Beata Hanus-Lorenz

This study examined the toxicological, and bioaccumulative effects of dietary lead (Pb) on Tenebrio molitor larvae, increasingly considered for human and animal consumption within sustainable food and feed production systems. Larvae were exposed for 21 days to an oat-based diet contaminated with lead salts (125–2000 mg Pb/kg). Body mass, and Pb accumulation in the intestine, internal tissues, and cuticle were analyzed. Pb concentrations in larval compartments increased with increasing nominal Pb levels in feed, with concentrations in internal tissues and cuticle reaching 5–6 times higher than in the control. Estimated bioaccumulation factors (BAF) were below 1 in all cases, indicating no biomagnification. Despite high exposure levels, no significant effects on larval survival or biomass gain were observed. These findings indicate that growth-related parameters are not sensitive indicators of Pb exposure. At the same time, substantial Pb accumulation occurred, particularly in the gut and cuticle, highlighting a risk of “hidden” contamination in insect-based production systems. The results emphasize the need for substrate monitoring and the inclusion of sensitive chemical indicators in food safety risk assessment.

Mercury contamination from human activities is a severe environmental problem. The low cost of rhizofiltration of heavy metal-contaminated environments is causing an increasing interest in these technologies. The present study demonstrates the effectiveness of mercury removal from water by phytoremediation using S. natans. Plants cultured and collected from the environment were used. The study used Hoagland’s liquid medium contaminated with mercury: 0.15, 0.20, and 0.30. The bioconcentration factor obtained was 275–780. The relative growth rate was up to 0.12 g/gd and was much better for cultured plants than those collected from the environment. The removal rate of toxic metal was up to 94%. Total protein increased for cultures plants by up to 84%, while it decreased by up to 30% for those taken from the environment. Total chlorophyll for cultured plants decreased by up to 54%, which could be due to the toxic effect of the metal.

This study assessed the possible impact of a former ferrochromium plant in Siechnice (Lower Silesia, Poland) on water reservoirs and living organisms. The metal concentrations (Zn, Cu, Pb, Fe, and Cr) in the sediments were determined, along with ecotoxicological studies that were conducted on both the sediments and the surface water of three water bodies that border the slag heap. The samples of the sediments and water were taken at different distances from the landfill area. The studies also covered a human health risk assessment. The highest concentrations of all the studied elements were observed in the sediments taken from the water reservoir closest to the landfill. In the case of the sediments, a 30% death rate for Heterocypris incongruens (Ostracodtoxkit F) was recorded at the same site. Additionally, at this site, the ecotoxicological studies on the surface water revealed the highest mortality for Daphnia magna (Daphtoxkit F magna) and the lowest values of LC50 for algae (Algaltoxkit). The health risk assessment of the sediments was estimated by calculating the noncarcinogenic health risk using the hazard quotient (HQ) and hazard index (HI), and the carcinogenic risk was calculated using the excessive risk of cancer development (ECR) measurement. The hazard index (HIing) for Cr exceeded 1 for children, which suggests that possible adverse health effects might occur for humans. The ECR values calculated for Cr and Pb were above the range limit of 10⁻⁶. The value for Cr was the highest for the sediments from the closest water reservoir to the landfill for both children and adults. Studies prove that the water reservoirs located near landfills pose potential ecological risks, and the risk is the highest where the distance is the shortest from the slag heap. In prospective human health risk assessments, the sediments from the closest water body pose a potential carcinogenic health risk to humans, especially to fish consumers, i.e., the residents of neighboring areas who might experience severe health problems from the intake of Cr and Pb through fish consumption. Significant steps should be taken to reduce Cr concentrations in the sediments to minimize the risk of human health adverse effects.

In our studies biodegradation of four variants of polystyrene was performed. We tested: raw material (PS), processed polystyrene (PSr), building insulation material (EPS) and food packaging boxes (PSp). Materials were characterized by means melt flow ratio (MFR), shore hardness and gloss. The biochemical assessment of macromolecules (proteins, lipids and sugars) in the mealworms organisms fed with tested forms of polystyrene allowed us to set how efficient and beneficial the biodegradation of types of polystyrene is. We also evaluated the variability of bacterial community in larval guts by the use of denaturing gradient gel electrophoresis (DGGE) on the bacterial DNA of 16S rRNA genes amplified in polymerase chain reaction (PCR). The results suggest that EPS and PSp polystyrene are the most digestible for T. molitor larvae. The metabolic degradation of polystyrene is probably strictly connected with the changes in biodiversity of gut bacteria.