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.

Macro and Trace Elements in Hemp (Cannabis sativa L.) Cultivated in Greece: Risk Assessment of Toxic Elements.

The accumulation of hazardous contaminants in Cannabis sativa L. raises warning signs regarding possible adverse effects on human health due to the consumption of herbal medicines and/or other herbal edible products made from cannabis. Thus, there is an urge to investigate the levels of hazardous contaminants, such as heavy metals, in cannabis plant. In the present study, 29 macro and trace elements, including both beneficial and toxic elements (heavy metals and metalloids), were investigated in 90 samples of Cannabis sativa L. collected from Greece. According to the results, the detected concentrations of macro elements in the leaves/flowers of cannabis ranged between 28 and 138,378 ppm, and of trace elements between 0.002 and 1352.904 ppm. Although the concentrations of elements varied among the samples, their accumulation pattern was found to be similar, with the contribution of toxic elements to the total concentration of trace elements being below 1%. The detected levels of the most toxic elements were below the prescribed limits established by the WHO, while the calculated THQ and CR values showed no risk (non-carcinogenic and carcinogenic) for the population exposed to the current cannabis samples. Positive correlation between the concentration of elements and cannabis geographical origin and variety was observed. Cannabis leaves/flowers were more contaminated with trace and macro elements than seeds.

Pesticides residues and metabolites in honeybees: A Greek overview exploring Varroa and Nosema potential synergies.

The aim of this study was to investigate reported cases of honeybee mortality incidents and the potential association to pesticide exposure and to their metabolites. The same honeybee samples were also assessed for Varroa mites, and Nosema microsporidia provoked infections to provide an integrated picture of all observable stressors that may impact bees' survival. Thus, honeybee samples from different areas of Greece (2014-2018) were analyzed for the presence of pesticide residues and metabolites. In this context, an existing LC-ESI-QqQ-MS multiresidue method of analytes of different chemical classes such as neonicotinoids, organophosphates, triazoles, carbamates, was enriched with additional active substances, developed and validated. A complementary GC-EI-QqQ-MS method was also exploited for the same scope covering pyrethroid compounds. Both methods monitored more than 150 active substances and metabolites and presented acceptable linearity over the ranges assayed. The calculated recoveries ranged from 65 to 120% for the three concentration levels, while the precision (RSD%) values ranged between 4 and 15%. Therefore, this approach proved sufficient to act as a monitoring tool for the determination of pesticide residues in cases of suspected honeybee poisoning incidents. From the analysis of 320 samples, the presence of 70 active substances and metabolites was confirmed with concentrations varying from 1.4 ng/g to 166 µg/g. Predominant detections were the acaricide coumaphos, several neonicotinoids exemplified by clothianidin, organophosporous compounds dimethoate and chlorpyrifos, and some pyrethroids. Metabolites of imidacloprid, chlorpyrifos, coumaphos, acetamiprid, fenthion and amitraz were also identified. Concerning Nosema and Varroa they were identified in 27 and 22% of samples examined, respectively, verifying their prevalence and coexistence with pesticides and their metabolites in honeybees.