Innovative isotopic method to evaluate bioaccumulation of As and MTEs in Vitis vinifera

Strontium leaching from municipal waste subjected to incineration

The aim of the study was to determine the content and leachability of Sr in ashes obtained through combusting municipal waste in household furnaces. The waste had been collected as a mixed stream and as separate fractions (i.e. furniture, sponges, waste paper, PCV packaging, plastic-coated paper cartons, imitation leather, rubber, textiles and polystyrene). Using single-step chemical extractions, (HCl + HNO3, H2O, 0.01 M CaCl2, 0.1 M CH3COOH), we determined the total content of Sr (TC) and proportions of the following fractions: water-leachable, phytoavailable and easily soluble and bound to carbonates. We also analyzed the effect of reducing pH in the extraction solutions on St leachability from the study material. The study showed that Sr concentration in ash generated from the combustion of conventional fuels, alternative fuels and municipal waste ranged from 114 to 1006 mg/kg. The largest amounts of Sr were found in ash generated from the combustion of alternative fuels (coal pellets 488-1006 mg/kg), conventional fuels (hard coal 430-670 mg/kg) and mixed waste (237-825 mg/kg). The most mobile fraction of Sr (water-leachable) comprised from 1.3% to nearly 91% TC; the phytoavailable fraction and the ion-exchange and carbonate-bound fraction comprised 3-92% TC and 9-72% TC, respectively. We also found that the greatest pH reductions do not always entail the greatest amounts of extracted Sr. A much more significant factor in this respect is the mineral and chemical composition of primary materials, which can buffer changes in pH. The Risk Assessment Code (RAC) values pointed to a varied environmental risk and the highest RAC values (> 70) were found for coal pellets, wood pellets, straw, rubber and plastic containers for mixed oils.

Environmental exposure to metallic pollution impairs honey bee brain development and cognition

Laboratory studies show detrimental effects of metallic pollutants on invertebrate behaviour and cognition, even at low levels. Here we report a field study on Western honey bees exposed to metal and metalloid pollution through dusts, food and water at a historic mining site. We analysed more than 1000 bees from five apiaries along a gradient of contamination within 11 km of a former gold mine in Southern France. Bees collected close to the mine exhibited olfactory learning performances lower by 36% and heads smaller by 4%. Three-dimensional scans of bee brains showed that the olfactory centres of insects sampled close to the mine were also 4% smaller, indicating neurodevelopmental issues. Our study raises serious concerns about the health of honey bee populations in areas polluted with potentially harmful elements, particularly with arsenic, and illustrates how standard cognitive tests can be used for risk assessment.

Masking Phosphate with Rare-Earth Elements Enables Selective Detection of Arsenate by Dipycolylamine-ZnII Chemosensor

Functional reassessment of the phosphate-specific chemosensors revealed their potential as arsenate detectors. A series of dipicolylamine (Dpa)-ZnII chemosensors were screened, among which acridine Dpa-ZnII chemosensor showed the highest capability in sensing arsenate. The presence of excess ZnII improved sensitivity and strengthened the binding between acridine Dpa-ZnII complex to arsenate as well as phosphate. However, due to their response to phosphate, these sensors are not suited for arsenate detection when phosphate is also present. This study demonstrated for the first time that rare-earth elements could effectively mask phosphate, allowing the specific fluorescence detection of arsenate in phosphate-arsenate coexisting systems. In addition, detection of arsenate contamination in the real river water samples and soil samples was performed to prove its practical use. This sensor was further employed for the visualization of arsenate and phosphate uptake in vegetables and flowering plants for the first time, as well as in the evaluation of a potent inhibitor of arsenate/phosphate uptake.