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

Abstract

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 use of the Hazard Quotient approach to assess the potential risk to honeybees (Apis mellifera) posed by pesticide residues detected in bee‐relevant matrices is not appropriate

“…links to adverse effects at individual bee‐level or at the colony‐level. The use of the HQ threshold in assessing the risk posed by residues in wax 7,11,13,14,19,20 (or for solitary bees in soil 37 ), where contact transfer factors for compounds are required, 38,39 and in dead bees, 11,14,18,21 without relating to residues following exposure at the LD 50 are not defined, 40 are even more obscure. To compound matters, in assessing the significance of residues in pollen and nectar, the contact LD 50 has also been used, 2,9,13,17 or even an ‘average’ of acute toxicity values, 11,12,18 even though the acute oral LD 50 is clearly more relevant for this exposure route.…”

Honey bee exposure scenarios to selected residues through contaminated beeswax

“…Regarding scenario 3 (adult worker honey bees: wax chewing), we have considered that an adult worker honey bee chews 38.3 mg wax per day (El Agrebi et al, 2019) and we have assumed, as a worst case scenario, that wax chewing leads to the intake of the total amount of contaminants contained in the contaminated beeswax. Indeed, worker honey bees use their mandibles to manipulate the wax in order to shape the hexagonal cells during the comb-building sequence (Bauer and Bienefeld, 2013;Snodgrass, 1910).…”

“…Wilmart et al (2016) listed pesticides and veterinary drugs of which residues were detected in beeswax in Europe. This list was then completed with results of more recent studies (Herrera López et al, 2016;Calatayud-Vernich et al, 2017;Daniele et al, 2018;Perugini et al, 2018;Lozano et al, 2019;Shimshoni et al, 2019;El Agrebi et al, 2019, 2020a, 2020b. Table 1 summarizes, for each of these chemical substances, (contact/oral) acute median lethal doses (LD 50 ) to honey bees (adults and/or larvae) and octanol/water partition coefficients at pH 7 and 20°C (=Log K ow (with 'ow' meaning 'octanol/water') = Log P).…”

Risk assessment of beeswax adulterated with paraffin and/or stearin/stearic acid when used in apiculture and as food (honeycomb)

“…Several good beekeeping management practice guidelines were proposed (e.g. Bee Research Institute, 2009; KonVIB/FAB BBF, 2009;ITSAP, 2018;FAO, 2019;El Agrebi et al, 2019, 2020 with the following recommendations:…”