Use of reference pools to compare the qualitative and quantitative determination of polychlorinated biphenyls by packed and capillary gas chromatography with electron capture detection. Part 1. Serum.

Serum for reference pools of in vivo polychlorinated biphenyls (PCBs) was obtained from four goats that had received one dose (100 mg kg-1) of a selected technical Aroclor (AR) (1016, 1242, 1254 or 1260) and were allowed to recover for 30 d. These pools were used to assess the differences in an analytical method that determines and quantifies PCBs using packed-column gas chromatography (PCGC) (quantified on the basis of mean mass percent. data for grouped PCB peaks) and capillary-column gas chromatography (CCGC) (quantified on the basis of percent. composition data for specific congeners). With CCGC, results were statistically significantly different (p less than or equal to 0.0002) from results with PCGC for ARs 1016, 1242 and 1254 but not for AR 1260 (p = 0.23). When comparing these gas chromatographic methods using bovine serum spiked in vitro with the same ARs at 17-25 p.p.b., it was found that the methods were not statistically significantly different for any of the ARs (p = 0.30-0.92). Levels of serum PCB determined by the two methods for 12 persons, divided into two groups according to exposure, were compared using the paired t-test. Group 1 consisted of three persons with dietary and/or environmental exposure; one with dietary and/or environmental exposure in addition to occupational exposure dating back 20 years. Group 2 consisted of eight persons with recent occupational exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Association of blood pressure and polychlorinated biphenyl levels.

The geometric mean serum level of polychlorinated biphenyls (PCBs) of 458 persons in a communitywide study was 17.2 microgram/L, with 80% to 90% having levels within the range found in other community groups. As a dependent variable, PCB levels were found to be positively related to age, even when controlled for all other variables associated with PCB level: sex, local fish consumption, obesity, serum cholesterol level, and alcohol consumption. No major point source of PCB contamination was found, and fish taken in the drainage of a major population center had mean PCB levels below the current enforceable Food and Drug Administration tolerance of 5 mg/kg. As an independent variable, serum PCB levels were positively associated with gamma-glutamyl transpeptidase level, serum cholesterol level, and measured blood pressure. The PCB-blood pressure association, which was independent of age, sex, body mass index, and social class, must be confirmed in other exposed populations.

Cross-sectional study of a community with exceptional exposure to DDT.

The geometric mean level of total DDT in serum samples (76.2 ng/mL) from 499 persons living downstream from a defunct DDT-manufacturing plant was several times the national geometric mean (15.0 ng/mL). DDE isomers, metabolites of DDT, accounted for an average of 86.7% of total DDT. Total DDT levels increased with age, even when controlled for other independent variables also significantly associated with DDT: race, sex, fish consumption, years of residence, socioeconomic status, alcohol consumption, and serum triglyceride levels. Fish consumption, the second strongest determinant of DDT level, had one third the predictive power of age. Total DDT levels were not associated with specific illness or ill health. However, total DDT levels were positively associated with levels of serum cholesterol, triglyceride, and gamma-glutamyl transpeptidase. The finding that serum DDE levels increase with age suggests that no equilibrium in body burden has been reached or that pharmacokinetics or serum/adipose partition may vary with age.

A fatal episode of accidental methomyl poisoning.

Three fatalities from the accidental ingestion of methomyl, a carbamate pesticide, are reported. The methomyl had been stored in an unlabeled tin can and was accidentally used in preparing "roti," an Indian dish. The identification of the source of the poison through animal tests and further chemical identification is described. The lethal dose of methomyl was estimated to have been between 12 and 15 mg/kg body weight.

Fatal parathion poisoning caused by contamination of flour in international commerce.

In January 1976, 79 persons in Jamaica were acutely poisoned by the organophosphorus insecticide parathion. Seventeen died. Cases occurred in three episodes at separate locations, but all patients had consumed wheat flour from a single lot consisting of 5264 cotton bags. Parathion in concentrations of less than 1 to 9900 ppm was identified in flour from six bags in this lot; three had splash marks. The flour had been milled in Western Europe from European wheat, carried in trucks to a dockside warehouse, and loaded aboard ship after 2-5 days' storage. In Jamaica, the flour had moved from quayside to outbreak locations along separate routes through two import houses. Site inspections and review of shipping records suggested that the likely point of contamination was the European port, where foodstuffs and insecticides were stored in the same warehouse.

Epidemic lead absorption near an ore smelter. The role of particulate lead.

Blood lead levels were determined on a random sample of persons in all age groups living near a lead-emitting smelter in El Paso, Texas. A blood lead level of greater than or equal to 40 mug per 100 ml, which was considered indicative of undue lead absorption, was found in 53 per cent of the children one to nine years old living within 1.6 km of the smelter and in 18 per cent of those from 1.6 to 6.6 km; beyond that distance in older persons levels were lower. Children in the first 1.6 km with blood levels of greater than or equal to mug per 100 ml were exposed to 3.1 times as much lead in dust as children there with lower blood values (6447 vs 2067 ppm). There was also airborne lead exposure (8 to 10 mug per cubic meter, annual mean). Paint, water, food, and pottery were less important as sources. The data suggest that particulate lead in dust and air accounted for most of the lead absorption in El Paso children. The smelter was the principal source of this lead, especially within 1.6km of itself.