Offspring sex ratios of people exposed to dioxin and dioxin-like compounds

• offspring sex ratio
• dioxins

Yoshimura et al¹ reported that although exposure to dioxin (TCDD) (after the explosion at Seveso) was associated with a subsequent significant and substantial drop in offspring sex ratio (proportion male),² there was no obvious similarity in the offspring sex ratios after accidental ingestion of polychlorinated biphenyls (PCBs) and dibenzofurans (PCDFs) in Yusho, Japan,¹ and Yucheng, Taiwan.³ PCBs and PCDFs are toxicologically similar to (although less potent than) TCDD. The authors wrote that in Taiwan, despite exposure to chemicals similar to TCDD sufficient to produce obvious clinical disease, the sex ratio was not altered. They inferred that sex ratio is unlikely to be a sensitive indicator of exposures to chemicals such as PCBs, PCDFs, and dioxins. The argument is not decisive and Yoshimura et al¹ called for further research.

I had predicted⁴ Mocarelli's low paternal offspring sex ratio on the …