Occurrence and human health risk assessment of mineral elements and pesticides residues in bee pollen.

Bee pollen contains a diversity of bioactive components. Nevertheless, since pollen is retrieved from a variety of plants, including the cultivated ones which are subjected to agrochemical treatments, its contamination is unavoidable. In this context, 45 samples of pollen were analysed with optimized analytical methods for trace and macro elements (ICP-MS), pesticides and metabolites residues (LC & GC-MS/MS) content. According to the results, potassium and iron were the most abundant in terms of concentration and frequency of detection, while the contribution of the most hazardous elements, such as lead, arsenic, cadmium and mercury, to the total concentration of trace elements was lower than 1%. For pesticides, coumaphos was the most frequently detected in the examined samples (22%), followed by propargite, azoxystrobin, dimethoate and cypermethrin. Non-carcinogenic health risk assessment demonstrated in the majority of cases negligible risk for adults and children. On the contrary, carcinogenic risk assessment considering a worst case scenario disclosed nickel and in less extent chromium and arsenic, as risk drivers, exhibiting in several samples carcinogenic risk values for adults above the safety threshold. Yet, regarding that both adults and children unlikely will daily consume such pollen quantities, especially on a long-term basis, an overestimation of risk should be appraised.

A Pesticide Residues Insight on Honeybees, Bumblebees and Olive Oil after Pesticidal Applications against the Olive Fruit Fly Bactrocera oleae (Diptera: Tephritidae).

In 2017 and 2018, a field survey was initiated on Greek olive orchards to investigate the attractiveness of bait spray applications and the impact of cover and bait sprays applied against the olive fruit fly Bactrocera oleae (Diptera: Tephritidae), on the honeybee, Apis mellifera L. and bumblebees Bombus terrestris, by investigating the pesticides' residual prevalence. Bee colonies were evenly distributed in three sites located on coastal areas of Western Crete and visited almost weekly between July and October. Samples collected, were analyzed using existing or developed-optimized liquid and gas chromatographic methods. In bee samples, concentrations varied from 0.0013 to 2.3 mg/kg for dimethoate, from 0.0013-0.059 mg/kg for its metabolite omethoate, and from 0.0035 to 0.63 mg/kg regarding the pyrethroids, ß-cyfluthrin and λ-cyhalothrin. In one bee sample dimethoate concentration exceeded both acute oral and contact median lethal dose (LD50). Residue findings in bees, along with verified olive oil residues corroborated that those insecticides had been applied in the olive orchards and transferred to bees. The possibility of non-target effects of the bait sprays to the bees, as well as the impact of the contaminated olive to the bees are discussed.