Marty S. Kanarek

Fish consumption and reproductive outcomes in Green Bay, Wisconsin.

Prenatal exposure to polychlorinated biphenyls (PCBs) and reproductive outcome was determined in a population of 1112 women during 1987-1989. The women studied were from the Green Bay, Wisconsin area, thereby providing a population with potential PCB exposure from Lake Michigan sport fish consumption. All women with positive pregnancy tests from two Green Bay prenatal clinics were asked to complete a self-administered questionnaire on fish consumption, health and reproductive history, and other relevant issues and to provide blood samples for PCB analysis. A positive correlation was found between the amount of Lake Michigan fish mothers claimed to consume and their PCB serum levels. After the pregnancy period, reproductive outcome measures (fetal wastage; stillbirths; and birth weight, birth length, head circumference, ponderal index, and birth weight percentiles for live births) were abstracted from hospital labor reports. Typical negative associations between birth size measures and consumption of caffeine, smoking, and alcohol were found. Birth size was positively associated with gestational age, birth order, weight gain during pregnancy, male babies, and rural residence. Birth size was also associated with PCB exposure; however contrary to expectations, a positive association was found (P < 0.044) for most mothers (the exception being those mothers who gained more than 34 lb during their pregnancy). PCB exposures were lower than the other studies that found that birth size was negatively associated with PCB exposure.

Formaldehyde exposure in nonoccupational environments

Free formaldehyde may be released from wood products and foam insulation where urea-formaldehyde resins have been used. From January, 1978 to November, 1979, 100 structures were investigated by the Wisconsin Division of Health after receiving complaints of health problems from occupants. Air samples were collected in midget impingers and analyzed for formaldehyde content by the chromotropic acid procedure. Health information was obtained from the occupants via questionnaires. Mean formaldehyde concentration observed ranged from below the limit of detection to 3.68 ppm. Eye irritation, burning eyes, runny nose, dry or sore throat, headache, and cough were the primary symptoms which were reported by the occupants. Statistically significant associations were seen between formaldehyde levels and age of home/building materials. Observations presented suggest nonoccupational, indoor environmental exposure to formaldehyde is significant and may reach levels which exceed occupational exposure standards.

Personal exposure to nitrogen dioxide: relationship to indoor/outdoor air quality and activity patterns.

Personal NO/sub 2/ exposures and indoor and outdoor concentrations were measured for nearly 350 individuals in the Portage, WI, area. Concentrations in homes with gas stoves averaged 18 ..mu..g/m/sup 3/ higher in the summer (median indoor/outdoor ratio 2.4) and 36 ..mu..g/m/sup 3/ (median indoor/outdoor ratio 3.2) higher in the winter than outdoor levels. Personal exposures were closely related to indoor averages for households with gas stoves (r = 0.85 summer, r = 0.87 winter) and with electric stoves (r = 0.68 summer, r = 0.61 winter); more than 65% of the average day was spent at home while about 15% was spent outdoors in summer and less than 5% in winter. The association between personal exposure and outdoor levels of NO/sub 2/ was weakest during the winter for both gas (r = 0.20) and electric (r = 0.28) stove groups. The measures of exposure and time allocation indicate that there is a wide range of variability in personal exposures to NO/sub 2/ that may not be adequately accounted for by simple stratifications based on cooking fuel type. 46 references, 7 tables.

Mesothelioma from Chrysotile Asbestos: Update

PURPOSE There are different mineral classes of asbestos, including serpentines and amphiboles. Chrysotile is the main type of serpentine and by far the most frequently used type of asbestos (about 95% of world production and use). There has been continuing controversy over the capability of chrysotile asbestos to cause pleural and peritoneal mesothelioma. This review is to help clarify the issue by detailing cases and epidemiology studies worldwide where chrysotile is the exclusive or overwhelming fiber exposure. METHODS A worldwide literature review was conducted of asbestos and associated mesothelioma including case series, case-control and cohort epidemiology studies searching for well documented chrysotile asbestos associated mesothelioma cases. RESULTS Chrysotile asbestos exposures have occurred in many countries around the world from mining, manufacturing and community exposures. There have been many documented cases of mesothelioma from those exposures. CONCLUSIONS Chrysotile asbestos, along with all other types of asbestos, has caused mesothelioma and a world-wide ban of all asbestos is warranted to stop an epidemic of mesothelioma.

Gastric Cancer Mortality and Nitrate Levels in Wisconsin Drinking Water

The association between nitrate levels in public and private sources of drinking water and gastric cancer mortality in Wisconsin was investigated in a case-control study. All gastric cancer deaths of Wisconsin residents from 1982 through 1985 were compared with deaths from other causes (controls), and nitrate levels in the home drinking water of these residents were determined. Nitrate measures for public sources were obtained from historic nitrate data from municipal sources that existed in 1970. Nitrate measures for private water sources were obtained by testing the wells individually at the existing residences. Controls were matched individually to gastric cancer cases with respect to sex, year of birth, year of death, Wisconsin birth, and Wisconsin residency at the time of death. Matched-pair analyses were performed on the paired data, and the following levels of nitrate-nitrogen exposure were used as indicators of exposure: 0.5, 2.5, 5.0, and 10.0 mg/l. Matched-pair analysis was also performed for which private water supply constituted exposure. Odds ratios and 95% confidence intervals were, respectively, 0.92 (0.75, 1.12); 0.97 (0.74, 1.35); 0.86 (0.69, 1.08); 1.50 (0.12, 18.25); and 1.09 (0.82, 1.47) for exposure to private well-water sources. These results did not indicate an increased risk of gastric cancer at any level.

Personal monitoring for nitrogen dioxide exposure: Methodological considerations for a community study

Personal exposure to nitrogen dioxide (NO2) and time spent in various locations were measured for 66 family members from 19 homes in the Portage, WI area during March 1981. Passive diffusion NO2 monitors were placed outdoors, in the kitchen, and in one bedroom on each floor of the homes, and were worn by family members. Individuals from gas-cooking homes had significantly higher average NO2 exposures than those from homes using electricity for cooking (mean difference 19.37 μg/m3). Personal exposures were more closely related to bedroom levels than to kitchen or outdoor concentrations for both cooking fuel groups. Several preliminary models are presented which relate average personal NO2 exposure to indoor and ambient levels, and also to the proportion of time spent in different locations. These models are capable of explaining nearly 90% of the variation about the mean in personal exposure.

Asbestos in drinking water and cancer in the San Francisco Bay Area: 1969-1974 incidence.

The relationship between ingested asbestos (through drinking water) and cancer of various body sites was examined. This study was a follow-up to another article that investigated this relationship. Age-adjusted, sex and race specific 1969–1974 cancer incidence ratios for 410 census tract groupings (‘super tracts’) of the San Francisco-Oakland Standard Metropolitan Statistical Area were compared with measured chrysotile asbestos counts in drinking waters of super tracts. The earlier article analyzed cancer data for the 3 yr period, 1969–1971. The present study used that data and an added set of cancer cases for 1972–1974. The water supplies serving the area have varying contact with naturally occurring serpentine. The t-test for multiple regression coefficients and the t-test for correlation coefficients showed significant (p < 0.01) relationships between chrysotile asbestos content of super tract drinking water and white male digestive tract, esophageal, stomach and pancreatic cancers. For white females, significant (p < 0.01) relationships on these tests were found for esophageal, stomach, digestive related organs, and pancreatic cancers. These associations appeared to be independent of income, education, asbestos occupation, marital status and mobility.

Fish Consumption Patterns and Blood Mercury Levels in Wisconsin Chippewa Indians

Methylmercury is a known neurotoxin at high blood levels (> 400 micrograms/l) and is thought to cause neurologic symptoms at substantially lower levels in susceptible adults and infants. Given that levels of methylmercury in fish in northern Wisconsin lakes can be high (> 1 ppm, FDA standard) and Chippewa Indians take large amounts of fish from these lakes, the extent of their exposure to methylmercury was investigated. Using tribal-maintained registries, 465 Chippewa adults living on reservation were selected randomly and were invited to participate; 175 (38%) participated in the study. In an effort to characterize nonrespondents, 75 nonrespondents were selected randomly and were followed up aggressively. An additional 152 volunteers who were selected nonrandomly also participated in the study. Subjects completed a questionnaire about fish consumption patterns and had blood drawn for mercury determination. Sixty-four persons (20%) had blood mercury levels in excess of 5 micrograms/l (i.e., upper limit of normal in nonexposed populations); the highest level found was 33 micrograms/l. Fish consumption was higher in males and the unemployed. Blood mercury levels were highly associated with recent walleye consumption (p = .001). Methylmercury levels in some Wisconsin Chippewa were found to be elevated, but were below the levels associated with adverse health effects. We recommend a continuation of efforts to limit exposures in this high-risk population.

Thermotolerant non-fecal source Klebsiella pneumoniae: validity of the fecal coliform test in recreational waters.

Wisconsin pulp and paper mill processing plants were evaluated for fecal coliform and total Klebsiella (i.e., thermotolerant and thermointolerant) bacterial concentrations. Using the standard fecal coliform test, up to 90 per cent of non-fecal source thermotolerant K. pneumoniae was falsely identified as fecal source bacteria. Since there is a lack of specificity in the currently used standard for fecal coliform evaluation, a more reliable health risk assessment for fecal coliform bacteria is recommended.

Osteosarcoma, seasonality, and environmental factors in Wisconsin, 1979-1989.

Proxy exposure measures and readily available data from the Wisconsin Cancer Reporting System were used to contrast 167 osteosarcoma cases with 989 frequency-matched cancer referents reported during 1979-1989. Differences in potential exposure to water-borne radiation and fluoridated drinking water, population size for the listed place of residence, and seasonality were assessed. An association was found between osteosarcoma and residence in a population of less than 9,000 (odds ratio = 1.6, 95% confidence interval = 1.1-2.4). In addition, an association between month of birth (May through July versus other months of birth) and osteosarcoma among individuals who were less than 25 y of age (odds ratio = 1.9, 95% confidence interval = 1.1-3.4). Overall, no association was found between potential exposure to fluoridated drinking water and osteosarcoma (odds ratio = 1.0, 95% confidence interval = 0.6-1.5). The association between osteosarcoma and water-borne radiation was weak and was not significant statistically (odds ratio = 1.5, 95% confidence interval = 0.8-2.8).