Dietary exposure to persistent organochlorine compounds and health effects in women and their infants - Epidemiological studies on birthweight, cancer incidence, and mortality

Sammanfattning: In Sweden the main exposure route for both polychlorinated biphenyls (PCB) and other persistent organochlorine compounds is through consumption of fatty fish species from the Baltic Sea (the eastern coast of Sweden). Cohorts of fishermen's wives from the Swedish east and west coasts were established. Interviewed east and west coast cohort women ate locally caught fish at least twice as often as women from the general population. The east coast cohort women displayed during the period 1968-1989 an increased breast cancer incidence (incidence rate ratio 1.34, 95% confidence interval (CI) 0.97-1.86) and mortality in ischemic heart disease (mortality rate ratio 1.31, 95% CI 1.01-1.70) as compared with the west coast cohort. Due to lack of individual data on exposure and confounding factors, it is not possible to conclude that the differences were caused by fish intake. Infants from the east coast cohort had during the period 1973-1991 an increased risk for low birthweight,as compared with infants from the west coast cohort. A nested case- referent study within the east coast cohort indicated an increased risk of low birthweight among infants born to mothers who reported a relatively high current intake of fish from the Baltic Sea, as well as among mothers who had grown up in a fishing village. Moreover, maternal 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153, which was showed to be a feasible biomarker for exposure to PCB) concentrations in plasma drawn in 1995 and the estimated concentrations during the year of childbirth showed effects on the risk for having an infant with low birthweight (odds ratios around 2, with lower 95% confidence limits between 0.8 and 1.0). Employing alternative plausible kinetic models, an increased risk for low birthweight was observed at a CB-153 concentration in plasma during year of childbirth around 300-400 ng/g lipid.