Routine analysis of 101 polychlorinated biphenyl congeners in human serum by parallel dual-column gas chromatography with electron capture detection.

Polychlorinated biphenyl (PCB) exposure has been linked to a variety of toxic effects in animal experiments and in certain human case reports and epidemiologic studies. A total of 209 individual PCB congeners are possible, based on chlorination level and ring substitution pattern. Commercial PCBs are a complex mixture of congeners, and over 75 of these have been reported to be present in human tissues at widely varying levels. Because the biologic activity of individual PCBs is a function of extent and pattern of chlorine substitution, "congener-specific" PCB analysis of human tissue has gained increasing importance in assessing possible links between PCB exposure and toxic effects. A high-sensitivity analytical method using dual-column gas chromatography (GC) with electron capture detection (ECD) for determining 101 PCB congeners (83 individual, 18 as pairs/triplets) plus 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), hexachlorobenzene (HCB), and mirex, in human serum is described. Separation is performed concurrently on parallel-configured DB-5 and Apiezon-L capillary columns. The current method is a modification of previously reported dual-column GC-ECD systems with improvements to the extraction and analytical protocols and the implementation of a comprehensive QA/QC program. The method employs two surrogate standards (PCBs IUPAC 125 and 192) and internal standard (IUPAC 104)-based quantitation, in addition to per-batch check standards and method blanks. Although optimized for serum, the method is applicable to all human, experimental animal, and environmental biota samples. The accuracy, precision, and reliability of the method were assessed using a variety of QA/QC endpoints. Finally, the use of the method in determining level and prevalence of PCB congeners in a cohort of adult Native-American individuals with historical environmental PCB exposure is reported.

Local fish consumption and serum PCB concentrations among Mohawk men at Akwesasne.

A study was conducted to assess local fish consumption patterns and their relationship to concentrations of total polychlorinated biphenyls (PCBs) in the serum of Mohawk men residing near three hazardous waste sites. From 1992 to 1995, 139 men were interviewed and donated a 20-ml venous blood sample. The results indicated that the men ate a mean of 21.2 local fish meals during the past year, compared with annual means of 27.7 meals 1-2 years before and 88.6 meals more than 2 years before (P<0.001 for test of trend). This change is probably a consequence of advisories issued against the consumption of local fish, since 97% of the men were aware of the advisories and two-thirds had changed their behavior as a result. Multiple regression analysis revealed that serum PCB levels increased with age (beta=0.036, P<0.001) and local fish consumption (beta=0.088, P=0.006). The data suggest that local fish consumption has contributed to body burdens in this population and that the advisories have been effective in modifying local fish consumption habits.

Assessing environmental exposure to PCBs among Mohawks at Akwesasne through the use of geostatistical methods.

The Mohawk Nation at Akwesasne is a Native American community located along the St. Lawrence River in New York State, Ontario, and Quebec. One component of a multiphase human health study was to assess the impact of different pathways of human exposure resulting from the off-site migration of polychlorinated biphenyl (PCB) contamination in this area. This paper illustrates how mapped residential information and environmental sampling data can be united to assist in exposure assessment for epidemiologic studies using geographic information system (GIS) technology and statistical methods. A proportional sampling scheme was developed to collect 119 surface soils. Using a method of cross validation, the average estimated error can be computed and the best estimator can be selected. Seven spatial methods were examined to estimate surface soil PCB concentrations; the lowest relative mean error was 0.42% for Inverse 3 nearest neighbor weighted according to the inverse distance, and the highest relative mean error was 4.4% for Voronoi polygons. Residual plots indicated that all methods performed well except near some of the sampling points that formed the outer boundaries of the sampling distribution.

A partnership study of PCBs and the health of Mohawk youth: lessons from our past and guidelines for our future.

This paper describes a research partnership between the people of Akwesasne and researchers from the State University of New York at Albany for the study of polychlorinated biphenyls and the health of Mohawk youth. The study is distinctive because its goals have been set by the scientists and the community members and is being conducted jointly by these groups. The research partnership recognizes the history of relationships between native and nonnative peoples, particularly scientists, and seeks not only to fulfill certain scientific goals but to further community ones as well. The relationship is based on three principles: mutual respect, mutual equity, and mutual empowerment. These principles guided every aspect of the research process. The project goals were determined jointly to maximize data quality and minimize the intrusion of research activities into the lives of community members. Data collection is performed by research assistants who received extensive and ongoing training in data collection methods, and who are members of the community. Feedback procedures were designed by community members and scientists jointly to maximize understanding. Feedback regarding individuals' pollutant levels and assessments of growth and development are provided to each individual. Information about community pollutant levels are provided to the community. Hypothesis testing is carried out by research scientists, and the results presented first at a community meeting. Research conducted in this way--as a partnership--requires more communication, discussion, and travel, but the result is mutual satisfaction and growth.

Human exposure to PCBS: modeling and assessment of environmental concentrations on the Akwesasne reservation.

The Mohawk Nation at Akwesasne, comprised of approximately 10,000 people, is located along the St. Lawrence River in upstate New York. The Akwesasne reservation has been contaminated by local industries, which are located on the St. Lawrence River and its tributaries, and by upstream sources on the Great Lakes. The closest known source of contamination to the reservation is General Motors (GM) Foundry, which is located less than 100 feet from the reservation's border. This facility is listed on the Environmental Protection Agency's National Priority List and the New York State's Department of Environmental Conservation's (NYSDEC) inactive hazardous waste disposal site list. Contamination to the reservation arising from discharge and secondary transport mechanisms has caused concern to the Mohawk people of Akwesasne. The characterization of the environment at Akwesasne required a historical review of existing environmental data, generation of a database, review of existing data, sampling to augment existing data, data analysis, data modeling and data generation based on a chosen model for all environmental pathways of interest. The objectives this work were to: 1) assess the quality of existing data, 2) create a database which will manage the over 6000 samples recorded taken from the local area, 3) augment the existing data with additional sampling, 4) determine the degradation or attenuation of PCBs and specific congeners in various environmental media over time, and 5) create a model that estimates environmental concentrations of PCBs retro- and pro-spectively for times that sampling had not occurred. The results of this process yielded concentrations of PCBs, congener specific and total, in several environmental medium. Modeling of environmental concentrations through a thirteen-year time period was performed for a fish, wildlife and surface soil. Other media were not modeled due to limited information or non-detectable concentrations reported in past work. Additionally, the study participants activity, consumption and residential information was considered when limiting this modeling effort. The results of this work were used to estimate environmental concentrations through time and space. The results of this work were extremely valuable when determining areas of concern and provided the basis for a detailed exposure assessment of 97 women who reside at the Reservation.

Polychlorinated biphenyl (PCB) and dichlorodiphenyl dichloroethylene (DDE) exposure among Native American men from contaminated Great Lakes fish and wildlife.

The New York State Department of Health is performing an investigation of Mohawk men, women, and infants who live at the Akwesasne Reserve along the St. Lawrence River in New York, Ontario, and Quebec Three large industrial facilities bordering the Akwesasne Reserve have seriously contaminated the soil and the sediments and fish of the adjacent St. Lawrence River with polychlorinated biphenyls (PCBs). The main study goals are to investigate the associations among the consumption of locally caught fish, residential exposure, body burdens of PCBs, and liver enzyme induction. Contamination with PCBs, polychlorinated dibenzofurans, polychlorinated dibenzodioxins, polyaromatic hydrocarbons, dichlorodiphenyl dichloroethylene (DDE) and other chemicals has been documented in locally caught fish, ducks, and other wildlife. The contamination of fish and wildlife is a major concern of the Mohawk people, since their tradition and culture emphasize the interdependence of man and his environment and because many residents formerly depended heavily on local fish and waterfowl for food. The focus of this research from 1986-1992 was on nursing women and infants. The major purpose of the current project is to determine if there are associations between dietary, residential, and occupational exposures to PCBs and DDE and individual body burdens in Mohawk men, specifically the husbands, partners, fathers, brothers, or other male relatives of the women in our other studies. In other fish-eating populations, adult men have tended to demonstrate higher PCB and DDE body burdens than women and children. Exposure estimates based on the reported consumption of locally caught fish and wildlife and residential histories will be correlated with the specific pattern of PCB congeners found in serum, thereby establishing a direct relationship between two potential sources of exposure and body burdens. Liver function will be examined through the caffeine breath test (CBT), a sensitive, noninvasive method of assessment of enzyme induction, one of the earliest detectable biological responses to PCBs in laboratory animals. This test appears promising as a method to detect subtle subclinical effects before the onset of overt clinical symptoms. The project is among the first to explore differences in dietary and other exposures, body burdens, and potential adverse health effects due to specific PCB congeners in men and women from the same source population.