Formesafen is a diphenyl ether herbicide that has adverse effects on non-target animals. However, knowledge about the effect of fomesafen on the antioxidant defense system in earthworms is vague. Thus, it is essential to investigate the effects of fomesafen on the antioxidant defense system in earthworms as a precautionary method. In the present study, earthworms (Eisenia fetida) were exposed to artificial soil treated with a range of concentrations of fomesafen (0, 10, 100, and 500 μg kg⁻¹) and were collected on the 3rd, 7th, 14th, 21st, and 28th days of exposure. Subsequently, the antioxidant enzyme activities (superoxide dismutase (SOD); catalase (CAT); and guaiacol peroxidase (POD)), reactive oxygen species (ROS) level, and malondialdehyde (MDA) content due to fomesafen treatment were examined in earthworms. Compared with the control, the SOD activity increased on the third and seventh days but decreased on the 14th day due to treatment with 100 and 500 μg kg⁻¹ of fomesafen. The activities of CAT and POD increased significantly on the third, seventh, and 14th days of exposure. In addition, the ROS level was significantly enhanced throughout the entire experimental period and showed a statistically dose-dependent relationship on the seventh and 14th days. The MDA content markedly increased on the seventh day of exposure; however, obvious changes were not detected at other exposure period. Low doses of fomesafen (≤500 μg kg⁻¹) may result in oxidative damage and lipid peroxidation in E. fetida by inducing the generation of ROS at short exposure periods (14 days). However, the adverse effects of fomesafen gradually disappear as the cooperation of antioxidant enzymes and exposure time are prolonged. This result may be helpful for further studies on the toxicological mechanisms of fomesafen to earthworms.

The levels of organochlorine pesticides (OCPs) in the water, suspended solids, and sediments from Lake Chaohu during the high water level period were measured by a solid-phase extraction gas chromatograph–electron capture detector. The spatial distributions of the three phases and the water/suspended solids and sediment/water partition coefficients were analyzed. The results showed the following: (1) The mean contents of OCPs in the water, suspended solids, and sediments were 132.4 ± 432.1 ng/L, 188.1 ± 286.7 ng/g dry weight (dw), and 13.7 ± 9.8 ng/g dw, respectively. The dominant OCP components were isodrin (85.1 %) for the water, DDTs (64.4 %) for the suspended solids, and both isodrin (48.5 %) and DDTs (31.8 %) for the sediments. (2) β-HCH was the primary isomer of HCHs in the water and sediments, and the proportions were 61.7 and 41.3 %; γ-HCH was the primary isomer in the suspended solids, accounting for 49.3 %; p,p′-DDT was the dominant content of DDTs in the water and suspended solids, whereas p,p′-DDD was the main metabolite of DDTs in the sediments. (3) The concentrations of contaminants in the water from the western lake were greater than those from the eastern lake, but the concentrations in the suspended solids from the western lake were less than those from the eastern lake. (4) There was no significant correlation between the water–suspended solids partition coefficient K d and the n-octanol–water partition coefficient K ₒw, and between the sediment–water organic-C weighted sorption coefficients K ₒc and K ₒw.

Controversy exists as to whether working or living in the vicinity of a petroleum refinery (RF) increases the risk of haematological cancer (HC). The European Pollutant Release and Transfer Register obliges petroleum refineries to notify their emissions of toxic substances which include carcinogenic substances. Our objective is to determine if living in the proximity of an RF is associated with a greater risk of mortality due to HC in the census tracts (CTs) of the Spanish cities of Bilbao, Cartagena, Castellón, La Coruña, Huelva, and Santa Cruz de Tenerife. This is an ecological study of mortality in the years 1996–2007 which includes 968 CTs with 1,263,371 inhabitants. Exposure has been measured as the distance from the centroid of each CT to the RF. The Besag–York–Mollié autoregressive spatial model has been fitted by R-INLA to estimate the relative risk (RR) and 95 % credible intervals (95 % CrI) for distance in quintiles. The most distant quintile has been taken as the reference. A total of 2,574 persons died of HC. The distances from the CTs to RFs ranged from 0.5 to 22.5 km (median = 7.6 km). All of the RRs for the quintiles of distances in Huelva were greater than 1. Statistically significant excess risk was shown in Cartagena in the nearest CT (1.8 to 6.8 km; RR = 1.43, 95 % CrI 1.02 to 2.02). Radial effects have not been detected between the CT of residence and the petroleum RF in mortality due to HC in any of the cities.

The goal of this study was to characterize microbial eukaryotes over a 12-month period to provide insight into the occurrence of potential bacterial predators and hosts in premise plumbing. Nearly 6,300 partial 18S rRNA gene sequences from 24 hot (36.9-39.0 °C) and cold (6.8-29.1 °C) drinking water samples were analyzed and classified into major eukaryotic groups. Each major group, consisting of free-living amoebae (FLA)/protozoa, algae, copepods, dinoflagellates, fungi, nematodes, and unique uncultured eukaryotic sequences, showed limited diversity dominated by a few distinct populations, which may be characteristic of oligotrophic environments. Changes in the relative abundance of predators such as nematodes, copepods, and FLA appear to be related to temperature and seasonal changes in water quality. Sequences nearly identical to FLA such as Hartmannella vermiformis, Echinamoeba thermarmum, Pseudoparamoeba pagei, Protacanthamoeba bohemica, Platyamoeba sp., and Vannella sp. were obtained. In addition to FLA, various copepods, rotifers, and nematodes have been reported to internalize viral and bacterial pathogens within drinking water systems thus potentially serving as transport hosts; implications of which are discussed further. Increasing the knowledge of eukaryotic occurrence and their relationship with potential pathogens should aid in assessing microbial risk associated with various eukaryotic organisms in drinking water.

Using bio-disturbed sulphide to trace the mobility and transformation of Cu, Pb, Ni and Zn in the sediments of the Spartina alterniflora-dominated salt marsh in the Yangtze River Estuary, measurements were made of the seasonal variations of acid-volatile sulphide (AVS) and of the simultaneously extracted metals (SEM) in the rhizosphere sediments. Microcosm incubation experiments recreating flooding conditions were conducted to evaluate the effect of AVS and other metal binding phases upon the dynamics of Cu, Pb, Ni and Zn in the salt marsh sediments. The results demonstrate that the ratio values of SEM/AVS have a significant seasonal variation in the rhizosphere sediments and that the anoxic conditions in the sediments were likely enhanced by S. alterniflora during the summer and autumn compared with the anoxic conditions resulting from the native species Phragmites australis and Scirpus mariqueter. The incubation experiments suggest that Fe(III) and Mn(IV/III) (hydr)oxides provide important binding sites for heavy metals under oxic conditions, and sulphide provides important binding sites for the Cu and Pb under anoxic conditions. Our observations indicate that the mobility of heavy metals in the salt marsh sediments is strongly influenced by biogeochemical redox processes and that the invasive S. alterniflora may increase the seasonal fluctuation in heavy metal bioavailability in the salt marsh ecosystem.

A cost-effective biosorbent was prepared by a green chemical modification process from muskmelon peel by saponification with alkaline solution of Ca(OH)₂. Its adsorption behavior for lead ions was investigated and found to exhibit excellent adsorption properties. Results showed that the optimal equilibrium pH range for 100 % adsorption is from 4 up to 6.4. Adsorption equilibrium was attained within 10 min. The adsorption process can be described well by Langmuir model and pseudo-second-order kinetics equation, respectively. The maximum adsorption capacity for lead ions was found to be 0.81 mol/kg. Pectic acid contained in the muskmelon peel is the main factor responsible for the uptake of lead ions onto the gel, and the chemical modification process presented in this study can be assumed effective to prepare other similar biomaterials. The large adsorption capacity and the fast adsorption rate indicated that chemically saponified muskmelon peel gel in present study has great potential to be used as a cost-effective adsorbent for the removal of lead ions from the water.

Preservation or curing of hides and skins is performed as the primary step of leather processing. Common salt is employed as the conventional agent for curing purpose. Use of salt enhances the pollution load of tannery effluent which becomes highly contaminated with increased total dissolved solids and chlorides. To overcome this hurdle, researchers are in constant search of alternative preservation techniques which are either totally void of salt or use only a meager amount of salt. In the present study, we had explored the possibility of using Semecarpus anacardium nut extract as an alternative to salt for the curing process by assessing different parameters like hair slip, putrefaction odor, volatile nitrogen content, moisture content, bacterial count, and shrinkage temperature in comparison to the salt curing method. The antibacterial property of the plant extract was also investigated. The results obtained substantiated that the nut extract of S. anacardium effectively could preserve the skins for more than a month, by its antibacterial activity along with the dehydrating property of acetone.

The reuse of treated wastewater (TWW) for irrigation is a practical solution for overcoming water scarcity, especially in arid and semiarid regions of the world. However, there are several potential environmental and health-related risks associated with this practice. One such risk stems from the fact that TWW irrigation may increase antibiotic resistance (AR) levels in soil bacteria, potentially contributing to the global propagation of clinical AR. Wastewater treatment plant (WWTP) effluents have been recognized as significant environmental AR reservoirs due to selective pressure generated by antibiotics and other compounds that are frequently detected in effluents. This review summarizes a myriad of recent studies that have assessed the impact of anthropogenic practices on AR in environmental bacterial communities, with specific emphasis on elucidating the potential effects of TWW irrigation on AR in the soil microbiome. Based on the current state of the art, we conclude that contradictory to freshwater environments where WWTP effluent influx tends to expand antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes levels, TWW irrigation does not seem to impact AR levels in the soil microbiome. Although this conclusion is a cause for cautious optimism regarding the future implementation of TWW irrigation, we conclude that further studies aimed at assessing the scope of horizontal gene transfer between effluent-associated ARB and soil bacteria need to be further conducted before ruling out the possible contribution of TWW irrigation to antibiotic-resistant reservoirs in irrigated soils.

Dyes used in various industries are discharged into the environment and pose major environmental concern. In the present study, fungal isolate Aspergillus lentulus was utilized for the treatment of various dyes, dye mixtures and dye containing effluent in dual modes, bioaccumulation (employing growing biomass) and biosorption (employing pre-cultivated biomass). The effect of dye toxicity on the growth of the fungal isolate was studied through phase contrast and scanning electron microscopy. Dye biosorption was studied using first and second-order kinetic models. Effects of factors influencing adsorption and isotherm studies were also conducted. During bioaccumulation, good removal was obtained for anionic dyes (100 mg/l), viz. Acid Navy Blue, Fast Red A and Orange-HF dye (99.4 %, 98.8 % and 98.7 %, respectively) in 48 h. Cationic dyes (10 mg/l), viz. Rhodamine B and Methylene Blue, had low removal efficiency (80.3 % [48 h] and 92.7 % [144 h], respectively) as compared to anionic dyes. In addition to this, fungal isolate showed toxicity response towards Methylene Blue by producing larger aggregates of fungal pellets. To overcome the limitations of bioaccumulation, dye removal in biosorption mode was studied. In this mode, significant removal was observed for anionic (96.7–94.3 %) and cationic (35.4–90.9 %) dyes in 24 h. The removal of three anionic dyes and Rhodamine B followed first-order kinetic model whereas removal of Methylene Blue followed second-order kinetic model. Overall, fungal isolate could remove more than 90 % dye from different dye mixtures in bioaccumulation mode and more than 70 % dye in biosorption mode. Moreover, significant color removal from handmade paper unit effluent in bioaccumulation mode (86.4 %) as well as in biosorption mode (77.1 %) was obtained within 24 h. This study validates the potential of fungal isolate, A. lentulus, to be used as the primary organism for treating dye containing wastewater.

Atmospheric lead (Pb) pollution during the last century in central Yunnan province, one of the largest non-ferrous metal production centers in China, was reconstructed using sediment cores collected from Fuxian and Qingshui Lakes. Lead concentrations and isotopic ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) were measured in sediment cores from both lakes. The operationally defined chemical fractions of Pb in sediment core from Fuxian Lake were determined by the optimized BCR procedure. The chronology of the cores was reconstructed using (210)Pb and (137)Cs dating methods. Similar three-phase variations in isotopic ratios and enrichment factors of Pb were observed in the sediment cores from both lakes. Before the 1950s, the sediment data showed low (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios and enrichment factors (EFs = ~1), indicating that the sedimentary Pb was predominantly of lithogenic origin. However, these indices were increased gradually between the 1950s and the mid-1980s, implying an atmospheric Pb deposition. The EFs and isotopic ratios of Pb reached their peak during recent years, indicating aggravating atmospheric Pb pollution. The average anthropogenic Pb fluxes since the mid-1980s were estimated to be 0.032 and 0.053 g m(-2) year(-1) recorded in Fuxian and Qingshui cores, respectively. The anthropogenic Pb was primarily concentrated in the reducible fraction. Combining the results of Pb isotopic compositions and chemical speciations in the sediment cores and in potential sources, we deduced that recent aggravating atmospheric Pb pollution in central Yunnan province should primarily be attributed to regional emissions from non-ferrous metal production industries.