A comprehensive re-analysis of pesticide dermal toxicity data in birds and comparison with the rat

Dermal exposure is not considered in the routine assessment of pesticide risk to birds but is known to be important. There is no routine testing of pesticide dermal toxicity in birds necessitating that we make better use of information currently collected on mammalian species. This paper assembles and analyses all known avian dermal toxicity data for pesticides. The analysis relies on deriving a Dermal Toxicity Index (DTI) or a ratio of oral to dermal toxicity for each test result. In this paper, I show that: (1) DTI values are chemical specific and apply to any bird; (2) that the site of testing appears to matter more than the exact method of testing; (3) that the avian DTI does indeed track the rat DTI very well for those compounds that do not need metabolic activation to express their toxicity. Mammalian skin penetration data can be used to infer avian risk.

► Different bird species show similar relative dermal to oral toxicity. ► The site of testing (foot vs. underwing area) is important. ► Mammalian skin penetration data can be used to infer avian risk. ► This reduces the need for testing in birds.