevalence study do not appear to be correlated.
2. Incomplete Exposure Pathways
In addition to the THMs, two other chemicals were found in BTMUA wells (#2 and #8) in 1987 and 1988. These were trichloroethylene (TCE) and tetrachloroethane. TCE and tetrachloroethane are not evaluated further in this report, since they were not detected in finished water or the distribution system. Therefore there would be no completed exposure pathway. To prevent possible exposure to these substances the BTMUA discontinued the use of wells 2 and 8 in January 1988.
3. Potential Exposure Pathways
The groundwater beneath the Brick Township Landfill has been shown to be contaminated with a variety of Volatile Organic Compounds (VOC's) and metals (see Appendix C, Table 2). ATSDR completed a Public Health Assessment (PHA) in 1989 and a Site Review and Update (SRU) in 1995 for the Brick Township Landfill. Copies of the PHA and SRU are available by request from ATSDR.
The landfill operated from 1949 through 1979. Disposal operations ceased at the landfill in May 1979. The landfill also has been known as McCormick's Dump, French's Landfill and as the Brick Township Landfill. The landfill was used for the disposal of municipal solid waste, bulk liquid waste, commercial and construction waste, and sewage and septic waste. Disposal records indicate that sewage and septic wastes, municipal solid wastes, and bulk liquid wastes were the most common materials disposed. An undetermined quantity of labeled and unlabeled 55 gallon drums were also disposed of at the landfill. The Brick Township Landfill was added to the EPA's National Priority List (NPL) in December 1982.
Sampling data has shown that the groundwater beneath the site is contaminated and the contaminant plume is migrating southeast from the site. In addition to groundwater contamination, the PHA noted on-site soil contamination and low level contamination of one private well in the landfill vicinity.
ATSDR previously concluded that the Brick Township Landfill presented no apparent public health hazard, because all residents in the area are supplied water by the municipal drinking water system, preventing exposure to contaminated groundwater. ATSDR recommended in its SRU that the landfill be secured on all boundaries to restrict entry and exposure to physical hazards, erect warning signs, and to fill in the borrow pit to prevent accidents. An ATSDR representative visited the site in January 2000 and noted that access to the site has been restricted and warning signs have been posted. The borrow pit has not been filled, but Brick Township plans to fill the pit by summer 2000.
ATSDR also concluded in the SRU that the site constituted no apparent public health hazard in the past as a result of the ingestion of contaminated groundwater, because maximum exposure doses of chloroform and trichloroethylene detected in residential wells were below levels where adverse health effects were likely. This conclusion was based upon calculated exposure doses. It is unlikely that those residents exposed to chloroform or trichloroethylene in the past by drinking contaminated private well water will experience significant additional carcinogenic risk.
ATSDR received and reviewed additional data for this report on the contaminated groundwater plume that is migrating southeast from the site. The groundwater plume has spread further than noted in the past, but still does not present a public health hazard, because all residents in the area are on the municipal drinking water supply, which is supplied by the Brick Township Municipal Utilities Authority.
Based on the results from recent testing of the groundwater plume, Brick Township imposed a restriction on the use of private irrigation wells in the vicinity of the Brick Township Landfill in September 1999. This restriction remains in effect. As an added precaution, persons with private irrigation wells in the vicinity of the landfill will have their wells disconnected and sealed by Brick Township. These persons will then be hooked up by the Township to the municipal water system for irrigation purposes. ATSDR has reviewed recent sampling data and determined that levels of contamination from use of irrigation wells were not high enough or frequent enough to have caused adverse health effects. The disconnection and sealing of irrigation wells in the vicinity of the Brick Township Landfill will prevent future exposures to groundwater contaminants.
ATSDR plotted residence during pregnancy and distance to the Brick Township Landfill for children who participated in the clinical exams and were diagnosed with ASD (see Figure 7). There were three residences of study participants in the vicinity of the landfill. Two of the three residences are southwest of the landfill and one residence is south-southwest of the landfill. The closest of these three residences is approximately 0.3 miles to the southwest. Groundwater sampling indicates that the groundwater plume is moving away from the landfill site to the southeast, away from the residences of the study participants. Therefore, it is unlikely that the contaminated groundwater plume from the Brick Township Landfill is associated with the ASD for children in the prevalence study.
ATSDR reviewed the BTMUA report and sampling data regarding Fluid Packaging's discharge of VOC's and metals to the Cedar Branch Creek of the Metedeconk River. ATSDR agrees with the BTMUA conclusion that the BTMUA's intake on the Metedeconk River was not impacted from the discharges from Fluid's storm sewer outfall. The storm sewer outfall from Fluid Packaging goes to the Cedar Bridge Branch which is more than a mile below Forge Pond, where the BTMUA collects water from the river. The BTMUA took surface water samples upstream from its intake as an added safety measure. The results of these samples showed no VOC's or semi-volatiles above ATSDR comparison values. The report also determined that groundwater flows established from the monitoring wells have not affected the BTMUA's well field, because groundwater contamination affiliated with Fluid is in shallow bearing zones and has an easterly flow. BTMUA wells are northeast of these monitoring wells.
ATSDR reviewed sediment data from the storm sewer outfall at Fluid Packaging. Most likely the VOC's found near the storm sewer outfall would be volatilized in the Cedar Branch Creek before they reached the Metedeconk River. Of the metals detected at the storm sewer outfall mercury was the most significant and it would tend to bind tightly with sediment near the outfall. Any remaining mercury would be significantly diluted as it moved downstream through Cedar Branch Creek and further diluted once entering the Metedeconk River.
c. Swimming in the Metedeconk River
ATSDR requested available environmental data for the Metedeconk River and the Windward Beach swimming area from the NJDEP, the OCHD and the BTMUA. Data for evaluating this possible exposure pathway was limited. The data reviewed indicated no chemical contaminants above ATSDR Comparison Values for VOC's for the Metedeconk River upstream from the BTMUA's water intake. No VOC data was available for the Windward Beach swimming area. The Metedeconk River is more than a half mile wide where Cedar Branch Creek enters and it is highly unlikely that contaminants from Fluid Packaging would reach the swimming area. In addition, ATSDR believes that due to the continual current and tidal fluctuation of the Metedeconk River that any past chemical releases to the river would be diluted to trace amounts. Exposure to these trace amounts through occasional swimming in the river (even more frequent swimming in summer months) would not be great enough to cause adverse health effects to pregnant mothers or young children.
4. ATSDR Child Health Initiative
To ensure that the health of the nation's children is protected, ATSDR has implemented an initiative for each investigation to protect children from exposure to hazardous waste. ATSDR recognizes the unique vulnerabilities of infants and children demand special emphasis in communities faced with contamination of their water, soil, air, or food. Infants and children are usually more susceptible to toxic substances than adults due to immature and developing organs. Children are more likely to be exposed to contaminants, because they play outdoors and they often bring food into contaminated areas. These activities may increase their exposure to toxicants in dust, soil, and airborne particulate matter. Some children exhibit excessive hand to mouth behavior (pica), which may increase their intake of toxicants. Children are smaller, which results in higher doses. Most importantly, children depend completely on adults for risk identification and management decisions, housing decisions, and access to medical care. ATSDR's evaluation contained within this document considered children as a susceptible sub-population. Estimates of exposure were calculated using conservative values for children (i.e. weight, ingestion rate, etc.).
ATSDR staff met several times with the community, individually and during public forums. ATSDR held public meetings on September 24, 1998 and January 12, 1999. ATSDR also held availability and information sessions on January 13, 1999 and July 20, 1999. These meetings helped ATSDR understand and collect specific health concerns from the community. In addition to public meetings and availability sessions, ATSDR staff worked in conjunction with the OCHD to collect environmental information and concerns by mail. ATSDR and CDC also called and met with parents of children with autism during the investigation. The three main concerns from community members were incorporated into the PHAP: (1) Were there chemicals in the municipal drinking water supply at levels that may have adversely affected the health of pregnant mothers or children diagnosed with autism, (2) Could swimming in the Metedeconk River have adversely affected my child's health, and (3) Could environmental contamination at the Brick Township Landfill have adversely affected the health of pregnant mothers or children diagnosed with autism? These questions are addressed in the conclusions section below. ATSDR released the Public Comment version of this PHA on April 4, 2000 with a 30 day comment period beginning April 18th and ending May 22nd. On April 18th, ATSDR met with parents; local, state, and federal officials; and media representatives to discuss the PHA and answer questions regarding the document.
1. Were there chemicals in the municipal drinking water supply at levels that may have adversely affected pregnant mothers or children diagnosed with autism?
After reviewing and analyzing the data provided from the NJDEP, BTMUA and the OCHD on TCE, PCE, and THMs ATSDR concludes the following: (1) Based on the information provided TCE was never found in the distribution of the municipal drinking water supply and therefore, would not cause adverse health effects to children or pregnant mothers. (2) PCE was detected at low levels in the municipal drinking water supply several times between 1987 and 1994, but was mixed after the point of detection with millions of gallons of uncontaminated water prior to being distributed to any residents of the township. Therefore, any PCE that may have reached a residence would have been diluted to a very low quantity and would not be expected to cause adverse health effects to children or pregnant mothers. (3) Total THM levels in the municipal drinking water supply exceeded 80 parts per billion (ppb) several times during the study period.
Since there is no clear pattern linking the residences of the cases, during mothers' pregnancies, with location and timing of the high THM levels, it appears unlikely that THMs in the municipal drinking water supply were associated with ASD in Brick Township.
2. Could swimming in the Metedeconk River have adversely affected my child's health?
ATSDR does not believe that levels of chemicals in the Metedeconk River, from the Fluid Packaging spill, would have been at sufficient levels to cause adverse health effects to children or pregnant mothers who swam in the river in the past, because the continual current and tidal fluctuation of the Metedeconk River would dilute any past chemical releases to the river to trace amounts. Exposure to trace amounts through occasional swimming in the river (even more frequent swimming in summer months) would not be likely to cause adverse health effects.
3. Could environmental contamination at the Brick Township Landfill have adversely affected pregnant mothers or children diagnosed with autism?
The groundwater beneath the Brick Township Landfill is contaminated with a variety of VOC's and metals. ATSDR believes that the contaminated groundwater would not have adversely affected pregnant mothers or children near the site, because residents in the area are supplied water by the municipal drinking water system, preventing exposure to the contaminated groundwater.
The municipal drinking water supply is maintained by the Brick Township Municipal Utilities Authority. ATSDR believes that any exposure to contaminated groundwater through the use of irrigation wells near the site would not have been at high enough levels or frequent enough to adversely affect the health of pregnant mothers or children.
Based on the review and analysis of data from the municipal drinking water supply, the Metedeconk River and the Brick Township Landfill ATSDR believes there to be no apparent public health hazard from these areas.
- ATSDR encourages the BTMUA to continue to monitor and control THM levels in accordance with current regulations.
The Public Health Action Plan (PHAP) for the Brick Township Autism Investigation contains a description of actions taken and actions planned by the Agency for Toxic Substances and Disease Registry (ATSDR) and/or other government agencies after completion of this public health assessment.
A. Public Health Actions Taken
- ATSDR and CDC developed a draft PHAP in March 1998. On April 1, 1998 Senator Torricelli, Representative Smith, and the parents were briefed on the PHAP and their comments were solicited.
- ATSDR and CDC met with parents and Dr. Eric London of the National Alliance for Autism Research to learn more about concerns and obtain additional feedback on the PHAP.
- ATSDR and CDC conducted public meetings in Brick Township on September 24, 1998 and January 12, 1999 to discuss the PHAP plan and provide additional opportunities for parents and community members to discuss the PHAP or specific community health concerns.
- ATSDR prepared a draft consultation of current literature on possible associations between chemical exposure and autism. The draft consultation was completed and distributed in January 1999.
- ATSDR also held availability and information sessions on January 13, 1999 and July 20, 1999.
- In addition to meetings, ATSDR has provided two fact sheets and several update letters to the community. The last update letter was mailed in December 1999.
- ATSDR released the Public Comment version of the Brick Township Investigation PHA on April 4, 2000 and allowed a 30 day comment period, which began April 18, 2000 and ended May 22, 2000.
- ATSDR held meetings on April 18, 2000 with parents; local, state, and federal officials; and media representatives to discuss the Public Comment version of the PHA and to address questions and concerns regarding the document.
B. Public Health Actions Planned
- ATSDR will continue to review any new environmental data associated with this investigation and if necessary, revise the conclusions and recommendations contained in this public health assessment.
- Agency for Toxic Substances and Disease Registry. 1990. Toxicological Profile for Bromoform. ATSDR.
- Agency for Toxic Substances and Disease Registry. 1995. Toxicological Profile for Chloroform. ATSDR.
- Agency for Toxic Substances and Disease Registry. 1993. Toxicological Profile for Tetrachloroethylene. ATSDR.
- Agency for Toxic Substances and Disease Registry. 1989. Health Assessment for Brick Township Landfill. ATSDR.
- Agency for Toxic Substances and Disease Registry. 1995. Site Review and Update for Brick Township Landfill. ATSDR.
- Agency for Toxic Substances and Disease Registry. 1998. DRAFT Chemical Specific Consultation: Hazardous Substance Exposure and Autism. ATSDR.
- Agency for Toxic Substances and Disease Registry. 1997. Volatile Organic Compounds In Drinking Water and Adverse Pregnancy Outcomes: United States Marine Corps Base Camp Lejeune, North Carolina. ATSDR.
- Agency for Toxic Substances and Disease Registry. 2000. Groundwater Consultation for the Brick Township Landfill. ATSDR.
- Birdsall Engineering, Inc. 1999. Remedial Investigation Report: Brick Township Landfill. Birdsall Engineering.
- Boorman GA, Dellarco V, Dunnick JK, et al. 1999. Drinking Water Disinfection By-Products: Review and Approach to Toxicity Evaluation. Environmental Health Perspectives 107: 207-217.
- Bove FJ, Fulcomer MC, Klotz JB, et al. 1995. Public Drinking Water Contamination and Birth Outcomes. American Journal of Epidemiology 141:850-862.
- Brick Township Municipal Utilities Authority. 1998. Results of Fluid Packaging Data Review. BTMUA.
- Cantor KP, Lynch CF, Hildesheim ME, et al. 1999. Drinking Water Source and Chlorination Byproducts in Iowa. III. Risk of Brain Cancer. American Journal of Epidemiology 150: 552-560.
- Cantor, KP. 1997. Drinking Water and Cancer. Cancer Causes and Control 8: 292-308.
- Dodds L, King W, Woolcott C, Pole J. 1999. Trihalomethanes in Public Water Supplies and Adverse Birth Outcomes. Epidemiology 10: 233-237.
- Federal Register: December 16, 1998 (Volume 63, Number 241)] National Primary Drinking Water Regulations: Disinfectants and Disinfection Byproducts.
- Lagakos SW, Wessen, BJ, Zelen, M E. 1986. An Analysis of Contaminated Well Water and Health Effects in Woburn, MA wells. JAM Statistical Association 81:583-596.
- Klotz JB, Pyrch LA. 1999. NTD's and Drinking Water Disinfection By-Products. Epidemiology 10:383-390.
- Mills CJ, Bull RJ, Cantor KP, et al. 1998. Health Risks of Drinking Water Chlorination By-Products: Report of an Expert Working Group. Chronic Diseases in Canada 19: 91-102.
- National Research Council (NRC), Subcommittee on Disinfectants and Disinfection By-Products. National Academy Press. Washington D.C. 1987.
- New Jersey Department of Health. 1992. Report on Phase Iv-A: Public Drinking Water Contamination and Birth Weight, Fetal Deaths, and Birth Defects. NJDOH.
- New Jersey Department of Environmental Protection and Energy. 1992. Decision Document: Brick Township Landfill Site. NJDEP.
- Rodier PM, Ingram JL, Tisdale B, et al. 1997. Linking Etiologies in Humans and Animal Models: Studies of Autism. Reproductive Toxicology 11:417-422.
- Stromland K, Nordin V, Miller M, et al. 1994. Autism in Thalidomide Embryopathy: A Population Study. Developmental Medicine and Child Neurology 36:351-356.
- Waller K, Swan SH, DeLorenze G, Hopkins B. 1998. Trihalomethanes in Drinking Water and Spontaneous Abortion. Epidemiology 9:134-140.
Copies of ATSDR documents reviewed and cited in this PHA can be obtained by request from the Program Evaluation, Records, and Information Services Branch.
Agency for Toxic Substances and Disease Registry
Division of Health Assessment and Consultation
Attn: Chief, Program Evaluation, Records, and Information Services Branch, E-56
1600 Clifton Road, N.E., Atlanta, Georgia 30333
Frank J. Bove, Sc.D., ATSDR, Division of Health Studies
Robert B. Knowles, M.S., REHS, ATSDR, Division of Health Assessment and Consultation
ATSDR TEAM MEMBERS
FOR THE BRICK TOWNSHIP INVESTIGATION
Stephen R. Blackwell, M.P.H., ATSDR, Division of Health Education
and Promotion
Lafreta Dalton, ATSDR, Division of Health Assessment and Consultation
William D. Henriques, Ph.D., ATSDR, Division of Health Assessment and Consultation
A. Thomas Mignone, M.P.H., REHS, ATSDR, Office of Regional Operations, Region II
Ralph O'Connor, Ph.D., ATSDR, Division of Health Education and Promotion
ACKNOWLEDGMENT
FOR CONTRIBUTIONS TO REPORT
Jacquelyn Bertrand, Ph.D., CDC, Division of Birth Defects, Child
Development, and Disability and Health
Coleen Boyle, Ph.D., CDC, Division of Birth Defects, Child Development, and
Disability and Health
Pierre Decoufle, Sc.D., CDC, Division of Birth Defects, Child Development, and
Disability and Health
Eric London, M.D., National Alliance for Autism Research
Audrey Mars, M.D., Robert Wood Johnson Medical School
Marshalyn Yeargin-Allsopp, M.D., CDC, Division of Birth Defects, Child Development,
and Disability and Health
1. This percentage varies slightly from the one in the prevalence investigation, because CDC used maternal address information and ATSDR used actual available street addresses and different denominators.
2. This 251 ppb THM value was used as the maximum value by ATSDR even though the BTMUA has suggested that the value is "out of line". Even though the value appears to be high it could not be refuted. ATSDR did note that over the study period (1987-1995) the next closest value was 142 ppb for this same sampling location.
3. This 240 ppb chloroform value was used as the maximum value by ATSDR even though the BTMUA has suggested that the value is "out of line". ATSDR did note that over the study period (1987-1995) the next closest value was 116 ppb for this same sampling location. Even though the value appears to be high it could not be refuted. The possibility exists that persons may have been exposed at this level.
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