Intergenerational and Biochemical Responses of the Western Honey Bee ( <i>Apis mellifera</i> ) to Sublethal Perfluorooctanesulfonate (PFOS) Exposures

Bees are threatened by multiple stressors, including environmental contaminants such as perfluorooctanesulfonate (PFOS). In this exposure-effect study, small whole colonies of the western honey bee ( A. mellifera ) (2500 individual bees) were exposed to sublethal PFOS concentrations (5 to 20 μg L –1 in sugar syrup) over a 25-day period using a purpose-built cage system. The PFOS was transferred to honey, accumulated in bee tissue, and was detected in feces at all exposure concentrations. At the sublethal exposures, adult bee colonies in all treatments appeared healthy, colonies were sustained, brood was produced, and resources were stored, but adverse life stage development and intergenerational effects were evident even at the lowest exposure concentration of 5 μg L –1 . Analysis of bee heads indicated no oxidative damage based on protein carbonyl and malondialdehyde (MDA) biomarkers, but significant differential expression of some proteins important for bee health was observed in the 10 μg L –1 (proteins n = 2) and 20 μg L –1 (proteins n = 15) exposure treatments. This study provides the first confirmation that sublethal PFOS exposure may adversely influence the long-term viability of honey bee colonies and that PFOS will accumulate in exposed bees and transfer to honey, presenting a potential threat to food security and human health.