Waste water of the Kettara village, as well as the abandoned tailings, constitute a potential environmental issue with direct consequences on air, soil, water resources qualities and, on human health. In this paper, experimental investigations examine the environmental impact which is induced by the wastewater, mine tailings and the lithological factors of rocks. This multidisciplinary research allows to i) understand the transfer of the Metallic Trace Elements (selenium, arsenic, nickel and zinc) and sulfate ions in the fractured shales media, ii) to assess the water potability by using the microbiological analysis. The microbiological results reveal the domestic impact by the presence of several kinds of bacteria in the groundwater resources: E. coli, Fecal coliforms, Total coliforms, Enterococci, Mesophilic Aerobic Flora, Sulphite-reducing bacteria and Salmonella.Selenium, arsenic and the bacteriological contamination of the groundwater could be explained by five kinds of factors: i) the geological formations and the nature of the hydrogeological system (unconfined layer), ii) the groundwater flow, the hydraulic relation between the hydrogeological wells and, the fractures network in the shale aquifer. The piezometric map allows to highlight the groundwater flow from the North-East to North-West and to the South-West, the drainage axis towards the P21 well and the presence of the dividing axis in the contaminated zone by the arsenic, iii) the absence of the unhealthy habitats with permeable traditional septic tanks in the village; iv) the transfer of the spreading animal excrements from the soil to groundwater and, v) the migration of the wastewater towards downstream of the groundwater flow. The presence of the reed beds could explain the reduction of bacteria in the hydrogeological wells of the study area.

Particulate matter (PM) is considered an atmospheric pollutant that mostly affects human health. The finest fractions of PM (PM2.5 or less) play a major role in causing chronic diseases.The aim of this study was to investigate the genotoxic effects of PM0.5 collected in five Italian towns using different bioassays. The role of chemical composition on the genotoxicity induced was also evaluated.The present study was included in the multicentre MAPEC_LIFE project, which aimed to evaluate the associations between air pollution exposure and early biological effects in Italian children.PM10 samples were collected in 2 seasons (winter and spring) using a high-volume multistage cascade impactor. The results showed that PM0.5 represents a very high proportion of PM10 (range 10–63%). PM0.5 organic extracts were chemically analysed (PAHs, nitro-PAHs) and tested by the comet assay (A549 and BEAS-2B cells), MN test (A549 cells) and Ames test on Salmonella strains (TA100, TA98, TA98NR and YG1021).The highest concentrations of PAHs and nitro-PAHs in PM0.5 were observed in the Torino, Brescia and Pisa samples in winter. The Ames test showed low mutagenic activity. The highest net revertants/m3 were observed in the Torino and Brescia samples (winter), and the mutagenic effect was associated with PM0.5 (p < 0.01), PAH and nitro-PAH (p < 0.05) concentrations. The YG1021 strain showed the highest sensitivity to PM0.5 samples. No genotoxic effect of PM0.5 extracts was observed using A549 cells except for some samples in winter (comet assay), while BEAS-2B cells showed light DNA damage in the Torino, Brescia and Pisa samples in winter, highlighting the higher sensitivity of BEAS-2B cells, which was consistent with the Ames test (p < 0.01).The results obtained showed that it is important to further investigate the finest fractions of PM, which represent a relevant percentage of PM10, taking into account the chemical composition and the biological effects induced.

Despite intensive research carried out on particulates, correlation between engine-out particulate emissions and adverse health effects is not well understood yet. Particulate emissions hold enormous significance for mega-cities like Delhi that have immense traffic diversity. Entire public transportation system involving taxis, three-wheelers, and buses has been switched from conventional liquid fuels to compressed natural gas (CNG) in the Mega-city of Delhi. In this study, the particulate characterization was carried out on variety of engines including three diesel engines complying with Euro-II, Euro-III and Euro-IV emission norms, one Euro-II gasoline engine and one Euro-IV CNG engine. Physical, chemical and biological characterizations of particulates were performed to assess the particulate toxicity. The mutagenic potential of particulate samples was investigated at different concentrations using two different Salmonella strains, TA98 and TA100 in presence and absence of liver S9 metabolic enzyme fraction. Particulates emitted from diesel and gasoline engines showed higher mutagenicity, while those from CNG engine showed negligible mutagenicity compared to other test fuels and engine configurations. Polycyclic aromatic hydrocarbons (PAHs) adsorbed onto CNG engine particulates were also relatively fewer compared to those from equivalent diesel and gasoline engines. Taken together, our findings indicate that CNG is comparatively safer fuel compared to diesel and gasoline and can offer a cleaner transport energy solution for mega-cities with mixed-traffic conditions, especially in developing countries.

Particulate Matter (PM) air pollution is one of the major concerns for environment and health. Understanding the heterogeneity and complexity of fine and ultrafine PM is a fundamental issue notably for the assessment of PM toxicological effects. The aim of this study was to evaluate mutagenicity and cytotoxicity of a multi-influenced urban site PM, with or without the ultrafine fraction. For this purpose, PM2.5-0.3 (PM with aerodynamic diameter ranging from 0.3 to 2.5 μm) and PM2.5 were collected in Dunkerque, a French coastal industrial city and were extensively characterized for their physico-chemical properties, including inorganic and organic species. In order to identify the possible sources of atmospheric pollution, specific criteria like Carbon Preference Index (CPI) and PAH characteristic ratios were investigated. Mutagenicity assays using Ames test with TA98, TA102 and YG1041 Salmonella strains with or without S9 activation were performed on native PM sample and PM organic extracts and water-soluble fractions. BEAS-2B cell viability and cell proliferation were evaluated measuring lactate dehydrogenase release and mitochondrial dehydrogenase activity after exposure to PM and their extracts. Several contributing sources were identified in PM: soil resuspension, marine emissions including sea-salt or shipping, road traffic and industrial activities, mainly related to steelmaking or petro-chemistry. Mutagenicity of PM was evidenced, especially for PM2.5, including ultrafine fraction, in relation to PAHs content and possibly nitro-aromatics compounds. PM induced cytotoxic effects at relatively high doses, while alteration of proliferation with low PM doses could be related to underlying mechanisms such as genotoxicity.

Treated wastewater is expected to be increasingly used as an alternative source of irrigation water in areas facing fresh water scarcity. Understanding the behaviors of contaminants from wastewater in soil and plants following irrigation is critical to assess and manage the risks associated with wastewater irrigation. The objective of this study was to evaluate the effects of soil texture and drought stress on the uptake of antibiotics and the internalization of human pathogens into lettuce through root uptake following wastewater irrigation. Lettuce grown in three soils with variability in soil texture (loam, sandy loam, and sand) and under different levels of water stress (no drought control, mild drought, and severe drought) were irrigated with synthetic wastewater containing three antibiotics (sulfamethoxazole, lincomycin and oxytetracycline) and one Salmonella strain a single time prior to harvest. Antibiotic uptake in lettuce was compound-specific and generally low. Only sulfamethoxazole was detected in lettuce with increasing uptake corresponding to increasing sand content in soil. Increased drought stress resulted in increased uptake of lincomycin and decreased uptake of oxytetracycline and sulfamethoxazole. The internalization of Salmonella was highly dependent on the concentration of the pathogen in irrigation water. Irrigation water containing 5 Log CFU/mL Salmonella resulted in limited incidence of internalization. When irrigation water contained 8 Log CFU/mL Salmonella, the internalization frequency was significantly higher in lettuce grown in sand than in loam (p = 0.009), and was significantly higher in lettuce exposed to severe drought than in unstressed lettuce (p = 0.049). This work demonstrated how environmental factors affected the risk of contaminant uptake by food crops following wastewater irrigation.

The use of wastewater for irrigation may introduce antimicrobials and human pathogens into the food supply through vegetative uptake. The objective of this study was to investigate the uptake of three antimicrobials and Salmonella in two lettuce cultivars. After repeated subirrigation with synthetic wastewater, lettuce leaves and soil were collected at three sequential harvests. The internalization frequency of Salmonella in lettuce was low. A soil horizon-influenced Salmonella concentration gradient was determined with concentrations in bottom soil 2 log CFU/g higher than in top soil. Lincomycin and sulfamethoxazole were recovered from lettuce leaves at concentrations as high as 822 ng/g and 125 ng/g fresh weight, respectively. Antimicrobial concentrations in lettuce decreased from the first to the third harvest suggesting that the plant growth rate may exceed antimicrobial uptake rates. Accumulation of antimicrobials was significantly different between cultivars demonstrating a subspecies level variation in uptake of antibiotics in lettuce.

Surface water is one of the primary sources of irrigation water for produce production; therefore, its contamination by foodborne pathogens, such as Salmonella, may substantially impact public health. In this study, we determined the presence of Salmonella in surface water and characterized the relationship between Salmonella detection and environmental and anthropogenic factors. From April 2019 to February 2020, 120 samples from 30 sites were collected monthly in four watersheds located in two different central Chile agricultural regions (N = 1080). Water samples from rivers, canals, streams, and ponds linked to each watershed were obtained. Surface water (10 L) was filtrated in situ, and samples were analyzed for the presence of Salmonella. Salmonella was detected every month in all watersheds, with a mean detection percentage of 28% (0%–90%) across sampling sites, regardless of the season. Overall, similar detection percentages were observed for both regions: 29.1% for Metropolitan and 27.0% for Maule. Salmonella was most often detected in summer (39.8% of all summer samples tested positive) and least often in winter (14.4% of winter samples). Random forest analysis showed that season, water source, and month, followed by latitude and river, were the most influential factors associated with Salmonella detection. The influences of water pH and temperature (categorized as environmental factors) and factors associated with human activity (categorized as anthropogenic factors) registered at the sampling site were weakly or not associated with Salmonella detection. In conclusion, Salmonella was detected in surface water potentially used for irrigation, and its presence was linked to season and water source factors. Interventions are necessary to prevent contamination of produce, such as water treatment before irrigation.

Mitigation of air pollution by plants is a well-established phenomenon. Trees planted on the roadside are known to reduce particulate matter pollution by about 25%. In an urban ecosystem, especially in a metropolitan city such as Delhi, roadside trees are constantly exposed to air pollution. We, therefore, evaluated the effect of air pollution on a common Indian roadside tree, Neem (Azadirachta indica), and its associated microbes in areas with high and low levels of particulate matter (PM) pollution in Delhi. We hypothesized that alteration in the air quality index not only influences plant physiology but also its microbiome.A 100-fold increase in the number of epiphytic and 10–100 fold increase in endophytic colonies were found with 1.7 times increase in the level of pollutants. Trees in the polluted areas had an abundance of Salmonella, Proteus and Citrobacter, and showed increased secondary metabolites such as phenols and tannins as well as decreased chlorophyll and carotenoid. The number of unique microbes was positively correlated with increased primary metabolites.Our study thus indicates that, alteration in air quality affects the natural micro-environment of plants. These results may be utilized as sustainable tools for studying plant adaptations to the urban ecosystem.

In developing countries, many urban rivers are suffering from heavy contamination by untreated sewage, which implies great microbial risks. However, information regarding the bacterial pathogen diversity and distribution in urban rivers is highly limited. In this study, 41 water samples of fifteen rivers and eight samples from two sewage treatment plants in Changzhou City of Yangtze River Delta were sampled. Next-generation sequencing and a self-built reference pathogen database were used to investigate the diversity of enteric and environmental pathogens. The results indicated that the studied urban rivers were harboring diverse potential pathogen species, which primarily included enteric pathogens in Arcobacter and Bacteroides, and environmental pathogens in Acinetobacter, Aeromonas and Pseudomonas. Quantification of twelve pathogens/indicators of interest by qPCR showed that Escherichia coli, Enterococcus faecalis, Campylobacter jejuni, Arcobacter cryaerophilus, Acinetobacter johnsonii, Acinetobacter lwoffii and Aeromonas spp. were abundant, with median values ranging from 3.30 to 5.85 log10 copies/100 mL, while Salmonella, Legionella pheumophila, Mycobacterium avium, Pseudomonas aeruginosa and Staphylococcus aureus were infrequently quantified. The pollution of nutrients and human intestinal microorganisms indicated by specific markers were found to be prevalent but with different levels in the rivers. The correlation analyses revealed that the diversity (p < 0.01) and concentrations (p < 0.05) of the enteric pathogens highly correlated to the human fecal marker abundances, which indicated that the enteric pathogens in the urban rivers were likely to have originated from domestic sewage. The environmental pathogens, which are different from the enteric ones, showed various distribution patterns, and some of them were more abundant in the rivers of rich nutrient. Our findings provide a comprehensive understanding of the bacterial pathogen distribution and influencing factors in urban rivers that are impacted by domestic sewage, thereby establishing the foundation for urban water management.