by Ken Sexton

The

The suggestion that social class or race plays an important role in determining the degree to which people are exposed to environmental hazards, as well as in influencing the effects of those hazards on health and well being, is a disturbing, albeit all too plausible, hypothesis. It does not take much imagination to speculate that poor people, a disproportionate share of which are minorities, routinely encounter elevated levels of pollution in the air they breathe, the water they drink, and the food they eat.

Within the field of environmental health, there are two groups generally considered to be at higher risk: those who experience the highest exposures, and those who are more biologically susceptible to the effects of a given exposure. The subgroup at highest risk is made up of those individuals who are both biologically susceptible and who also come into contact with the highest pollutant concentrations.

Currently, very little data exist on differences between races according to biological susceptibility to

environmental pollutants. There is

certainly evidence of biological differences, but their relationship to susceptibility is not well understood.

Further, it is difficult to separate the effects of class (socioeconomic status) from the effects of race (ethnicity) on environmental health risk. Poor people, typically, are less well informed about environmental health issues, lack adequate health care, have a substandard diet, and are more likely to have stressful and unhealthful lifestyles. Minority populations may be at higher risk as a result of their genetic makeup, cultural beliefs and practices, and social behaviors. The

(Dr. Sexton is Director of EPA's Office of Health Research.)

situation is complicated by the fact that minorities are statistically more likely to be disadvantaged in terms of their income, education, and occupation than their white counterparts. Consequently, although there is substantial anecdotal and circumstantial evidence suggesting that class and race, taken together, affect exposure levels, we do not now have sufficient data to differentiate between the two.

The calls for public action to mitigate environmental inequities present policy makers with a familiar dilemma. In the face of substantial scientific uncertainties, they must decide whether inequities exist, how serious they are, what are the causes, and what are the most cost-effective mitigation strategies.

As documented elsewhere in this issue of the Journal, there is clear evidence that certain groups-as, for example, subsistence fishermen, migrant farm workers, and residents of inner urban areas experience elevated exposures to hazardous environmental pollutants. It is unclear, however, whether these exposures account, in part, for the higher overall rates of death and disease observed among disadvantaged groups and ethnic minorities.

There are clear and dramatic differences between ethnic groups for both disease and death rates. Age-specific death rates, for example, are higher for African American males and females than for their white counterparts in all age groups from 0 to 84 years of age. Furthermore, overall death rates from cancer are greater in blacks than whites for both males and females. For other ethnic minorities, the overall cancer mortality is lower than for whites. There is, however, substantial variation in the mortality rates associated with different types of

cancer.

Surprisingly, very little data are available on disease and death rates categorized by important socioeconomic variables. Closer examination reveals that the United States is the only western country with a high standard of living whose government does not collect mortality statistics by class indicators, such as income, education, and occupation. Recently, there has been an academic debate about whether the

evidence is unequivocal: A higher percentage of black children than white children have elevated blood lead levels. All socioeconomic and ethnic groups have children with lead in their blood high enough to cause concern about adverse health consequences; however, a significantly higher percentage of black children compared to white children, regardless of socioeconomic strata, have unacceptable levels of lead in their blood.

In general, it is not possible based on the existing scientific evidence to

With the notable exception of link class and race directly to

lead, there is a paucity of data relating class and race to specific environmental pollutants and associated health effects.

differences in cancer rates between blacks and whites can be explained by the effects of poverty. Some scientists believe that if the differences in socioeconomic characteristics could be eliminated, then blacks would actually have a lower overall cancer rate than whites. Others suggest that while poverty and lifestyle can explain part of the difference, there is still a significant amount of variation that can only be explained by race.

The observed differences in the rates of disease and death among ethnic groups are undoubtedly caused by a combination of factors, including economic, social, cultural, biological, and environmental variables. Although some of the differences are dramatic, as with cancer rates, for example, the contribution of environmental pollution is unclear.

With the notable exception of lead, there is a paucity of data relating class and race to specific environmental pollutants and associated health effects. In the case of lead, the

differences in the rates of

environmentally induced disease or injury. There is evidence, however, as mentioned earlier, to suggest that exposures to some environmental pollutants vary according to socioeconomic and ethnic variables. These differences in exposures result from the fact that disadvantaged people, including ethnic minorities, tend to come into contact with higher pollution levels because of where they live, what they eat and drink, and how they earn their living. The available scientific basis for evaluating the equity question, although meager, is sufficient to raise serious and immediate concerns for researchers, risk assessors, and risk managers. Owing to the complexity of environmentally induced disease, it is often difficult or impossible to establish a direct causal link with pollutant exposures. Nevertheless, the evidence suggesting that poor people and ethnic minorities experience higher exposures to many environmental contaminants is compelling.

The Agency for Toxic Substances

and Disease Registry (ATSDR) is a U.S. Public Health Service agency headquartered in Atlanta, Georgia. ATSDR was created to implement the health-related measures mandated under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (the "Superfund" law). As part of its response to this charge, ATSDR established a minority health initiative to address the health impact of hazardous waste on minority communities. The initiative focuses on four areas: demographics, health perspectives, health communication, and health education.

Demographics

To determine the proximity of hazardous waste sites to minority communities, ATSDR will utilize the Geographic Information System (GIS). A pilot of five National Priorities List (NPL) sites has been tested using both manual and computerized methodologies for determining population densities and demographics. In addition, ATSDR is currently using GIS to evaluate a randomly selected set of 30 NPL sites. As a result of our pilot tests, we have determined the GIS to be the best methodology for identifying potentially impacted minority populations.

In the future, ATSDR will focus on determining the relative proximity of minority communities to all sites on the NPL. Data for each site can then be integrated into a larger database and analyzed using descriptive and inferential statistical techniques. An important data source for that integration is the 1990 Census of Population and Housing, which includes 100 percent population and housing counts and characteristics. Other possible sources of data that will

be tapped include city directories (the city directory often lists occupation and is broken down alphabetically by name and also by street address), plat maps in rural areas (plat maps indicate ownership of land), the county courthouse (mortgage and other housing information might help establish the variable length of residence), and planning commissions (building permits).

Health Perspectives

Health status and access to adequate health care may contribute significantly to the impact of environmental contamination on minority communities. Significant data gaps exist regarding the relationships between low-level exposures and effects. For example, lead is a pervasive contaminant that has disproportionately affected minority communities; however, additional research is needed to determine its bioavailability in various media (water, soil, slag) and to further define effects that may result from low-level exposures (blood lead levels of less than 10 micrograms per deciliter (μg/dl)).

Through an extensive literature search and the establishment of a strong environmental health data base, we have confirmed the paucity of information specifically linking pre-existing health factors and increased risk to environmental contamination. ATSDR is therefore sponsoring a substance-specific research program through the Association for Minority Health Professions Schools (AMHPS). ATSDR's public health studies have identified specific sites adversely impacting minority communities. The impact of lead in soil (as high as 20,000 parts per million (ppm)) on a predominantly Hispanic community in

by Cynthia H. Harris and Robert C. Williams

Colorado resulted in ATSDR's issuing a public health advisory. In addition, ATSDR and the state of Colorado collected samples of blood to detect lead levels in potentially exposed susceptible populations (i.e., children, pregnant women).

ATSDR is currently conducting various pilot and epidemiological health studies for Native American communities. Mercury contamination in fish is a primary concern in the Everglades (Florida), in Fond-du-lac (Minnesota), and with the Puyallup tribe (Washington). The prevalence of PCBs in the breast milk of Native American women of the St. Regis Mohawk tribe (of New York) was discussed during ATSDR's National Minority Health Conference held in December 1990. Consequently, a health study is being sponsored by the Agency. In addition, ATSDR has signed an interagency agreement with the Indian Health Service to address the public health needs and concerns of Native Americans as they relate to the release of hazardous substances into the environment.

Lifestyle and culture can play important roles. In conjunction with the Connecticut Department of Health and the Hispanic Health Council, ATSDR helped identify the prevalence of the use of elemental mercury (azogue) for ritualistic purposes (Santeria). Specific botanicas that sold azogue were identified in the Hartford area, and it was found that the most prevalent users were within the Hispanic community. The Connecticut Department of Health is determining

(Dr. Harris is Chief of the Community Health Branch and Williams is Director of the Division of Health Assessment and Consultation at the Agency for Toxic Substances and Disease Registry in Atlanta, Georgia.)

how best to convey information regarding the potential health hazards associated with the use of the material.

Health Education and Communication The toxic effects of environmental contamination and environmental health issues must be communicated to minority communities. Such communication can be aided by

training minority health care providers in how to address environmental health concerns.

ATSDR is attempting to meet those training needs and has developed and implemented several health education activities. For instance, ATSDR is working closely with AMHPS schools to identify and conduct pertinent environmental substance-specific research. ATSDR has also assisted in

Copyright Sam Kittner.

establishing a doctoral program in environmental toxicology at Florida A&M University in which ATSDR staff serve as advisory board members. In many rural communities, pharmacists are the first line of health care, so ATSDR has identified minority pharmacists as local health professionals responsible for identifying populations at risk and communicating that risk to their communities. The National Medical Association (NMA) is one of the oldest minority health care professional organizations. ATSDR has become an active participant in NMA activities by

conducting environmental health workshops at regional NMA meetings and presenting at national NMA meetings.

ATSDR also realizes that

communities want to be informed and involved and has established Community Assistance Panels (CAPS) in several communities. The purpose is to provide a forum for exchanging information between ATSDR and the affected community during the preparation of a public health assessment or conduct a health study.

For example, a CAP has been

established to address concerns

regarding environmental

contamination in the Southeast

Chicago area. The CAP members have been active in assisting ATSDR determine community concerns, identify contamination sources, and disseminate information about ATSDR's programs and activities. For that site, CAP meetings will be held quarterly throughout the public health assessment process.

Fishing opposite a dump in south Chicago. Inner-city residents may find environmental risks at every turn-including, here, a possible dietary risk from contaminated fish.