Honey and bee pollen as bioindicators of mercury and thallium exposure in Kosovo

Honey and pollen are nutritious natural foods, but their contamination risk has increased, potentially turning them into health hazards. In Kosovo, data on mercury (Hg) and thallium (Tl) levels in honey and pollen are limited, especially across the entire territory. This study used a dense sampling grid and Inductively Coupled Plasma–Mass Spectrometry (ICP-MS) to assess Hg and Tl concentrations in honey and pollen samples from across Kosovo. Results revealed significant spatial variation. Median concentrations in honey were 0.014 mg/kg for Hg and 0.001 mg/kg for Tl; in pollen, 0.02 mg/kg Hg and 0.0013 mg/kg Tl. Maximum values reached 0.025 mg/kg Hg and 0.05 mg/kg Tl in honey, and 0.1 mg/kg Hg and 0.07 mg/kg Tl in pollen. Interestingly, the highest levels did not always align with known pollution sources, as confirmed by principal component analysis (PCA). Risk assessment based on a daily intake of 20g showed that the Hazard Index (HI) exceeded 1 (unsafe threshold) in several samples: honey from Zhegër-Gjilan, Janjevë-Lipjan, and Artanë (Novobërdë); and pollen from Voksh-Deçan and Artanë (Novobërdë). These findings highlight potential health risks and the need for regular monitoring of these widely consumed natural products.