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The concentrations of arsenic (As), chromium (Cr), lead (Pb) and zinc (Zn) and the human health risk of the metals were estimated through drinking water consumption. Totally, 48 samples of groundwater were collected and analyzed during 2019. Health risk indices were estimated using chronic daily intake (CDI), hazard quotient (HQ) and, hazard index (HI), as well as cancer risk (CR). Except for As (66.6% of the areas were above permissible limits), the concentrations of other three heavy metals were within the US EPA and WHO permissible limits. ∑ HI values in 100% and 75% of the areas were above 1 for children and adults, implying non-carcinogenic risk from sum of heavy metals. Children total cancer risk (CRt) in all areas (except one area with acceptable risk) fell within unacceptable risk. Adults CRt in all areas (except one area with unacceptable risk) were in acceptable risk category. As was the highest contributor to non-carcinogenic and carcinogenic risks both for children and adults. Our results showed that children were more exposed to health risks, due to intake of drinking water containing As, Cr, and Pb in the study areas. The study can provide a basis for local governments to properly manage drinking water quality and provide a reference for water quality management in neighborhood areas. [ABSTRACT FROM AUTHOR]

Trace elements in the environmental media contribute to toxicities of different types. Their presence in the arable pedosphere is a human-health risk factor. This study focused on Vicia faba represented by two Tunisian varieties of bean (Mamdouh) and faba bean (Badii). The objective was to analyze the effects of lead, copper and cadmium on their growth, chlorophyll-content and carotenoids-content, as well as the bioaccumulation and translocation factor, at different stages of growth. For each metal, the concentrations the plants were subjected to were 6, 0.3 and 0.03 mg/L of the metal in the compound for lead nitrate, copper nitrate and cadmium acetate, respectively. The analysis was carried out using an atomic absorption spectrophotometer (ICP-MS), encompassing all the parts of the plant. The authors detected a perceptible decrease in the fresh weight of roots and shoots, as well as a drop in the chlorophyll and carotenoid, for all the three heavy metals. Cadmium turned out to be the most toxic of the three metals and copper (which is incidentally an essential micronutrient for plant growth) the least. As far as the bioaccumulation factor was concerned, bean and faba bean exhibited different behaviours, both with regard to the growth stages and the heavy metal absorbed. During the vegetative growth stage, both were accumulators of all the three heavy metals (a translocation factor less than unity). However, in the flowering stage, faba bean was a hyper-accumulator of copper (TF > 1); while the bean plants accumulated a lot of lead in the pods-stage (TF > 1). It is worthwhile to pose new research questions and try to answer them in this study, if legumes are accumulator or hyper accumulator plants in which stage and in where organ accumulate more HMs. [ABSTRACT FROM AUTHOR]

Contamination of surface and groundwater resources to heavy metal due to mining activities is a worldwide major issue because of its probable health risks to local residents. In the present research, we measured the concentrations of As, Cd and Cr in 26 water samples collected from 13 rural areas in the vicinity of mines in Sabzevar, Iran, during January 2019 and estimated potential health risks among local residents. Heavy metal concentrations were analysed using an atomic absorption spectrometer and compared with guidelines set by the WHO. The results showed that As and Cr concentration in drinking water of rural areas in the vicinity of mines were estimated to be in the range of 0.0152 to 0.0220 and 0.0194 to 0.1806 mg/L, respectively, which exceeded the drinking water guidelines recommended by WHO. For cadmium, the concentrations ranged from 0.0003 to 0.0018 mg/L. Total HI (hazard index) values were above one in drinking water of all villages and generally, total HI values for children were much higher than those of adults in each studied area. The total cancer risk values of metals (sum of As, Cd and Cr) for children and adults in all the villages were above the USEPA limit. The CR (carcinogenic risk) values for both children and adults through the oral pathway were found in order of As>Cr>Cd. The findings of health risk assessment of groundwater near the mining area could be valuable for proper management of water resources in the rural areas in particular and to the other mining areas in general. [ABSTRACT FROM AUTHOR]

Sweden is one of the largest exporters of pulp and paper products in the world. It follows that huge quantities of sludge rich in carbonaceous organic material and containing heavy metals are generated. This paper carried out a comparative environmental analysis of three different technologies, which can be adopted to produce biochar and recover energy from the biosludge, using landfilling as the reference case. These three thermochemical biosludge management systems—using incineration, pyrolysis, and hydrothermal carbonization (HTC)—were modeled using life cycle assessment (LCA). Heat generated in the incineration process (System A) was considered to be for captive consumption within the kraft pulp mills. It was assumed that the biochars—pyrochar and hydrochar—produced from pyrolysis (System B) and HTC (System C), respectively, were added to the forest soils. The LCA results show that all the alternative systems considerably improve the environmental performance of biosludge management, relative to landfilling. For all systems, there are net reductions in greenhouse gas emissions (–0.89, –1.43, and –1.13 tonnes CO2‐equivalent per tonne dry matter biosludge in Systems A, B, and C, respectively). System B resulted in the lowest potential eutrophication and terrestrial ecotoxicity impacts, whereas System C had the least acidification potential. The results of this analysis show that, from an environmental point of view, biochar soil amendment as an alternative method for handling pulp and paper mill biosludge is preferable to energy recovery. However, an optimal biochar system needs to factor in the social and economic contexts as well. [ABSTRACT FROM AUTHOR]

This paper evaluates the environmental impacts of different alternatives for handling of sludge from paper and pulp mills in Sweden, using Life Cycle Assessment (LCA). The common practice of incineration of biosludge with energy recovery followed by landfilling of ash (System A) was compared with the alternative of digesting sludge anaerobically to produce biogas using different digestate residue management options. The digestate produced from anaerobic digestion (AD) was assumed to be incinerated for heat energy recovery in System B or pyrolyzed for biochar production in System C to be mixed with forest soils. The impact categories considered in this work are climate change, non-renewable energy use, mineral extraction, aquatic ecotoxicity, carcinogens and non-carcinogens. The LCA results demonstrate that the two proposed systems significantly reduce the environmental impacts of biosludge management relative to incineration. An 85% reduction in the aquatic ecotoxicity impact is achieved in System C, due to the reduced mobility of heavy metals in biochar relative to ash. System C, on the whole, outperformed the other two, leading the authors to the recommendation that the use of pulp and paper mill biosludge in biogas-biochar production systems is preferable to merely recovering energy from it. • Anaerobic digestion (AD)-pyrolysis and AD-incineration were modelled as biosludge treatment technologies. • Immobilization of the heavy metals in biochar significantly reduced aquatic ecotoxicity. • The lowest carcinogens and non-carcinogens impacts were offered by the AD-pyrolysis system. • From an environmental point of view, biogas-biochar is preferable to merely energy recovery. [ABSTRACT FROM AUTHOR]

To examine the level of contamination of Eshghabad region, Neyshabur, the concentration of heavy metals in soil was measured. For this purpose, 37 samples were taken from surface soil and the total concentration of heavy elements was measured by inductively coupled plasma (ICP). The mean concentration of Pb, Ni, Cu, Zn, and Fe was obtained to be 195, 87.3, 22.8, 274.8, and 2.5%, respectively. Using five valid indicators, the intensity of metal contamination in soil was calculated and compared. Furthermore, using statistical analyses, the relationships between the elements, their origins, and the spatial distribution of metals across various stations were investigated. The results indicated that the mean value of all of the studied metals (except for iron and copper) is greater than the mean concentration of metals in the Earth's crust. The indicators showed very high contamination for lead, while low to medium contamination for other elements of interest in the farming soils of the region. Statistical analyses indicated that there is a relatively similar contamination intensity across all of the studied stations. Considering the quality standards, the soils of this region are threatened by contamination of lead. [ABSTRACT FROM AUTHOR]

Heavy metals attract a great deal of attention nowadays due to their potential accumulation in living creatures and transference in the food chain. Sediments of water reservoirs are considered to be a source of accumulation of these metals that develop in response to human activities and soil erosion. This study collected 180 samples of the surface sediments of water reservoir 1 at Chahnimeh in Sistan. Efficiency of the ANFIS model was evaluated to estimate the five bonds following the measurement of parameters in the laboratory.The following results were obtained for the parameters: organic carbon (OC) %, 0.31; cation exchange capacity (CEC), 37.07 Cmol kg; total Pb, 25.19 mg/kg; clay %, 45.87; and silt %, 39.02. These parameters were used as input for the training model. In the output layer, lead bonds were chosen as modeling targets in the following way: Pb f1 (4.61); Pb f2 (0.54); Pb f3 (16.28); Pb f4 (3.42); and Pb f5 (0.38) mg/kg. The best input compound in this model was chosen using the gamma test. From a total of 180, 88 data were considered for the model training section. Eventually, the neural-fuzzy model (subtractive clustering), developed for the prediction of lead bonds in the studied region, was able to account for over 99% of lead bonds in the sediments; considering statistical criteria of root mean squares error or RMSE (0.0337-0.0813) and determination coefficient or R2 (0.92-0.99), this model showed good performance with regard to prediction. [ABSTRACT FROM AUTHOR]

There is a growing body of research that recognizes the potentials of biochar application in agricultural production systems. However, little is known about the effects of biochar, especially hydrochar, on production of containerized seedlings under nursery conditions. This study aimed to test the effects of hydrochar application on growth, quality, nutrient and heavy metal contents, and mycorrhizal association of containerized pine seedlings. The hydrochar used in this study was produced through hydrothermal carbonization of paper mill biosludge at 200 °C. Two forms of hydrochar (powder and pellet) were mixed with peat at ratios of 10% and 20% (v/v) under three levels of applied commercial fertilizer (nil, half and full rates). Application of hydrochar had positive or neutral effects on shoot biomass and stem diameter compared with control seedlings (without hydrochar) under tested fertilizer levels. Analysis of the natural logarithmic response ratios (LnRR) of quality index and nutrient and heavy metal uptake revealed that application of 20% (v/v) hydrochar powder or pellet with 50% fertilizer resulted in same quality pine seedlings with similar heavy metal (Cu, Ni, Pb, Zn and Cr) and nutrient (P, K, Ca and Mg) contents as untreated seedlings supplied with 100% fertilizer. Colonization percentage by ectomycorrhizae significantly increased when either forms of hydrochar were applied at a rate of 20% under unfertilized condition. The results of this study implied that application of proper rates of hydrochar from biosludge with adjusted levels of liquid fertilizer may reduce fertilizer requirements in pine nurseries. [ABSTRACT FROM AUTHOR]

Groundwater aquifers are considered the second most abundant water supply for drinking water all over the world. In Iran, ground waters are commonly employed for drinking water, irrigation, and industrial purposes. Heavy metals (HMs) pose human concerns about the groundwater contamination; these pollutants are recognized to be capable of bio-accumulation, long persistence in the natural environment, and toxic effects. In the present research, the content of HMs: Chromium (Cr), Cadmium (Cd), and Lead (Pb) were detected in 89 water samples collected in 2018 by underground water supplies (active wells) of Saravan city. Hazard Quotient (HQ) and Monte Carlo Simulation approach with 10,000 repetitions were applied to discover the human non-carcinogenic impacts of HMs in four groups of ages (adults, teenagers, children, and infants) of consumers. The concentrations of Cr, Pb, and Cd were in the range of 0.49–20, 0.1 to 58.34, and 0.11–12.8 μg/L, respectively. The mean HQ calculated due to exposure to Pb (0.0018–0.0023), Cr (0.0112–0.0186), and Cd (0.0370–0.0615) were lower than one. The findings of sensitivity analysis revealed that HMs concentration had the most contribution effect on human non-carcinogenic risk analysis in four different exposed populations. This study could assist researchers to perform more comprehensive studies with more samples. Therefore, further research is required for decision-makers to plan proper measurements properly. • HRA procedure was conducted to evaluate the health effects of different population exposed to three HMs. • Pb HQ for population groups were in the order of infant > children > teenager > adult. • The most influential parameters in the risk of non-carcinogenicity were in the order ofconcentration > ingestion rate > body weight. [ABSTRACT FROM AUTHOR]