Honey bee exposure scenarios to selected residues through contaminated beeswax.

Twenty-two pesticides and veterinary drugs of which residues were detected in beeswax in Europe were selected according to different criteria. The risk to honey bee health posed by the presence of these residues in wax was assessed based on three exposure scenarios. The first one corresponds to the exposure of larvae following their close contact with wax constituting the cells in which they develop. The second one corresponds to the exposure of larvae following consumption of the larval food that was contaminated from contact with contaminated wax. The third one corresponds to the exposure of adult honey bees following wax chewing when building cells and based on a theoretical worst-case scenario (= intake of contaminants from wax). Following these three scenarios, maximum concentrations which should not be exceeded in beeswax in order to protect honey bee health were calculated for each selected substance. Based on these values, provisional action limits were proposed. Beeswax exceeding these limits should not be put on the market.

Pesticide and veterinary drug residues in Belgian beeswax: Occurrence, toxicity, and risk to honey bees.

Pesticide and veterinary drug residues are one of the stress factors affecting bee health and mortality. To investigate the occurrence, the concentration and the toxicity risk to bees of pesticide residues in four different types of beeswax (brood comb wax, recycled comb wax, honey comb wax, and cappings wax), 182 samples were collected from apiaries located all over the Belgian territories, during spring 2016 and analysed by LC-MS/MS and GC-MS/MS for the presence of 294 chemical residues. The toxicity risk to bees expressed as the Hazard Quotient (HQ) was calculated for each wax sample, according to two scenarios with different tau-fluvalinate LD50 values. Residues showing the highest prevalence were correlated to bee mortality in a multivariate logistic regression model and a risk-based model was used to predict colony bee mortality. Altogether, 54 different pesticide and veterinary drug residues were found in the four types of beeswax. The residues with a higher likelihood to be retained in beeswax are applied in-hive or with a high lipophilic nature. The multivariate logistic regression model showed a statistically significant influence of chlorfenvinphos on bee mortality. All our results indicated that cappings wax was substantially less contaminated. This national survey on beeswax contamination provides guidelines on the re-use of beeswax by beekeepers and shows the necessity to introduce maximum residue levels for global trade in beeswax. An online tool was developed to enable beekeepers and wax traders to estimate the risk to honey bee health associated with contaminated wax.

Honeybee and consumer's exposure and risk characterisation to glyphosate-based herbicide (GBH) and its degradation product (AMPA): Residues in beebread, wax, and honey.

In order to assess bee and human exposure to residues of glyphosate-based herbicide (GBH) and its main degradation products aminomethylphosphonic acid (AMPA) and to characterise the risk posed by these substances, we analysed 3 different bee matrices; beebread (N = 81), wax (N = 100) and 10-paired samples of wax/honey collected in 2016/2017 from 379 Belgian apiaries. A high-performance liquid chromatography-electrospray ionisation tandem mass spectrometry (HPLC-ESI-MS-MS) was used as analytical method. Limit of quantification and detection (LOQ and LOD) for GBH residues and AMPA in the 3 matrices was respectively of 10 ng g-1 and 1 ng g-1. In beebread, 81.5% of the samples showed a residue concentration > LOQ and 9.9% of the samples a residue concentration < LOQ (detection without quantification); no significant difference in detection rate was found between the north and the south of the country. Glyphosate was detected in beeswax less frequently than in beebread (i.e. 26% >LOQ versus 81.5% >LOQ). The maximum GBH residues and AMPA concentration found in beebread (respectively 700 ng g-1 and 250 ng g-1) led to sub-lethal exposure to bees. The Hazard Quotient (HQ) for beebread and beeswax (7 and 3.2, respectively) were far below the "safety" oral and contact thresholds for bees. For human health, the highest exposure to GBH residues in pollen corresponded to 0.312% and 0.187% of the ADI and of the ARfD respectively and, to 0.002% and to 0.001% for beeswax. No transfer of glyphosate from wax to honey was detected. Considering our results and the available regulatory data on the glyphosate molecule considered solely, not including the adjuvants in GBH formulation, the consumption of these three contaminated matrices would not be a food safety issue. Nonetheless, caution should be taken in the interpretation of the results as new studies indicate possible glyphosate/GBH residues toxicity below regulatory limits and at chronic sub-lethal doses.

Belgian case study on flumethrin residues in beeswax: Possible impact on honeybee and prediction of the maximum daily intake for consumers.

To assess the health risk posed by flumethrin residues in beeswax to honeybees and honey consumers, 124 wax samples randomly distributed in Belgium were analysed for flumethrin residues using liquid chromatography/tandem mass spectrometry. The risk posed by flumethrin residues in beeswax to honeybee health was assessed through the calculation of a non-pondered and a pondered Hazard Quotient by the prevalence rate of flumethrin considering an oral or topical exposure. No statistical difference was found when comparing both the average flumethrin residues concentrations and contact and oral pondered hazard quotients between apiaries with lower and equal or higher than 10% of colony loss. Flumethrin residues estimated daily intake by Belgian consumers through honey and wax ingestion was estimated via a deterministic (worst-case scenario) and a probabilistic approach. The probabilistic approach was not possible for beeswax consumption due to the lack of individual consumption data. The highest estimated exposure was <0.1% of the theoretical maximum daily intake for both approaches, meaning no risk for human health.

Residues in Beeswax: A Health Risk for the Consumer of Honey and Beeswax?

A scenario analysis in regard to the risk of chronic exposure of consumers to residues through the consumption of contaminated honey and beeswax was conducted. Twenty-two plant protection products and veterinary substances of which residues have already been detected in beeswax in Europe were selected. The potential chronic exposure was assessed by applying a worst-case scenario based on the addition of a "maximum" daily intake through the consumption of honey and beeswax to the theoretical maximum daily intake through other foodstuffs. For each residue, the total exposure was finally compared to the acceptable daily intake. It is concluded that the food consumption of honey and beeswax contaminated with these residues considered separately does not compromise the consumer's health, provided proposed action limits are met. In regard to residues of flumethrin in honey and in beeswax, "zero tolerance" should be applied.