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Congressional Testimony
Superfund Sites: Adverse Health Impacts

Congressional Testimony by
Jeffrey Lybarger, M.D.
Director
Division of Health Studies
Agency for Toxic Substances and Disease Registry
Public Health Service
U. S. Department of Health and Human Services

Before the
Subcommittee on Superfund, Recycling, and
Solid Waste Management
United States Senate

April 12, 1993

The creation of ATSDR as a federal agency resulted from the Comprehensive Environmental Response, Compensation, and Liability Act, or what is more commonly known as "Superfund" legislation. Congress generated this legislation as part of its response to two highly publicized and catastrophic events of the late 1970's: discovery of the Love Canal waste site in Niagara Falls, New York, and an industrial fire in Elizabethtown, New Jersey, which set off the release of highly toxic fumes into the air in a densely populated area. The public was concerned then, and now, that the release of hazardous substances will cause adverse health effects in persons exposed to released substances.

Since 1986, ATSDR has accumulated a considerable body of information about the presence, release, and effects on human health of hazardous substances released from Superfund sites and from emergency releases, e.g., from transportation mishaps or industrial accidents. Overall, the Agency has conducted public health assessments of about 1,200 Superfund sites, provided several thousand consultations on matters of health and hazardous substances, developed a comprehensive toxicological database on hazardous substances, instituted a National Exposure Registry for three priority substances with two more planned, established a surveillance system with the Laborers International Union of North America for monitoring the health of site clean-up workers, developed a surveillance program that reports the occurrence of emergency releases of hazardous substances, provided training and education to physicians concerning hazardous substances, initiated substance-specific research to fill key data gaps in our knowledge of the toxicity and health effects of priority substances, and started a program of work targeting the effects of hazardous substances on minorities and persons of color. I will be pleased to answer any questions about any of these programs.

Over the past six years a considerable amount of information bearing on the effects of hazardous substances on human health has resulted from ATSDR's efforts. However, notwithstanding our efforts and that of others, there are major gaps in our knowledge of the relationships between human health and hazardous substances released from Superfund sites. One of the major gaps is the general lack of knowledge about levels of exposure experienced by persons near Superfund sites. Human levels of hazardous substances are often unknown or not easily reconstructed. Additionally, for many communities concerned about their health, the numbers of persons at potential risk of exposure are small, thus making epidemiological comparisons quite difficult. Another problem is the lack of toxicology data on such health endpoints as immune function and the nervous system. However, even with these considerable difficulties, ATSDR and others have accrued a considerable amount of information bearing on the health implications of Superfund sites.

ATSDR has identified a growing body of information which characterizes human exposures to hazardous substances in the environment. This concern for long-term exposure to low levels of hazardous substances to a large number of persons nationally is well exemplified by our experience in evaluating hazardous waste sites in New Jersey. In addition, and our greatest concern, is the growing evidence that a greater burden of adverse health effects may be occurring in some people living near hazardous waste sites. ATSDR's review of the published scientific literature, together with our first-hand contact with states and communities impacted by hazardous waste sites, leads us to conclude that releases from some waste sites may be, in some manner, associated with a small but increased risk for developing adverse health effects.

I would first like to describe our characterization of the potential for human exposure to hazardous substances in the environment. The 1986 Superfund Amendments expanded our responsibilities in several areas. However, the most significant added responsibility was the provision calling for a public health assessment at each of the National Priorities List (NPL) sites. This one provision, far greater than any other, allowed ATSDR the ability to provide a consistent and critical review of all the NPL waste sites and provide a comprehensive assessment of human exposures to hazardous substances, make site-specific health related recommendations, and determine the need for health education and epidemiological studies.

In addition, we were also given responsibility for determining which substances posed the greatest health hazard and for writing toxicological profiles for each of those substances. This increased our ability to determine which sites may pose the greatest hazards to human health by having the enhanced capacity of an organized review of the toxicities of the most hazardous substances related to Superfund hazardous waste sites. As a consequence of writing these profiles, we were also charged with determining where there were major gaps in information about the health effects of these substances, and for establishing an applied research agenda to fill the most critical information needs.

Perhaps the most pressing of the mandates deals with conducting public health assessments at abandoned hazardous waste sites. Since 1986, ATSDR has completed more than 1,500 public health assessments impacting an average of 1,900 people at each site. One-hundred thirty six of those public health assessments were conducted at 115 sites in New Jersey. These assessments are an evaluation of data and information on the release of hazardous substances into the environment to:

• assess any current or future impact on public health,

• develop health advisories or other health recommendations, and

• identify studies or actions needed to evaluate and mitigate or prevent human health effects.

The ATSDR public health assessments have allowed us the ability to learn a great deal about the consequences of living near abandoned, hazardous waste sites in New Jersey, as well as other states. An analysis of public health assessments conducted on all sites last year indicates that there was a potential risk for human exposure to site-related contaminants in approximately 80 percent of the sites. In New Jersey, 94 percent of the sites had the potential for human exposure to site related contaminants. ATSDR considered one site to be an urgent public health hazard and issued a public health advisory to the Administrator of the U.S. Environmental Protection Agency. An additional 23 sites had a completed pathway of potential human exposure. These sites were considered to be a public health hazard.

Of the 115 sites in New Jersey, 111 or 96.5 percent are on the National Priorities List sites. Seventy-seven, or 67 percent of the sites are privately owned; 13 or 11.3 percent are owned by a municipality; and 5 or 4.3 percent are the responsibility of a Federal agency. One site is owned by the state of New Jersey. Fifty-five or 47.8 percent are waste storage/treatment facilities; 29 or 25.2 percent are manufacturing facilities, and 9 or 7.8 percent are waste recycling facilities. The remaining facilities are mining and government facilities.

ATSDR also has been able to make important observations about the types of contaminants found most often at NPL sites, including those in New Jersey; the environmental media that are most affected by those contaminants; and the pathways by which people are exposed to contaminants. Through the public health assessments at the sites in New Jersey, we have learned that the most commonly occurring contaminants and the percentage of sites at which they occur are industrial solvents called volatile organic chemicals (VOCs) and heavy metals. The most common VOCs found contaminating groundwater and human drinking water are trichloroethylene (TCE) found at 64% of the sites, benzene at 52% of the sites and, toluene at 50% of the sites. The most prevalent heavy metals are lead found at 63% of the sites and chromium at 50% of the sites. Of the 24 sites of major concern, TCE, and some other VOCs, were contaminates at 17, or 70 percent of these sites, and lead was a contaminant at 14 of these sites. Although these are the most commonly encountered contaminants, thousands of different chemicals can be found at hazardous waste sites.

Once hazardous substances are discovered at a hazardous waste site, it is critical to understand how they are being released from the site and whether and how humans may be contacting these hazardous substances.

Through the public health assessments we have learned that the two most frequently contaminated media for the sites in New Jersey are soil and groundwater. Groundwater was found to be contaminated at 108, or 94 percent of the New Jersey NPL sites, and this contamination contributed to documented or possible human exposures at 47, or 40 percent of the sites. For the 24 sites of major concern as public health hazards, groundwater contamination was a principal pathway of human exposure in 20 of the 24 sites. VOCs were the principal contaminant at each of these sites although heavy metals, principally lead, were also present.

When water is contaminated, ingestion is frequently a major concern. In 24% of the sites, oral ingestion was a route of exposure of concern. However, especially with VOCs, water contamination may create human exposures through inhalation and dermal absorption. Contaminated water in the home can cause volatilization, or offgassing, of VOCs from water used for cooking, dish and clothes washing, or during the flushing of toilets. Although no single event constitutes a great concern, each contributes to the low-level, chronic exposures to these chemicals. Of singular importance is the use of VOC contaminated water for bathing and showering. Bathing can allow for dermal absorption and be another important source of VOC vapors. Studies at the University of Pittsburgh have documented substantial volatilization of VOCs during a single shower. There is evidence that human exposure through water has occurred at levels of public health concern.

Contaminated soil was also found to be a concern for the New Jersey NPL sites. Surface and subsurface soil was found to be contaminated at 77 percent of the New Jersey NPL sites and was considered a media for potential human exposure for at least 54 of the sites. Soil contamination is an important concern for human exposure. It is difficult to control and can be a component of human exposure for ingestion and, to a smaller extent, inhalation. Volatile organic chemicals, heavy metals, as well as a variety of other hazardous substances may be contaminants of soil.

Ingestion of soil is a special concern for children. Studies of lead contamination through soil have documented that children between 6 months and 6 years of age are especially prone to soil ingestion because of their natural tendency for hand-to-mouth behaviors. This natural tendency for children to place objects into their mouths places them at risk for greater exposure to hazardous substances such as heavy metals contaminating soil on those objects.

Generally, information about how the public is exposed to contaminants in New Jersey is consistent with the national trends. In the public health assessments for sites in New Jersey where people were reported as having been exposed to a medium, the most common routes of exposure were ingestion (24.3%), inhalation (20.6%), and dermal (17.6%). For all sites nationally, ingestion, inhalation, and dermal contact were also the most frequent routes of exposure for people known to have been exposed to site-related contaminants.

The public health assessments review information from 3 sources. I have informed you about our review of environmental information that is collected to characterize the site and the potential public health concerns. The other two types of information reviewed by ATSDR are available health information and community concerns. Community concerns are critical to ATSDR. We obtain these expressions of concern from our very informative and important discussions with health officials and residents living near the waste sites. For the health assessments done in New Jersey, nearly all of the sites had some expression of health concerns by some member of the public. Of these concerns 49% of the sites had concerns related to non-cancer adverse health effects and 52% of the sites had concerns related to cancer.

The final factor considered by ATSDR in evaluating NPL sites is available health information. Although ATSDR commonly evaluates this information on a site specific nature, I will present it in a manner that will assess the concerns for adverse health effects that may result from the exposures that have been characterized by the ATSDR public health assessments in New Jersey and throughout the nation. Through studies conducted by ATSDR, either independently or through our partnership with States, and by others, there is a growing body of knowledge which defines a concern for adverse health effects related to long-term, low dose exposure to hazardous substances.

I would like to describe the studies and health activities supported by both ATSDR and other investigators regarding the adverse health effects of VOCs.

ATSDR has supported an important health study in New Jersey. The study was conducted by Dr. Frank Bove, while with the New Jersey Department of Health and currently with ATSDR, and it was published in December 1992. The study evaluated reproductive outcomes related to public drinking water systems serving 75 towns in northern New Jersey. Hazardous waste sites were thought to have been among several sources of contaminants in the water supplies. All live births and stillbirths (excluding chromosomal defects and plural births) born during the period 1985 through 1988 to residents of the 75 towns were included in the study. The towns selected were not known to have excessive health problems.

Information on birth outcome status and maternal risk factors was obtained from vital records and the New Jersey Department of Health Birth Defects Registry. Exposures during each month of pregnancy to drinking water contaminants were estimated for all births in the study using sample data for the public water system serving the town of maternal residence at time of birth. Contaminants evaluated included total trihalomethanes; trichloroethylene; tetrachloroethylene; total dichloroethylenes; carbon tetrachloride; and 1,2-dichloroethane. Although some water systems had levels of certain contaminants above federal standards at the time of the study, the study area was not considered to have contamination levels that were atypical of other areas in the U.S.

For live births, the outcomes evaluated were birth weight among term births, low birth weight (<2,500 grams) among term births, intrauterine growth retardation, prematurity (<37 weeks gestational age), and very low birth weight (<1,500 grams). For all births, selected birth defect categories were evaluated.

Significant associations were found for the following:

1. Total trihalomethanes were associated with term low birth weight, intrauterine growth retardation, central nervous system defects, and major cardiac defects.
2. Trichloroethylene was associated with neural tube defects and oral cleft defects.
3. Carbon tetrachloride was associated with term low birth weight, intrauterine growth retardation, central nervous system defects, and oral cleft defects.
4. Tetrachloroethylene was associated with oral cleft defects.
5. Dichloroethylenes were associated with central nervous system defects.
6. Dichloroethane was associated with major cardiac defects.

ATSDR supported an additional important study on this topic with the California Department of Health Services. They conducted a study to investigate the relationship between maternal residence and the presence of hazardous waste sites for the risk of congenital malformations. The study evaluated births between 1983 and 1985. During this study 5,617 births with congenital malformations were evaluated. The study concluded that maternal residence at the time of the child's birth, in a census tract with a hazardous waste site, significantly increased the risk of giving birth to infants with malformations of the heart and circulatory system.

A similar study has been recently conducted in New York. In 1992, Dr. Sandra Geschwind linked 2 data bases in the New York Department of Health to evaluate the relationship between congenital malformations and residential proximity to hazardous waste sites (American Journal of Epidemiology, Vol. 135, No. 11, pg. 1197). This study of 9,313 newborns with congenital malformations in proximity to 590 hazardous waste sites in 1983 and 1984 concluded that maternal proximity to hazardous waste sites carries a small additional risk of bearing children with congenital malformations. As with the New Jersey study, the authors warned of the need for additional studies before causal relationships could be determined.

A final study, which was published in 1990, with findings consistent to the 3 studies previously described was a study of cardiac congenital malformations in Tucson, Arizona (Pediatric Cardiology, Vol. 16, No. 1, pg. 155). In this study, Dr. Stanley Goldberg reported that the proportion of cases of congenital heart disease among live births was significantly greater for mothers who had residential exposure to the contaminated water area than mothers whose first trimester exposure was limited to the uncontaminated portion of the Tucson valley. The exposure of concern was VOCs, especially trichloroethylene.

VOC chemicals, especially trichloroethylene, have been evaluated for other adverse health effects. ATSDR established a trichloroethylene subregistry of the National Exposure Registry. The trichloroethylene subregistry consists of 4,522 living and 254 deceased registrants from 13 locations. Analysis of the baseline data for the registrants has been recently completed by comparing the self-reported health conditions of the registrants with responses of persons participating in the National Health Interview Survey conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention. A number of adverse health conditions have been reported at a higher rate by the registrants. At this time, ATSDR does not know the reason for the higher rates of some adverse health conditions. Follow-up studies are planned which will evaluate possible explanations such as exposures to hazardous substances, other factors related to illness occurrence, and the manner in which the questions were worded. ATSDR expects to be able to inform the registrants of these findings in the near future and will make the reports public once the registrants have been notified.

In addition to health studies, ATSDR is conducting a number of health activities which will assist us in obtaining and understanding community health concerns. One example in New Jersey is a grant to the borough of Pitman, New Jersey, to support the residents in establishing a voluntary tracking system (i.e., a system developed and maintained by the community). The nearby Lipari landfill is ranked first on the list of NPL sites.

The voluntary residence tracking system will identify present and past residents who may have been exposed to air contaminants emanating from the landfill. Initial inquiries were sent to 1,389 participating households in the area with a 77% return rate.

Several other studies are also in progress. In August 1990, ATSDR also awarded a grant to the New Jersey Department of Health to conduct an expanded study of low birth weight for communities near the Lipari landfill. This study will build upon one already begun by the New Jersey Department of Health and will include data for the years 1965-69 and 1975-79. This project was completed in 1992, and a final report is expected in 1993.

In 1992, ATSDR funded an additional study with New Jersey to evaluate the relationship between neurological congenital defects (neural tube defects) and drinking water contaminants. In addition, studies designed to evaluate the relationship between adverse health effects and proximity to hazardous waste sites were funded with the California and New York Departments of Health.

A key partner of ours has been state health departments. One main purpose of our support to state and local health departments is to improve how health agencies respond to community health concerns. I refer to communities around Superfund sites and other areas of pollution. Their legitimate health concerns need the coordinated response of government at all levels. ATSDR believes that communities around Superfund sites are our primary constituencies. ATSDR has benefitted from advice and guidance from the state and local health departments on matters of toxics in the environment, and I believe the state health departments have been able to improve their relationship and play a larger role with their state environmental protection partners on matters of risk assessment and public health interventions. The result is better decisions on environmental health risks and attendant risk management actions.

We have also continued to strengthen our focus on community involvement as an integral part of conducting our activities. During the past year, ATSDR personnel made contact with approximately 8,000 members of communities near hazardous waste sites. This was done through convening 5 meetings of community assistance panels, 18 public meetings, 34 public availability sessions, and 6 small group briefings, as well as other community involvement efforts.

Community Assistance Panels have been found to be an effective means of fostering communication between ATSDR and site communities. A community assistance panel has three primary purposes: 1) to facilitate communication between ATSDR and the affected community; 2) to provide an ongoing series of community-based meetings to ensure community involvement throughout the public health assessment process; and 3) to provide information to ATSDR on the community's health concerns for inclusion in public health assessments and health studies.

ATSDR also is increasing its use of public availability sessions-informal, drop-by meetings at which community members can meet one-on-one with ATSDR staff to discuss health and site concerns. Other site-specific community involvement activities that we have found useful include small group briefings for key community leaders, a practice that enables ATSDR to solicit information from grassroots leaders about how best to interact with their constituents and to address their concerns, and to provide up-to-date information about ATSDR activities in their community. For example, a citizen's advisory group was formed for the GEMS Landfill site here in New Jersey. Meetings were held between community members and the New Jersey Department of Environmental Protection and Energy. Community concerns regarding odors and fire were addressed in the site's Construction Operations Plan.

In summary, ATSDR has acquired a great amount of information over the past 6 years on the associations between human health and exposure to hazardous substances from waste sites and from emergency releases. There is now information which describes how human exposures to hazardous substances may be occurring and a growing body of information that a greater burden of adverse health effects may be occurring among some people living near hazardous waste sites. ATSDR will continue our site-specific evaluations and other health studies to further evaluate whether these adverse health effects may be related to the release of hazardous substances into the environment. The vital business of conducting the health studies and other scientific investigations to characterize the public health impact of environmental hazards must be continued. We look forward to sharing information with the Congress during this and future hearings on Superfund.

Mr. Chairman, this concludes my testimony. I will be pleased to answer questions.

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