Comments on "Children's health, susceptibility, and regulatory approaches to reducing risk from chemical carcinogens".

In their recent commentary, “Children’s Health, Susceptibility, and Regulatory Approaches to Reducing Risk from Chemical Carcinogens,” Charnley and Putzrath (1) noted the seminal importance of the National Academy of Sciences (NAS) report Pesticides in the Diets of Infants and Children (2) in having catalyzed current concern about risks to children’s health from environmental chemicals. As members of the NAS committee who wrote that report, we thank Charnley and Putzrath (1) for their acknowledgement. We are concerned, however, that their suggestion that child-protective safety factors be subjected to cost–benefit analysis would undercut a major recommendation of the NAS committee as well as a central provision of the Food Quality Protection Act (FQPA) (3). Specifically, the FQPA, motivated in part by our committee’s report, calls for the application in risk assessment of an additional margin of safety to protect children’s health in two circumstances: a) in the absence of data demonstrating assurance of safety, and b) in the presence of data showing children to be at greater risk to a particular chemical than adults. Child-protective safety factors would not be a necessary default in risk assessment if good data were available on children’s exposure and sensitivity to each of the many chemicals that they encounter. That, however, is not the case. Quantitative data on the exposures of fetuses, infants, and children to most chemicals are limited, as are data on the toxicity of most chemicals. A recent analysis by the U.S. Environmental Protection Agency (4) indicates that even minimal toxicologic data exist for only 43% of the 15,000 chemicals produced each year in quantities of over 10,000 pounds; data on developmental toxicity, the sort of data that would permit direct comparison of child versus adult sensitivities, are available for only about 20% of these high-production volume chemicals. To address these large gaps in data, the NAS Committee on Pesticides in the Diets of Infants and Children (2) recommended that “there should be a presumption of greater toxicity to infants and children.” The committee suggested that