Appendix A - Contaminants of Concern
Appendix C, Table 1 - Contaminants
Detected in Brick Township
Municipal Drinking Water. Above Environmental Screening Values
Appendix C, Table 2 - Contaminants
Detected in Groundwater, Above
Environmental Screening Values
Appendix D - Theoretical Cancer
Risk Associated with Exposure
to Bromoform, Chloroform, and PCE in the Brick Township Municipal Drinking
Appendix E, Figure 1 - Graph, Place of Birth
Appendix E, Figure 2 - Demographic Map
Appendix E, Figure 3 - Brick Township Municipal Water System Map
Appendix E, Figure 4 - Brick Township Study Participants
Appendix E, Figure 5 - Locations of Total
Trihalomethane Levels with at Least
One Sample Avove 80 Parts Per Billion
Appendix E, Figure 6 - Locations of Total
Trihalomethane Levels with at Least
One Sample Above 80 Parts Per Billion with Residence at Birth/Conception for
Appendix E, Figure 7 - Brick Township
Landfill and Residence at
This public health assessment 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 chemicals 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 sources.
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) 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 mother's 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 VOC's and metals. Contaminated groundwater would be unlikely to adversely affect 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. 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 (CDC) 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 draft 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-phase 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. Although there are no current prevalence rates from studies based in the U.S., recent studies from outside the U.S. and recent reports from service providers in the U.S. suggest that a conservative estimate for autism is 1-2 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. The intense case-finding of this study may have contributed to this higher rate B some other studies with intense case finding methods have found similar rates of autism.
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.]
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.