Secondary sex ratio in relation to exposures to polychlorinated biphenyls, dichlorodiphenyl dichloroethylene and methylmercury

Abstract

This study was undertaken to assess the potential impact of maternal exposures to polychlorinated biphenyl (PCB), dichlorodiphenyl dichloroethylene (DDE) and methylmercury on the secondary sex ratios (the ratio of male to female live births) over a span of 23 years. The study includes prospective data from three Faroese birth cohorts, with a total of 2,152 healthy mother–child dyads recruited between 1986 and 2009. The Faroe Islands is a subarctic fishing community, where pilot whale meat and blubber are part of the traditional marine diet. Exposures were measured in maternal hair, serum or umbilical cord blood. Confounder adjusted logistic regression models were used to assess the associations between maternal exposures and the secondary sex ratio. A doubling in ΣPCB, p,p’-DDE and mercury concentrations were associated with increased odds by 8% (95% CI = 0–16%), 7% (95% CI = 0–14%) and 9% (95% CI = 2–17%), respectively, of giving birth to a boy. In conclusion, maternal exposure to ΣPCB, DDE and methylmercury was associated with a slightly increased secondary sex ratio. The impact of paternal exposures could not be taken into account and deserves attention.

Paternal occupational exposure to chemicals and secondary sex ratio: results from the Japan Environment and Children's Study

“…Furthermore, even when the reference group was fathers exposed to none of the 23 substances, the proportion of boys was smaller in fathers regularly exposed to insecticides (appendix pp 10-12). In a multivariable analysis, the association with exposure to insecticides was similar (appendix pp [13][14][15].…”

“…Exposures to mercury 13 and radiation 29 have been reported to affect the proportion of boys and semen quality. At present, these substances are regulated in Japan and the exposure levels among workers are minimal.…”

“…However, the GHS does not consider the influence on the secondary sex ratio (SSR); ie, the ratio of male to female offspring. 9 Previous studies [10][11][12][13][14][15][16][17] have shown that some chemical substances influence the SSR. Girls were reportedly more likely to be born to fathers with increased serum dioxin concentrations.…”

“…Girls were reportedly more likely to be born to fathers with increased serum dioxin concentrations. 10,11 Exposures to polychlorinated biphenyls [12][13][14] and mercury 13 have also been shown to affect the SSR. Gupta and colleagues 15 reported that parents who worked in anaesthesiology and used inhalational anaesthetic agents in their workplace were more likely to have female offspring.…”