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Contents
This annual report highlights the accomplishments of FY 1999 in sufficient detail for the reader to appreciate the wide breadth of ATSDR's programs and the advances in public health that occurred during the year.
The employees of the agency take great pride in its accomplishments and the contributions made in FY 1999 toward improving public health and environmental protection. Comments from interested readers are always welcome.
Jeffrey P. Koplan, MD, MPH
Administrator
ATSDR is the lead public health agency responsible for implementing the health-related provisions of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), also known as Superfund. ATSDR's primary goals are:
ATSDR accomplishes these goals through its work in four major program areas:(1) health assessment and consultation, (2) toxicological research, (3) health studies, and (4) health education and promotion. This report highlights ATSDR's accomplishments and activities conducted in fiscal year (FY) 1999, with a chapter devoted to each of ATSDR's program areas. These program areas, some key findings, and examples of activities from FY 1999 are summarized below.
During FY 1999, ATSDR's Division of Health Assessment and Consultation and its cooperative agreement states performed more than 1,500 health activities in 49 states, Puerto Rico, and the U.S. Virgin Islands. These activities included issuing 196 public health assessment documents for 151 sites and issuing one public health advisory. The division also conducts health consultations, which provide advice on specific questions about human health hazards associated with hazardous waste sites. The agency provided 408 health consultations in FY 1999.
ATSDR's 607 Cooperative Agreement Program provides funds and technical oversight for participating states to conduct health assessments, consultations, and studies, as well as to provide health education in communities near hazardous waste sites. Staff in participating state health departments use ATSDR guidance for conducting public health assessments, consultations, and studies. Through the partnership, state staff members receive training and experience in assessing the public health impact of hazardous waste sites and have access to ATSDR's scientific resources. In FY 1999, the program provided about $9.5 million to 23 states. ATSDR also provided about $500,000 to five states under a similar program that allows states to conduct health assessments and consultations and health education activities.
Of the sites that ATSDR and states assessed in FY 1999, 106 had completed exposure pathways. ATSDR estimates that about 1.4 million people live within a 1-mile radius of these sites with completed exposure pathways, which are sites at which people might be in contact with hazardous substances. Water and soil were the environmental media most often associated with sites where completed exposure pathways were identified.
Inorganic substances, found at 30% of sites assessed in FY 1999, and volatile organic compounds (VOCs) (26%) were the most common classes of contaminants identified, followed by polyaromatic hydrocarbons (15%) and halogenated pesticides (13%). The inorganic substances found most often at sites were lead, arsenic, and chromium. The VOCs included benzene, trichloroethylene, and toluene.
Following are two examples of public health activities the Division of Health Assessment and Consultation conducted in FY 1999:
- ATSDR issued a public health advisory in March 1999 for the Hudson Oil Refinery site in Cushing, Oklahoma, because of the site's immediate potential for fire, explosion, and exposure to hazardous substances. The public health advisory assisted the Environmental Protection Agency (EPA) in proposing that the Hudson Oil Refinery Site be placed on the National Priorities List. The advisory also helped EPA obtain necessary funds to continue removal actions without interruption.
- ATSDR's public health assessment of Kelly Air Force Base, Texas, concluded that the community is not currently exposed to levels of contaminants from the base that would cause people to become sick, but that the community may have been exposed to higher levels of contaminants in the past. ATSDR recommended follow-up activities that involve health education and further evaluation of health outcomes.
ATSDR's Division of Toxicology oversees the agency's toxicologic research, disseminates information about hazardous substances, and responds to emergencies such as spills of hazardous substances. The division directs two major research programs designed to help fill data gaps about the health effects of hazardous substances--the ATSDR Great Lakes Human Health Effects Research Program and the ATSDR Minority Health Professions Foundation Research Program.
The Great Lakes program provides funds for researchers to study the human health consequences of exposure to persistent toxic substances found in the Great Lakes basin. The program supported ongoing research conducted by nine universities or state health departments in FY 1999. The program is adding to the body of research findings about persistent toxic substances, such as dioxin and polychlorinated biphenyls, found in the Great Lakes. One example of a study being conducted through the Great Lakes program follows.
A study being conducted by the State University of New York at Oswego reported that initial test results for 3-year-olds who were exposed to polychlorinated biphenyls (PCBs) prenatally (via their mothers' fish consumption) indicate their scores on tests of memory, verbal, and perceptual performance are lower than those of children whose mothers consumed low amounts of Great Lakes fish or no fish. These deficits among the children exposed to PCBs prenatally were also seen when they were tested as newborns.
The Minority Health Professions Foundation (MHPF) Environmental Health and Toxicology Research Program provides funds for toxicologic research to be conducted at seven minority health-professions schools. Researchers work on projects designed to fill data gaps about the health effects of hazardous substances. During FY 1999, the research program continued funding for 11 studies that are providing information about the neurotoxic or other health effects of substances such as zinc, manganese, lead, and chlordane.
The Division of Toxicology also disseminates information through its Information Center and provides echnical assistance and response through its Emergency Response Section. The Information Center received more than 77,250 requests for technical information assistance and distributed more than 284,210 documents during FY 1999. Most of the requests for information came from private citizens. In FY 1999, ATSDR's toll-free telephone system received approximately 9,650 calls, about 3,000 more calls than in FY 1998. ATSDR's Web site was accessed by more than 500,000 visitors in FY 1999.
In FY 1999, at the request of EPA's regional offices, other federal agencies, and state and local agencies, ATSDR emergency-response personnel responded to requests for information related to 42 acute events (13%), 227 time-critical requests (42%), and 247 non-time critical requests (45%) about hazardous substances. Emergency-response staff provided on-site responses for one acute and two nonacute events. Following is an example of the assistance ATSDR provided to emergency responders.
ATSDR's Division of Health Studies conducts or funds health studies to evaluate the relationship between exposure to hazardous substances and adverse health effects. It also oversees the Hazardous Substances Emergency Events Surveillance System (HSEES). During FY 1999, the division finalized 10 studies that it had conducted or funded. It also issued the 1998 report of the HSEES.
Studies finalized in FY 1999 added to ATSDR's body of knowledge about the relationship between various hazardous substances and seven priority health conditions. These priority health conditions are health outcomes that ATSDR has identified as being associated with exposure to hazardous substances. The seven conditions are birth defects and reproductive disorders, cancer, immune function disorders, kidney dysfunction, liver dysfunction, lung and respiratory diseases, and neurotoxic disorders. Many of ATSDR's health studies look at one or more of these conditions. Of the studies finalized in FY 1999, two dealt with birth defects and reproductive disorders, two with cancer, and two with lung disease and respiratory disease. In addition, two studies included several health outcomes.
Examples of findings from studies finalized in FY 1999 include the following:
During FY 1999, ATSDR also published the HSEES report for 1998. The report summarized the characteristics of events reported to the 13 states that participated in the program in 1998. These states reported a total of 5,987 events for 1998. Approximately 79% of the events occurred at fixed facilities and 21% were transportation related. In 96% of events, only a single substance was released. VOCs were the most commonly reported categories of substances released. During 1998, 405 events (approximately 7% of all reported events) resulted in a total of 1,533 victims.
ATSDR's Division of Health Education and Promotion works to educate individuals, communities, and health-care providers about the health effects of hazardous substances in the environment. In FY 1999, ATSDR and its partners conducted health education and promotion activities at approximately 315 sites. These activities included establishing five pediatric environmental health specialty units at major medical centers across the country, providing environmental medicine training to health care professionals, and developing a variety of educational materials for specific communities.
The states that participate in ATSDR's cooperative agreement programs contribute greatly to ATSDR's health education services and products for people living near hazardous waste sites throughout the United States. Cooperative agreement states, in conjunction with ATSDR, developed fact sheet, brochures, fliers, and training and community education. Grand rounds, conferences, exhibits, public meetings, and school presentations were the venues to provide information to and encourage capacity building in often underserved communities. Following is an example of a cooperative agreement state's efforts to educate the public about health hazards posed by a site in their community.
ATSDR's Division of Health Education and Promotion worked in partnership with five national organizations in FY 1999--the American Association of Occupational Health Nurses (AAOHN), the Association of Occupational and Environmental Clinics (AOEC), the American College of Occupational and Environmental Medicine (ACOEM), the Association of State and Territorial Health Officials (ASTHO), and the National Association of County and City Health Officials (NACCHO). Through these partnerships, ATSDR was able to provide such services as training local health officials, providing medical referrals at sites, and developing case studies on environmental health for health care professionals.
ATSDR also works in partnership with other federal agencies to provide health education. For example, through an interagency agreement with EPA, ATSDR initiated a national distribution of the fish consumption guidelines Should I Eat the Fish I Catch? in three languages. In FY 1999, approximately 100,000 copies of the guidelines were mailed to active members of the American College of Obstetrics and Gynecology, the American Academy of Pediatrics, and the American Academy of Family Physicians. These guidelines are intended to help physicians identify and counsel the susceptible populations they serve.
The Agency for Toxic Substances and Disease Registry (ATSDR) is a federal agency created in 1980 by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), or what is more commonly known as Superfund legislation. Congress enacted Superfund as part of its response to two highly publicized and catastrophic events: discovery of the Love Canal hazardous waste site in Niagara Falls, New York, and an industrial fire in Elizabethtown, New Jersey, that set off the release of highly toxic fumes into the air in a densely populated area. Congress also created ATSDR to implement the health-related sections of laws that protect the public from hazardous wastes and environmental spills of hazardous substances.
In 1983, the Secretary of the U.S. Department of Health and Human Services (DHHS) by administrative order established ATSDR as a separate agency of the Public Health Service. In June 1985, ATSDR was formally organized to begin to implement provisions of CERCLA, one of the most challenging and innovative environmental laws relating to public health. ATSDR was to work in concert with the Environmental Protection Agency (EPA), the Centers for Disease Control (CDC, now the Centers for Disease Control and Prevention), and the National Institute of Environmental Health Sciences.
In 1986, when Congress passed the Superfund Amendments and Reauthorization Act (SARA), ATSDR received major new mandates. By August 1989, the agency had assumed its current structure. Since 1989, ATSDR has received additional non-CERCLA statutory responsibilities. The agency, which is headquartered in Atlanta, had a staff of about 410 employees during FY 1999.
ATSDR's mission is to prevent exposure and adverse human health effects and diminished quality of life associated with exposure to hazardous substances from waste sites, unplanned releases, and other sources of pollution. ATSDR works closely with state, local, and other federal agencies to reduce or eliminate illness, disability, and death that result from exposure of the public and workers to toxic substances at waste disposal and spill sites.
As the lead public health agency responsible for implementing the health-related provisions of CERCLA, ATSDR is charged with assessing the presence and nature of health hazards at specific Superfund sites, helping to prevent or reduce further exposure and the illnesses that result, and expanding the knowledge base about the health effects of exposure to hazardous substances. CERCLA mandated that ATSDR (1) establish a National Exposure and Disease Registry, (2) create an inventory of health information on hazardous substances, (3) create a list of closed and restricted-access sites, (4) provide medical assistance during hazardous substance emergencies, and (5) determine the relationship between hazardous substance exposure and illness.
The Resource Conservation and Recovery Act (RCRA), as amended in 1984, mandated that ATSDR work with EPA to (1) identify new hazardous wastes to be regulated, (2) conduct health assessments at RCRA sites at EPA's request, and (3) consider petitions for health assessments by the public or states.
SARA broadened ATSDR's responsibilities, giving ATSDR mandates to conduct public health assessments, establish and maintain toxicologic databases, disseminate information, and provide medical education in the areas of public health assessments, establishment and maintenance of toxicologic databases, information dissemination, and medical education. The Great Lakes Critical Programs Act of 1990 required EPA, in cooperation with ATSDR, to report to Congress on the adverse health effects of water pollutants on people, fish, shellfish, and wildlife.
ATSDR executes its operations through four program-specific divisions--the Division of Health Assessment and Consultation, the Division of Toxicology, the Division of Health Studies, and the Division of Health Education and Promotion.
The responsibilities of the Division of Health Assessment and Consultation include the following activities:
The responsibilities of the Division of Toxicology include the following activities:
The responsibilities of the Division of Health Studies include the following activities:
The responsibilities of the Division of Health Education and Promotion include the following activities:
In addition, ATSDR has several offices that provide administrative, scientific, or management support to the agency and its divisions. These offices are contained within the Office of the Assistant Administrator.
The Office of the Associate Administrator for Science serves as the agency focal point for science issues that have an impact on ATSDR programs and activities. The office provides administrative and technical support to the agency's Board of Scientific Counselors and its Community/Tribal Subcommittee, the ATSDR peer review process, and a science forum for sharing scientific information among staff members.
In 1998, ATSDR established an Office of Children's Health to coordinate child health programs throughout the agency; (2) identify in collaboration with other divisions and offices new projects that benefit children; and (3) solicit input from, and disseminate information to, partner agencies and organizations. ATSDR's office complements EPA's formation of the Office of Children's Health Protection and the federal Task Force on Children's Environmental Health and Safety Risks (established under Executive Order No. 13045).
The Office of Federal Programs was established to plan, recommend, manage, and coordinate the policies and procedures under which ATSDR works with federal agencies in the development of toxicological profiles for unregulated hazardous substances found at federal facilities and in the conduct of public health assessments and other related health activities.
The Office of Policy and External Affairs promotes the mission of ATSDR by coordinating the agency's efforts to build public health capacity in state and local entities, providing analysis of agency policy, and communicating information about ATSDR's activities. The office coordinates public affairs activities, provides editorial and graphics services to the agency, and produces various publications, reports, and fact sheets to communicate agency activities.
The Office of Program Operations and Management develops and executes ATSDR's budget, including Superfund and other federal program funds. In addition to managing the ATSDR budget, OPOM provides management support for the agency in the areas of program planning; recruitment and employee development; information access, exchange, and utilization; training; travel; procurement; and other administrative services.
The Office of Regional Operations assists in the implementation of ATSDR activities across the country. ORO has ATSDR regional representatives at each of the 10 EPA Regional Offices and a liaison at EPA headquarters in Washington, DC. This distribution of staff in regional locations promotes communication and interaction with ATSDR's main partners: the public, EPA, and state and local environmental and public heath agencies.
The Office of Urban Affairs coordinates the agency's efforts on issues related to environmental justice, minority health, and Brownfields sites.
The ATSDR Washington Office links the agency with other executive branch departments and agencies and the legislative branch of government. Through this office, ATSDR is positioned to respond quickly to issues raised in Congress and other federal governmental and nongovernmental organizations that relate to agency programs.
ATSDR is funded through EPA and its personnel are allocated through the CDC. Funding for ATSDR activities at federal facility sites is negotiated with the U.S. Department of Defense (DOD) and Department of Energy (DOE).
Figure 1 contains a breakdown of ATSDR's Superfund budget obligations, by budget activity, for FY 1994 through FY 1999.
Figure 1. ATSDR CERCLA (Nonfederal obligations), FY 1994 through FY 1999
ATSDR is mandated by Congress to conduct public health assessments, health studies, surveillance activities, and health education at federal NPL waste sites, as well as develop toxicological profiles of high-priority chemicals found at these sites. These tasks are made complex by the absence of a congressional mandate to federal agencies (with the exception of DOD) to provide ATSDR with the necessary staff and budget to conduct these activities. ATSDR negotiates with DOD and DOE to establish annual work plans and budgets required to conduct its programs at DOD and DOE facilities. Figure 2 illustrates ATSDR's FY 1999 DOD and DOE operating budgets, by budget activity.
Figure 2. ATSDR's FY 1999 Operating Budget from DOD and DOE
The Division of Health Assessment and Consultation conducts public health assessments and related activities, issues public health advisories, and provides public health consultations. The health assessment process conducted by this division is often the trigger for a variety of other ATSDR activities and public health recommendations that are shown below.
A key component of the public health assessment process is exposure evaluation. For people to possibly suffer adverse effects or disease associated with hazardous substances, they must be first exposed to them. In 1991, the National Research Council recognized that public health assessments could be an important source of information about the nature and extent of environmental exposure to hazardous substances. The National Research Council pointed to the general lack of scientifically based information on how substances move from a source to expose persons living near sites. In response, ATSDR initiated a series of activities intended to better determine the factors that influence how substances reach nearby populations, estimate the extent of exposure, and better define who is actually likely to be exposed as a result of chemical releases into the environment. After a period of development, ATSDR began to routinely use a variety of methods and approaches as integral components of the public health assessment process. These include
These techniques provide the scientific support for evaluating exposures when conducting public health assessments. This chapter highlights these methods and approaches and gives examples of how they have been used in the public health assessment process. The integration of these techniques helps to provide a clearer spatial and temporal picture (i.e., a series of snapshots of places and time) of the potential for exposures in the past, present, and future.
This chapter also provides an overview of some significant ATSDR program activities and accomplishments. Highlighted are ATSDR's commitments to working more closely with tribal nations and communities and to protecting the health of children living near hazardous waste sites. These programmatic activities, along with the expanding use of better scientific tools and methods, are critical to addressing exposure and ultimately evaluating the impact of hazardous waste sites on the health of communities.
ATSDR's 607 Cooperative Agreement Program provides funds and technical oversight for participating states to conduct health assessments, consultations, and studies, and to provide health education in communities near hazardous waste sites. Staff members in participating state health departments use ATSDR guidance for conducting public health assessments, consultations, and other activities. In FY 1999, ATSDR had cooperative agreements with 23 states under this program. ATSDR also had cooperative agreements in FY 1999 with five other states under a similar program that allows states to conduct health assessments, consultations, and health education activities.
During FY 1999, ATSDR and its 28 cooperative agreement states performed more than 1,500 health activities in 49 states, Puerto Rico, and the U.S. Virgin Islands. These activities included 196 public health assessments and a public health advisory for uncontrolled hazardous waste sites.
The agency estimates that more than 1.7 million people live within a 1-mile radius of the sites that were the subjects of the FY 1999 public health assessments and public health advisory. The population living within a 1-mile radius of the 106 sites that had completed exposure pathways numbered about 1.4 million. Water and soil were the environmental media most often associated with sites where completed exposure pathways were identified.
ATSDR made three types of public health assessment recommendations: recommendations to provide better site characterization, recommendations to cease or reduce exposure, and recommendations for public health actions. The most common recommendations were for additional or continuation of monitoring efforts, additional characterization of environmental media, institutional and physical restrictions on site access, health statistics reviews, and site-specific health education to increase community members' understanding of the public health implications. Although less common, there were also recommendations for biomedical testing, evaluations of exposure indicators, and additions of exposed populations to specific subregistries. Following are details of ATSDR's FY 1999 public health assessment activities.
The agency, in collaboration with state health departments under cooperative agreements, prepared 196 public health assessment documents and one public health advisory for 151 sites during FY 1999.
The public health assessments and the advisory completed in FY 1999 classified 22% of the sites investigated as being of public health concern or urgent public health concern. Another 27% of sites were classified as indeterminate or potential health concerns.
Inorganic substances, found at 30% of sites assessed in FY 1999, and VOCs (26%) were the most common classes of contaminants identified, followed by polyaromatic hydrocarbons (15%) and halogenated pesticides (13%) (Figure 1). The inorganic substances found most often at sites were lead, arsenic, and chromium. The VOCs included benzene, trichloroethylene, and toluene. For the most part, contaminants for sites in all health hazard categories with completed exposure pathways were identified in soil (30%), groundwater (municipal and private wells) (26%), and air (17%). The frequency with which the contaminants were identified in those media may reflect the fact that those media were most frequently sampled, rather than that the media were more likely to be contaminated. Data gaps exist for some media.
Figure 1. Major Contaminants Found at Sites Assessed in FY 1999
The site is an inactive refinery that produced aviation fuel, diesel fuel, gasoline, liquid propane gas, coke, and fuel oils for 60 years. The refinery was shut down in 1982, but chemicals remained stored at the site. Highway 33, the main highway in Cushing, runs through the site. An estimated 3,485 of Cushing's 7,218 residents live within a 1-mile radius of the refinery. In September 1998, EPA initiated emergency removal action of loose asbestos at the south refinery and began to investigate other hazards at the site.
The public health advisory supported the work being conducted by EPA, Oklahoma, and Cushing to address public health issues at the site. In the advisory, ATSDR recommended that EPA continue its emergency removal actions and decontamination of the site and that Hudson Oil Refinery be considered for addition to the NPL. ATSDR issued the public health advisory in response to a request from EPA Region VI regarding hazards at the site and emergency removal activities. Some containers of hazardous, flammable chemicals that were stored there were leaking, the advisory noted.
EPA, the city of Cushing, and the Oklahoma Department of Environmental Quality implemented a number of public health actions in response to the public health advisory, including
In addition, ATSDR recommended stabilizing site conditions by removing other chemical and physical hazards. ATSDR also recommended removing, after EPA emergency actions are completed, asbestos-containing material at the north refinery area while following strict asbestos abatement guidelines.
Health consultations provide advice and recommendations on specific, health-related questions concerning actual or potential human exposure to hazardous substances or with any other related human health hazards. A health consultation is often quickly needed to permit mitigation or prevention of adverse human health effects from exposure to hazardous substances in the environment.
Consultations vary in complexity; either an individual health professional or a team may respond to a question about a site or issue. In some cases, ATSDR prepares more than one health consultation in response to a request for help with an exposure or potential exposure. Health consultations may be either written or oral, and they are timely; for example, an oral consultation might be provided on the day a request reaches ATSDR.
In FY 1999, ATSDR and the cooperative agreement states prepared 408 health consultations. These health consultations were prepared in response to requests from citizens, state environmental agencies, EPA, and other groups. The health consultations covered a variety of topics, including cleanup of contaminated soils, ingestion of solvent-contaminated well water, inhalation of lead-contaminated dust, and final cleanup actions at a landfill. Following is an example of a health consultation.
ATSDR's health consultation at Naval Station Newport, in Newport, Rhode Island, helped reduce the community's concerns by confirming that the contaminant levels found in a playground did not pose a health hazard to children.
EPA requested that ATSDR provide health information about the safety of the playground, which formerly was used as a fire fighter training ground. ATSDR attended a series of public meetings from November 1998 through April 1999 to address the concerns of the community. The parents of children who had played at the playground were trying to decide if they should have their children medically tested.
ATSDR recommended that additional soil samples be collected in specific areas. These data enabled ATSDR to conclude that the playground did not pose a health hazard. The agency informed the community of its findings at meetings and in a health consultation issued in March 1999. ATSDR's finding that the playground did not pose a health hazard resulted in lower remediation costs. Additionally, the information provided to the public helped parents make choices about seeking medical testing for their children.
Exposure assessment is the first critical step in establishing a link between the release of hazardous substances and an impact on community health. Public health assessments try to get information that answers the following series of related questions for past, present, and future time frames of exposure:
ATSDR uses geographic information systems, exposure investigations, fate and transport models, and exposure dose reconstruction to answer exposure-related questions. Although the merits and key features of each method and approach are described separately here, they are often used together in a comprehensive integrated approach to assess exposure.
The use of geographic information systems (GIS) technology has become an integral part of the public health assessment process. GIS is a computer software application that compiles multiple data layers (e.g., environmental, contaminant, outcomes, and demographic) and then relates these layers to one another in a geographic area. It helps answer questions about who lives around sites (that is, the demographic data) and where they live. Maps can help communities and those involved with assessing hazards associated with the site to better visualize where things are and how people might be exposed. Knowing the demographics of surrounding populations could be critically important, and GIS helps provide initial information to health assessors before they ever visit the site.
GIS is used to put a demographic face on the populations living within 1 mile of the sites on the National Priorities List (NPL) of Superfund sites. Staff members use site boundaries, data from the 1990 U.S. census, and an area proportion technique to identify the number of people living within a mile of these sites. To date, this technique has been used at approximately 1,600 sites. ATSDR estimates that almost 15.5 million people live within a mile of a hazardous waste site. Of those, nearly 4 million (25%) are nonwhite. Hispanics are the largest ethnic group in the site population, with more than 2 million people (14%).
GIS and census data are also used to identify the size of potentially sensitive subpopulations (e.g., the young, the elderly, and women of childbearing age) around the sites. One example is the number of children less than 6 years of age. There are more than 1.5 million (11%) children less than 6 years old in the site populations. ATSDR's Child Health Initiative is concerned with children and teenagers less than 18 years of age. Using GIS, it is estimated that there are almost 3 million (19%) children and teenagers in the site populations. To further enhance our understanding of the site populations, in 1999 ATSDR began to incorporate into its site analyses neighborhood segmentation data from PRIZM, a database containing up-to-date population estimates and socioeconomic information for census block groups. This information gives added depth to the analysis of site populations.
"Fate and transport" refers to the movement of a hazardous substance from its source through the environment, until it comes into contact with people. Scientists have developed mathematical models that predict the fate and transport of hazardous substances through the environment. These models predict how chemicals travel through the environment, how they break down, and how key physical and chemical properties of chemicals (including water solubility, volatility, and soil adsorption) affect the potential for exposure. One such model is ATSDR's Analytical Contaminant Transport Analysis System (ACTS) software package. ACTS is designed for use as a "screening level" tool that helps health assessors understand basic concepts of fate and transport of contaminants within an environmental system.
Exposure investigations are conducted to gather and analyze site-specific information to determine if human populations have been exposed to hazardous substances. Information is obtained through biomedical testing, environmental testing, and exposure-dose reconstruction. Biomedical testing (e.g., urine or blood samples) can show current (and sometimes past) exposure to a contaminant. Environmental testing (for contamination of soil, water, or air) is focused on where people live, spend leisure time, or might come into contact with contaminants under investigation. Exposure-dose reconstruction analyses use environmental sampling information and computer models to estimate the contaminant levels that people may have been exposed to in the past or may be exposed to in the future. Estimations of the exposure dose are used to evaluate how a person's health might be affected. The results of exposure investigations are used to make public health decisions and to recommend appropriate public health actions.
Often not enough information is available about a community's past exposures to estimate health risks. Therefore, researchers have to reconstruct levels of hazardous substances that people may have been exposed to and the length of time they were exposed. Exposure-dose reconstruction modeling is used to estimate the patterns of movement and concentrations of contaminants from the source via a variety of environmental media. ATSDR researchers use computational models to test a variety of exposure estimates and make recommendations based on scientifically accepted techniques and procedures.
Below are several examples of public health activities ATSDR conducted in FY 1999 using new technologies.
In the spring of 1995, ATSDR and the New Jersey Department of Health and Senior Services began to investigate health concerns of the Dover Township, New Jersey, community. Community members were concerned about the number of childhood cancer cases and feared that exposure to environmental contaminants from the area's hazardous waste sites, including two National Priorities List (Superfund) sites, were related to the elevated incidence of childhood cancer.
ATSDR is helping state health officials assess whether exposure to contaminants in the drinking water is associated with increased incidence of childhood cancer. Because approximately 85% of the Dover Township area residents obtain their potable water from the water-distribution system, an analysis of the potential for distribution of contaminants through the water-distribution system was needed.
ATSDR initiated an exposure assessment approach for use in an epidemiologic study of childhood leukemia and central nervous system cancers that occurred from 1979 through 1996 in Dover Township. Groundwater contamination has been documented historically in public- and private-supply wells. The water-distribution system has 23 municipal wells distributed at eight points of entry. In 1997, it serviced a population of 92,160. Because the Dover Township area has been primarily served by a public water supply that relies solely on groundwater, a water-distribution system model, integrated with spatial analysis technologies, is being used to reconstruct historical water-distribution system characteristics and investigate the question of exposure.
ATSDR has developed a model that simulates the 1998 patterns of the water-distribution system serving the Dover Township area. This effort, which is expected to be completed in 2000, will allow the New Jersey health department to assess the association of the occurrence of childhood cancer with exposure to each of the sources of potable water entering the distribution system, including ones known to be historically contaminated.
The Paducah Gaseous Diffusion Plant was put on EPA's NPL in 1994. Elevated concentrations of trichloroethylene (TCE) and technetium 99 (Tc-99) in offsite groundwater were first discovered in residential wells in 1988. There was no earlier off-site groundwater monitoring. After the site was placed on the NPL, ATSDR explored potential contaminant exposure pathways to off-site populations and started the public health assessment process.
In 1952 the plant started operations to enrich uranium 235 by a gaseous diffusion process. Early processes included limited production of uranium hexafluoride and uranium metal. Over time, TCE and Tc-99 contaminated local groundwater. ATSDR's investigations also found other conventional and radiologic contaminants in air, surface soils, sediments, and surface waters. These originated from different sources at the site.
ATSDR obtained approximately 700,000 data values, geo-locators for each sample station, and other data from the plant's environmental database. By incorporating these data into a GIS system, ATSDR was able to visualize patterns of contaminant concentrations in the different media and to integrate this information with demographic information for the vicinity. GIS provided both a visual image of areas affected and a numerical value representing the persons potentially affected by the contaminants in each media. It also generated a demographic breakdown of different types of populations. When sample locations were depicted graphically, areas that had not been sampled were easily identified. ATSDR also determined past plume migration and estimated exposure durations.
ATSDR evaluated potential exposure doses to airborne radionuclides using EPA's Clean Air Act Assessment Package and demographic and off-site distance information provided by GIS. ATSDR also performed an air dispersion analysis for TCE and hexavalent chromium and put the results of the analysis onto maps to determine potentially exposed populations.
ATSDR released a public health assessment that generally concluded that the offsite community was not exposed to contaminants at levels of public health concern during normal plant operation. It did find that in five residential wells, past exposures to maximum concentrations of TCE or lead posed a health hazard for two or three young children. Additionally, it determined that if new wells are drilled into the contaminated groundwater plume or old wells are used, exposures to maximum concentrations in the groundwater plumes would pose a future health hazard for children and adults.
Members of the community neighboring Kelly Air Force Base, Texas, expressed concerns about fuel vapor odors and other odors coming from the base. They asked if there was a relationship between these odors and the occurrence of health effects, such as nausea, headaches, difficulty in breathing, and cancer. Todetermine if any emissions from the base could be linked to those symptoms, ATSDRgathered and researched several types of information, including historical information about the base, environmental information, health outcome data, and information provided by the community.
After reviewing information about the chemicals being emitted and their sources, ATSDR used an air dispersion model to estimate the dispersion of those emissions and the resulting concentrations from the base. The model contained data from the base's emission inventory for a variety of carcinogenic compounds. The modeled results included the average annual and 1-hour maximum concentration estimates for each hazardous substance. In concert with the air dispersion modeling, ATSDR also used GIS, risk assessment, and health outcome data to identify geographic areas that needed further study because of a potentially elevated cancer risk. These areas were further analyzed with dose reconstruction, refined modeling activities, and additional health outcome data.
While the ATSDR scientists were gathering, reviewing, and evaluating environmental and health information, other staff worked to establish good lines of communication with the community members living at the base. This was done by arranging meetings, including one with a small focus group, another with a citizens' group, and other meetings to talk individually with community leaders. Additionally, a public meeting with a poster session drew about 100 attendees. ATSDR's staff members have focused on increasing the opportunity for closer interaction with Spanish-speaking community members at this site and recording of their health concerns. The staff members have translated information for community meetings, press releases, fact sheets, fliers, and public service announcements into Spanish.
ATSDR's public health assessment concluded that the community is not currently exposed to levels of contaminants from the base that would cause people to become sick, but that the community may have been exposed to higher levels of contaminants in the past. ATSDR recommended follow-up activities that involve health education and evaluation of health outcomes.
The Division of Health Assessment and Consultation's Community Involvement Branch was established in 1998. By taking the lead in establishing and maintaining partnerships with communities near sites served by ATSDR, community involvement staff members are generally involved in most of ATSDR's site-specific activities, such as public health assessments and health consultations. Community involvement staff members facilitate collaboration and information exchange between ATSDR and communities and other government agencies involved at those sites. They provide an essential link between the community and the ATSDR scientists who are working to address the communities' health concerns and to protect public health.
Community involvement staff members also distribute fact sheets, press releases, and notices about upcoming meetings to keep communities informed. During FY 1999, copies of 225 different fact sheets and other materials were distributed to approximately 40,000 community members and other stakeholders. The increased use of community meetings that combine public availability sessions with poster sessions has provided an especially effective mode of information sharing. In these small group settings, community members can learn about ATSDR's activities, while they wait to share their health concerns individually with other ATSDR staff members. The Community Involvement Branch conducted 150 meetings, which were attended by about 4,400 community members.
In January 1999, ATSDR announced the establishment of an Office of Tribal Affairs within the Division of Health Assessment and Consultation. The office was established to better serve American Indian and Alaska Native populations by providing a central, identifiable point of contact. The Office of Tribal Affairs staff members are environmental health scientists with additional training and experience in tribal policy and culture.
American Indian and Alaska Native communities and governments' environmental public health needs are escalating. Many health concerns related to exposures from environmental contamination are being identified. The Office of Tribal Affairs staff members have begun to (1) provide cultural training for agency staff members, (2) provide tribal-cultural and policy expert assistance on site-specific projects (which may include direct technical responses), and (3) develop needed interagency coordination to address environmental health needs of American Indian and Alaska Native populations. Concerns at sites that the Office of Tribal Affairs has addressed include
In addition, the Office of Tribal Affairs works with an ATSDR Ad Hoc Tribal Workgroup to advise the agency on tribal programs and policies. The workgroup provided input to the agency's Consultation and Coordination Policy With Indian Tribal Governments, the Office of Tribal Affairs functional statement and communication efforts to others in Indian country, and advice on the tribal requests for an ATSDR National Tribal Forum on Environmental Health Needs. The forum is intended to establish needed collaborations between American Indian/Alaska Native governments and health departments, federal agencies, and academia to address the massive environmental public health issues of hundreds of tribal nations and thousands of native people.
Communities around Superfund sites often express concerns about childhood cancers and birth defects. Current guidance concerning toxicological evaluation of exposures to environmental toxicants is primarily focused on how to evaluate adult exposures to environmental toxicants. ATSDR convened a workshop in FY 1999 to develop a plan for providing more guidance on evaluating children's exposures.
On August 4-5, 1999, the Division of Health Assessment and Consultation and the ATSDR Office of Children's Health sponsored a Workshop on Children's Health Issues. The workshop examined how ATSDR's public health assessment activities evaluate children's exposure to environmental toxicants. Participation and input were solicited from child health advocates; health organizations; tribes; and local, state, and federal governments. ATSDR is developing a plan based on the following recommendations made in the workshop.
The Division of Toxicology is composed of three branches under the Office of the Division Director: the Emergency Response and Scientific Assessment Branch, the Research Implementation Branch, and the Toxicology Information Branch. The division is responsible for substance-specific research and technical assistance; dissemination of technical information; and emergency technical support to industry, local first responders, other government agencies, and the public.
The Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA, or Superfund) Priority List of Hazardous Substances contains the names of 275 substances found at NPL sites and that are believed to pose the most significant potential threat to human health. This list helps form ATSDR priorities on many issues. The Superfund Amendments and Reauthorization Act of 1986 (SARA) requires ATSDR to compile this priority list, which is drawn from the universe of hazardous substances known to exist at NPL sites. The ranking of substances on the list is based on three criteria: (1) frequency of occurrence at NPL sites, (2) toxicity, and (3) potential for human exposure.
To ensure that the most hazardous substances are on the priority list, ATSDR periodically reexamines its information database (HazDat) of hazardous substances known to exist at NPL sites. The list is updated annually and published biennially because EPA routinely adds new sites to the NPL, new data about how people might be exposed becomes available as public health assessments are completed, and important new toxicity information about substances is discovered. Each substance on the list may become the subject of an ATSDR toxicological profile and subsequently a candidate for the identification of priority data needs.
In late FY 1999, the preparatory work and most of the development of the 1999 CERCLA Priority List of Hazardous Substances was completed. The final 1999 list was published and its availability announced in the Federal Register during the first quarter of FY 2000. Arsenic was at the top of the 1999 list, followed by lead and mercury. The top 10 substances are shown in Table 1.
Table 1. Top 10 Substances on the 1999 Priority List of Hazardous Substances
In June 1999, Congressman John Dingell's office contacted ATSDR to request that the agency provide information on adverse effects associated with the top 50 substances on the Priority List that have latency periods of 6 years or greater. In response, the Division of Toxicology reviewed and compiled the information available in the existing toxicological profiles. The report noted that vinyl chloride, benzene, PCBs, trichloroethylene, hexavalent chromium, lead, arsenic, creosote, and benzidine are classified as "known to cause cancer in humans" or "probable human carcinogens," and they have a latency period of at least 6 years. In addition, a number of other substances on the list are classified as "reasonably anticipated to cause cancer in humans" because of limited evidence in humans, but sufficient evidence in animals. These substances include cadmium, chlordane, beryllium, carbon tetrachloride, and cobalt. The consultation also summarized the potential for developmental or neurologic effects with a latency of 6 years. This information was subsequently published as a scientific manuscript, "ATSDR's 1997 Priority List of Hazardous Substances: Latent effects--Carcinogenicity, Neurotoxicology, and Developmental Deficits in Humans and Animals" (Toxicology and Industrial Health 1999; 15:1-43).
Along with the priority list, ATSDR developed a Completed Exposure Pathway Site Count Report. A completed exposure pathway is an exposure pathway that links a contaminant source to a receptor population. The completed exposure pathway ranking is based on a site frequency count, and thus lists the number of sites at which a substance has been found in a completed exposure pathway. In late FY 1999, most of the development of the completed exposure pathway report was completed. Lead was the substance found most frequently in completed exposure pathways, followed by trichlorethylene and arsenic. The top 10 substances are shown in Table 2.
Table 2. Number of Sites with a Hazardous Substance in a Completed Exposure Pathway
CERCLA, as amended, requires ATSDR to prepare toxicological profiles that examine each hazardous substance on the CERCLA Priority List of Hazardous Substances. These profiles summarize the current scientific literature and interpret available toxicologic and epidemiologic information to determine levels of significant human exposure for the substance.
ATSDR also provides toxicological profiles at the request of the U.S. Department of Defense (DOD) and the U.S. Department of Energy (DOE). During FY 1999, ATSDR personnel developed or updated 44 draft or final versions of toxicological profiles. These profiles covered CERCLA substances and non-CERCLA substances identified by DOD and DOE. (See Appendix B for a list of toxicological profiles completed in FY 1999.)
In FY 1999, ATSDR published 20 updated or new toxicological profiles (see Appendix B). Eight toxicological profiles underwent public-comment review, after which relevant information identified during the review process was incorporated. These profiles will be published in final form in FY 2000. Eight toxicological profiles under development during FY 1999 will be distributed for a 90-day public-comment period.
Five toxicological profiles were finalized in FY 1999 for DOD. One toxicological profile (for total petroleum hydrocarbons) underwent a public-comment review and was updated to incorporate relevant information identified during the review process. This profile will be finalized in FY 2000.
Draft toxicological profiles for uranium and ionizing radiation were developed for DOE during FY 1999 and will be released for a 90-day public-comment period in FY 2000. These profiles will be published in final form in
FY 2000.
During FY 1999, the Division of Toxicology developed 35 toxicological profiles highlighting children's health issues by using Child Heath: Guidance for the Preparation of Toxicological Profiles. The guidance has been published as an appendix in Promoting Children's Health: Progress Report of the Child Health Workgroup, Board of Scientific Counselors With New Guidance for Toxicological Profiles, 1998-1999. A section on how to incorporate child health concerns has now been included in the Guidance to Prepare Priority Data Needs Documents. The toxicological profiles developed using the new guidance are now available either as drafts for public comment or in final form.
In FY 1999, 118 toxicological profiles were available on CD-ROM. The CD-ROM was developed under a cooperative research and development agreement with ATSDR and published by CRC Press. During FY 1999, ATSDR continued a quality control project to update and complete the process of placing all public health statements of final toxicological profiles on the agency's Internet site.
Fact sheets (ToxFAQs) containing material drawn from ATSDR public health statements have also been developed. ATSDR now has a total of 111 fact sheets in print and posted on the Internet.
ATSDR is working to determine the relationships between adverse human health outcomes and hazardous substances through its Substance-Specific Applied Research Program. CERCLA, Section 104(i)(5), requires that for each hazardous substance listed, ATSDR, in consultation with EPA and other public health agencies and programs, assess whether adequate information is available on the health effects of the substance. Furthermore, the law requires that ATSDR, in cooperation with the National Toxicology Program, initiate a research effort designed to determine the health effects of those substances for which adequate information is not available (or under development).
ATSDR used several mechanisms to fill priority data needs in FY 1999. These included industry testing through EPA, private-sector voluntarism, and academic-based research conducted through the Minority Health Professions Foundation. Additional research needs are being addressed through other agency programs (e.g., an interagency agreement with the National Toxicology Program and ATSDR's Great Lakes Human Health Effects Research Program). Significant progress has been made in filling these key research needs. Through FY 1999, ATSDR has identified 201 priority data needs. A total of 117 priority data needs are being addressed via these mechanisms. In addition, 39 priority data needs have been reclassified as data needs, and 14 priority data needs have been filled. Data obtained from the research program are used to update ATSDR toxicological profiles and to develop health-guidance values for hazardous substances evaluated in ATSDR's public health assessments conducted at waste sites.
The Toxic Substances Control Act of 1976 (TSCA) authorizes EPA to ensure that chemicals are safe for their intended use. EPA places some of this responsibility on chemical manufacturers and processors by requiring them to conduct toxicologic testing. Costs of conducting this research are completely borne by the industries.
During FY 1999, ATSDR and EPA finalized information to support development of a TSCA test rule for eight substances that ATSDR previously had identified as having research needs. A test rule is the legally enforceable document that describes (1) EPA's authority to require testing, (2) the specific testing required, (3) why it is required, and (4) who should conduct the testing. The proposed test rule will address substance-specific research needs identified in ATSDR's priority data needs documents. Publication of the proposed test rule is expected in the summer of 2000.
ATSDR encourages industry to voluntarily conduct needed research
into the toxicity of priority 
chemicals.
During FY 1999, ATSDR had memoranda of understanding (MOU) in place
with three private-sector organizations--General Electric Company
(GE), Halogenated Solvents Industry Alliance, Inc. (HSIA), and Chemical
Manufacturers Association (CMA)--to address some research needs for
five substances.
During FY 1999, ATSDR signed a second MOU with HSIA that covers an immunotoxicity study on methylene chloride, a substance found in at least 809 National Priority List sites. HSIA has completed the study and the final report is pending. This study addresses an important research need for methylene chloride, i.e., to determine if the immune system is a susceptible target organ for this chemical.
The MOU with GE includes a study to investigate environmental biodegradation of four polychlorinated biphenyl (PCB) mixtures (Aroclor 1016, Aroclor 1242, Aroclor 1254, and Aroclor 1260). During FY 1999, ATSDR accepted the final report of this study, thus completing all the studies covered under this MOU. The findings of the GE studies have filled three ATSDR research needs for these mixtures that rank sixth on the agency's Priority List of Hazardous Substances.
The Minority Health Professions Foundation (MHPF) Environmental Health and Toxicology Research Program, a partnership with seven minority health-professions schools, is designed to fill critical research needs and provide a major source of research data for the Substance-Specific Applied Research Program.
Research findings from this program have expanded the data base used by ATSDR health scientists for evaluating the potential human health risk for people exposed to toxic substances in the environment, and contribute to the public health service agenda of the agency. Some examples of research findings from the program include the following:
The Great Lakes Human Health Effects Research Program is intended to build on, and amplify, the results of past and ongoing fish-consumption research in the Great Lakes basin, using existing structures and institutions already involved in human health research. This ATSDR-supported research program studies known at-risk populations to further define the human health consequences of exposure to persistent toxic substances identified in the Great Lakes Basin. In FY 1999, 11 manuscripts and nine abstracts describing research under this program were published and presented at professional conferences. To date, the program has published more than 38 manuscripts in peer-reviewed journals.
During FY 1999, program accomplishments included the following:
ATSDR, in collaboration with Health Canada, has published the proceedings
of the international scientific conference on the effects of persistent
toxic substances in the Great Lakes and St. Lawrence River Basins
on human health and the environment. These proceedings are in the
Journal of Environmental Research -Special Issue: Proceedings of Health
Conference `97 -- Great Lakes/St. Lawrence (De Rosa et al. 1999; 80(Suppl
2):1-248).
Recent research findings include:
The principal aim of this program is to develop methods for assessing the joint toxicity of exposure to multiple chemicals that are frequently found at hazardous waste sites. During FY 1999, ATSDR supported experimental research at universities that has enhanced the understanding of the various steps and underlying mechanisms of toxicity following exposure to chemical mixtures. These research findings have been presented at national and international meetings of toxicology in eight separate oral and poster presentations.
ATSDR provides technical assistance 24 hours a day to federal, state, and local government and emergency-response organizations during emergency situations resulting from unplanned releases of hazardous substances. Emergency-response coordinators have immediate access to assistance from ATSDR experts in the areas of chemistry, toxicology, medicine, and environmental science. Site-specific consultation teams can usually be convened within 20 minutes of notification to provide support. On-site response can be provided anywhere in the continental United States, usually within 8 hours of a request.
In FY 1999, at the request of EPA's regional offices, other federal agencies, and state and local agencies, ATSDR emergency-response personnel responded to requests for information related to 42 (13%) acute events, 227 (42%) time critical requests, and 247 (45%) non-time critical requests. Emergency-response staff provided on-site assistance for one acute and two nonacute events. During these emergencies, ATSDR helped first responders address the public health needs of about 190 people who were injured and another 3,663 people who were otherwise affected because of airborne dispersion or who had to be temporarily evacuated. Thirteen percent of acute-event calls reported injuries, and 37% reported other problems. The majority of acute release event calls concerned air releases during a spill or fire in an urban residential or urban industrial/commercial setting east of the Mississippi River from January through March, 1999.
Most requests for information during acute chemical releases were from EPA, local responders, state agencies, or the federal on-scene coordinator. For incidents other than acute releases, the most frequent requesters for time-critical support were private citizens, with EPA as the second most common.
The majority of chemical releases resulting in a call to ATSDR involved releases to the air (both indoor and ambient, 67%) in an urban residential or industrial/commercial environment (57%). ATSDR also assisted EPA and local responders in identifying response options to protect public health.
ATSDR wrote a guidance manual--1999 Guidance for Developing Chemical Protocols (New or Updated) for Medical Management Guidelines for Acute Chemical Exposures--for incorporating pediatric concerns into ATSDR's Medical Management Guidelines ("Managing Hazardous Materials Incidents"). The Medical Management Guidelines are a series of three volumes aimed at first responders to emergency hazardous waste releases. The first two volumes are general, describing procedures and situations common to all hazardous chemical releases. The third volume is chemical-specific.
Following are summaries of some of the major activities in which ATSDR emergency-response personnel were involved during FY 1999:
Harris County Mercury Spill, Houston, Texas : ATSDR assisted the Harris County Health Department in Houston in its response to a mercury spill at the headquarters of a nonprofit organization. The facility housed a prenatal care clinic and administrative offices. In addition, noontime meals for the assisted target population were prepared in the kitchen and transported to clients' homes. Mercury was spilled in the clinic from a damaged sphygmomanometer (a blood pressure measuring device). Concentrations found in the clinic area were in excess of the American Council of Governmental Industrial Hygienists' threshold limit value for industrial locations. ATSDR recommended an indoor action level and additional precautions to prevent exposure of children and pregnant women. On the basis of ATSDR's recommendations, Harris County temporarily closed the clinic and required cleanup of the mercury contamination.
New Carlisle Water System, New Carlisle, Ohio : At the request of the Ohio Department of Health, ATSDR provided a hazard assessment for inorganic mercury salt found in a drinking water well that was measured at 20 parts per billion, slightly above regulatory levels. Approximately 7,000 people were served by the water system. The well water became contaminated when a seal containing inorganic mercury salt broke on a submersible pump used in the well. The water from the well was added to the output of other wells and then treated before entering the water system. Residents were temporarily advised by the state not to use their water for washing, drinking, or cooking until it could be determined that the mercury was adequately removed by the treatment process. Because of the form of mercury present initially and the dilution as it entered the water system, ATSDR concluded that the human health hazard from the contaminated well was minimal. There was no detectable mercury in the water after treatment.
Dairy Cattle Fluoride Exposure, Boyertown, Pennsylvania : A dairy herd in southeastern Pennsylvania became the focal point for a rural community's concerns regarding excess exposure to fluoride compounds emitted by a manufacturing facility. EPA confirmed the presence of elevated fluoride levels in forage crops fed to cattle and requested ATSDR's assistance in investigating reported dental lesions, lameness, and decreased milk production in the herd. ATSDR and EPA's Environment Response Team visited the site twice and observed postmortem examinations of three cows from the herd by pathologists at the New York Veterinary Diagnostic Laboratory. An evaluation of the herd's records for milk production and reproductive efficiency was performed in consultation with the herd health specialist at the University of Pennsylvania. After reviewing toxicologic and other data, ATSDR concluded that the herd had some early signs of excess fluoride body burden. However, the fluoride body burden was well below levels that would cause fluorosis, a condition marked by dental lesions, exostoses, and lameness.
Tire Fire, Sycamore, Ohio : At the request of the local health department, ATSDR reviewed air and surface water sampling data for a large tire fire that occurred in Sycamore. ATSDR recommended additional air sampling because data were limited. On the basis of water data, which were more extensive, ATSDR recommended that a temporary fish advisory be continued. The Sycamore Tire Dump is one of the largest scrap tire dumps in the eastern United States.
The Superfund Amendments and Reauthorization Act of 1986 broadened ATSDR's responsibilities in the area of information dissemination. The ATSDR Information Center, which is part of the Division of Toxicology, contributes to agency activities designed to meet this responsibility by providing scientific and technical information to support ATSDR staff, agency constituents, and the public.
The Information Center received more than 77,250 requests for technical information assistance and distributed more than 284,210 documents during FY 1999. Most of the requests for information came from private citizens. In FY 1999, ATSDR's toll-free telephone system (1-888-42-ATSDR [1-888-422-8737]) received approximately 9,650 calls, about 3,000 more calls than FY 1998. ATSDR's Web site was accessed by more than 500,000 visitors in FY 1999.
The Division of Health Studies has conducted and supported health studies to evaluate the relationship between exposure to hazardous substances and adverse health effects. This relationship can be described as a sequence of events leading from contamination in the environment to the possible presence of illness in people who have been exposed.
Since 1990 ATSDR has evaluated seven priority health conditions to assess the association between adverse health outcomes and exposures to hazardous substances and to determine agency strategies to address them.1 These health conditions are as follows:
This paradigm allows ATSDR to concentrate its activities on those adverse health effects considered to be most sensitive to exposures to hazardous substances and to systematically contribute to the knowledge base about the adverse health effects. ATSDR also conducts studies to evaluate biological dose estimates of hazardous substances.
The following are descriptions of findings from studies completed in FY 1999.
Birth Defects Among Children of Racial or Ethnic Minority Born to Women Living in Close Proximity to Hazardous Waste Sites--California, 1983-1988. This population-based, case-control study evaluated the relationship between birth defects in racial or ethnic minority children (i.e., Black/African American, Hispanic/Latino, American Indian/Alaska Native, Asian/Pacific Islander) and their potential exposure to contaminants from NPL sites in California. Almost 14,000 racial or ethnic minority infants with major structural birth defects were included in the study, which covered the period 1983-1988. Case subjects were identified by the California Birth Defects Monitoring Program. For comparison, a control group of about 14,500 infants was randomly selected from vital records of infants not reported to the birth defects monitoring program.
The study found that racial or ethnic minority infants whose mothers had lived in a census tract with an NPL site were at slightly increased risk for birth defects. The risk was highest for neural tube defects and musculoskeletal defects. In the analyses by racial or ethnic group, all groups except Black/African American had an increased risk for neural tube defects. The study also found that there was a significantly elevated risk for anencephaly among infants whose mothers lived near sites contaminated by volatile organic compounds, pesticides, or cyto-oxidase inhibitors (cyanides and hydrogen sulfide). Only Blacks/African Americans were at increased risk for integument defects, and only American Indians/Alaska Natives were at increased risk for oral clefts. Conotruncal heart defects and all heart or circulatory defects were not elevated in any group.
Waste sites and hazardous materials are often located in ethnic and racial minority communities. The potential impact these have on minority populations is of concern, especially when these groups already face many social and economic disadvantages that place them at risk for adverse pregnancy outcomes. Previous studies have linked various adverse reproductive health effects, including low birth weight and birth defects, with potential exposure to substances from hazardous waste sites.
Hanford Infant Mortality and Fetal Death Analysis, 1940-1952. People living in communities surrounding the Hanford Department of Energy facility in southeastern Washington were exposed to radionuclides, particularly iodine-131, during 1945 through 1951. This study was conducted to determine if exposure to iodine-131 (estimated through exposure dose reconstruction) was a risk factor for infant mortality, fetal death, and preterm birth in the years of highest releases from Hanford, 1945 and 1946.
The study used birth records and fetal and infant death records from 1940 through 1952 for an eight-county area surrounding the Hanford facility. The Hanford Environmental Dose Reconstruction project provided iodine-131 dose estimates for the period 1945 through 1952. The analysis included 72,154 births, 1,957 infant deaths, and 1,045 fetal deaths that occurred during the 13-year study period.
The study findings suggested that living in an area with relatively high estimated iodine-131 exposure in 1945, the year of the largest iodine-131 releases, may have had an effect on the fetus or the mother that resulted in preterm birth. High estimated iodine-131 exposure in the latter part of pregnancy was also associated with preterm birth and was somewhat associated with infant mortality. Additionally, the "high exposure area" had a lower infant mortality rate than did the "low exposure area" for nearly every year from 1940 through 1952, except for 1945 and 1946, the period when exposures were highest. Examination of causes of death did not reveal many differences for infant or fetal deaths by exposure groups in 1945.
Overall, it appears that iodine-131 exposure may be associated with preterm birth; however, there is no clear explanation for the finding. The modest increase in infant mortality in the high exposure group supports findings of other studies. Further research on more contemporary populations may be warranted. Assessment of the effects of iodine-131 exposure on other birth outcomes, such as birth weight, would also be useful.
Cancer Incidence in Populations Living Near Radiologically Contaminated Superfund Sites in New Jersey. The relationship between cancer incidence and residence near radiologically contaminated hazardous waste sites in New Jersey was examined. Cancer incidence data from 1979 through 1991 were collected for six towns contaminated by three Superfund sites:
The objective was to evaluate whether the population residing closest to the contaminated areas had elevated incidence of cancer. Cancer data from the New Jersey State Cancer Registry, a population-based cancer incidence registry, were used for the study. Standardized incidence ratios (SIRs) were calculated for all cancers combined and eleven site-specific cancers. Males and females were evaluated separately, and all races were combined in the analyses. Expected numbers were calculated using average state incidence rates and U.S. census data to estimate the population.
In comparison with average state rates, the number of newly diagnosed cancers in the total study population was not higher than expected for all cancer combined or any of the 11 type-specific cancer groupings. The U.S. Radium area had significantly lower total cancer incidence, while the Welsbach/General Gas Mantle areas had significantly higher total cancer incidence and total cancer incidence in males. The higher total cancer incidence for the Welsbach sites appears to be due to significantly higher lung cancer incidence in this population. While total cancer incidence was unremarkable for the Montclair/West Orange Radium sites, total pancreatic cancer and thyroid cancer incidences among females were significantly higher than expected.
When the study area was reduced to the areas closest to the sites (about one city block), only one SIR remained significant. Lung cancer incidence for the total population near the Welsbach/General Gas Mantle sites remained significantly higher than expected. SIRs for the closest areas were similar to those for the total areas, but these were based on smaller observed and expected numbers. Only two cases of thyroid cancer were diagnosed among residents of the closest area; neither of the two patients resided near the Montclair/West Orange sites.
These data should be interpreted cautiously. The study design had numerous limitations, including the inability to assess past individual exposure levels, the lack of knowledge about the length of residence for case subjects, the potential impact of population migration, and the absence of information on other risk factors, such as occupational exposures or personal lifestyle habits.
In conclusion, this study found little consistency in the results across the study areas.
Lung cancer incidence was significantly elevated near the Welsbach/General Gas Mantle sites, and total pancreatic cancer incidence and incidence of thyroid cancer in females were significantly elevated near the Montclair/West Orange sites. However, information on important confounding factors that might explain the elevations was not available for the analysis.
