Polychlorinated biphenyl exposure and neuropsychological status among older residents of upper Hudson River communities.

BACKGROUND: Polychlorinated biphenyls (PCBs) may accelerate the cognitive and motor dysfunction found in normal aging, but few studies have examined these outcomes and PCB exposure among older adults. OBJECTIVE: We evaluated neuropsychological status and low-level PCB exposure among older adults living along contaminated portions of the upper Hudson River in New York. METHODS: A total of 253 persons between 55 and 74 years of age were recruited and interviewed, and provided blood samples for congener-specific PCB analysis. Participants also underwent a neuropsychological battery consisting of 34 tests capable of detecting subtle deficits in cognition, motor function, affective state, and olfactory function. RESULTS: After adjustment for potential confounders, the results indicated that an increase in serum total PCB concentration from 250 to 500 ppb (lipid basis) was associated with a 6.2% decrease in verbal learning, as measured by California Verbal Learning Test trial 1 score (p = 0.035), and with a 19.2% increase in depressive symptoms, as measured by the Beck Depression Inventory (p = 0.007). CONCLUSIONS: The results suggest that exposure to PCBs may be associated with some measures of memory and learning and depression among adults 55-74 years of age whose current body burdens are similar to those of the general population. Although the results are useful in delineating the neuropsychological effects of low-level exposure to PCBs, further studies of whether older men and women are a sensitive subpopulation are needed.

Environmental exposures to polychlorinated biphenyls (PCBs) among older residents of upper Hudson River communities.

The upper Hudson River has been heavily contaminated with polychlorinated biphenyls (PCBs) due to discharges from former electrical capacitor plants in Hudson Falls and Fort Edward, NY. An epidemiologic study was conducted to assess the impact of dietary and residential exposure on PCB body burden among older, long-term, non-occupationally exposed adults living in the vicinity of these former capacitor plants. The study population consisted of 133 persons 55-74 years of age who had lived in Hudson Falls or Fort Edward for 25 years or more. The comparison group consisted of 120 persons from Glens Falls, which is upriver. Both groups were interviewed, and blood samples were obtained for congener-specific PCB analysis. Persons from the study area reported greater past consumption of Hudson River fish than did the comparison area, but current rates were very low in both areas. The geometric mean serum PCB concentrations for the study and comparison populations did not differ significantly (3.07 ppb wet weight and 3.23 ppb, respectively, for total PCB). Serum PCB concentrations increased with cumulative lifetime exposure to PCBs from Hudson River fish consumption (p<0.10). Persons who lived within 800 m of the river did not have significantly greater serum PCB concentrations than the control population, nor did persons who lived downwind and within 800 m of a PCB-contaminated site. The results indicate no detectable differences in serum PCB levels according to proximity or wind direction relative to local point sources, but lifetime consumption of Hudson River fish was positively associated with serum PCB concentrations.

A regional approach to assess the impact of living in a chemical world.

In the United States, some 80,000 commercial and industrial chemicals are now in use of which over 30,000 are produced or used in the Great Lakes region. Thus, the environmental quality within the Great Lakes basin has been compromised particularly with respect to persistent toxic substances (PTS). Information derived from wildlife studies, prospective epidemiological and toxicological studies, databases, demographics, and Geographical Information Systems (GIS) demonstrate significant public health implications. Studies of human populations indicate: (a) elevated body burden levels of PTSs, (b) decrease in gestational age, (c) low birth weight (LBW), (d) greater risk of male children with birth defects (OR = 3.01), (e) developmental and neurological deficits, (f) increased risk of infertility, (g) changes in sex ratio, and (h) fluctuations in thyroid hormones. These findings have been identified in vulnerable populations, such as the developing fetus, children, minorities, and men and women of reproductive age who are more susceptible because of their physiologic sensitivity and/or elevated exposure to toxic chemicals. Typically such health effects are assessed on a chemical specific basis; however, most human populations are exposed to hazardous chemicals as mixtures in air, water, soil, and biota. In this article we present an assessment of the potential for joint toxic action of these substances in combinations in which they are typically found. These evaluations represent an integration of all available scientific evidence in accordance with the "NAS paradigm" for risk assessment. In aggregate, our evaluations have demonstrated a need for community-based frameworks and computational techniques to track patterns of environmentally related exposures and associated health effects.

Human health research and policy development: experience in the Great Lakes region.

As a direct outgrowth of industrial and agricultural activities, the quality of the Great Lakes ecosystem has declined significantly because of toxic substances in the water, eutrophication, overfishing, and invasive species that have been introduced into the waterways. Although measures have been adopted to restore the health of the ecosystem, contamination of Great Lakes sport fish continues arising from conditions that still prevail, but on a more limited scale. As a consequence, the Great Lakes states have issued guidelines for the public in the form of health advisories for fish consumption to encourage practices that will minimize exposure to contaminants found in Great Lakes sport fish. Scientific research has strongly influenced many policy decisions, including the development of laws, rules, and guidelines applicable to public health not only in regard to fish advisories but also other issues impacting human health. This paper proposes to outline how policy has been influenced by scientific findings and the far-reaching effect that these decisions have had on the health status of the public in the Great Lakes area and its potential for influencing the nation as a whole and our global neighbors. Within the Great Lakes basin, polychlorinated biphenyls (PCB) and mercury are the subject of the greatest number of fish advisories. Great Lakes-based researchers have studied populations residing in the Great Lakes basin to determine their level of awareness concerning fish consumption health advisories. They found that almost 50% of the residents who consumed Great Lakes sport fish were aware of sport fish consumption advisories. Of those with awareness, almost 60% were males and only about 40% were females. The researchers attributed the greater awareness among males to the health advisory materials that males receive with their fishing licenses and to their contact with fishing-related groups. The lower level of awareness among women regarding fish consumption advisories subsequently prompted the researchers to recommend targeting risk communication programs for female consumers of Great Lakes sport fish, particularly women of reproductive age. The Wisconsin Department of Health and Family Services subsequently followed the recommendation and developed uniform outreach materials for women, minorities, and the general public to be used by the Great Lakes states. The policy change directing educational materials to at-risk groups (e.g., women of reproductive age and minorities) is a direct outgrowth of the finding of low awareness about fish advisories among women who were interviewed.

Sentinel human health indicators: to evaluate the health status of vulnerable communities.

The presence of toxic substances in the Great Lakes (GL) basin continues to be a significant concern. In the United States, some 70,000 commercial and industrial compounds are now in use. More than 30,000 are produced or used in the Great Lakes ecosystem. These substances include organochlorines (e.g., polychlorinated biphenyls (PCBs), dioxins, furans, dieldrin, etc.), heavy metals such as methylmercury, and alkylated lead, and polycyclic aromatic hydrocarbons (e.g., benzo[a]pyrene). The IJC has identified 42 locations in the GL basin of the United States and Canada as Areas of Concern (AOCs) because of high concentrations of these toxic substances. In 1990 the U.S. Congress amended the Great Lakes Critical Programs Act to create The Agency for Toxic Substances and Disease Registry (ATSDR) Great Lakes Human Health Effects Research Program (GLHHERP) to begin to address these issues. This program characterizes exposures to contaminants via consumption of GL fish and investigates the potential for short- and long-term adverse health effects. This paper reviews the GLHHERP program and indicators established to monitor and address the risks posed by these substances to vulnerable populations in the Great Lakes ecosystem.

Great lakes research--important human health findings and their impact on ATSDR's Superfund research program.

The Agency for Toxic Substances and Disease Registry (ATSDR) was created by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, commonly known as Superfund. ATSDR is the principal United States federal public health agency involved with issues of public health and applied science concerning the human health impact of living in the vicinity of a hazardous waste site, or emergencies resulting from unplanned releases of hazardous substances into community environments. In pursuing these mandates, 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 present in the environment. There are more than 2,000 toxic substances found at hazardous waste sites in the United States. ATSDR has developed a prioritized list of 275 substances that pose the greatest hazard to human health. In conducting its work ATSDR has identified data gaps in knowledge about the toxicity of various hazardous substances as well as gaps in human exposure characterization. As part of its mandate, ATSDR initiated a Substance-Specific Applied Research Program (SSARP) to address these data gaps. The ATSDR Great Lakes Human Health Effects Research Program (GLHHERP) is a congressionally-mandated research program that characterizes exposure to persistent toxic substances and investigates the potential for adverse health outcome in at-risk populations. The research findings from this program in the areas of exposure, sociodemographic data, and health effects have significant public health implications for ATSDR's Superfund research activities.