Contaminant dynamics in honey bees and hive products of apiaries from environmentally contrasting Argentinean regions

Abstract

Argentina is a leading honey producer and honey bees are also critical for pollination services and wild plants. Atthe same time, it is a major crop producer with significant use of insecticides, posing risks to bees. Therefore, thepresence of the highly toxic insecticide chlorpyrifos, and forbidden contaminants (organochlorine pesticides(OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs)) was investigated inhoney bee, beebread, wax and honey samples in apiaries from three contrasting regions of Argentina. Chlorpyrifoswas detected in all samples with higher levels during period 1 (spring) in contrast to period 2 (fall),agreeing with its season-wise use in different crops, reaching 3.05 ng/g in honey bees. A subsequent first-tierpesticide hazard analysis revealed that it was relevant to honey bee health, mainly due to the high concentrationsfound in wax samples from two sites, reaching 132.4 ng/g. In addition, wax was found to be the mostcontaminated matrix with a prevalence of OCPs (ΣOCPs 58.23–172.99 ng/g). Beebread samples showed thehighest concentrations and diversity of pesticide residues during period 1 (higher temperatures). A predominanceof the endosulfan group was registered in most samples, consistent with its intensive past use, especially inCentral Patagonia before its prohibition. Among the industrial compounds, lighter PCB congeners dominated,suggesting the importance of atmospheric transport. The spatio-temporal distribution of pesticides shows acongruence with the environmental characteristics of the areas where the fields are located (i.e., land use, type ofproductive activities and climatic conditions). Sustained monitoring of different pollutants in beekeepingmatrices is recommended to characterize chemical risks, assess the health status of honey bee hives and thepollution levels of different agroecosystems. This knowledge will set a precedent for South America and behelpful for actions focused on the conservation of pollination services, apiculture and ecosystems in Argentina.