Median lethal concentration of formaldehyde and its genotoxic potential in bullfrog tadpoles (Lithobates catesbeianus)

In order to avoid that contaminated frog farms animals escaping in the environment and become potential vector of emergent diseases, studies with disinfection protocol are strictly necessary. The formaldehyde is one of the compounds tested in fungal disinfection protocols and also used in aquaculture. This study aimed to determine the median lethal concentration (LC_50–96h) of formaldehyde in bullfrog tadpoles and to evaluate the possible genotoxic effects in acute exposition. Accordingly, the animals were exposed to formaldehyde in the concentrations of 6, 9, 12, 15, and 18 mg L^?1, and after 96 h blood samples were drawn for the micronucleus (MN) test. The LC_50–96h was 10.53 mg L^?1, and the MN frequency increased in proportion to the formaldehyde concentrations, with an estimated frequency in the negative control being 1.35 MN/individual. We concluded that formaldehyde is genotoxic to tadpoles of bullfrogs in the tested concentrations, and the choice of this chemical should be contemplated before its use in animals in captivity.     

Uptake,translocation, and control of trumpet flower (Tecoma stans) with aminocyclopyrachlor

To gain a better understanding of the physiology of the herbicide aminocyclopyrachlor in young plants of trumpet flower, the uptake and translocation were evaluated after the application of herbicide. This was determined by treating individual leaves with formulated herbicides plus ¹⁴C-aminocyclopyrachlor after the application of the formulated herbicide. This experiment used a randomized experimental design with three replications. In addition, field studies were conducted to assess the effectiveness of foliar applications of aminocyclopyrachlor in association with metsulfuton-methyl. The plant absorbed 20% of the herbicide applied. The translocation percentage did not surpass 5% of the total amount applied. Only 1% of the herbicide applied was translocated to the roots. Rate of 40 + 13 g a.i. 100 L^?1 of aminocyclopyrachlor+metsulfuron-methyl was effective to control T. stans.     

Relevant parameters for assessing the environmental impact of some pyridinium, ammonium and pyrrolidinium based ionic liquids

Several physico-chemical properties relevant to determine the environmental impact of ionic liquids - aqueous solubility, octanol/water partition coefficient, chromatographically derived lipophilicity and infinite dilution diffusion coefficients in water - were measured in ionic liquids based on pyridinium, ammonium and pyrrolidinium cations with bis(trifluoromethylsulfonyl)imide anions. The influence of the presence of hydroxyl or ester groups in the physico-chemical properties of these liquids was checked. It appeared that the presence of functional oxygenated moieties reduces the lipophilicity of ionic liquids and so decreases the risk of bioaccumulation in environment.     

Assessing the diurnal variability of pharmaceutical and personal care products in a full-scale activated sludge plant

An intensive sampling campaign has been carried out in a municipal wastewater treatment plant (WWTP) to assess the dynamics of the influent pharmaceutical active compounds (PhAC) and musks. The mass loadings of these compounds in wastewater influents displayed contrasting diurnal variations depending on the compound. The musks and some groups of PhACs tended to follow a similar diurnal trend as compared to macropollutants, while the majority of PhACs followed either the opposite trend or no repeatable trend. The total musk loading to the WWTP was 0.74 ± 0.25 g d⁻¹, whereas the total PhAC mass loading was 84.7 ± 63.8 g d⁻¹. Unlike the PhACs, the musks displayed a high repeatability from one sampling day to the next. The range of PhAC loadings in the influent to WWTPs can vary several orders of magnitude from one day or week to the next, representing a challenge in obtaining data for steady-state modelling purposes.     

Histopathological changes in the earthworm Eisenia andrei associated with the exposure to metals and radionuclides

Earthworms were exposed for 56 d to a contaminated soil, from an abandoned uranium mine, and to the natural reference soil LUFA 2.2. Histological changes in earthworm’s body wall (epidermis, circular and longitudinal muscles) and gastrointestinal tract (chloragogenous tissue and intestinal epithelium) were assessed, after 0, 14 and 56 d of exposure. Results have shown alterations in all the studied tissues after 14 d of exposure (except for the intestinal epithelium), yet more severe effects were registered after 56 d of exposure. Herein we report histopathological alterations as a good biomarker for the evaluation of soil quality. We also demonstrate that morphological changes in the body wall and gastrointestinal tract, are important endpoints that could be added to earthworm’s standardized tests, for the evaluation of soil toxicity, as part of the risk assessment of contaminated areas.     

Energy conservation and CO2 emission reductions due to recycling in Brazil

The present paper aims to make the energy saving potential provided by waste recycling in Brazil evident by pointing out more specifically the benefits regarding climate change mitigation. In this case, based on the energy saved due to the recycling process of an exogenous amount of waste, we have built two scenarios in order to show the potential for indirectly avoiding CO2 emissions in the country as a result of the recycling process. According to the scenario, 1 Mt and 3.5 Mt of CO2, respectively, would be avoided per year due to solid waste recycling. The international context for greenhouse gas emissions reduction, such as the United Nations Framework Convention on Climate Change and its Kyoto Protocol has been taken into account.     

Hg transfer from contaminated soils to plants and animals

Understanding the transfer of mercury (Hg) from soil to crops is crucial due to Hg toxicity and Hg occurrence in terrestrial systems. Previous research has shown that available Hg in soils contributes to plant Hg levels. Plant Hg concentrations are related to soil conditions and plant characteristics. Mechanistic models describing such soil–plant interactions are however difficult to quantify. Here we performed a field study in agricultural, mining and industrial areas in Portugal to evaluate potential food chain risks. The uptake of Hg by Italian ryegrass, ryegrass, orchard grass, collard greens and rye was measured to calculate daily intakes (DI) of Hg for cows and sheep grazing. A total of 136 soil samples and 129 plant samples were analysed. Results show that total Hg concentrations ranged from 0.01 to 98 mg kg⁻¹ in soils; 0.01–5.4 mg kg⁻¹ in shoots and 0.01–42 mg kg⁻¹ in roots. Calculated DI ranged from 0.18 to 132 mg d⁻¹ for cows, and from 0.028 to 23 mg d⁻¹ for sheep. In 27 grassland sites, daily intakes exceeded the acceptable daily intake of both cows and sheep in view of food safety considering Hg in animal kidneys evidencing potential risks to human health. The transfer of Hg from soil to crops was described using empirical Freundlich-type functions. For ryegrass, orchard grass and collard greens, the soil-to-root or soil-to-shoot transfer of Hg appeared to be controlled by the total soil Hg concentration and levels of Al_ox and Fe_ox. Empirical functions allowed us to obtain realistic estimates of Hg levels in crops and can be used as an alternative to mechanistic models when evaluating food chain risks of Hg contamination in agricultural soils.