Exposure and hormone associations of pesticides and flame retardants among primates in Uganda

Primates exhibit diverse diets and related dietary adaptations which are expected to play a role in the exposure and toxicity of persistent organic pollutants. In the habitat of four primate species in Kibale National Park, Uganda, we quantified brominated flame retardants and organochlorine pesticides (OCPs) in air samples (n = 9), dietary plant samples (n = 32), and fecal samples from adult males and juveniles (n = 53). We also measured the fecal hormone metabolites cortisol and estradiol in juveniles (n = 38). In dietary plant samples, Σ32 brominated flame retardants (BFRs) ranged from 12-22 ng/g and Σ21OCPs ranged from 61-334 ng/g across primate species. In primate fecal samples, median Σ32BFRs ranged from 6-158 ng/g and Σ21OCPs s ranged from 39-261 ng/g. In juveniles, higher Σ32BFRs were associated with decreased cortisol in baboons and chimpanzees as well as total polybrominated diphenyl ethers and dechlorane plus in baboons and chimpanzees, respectively. In red-tailed monkeys, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate and Σ21OCPs were positively associated with cortisol. No significant associations between targeted pollutants and hormones were found in red colobus nor between estradiol and any chemical for any species. Our results indicate that despite their phylogenetic relatedness, the exposure, movement, and potential endocrine activity of pollutants varies across primate species. We suggest future studies exploring the mechanisms underlying phytochemical detoxification may help further elucidate connections between dietary niche and pollutant sensitivity in primates and at a broad taxonomic scale.