Robert F. Kennedy Jr. on chemicals: what the evidence says · JRE #1999

What the evidence says 01 / RECORD

The frog study Kennedy describes is real: Hayes et al. (2010, Proceedings of the National Academy of Sciences) found that 10% of genetically male African clawed frogs (Xenopus laevis) exposed to 2.5 parts per billion (ppb) atrazine throughout larval development became functional females that mated with unexposed males and produced viable, fertile eggs; exposed males also showed reduced testosterone and fertility. That exposure concentration is close to, though below, the U.S. Environmental Protection Agency's legal drinking-water limit for atrazine of 0.003 mg/L (3 ppb). However, the EPA's human health risk assessment, which reviewed dietary and drinking-water exposure, found no risks of concern for the general population, including children, from atrazine at regulated levels; the agency identified elevated risk only for children who crawl or play on recently treated lawns and for workers who mix or apply the herbicide. Extrapolating amphibian endocrine-disruption findings directly to routine childhood exposure risk in humans is not supported by current regulatory risk assessments, even though the underlying frog research and the 10% figure are accurately stated. Amphibian ecological risk from atrazine remains an active, separately tracked regulatory concern distinct from the human dietary risk assessment.