Low proportion of male births and low birth weight of sons of flour mill worker fathers

Abstract

The Washington State Department of Health has collected and coded parental occupation information on birth certificates since 1980. We used these data to search for possible effects of parental occupational exposures on birth outcomes. We tabulated sex ratio, birth weight, and proportions of multiple births, still births, and malformations by mothers' and fathers' occupations. There were 59 births (22 boys and 37 girls) where the father's occupation was specified as flour mill worker. The sex ratio of 0.373 (95% confidence interval [CI]: 0.261-0.500) was lower than the mean sex ratio of 0.512. The mean birth weight for flour mill workers' boy babies was 3,180 g (95% CI: 2,971-3,389), compared to an overall mean of 3,511 g for all boy babies. The mean birth weight of flour mill workers' girl babies was 3,602 (95% CI: 3,380-3,824), compared to an overall mean of 3,389 for all girl babies. The low prevalence of male infants born to fathers of flour mill workers in Washington State suggests that fumigants that they are exposed to are causing testicular dysfunction. The very low birth weight seen in the male infants of flour mill fathers is unprecedented and may be another genotoxic endpoint.