Occurrence of pesticide residues in Brazilian Apis mellifera beeswax by gas chromatography-tandem mass spectrometry and pesticide hazard evaluation

Beeswax is known for its ability to retain pesticides for a long time, and the progressive accumulation of pesticides in wax has had adverse health effects on bees. This study aimed to determine the residue levels of pesticides in Brazilian beeswax and assess the health risk to bees due to exposure to these pesticides using hazard quotient calculation. Nineteen samples collected from different regions from São Paulo State, Brazil, were analyzed for the presence of 160 compounds, including 17 metabolites. A modified QuEChERS approach was used for sample preparation followed by gas chromatography-tandem mass spectrometry (GC/MS-MS) analysis. The method validation parameters followed the requirements established by the EU SANTE 11813/2017 guideline. In 90% of the samples, one or more pesticide residues were found; among them, the most frequently found pesticides were chlorpyrifos and permethrin, which were present in 74% and 79% of the samples and had maximum levels of 18.6 ng g−1 and 72 ng g−1, respectively. The hazard quotient estimate was determined considering the acute lethal dose (LD50) per contact for each pesticide residue in beeswaxes. Thus, it has been shown that exposure to chlorpyrifos and permethrin represents an elevated risk for the health of bees.