Metal Contamination of Canal Versus Sewage Water Irrigated Vegetables in Metropolitan Area of Sargodha, Pakistan

The reduction in the fresh water supply and increase in the domestic effluents with increase in population and urbanization in the Pakistan force the farmers to use untreated sewage water for the irrigation purposes. Besides high nutrient content Sewage water also have source of metal contamination in the food chain. The present field study was conducted to compare the nickel (Ni), copper (Cu) and lead (Pb) contamination in vegetables grown on soils irrigated with sewage water and canal water in Sargodha, Punjab, Pakistan. The Ni, Cu and Pb contamination was assessed using soil quality indices i.e., contamination factor (CF), metal translocation factor (MTF), pollution load index (PLI), geo-accumulation index (Igeo) and ecological risk index (ERI) were calculated in the collected samples. The physico-chemical properties of soil and water samples were determined. Based on the results, it was revealed that sewage irrigated areas were at higher risks of metals contamination compared to canal irrigated areas. From the studied metals, Pb showed highest contamination potential based on the soil quality indices. In sewage irrigated sites, metal concentrations were found higher in edible parts of the vegetables confirming that sewage water contains and supply more metals than canal irrigated water and pose more health and ecological risks.

Heavy metal contamination of Hg and Pb in water, sediment and Violet Batissa (Batissa violacea Lamark, 1818) meat in Teunom River, Aceh Jaya Regency, Indonesia

Violet Batissa (Batissa violacea) is an important economic organism on the west-south coast of Aceh, because it is relatively high consumed by the community. However, gold mining activities carried out around the watershed are estimated to pollute the river and cause B. violacea to also be affected. The purpose of this study was to determine the level of mercury (Hg) and Lead (Pb) contamination in clam meat in Teunom, Aceh Jaya Regency. The research was conducted from June to September 2021. Sampling of clam was done by purposive sampling method. Hg and Pb were analyzed in clam meat using the Atomic Absorption Spectrophotometer (AAS) method. The results of the analysis showed that the Hg content in clam meat was between 0.12-0.63 mg/kg (mean 0.35±0.26 mg/kg), water 0.0026-0.0103 mg/kg (mean 0.0052±0.004 mg/kg), and sediment 1.3224-3.8767 mg/kg (mean 2.2324±1.427 mg/kg). Furthermore, the results of the analysis showed that the Pb content in clam meat, water and sediment had the same value at 3 stations with values 0.0002±0 mg/kg, 0.0003±0 mg/kg, and 0.0002±0 mg/kg, respectively. The conclusion of this study is that the Hg content in water and sediment has exceeded the threshold, while the clam meat is still in good quality standards. The Pb content in clam meat, water and sediment were also in good quality standards. Based on our study, B. violacea is still safe for consumption, while the water has been polluted and is recommended not to be utilized for human consumption.Keywords:Heavy metalRiverWaterSedimentBatissa violacea

Analysis of metal accumulation and Phytochelatin Synthase (PCS) gene expression in Saccharum spontaneum L. as regards its function for remediation of lead (Pb) contamination

Pollution caused by heavy metals, has become a serious problem. Adverse effects arising from the increased use of heavy metals in a variety of human activities lead to any environmental degradation. Lead (Pb) is one of most common contaminants in the environment and highly toxic. Pb is less mobile, so its compound tends to accumulate in soil and sediments. Definitely, efforts are needed to remove this contaminant in the environment. Saccharum spontaneum L. is a perennial grass which has potential to be used as an accumulator plant to clean up pollutants. The ability of this plant as metal accumulator was tested in this study. S.pontaneum plants were treated using Pb in the concentrations of 0 ppm (control), 100 ppm, 200 ppm, and 300 ppm for 8 weeks. The results showed that there was an increase in the percentage of relative accumulation of Pb in the treated plants. This also indicated that plant roots accumulated more Pb than shoots. Meanwhile, expression of Phytochelatin synthase (PCS) gene increased 1.3-to-3.5-fold inductions in roots by increasing concentration of Pb treatments for 24 h. PCS gene expression showed the higher induction in the roots than in the shoots of S.spontaneum plant under Pb treatments.

Potentially Toxic Element Contaminations and Lead Isotopic Fingerprinting in Soils and Sediments from a Historical Gold Mining Site

Lead (Pb) isotopes have been widely used to identify and quantify Pb contamination in the environment. Here, the Pb isotopes, as well as the current contamination levels of Cu, Pb, Zn, Cr, Ni, Cd, As, and Hg, were investigated in soil and sediment from the historical gold mining area upstream of Miyun Reservoir, Beijing, China. The sediment had higher 206Pb/207Pb ratios (1.137 ± 0.0111) than unpolluted soil did (1.167 ± 0.0029), while the soil samples inside the mining area were much more variable (1.121 ± 0.0175). The mean concentrations (soil/sediment in mg·kg−1) of Pb (2470/42.5), Zn (181/113), Cu (199/36.7), Cr (117/68.8), Ni (40.4/28.9), Cd (0.791/0.336), As (8.52/5.10), and Hg (0.168/0.000343) characterized the soil/sediment of the studied area with mean Igeo values of the potentially toxic element (PTE) ranging from −4.71 to 9.59 for soil and from −3.39 to 2.43 for sediment. Meanwhile, principal component analysis (PCA) and hierarchical cluster analysis (HCA) coupled with Pearson’s correlation coefficient among PTEs indicated that the major source of the Cu, Zn, Pb, and Cd contamination was likely the mining activities. Evidence from Pb isotopic fingerprinting and a binary mixing model further confirmed that Pb contamination in soil and sediment came from mixed sources that are dominated by mining activity. These results highlight the persistence of PTE contamination in the historical mining site and the usefulness of Pb isotopes combined with multivariate statistical analysis to quantify contamination from mining activities.

Background modeling for dark matter search with 1.7 years of COSINE-100 data

We present a background model for dark matter searches using an array of NaI(Tl) crystals in the COSINE-100 experiment that is located in the Yangyang underground laboratory. The model includes background contributions from both internal and external sources, including cosmogenic radionuclides and surface $$^{210}$$ 210 Pb contamination. To build the model in the low energy region, with a threshold of 1 keV, we used a depth profile of $$^{210}$$ 210 Pb contamination in the surface of the NaI(Tl) crystals determined in a comparison between measured and simulated spectra. We also considered the effect of the energy scale errors propagated from the statistical uncertainties and the nonlinear detector response at low energies. The 1.7 years COSINE-100 data taken between October 21, 2016 and July 18, 2018 were used for this analysis. Our Monte Carlo simulation provides a non-Gaussian peak around 50 keV originating from beta decays of bulk $$^{210}$$ 210 Pb in a good agreement with the measured background. This model estimates that the activities of bulk $$^{210}$$ 210 Pb and $$^{3}$$ 3 H are dominating the background rate that amounts to an average level of $$2.85\pm 0.15$$ 2.85 ± 0.15 counts/day/keV/kg in the energy region of (1–6) keV, using COSINE-100 data with a total exposure of 97.7 kg$$\cdot $$ · years.

Adsorptive Removal of Arsenic and Lead by Stone Powder/Chitosan/Maghemite Composite Beads

Arsenic (As) and lead (Pb) contamination in groundwater is a serious problem in countries that use groundwater as drinking water. In this study, composite beads, called SCM beads, synthesized using stone powder (SP), chitosan (Ch), and maghemite (Mag) with different weight ratios (1/1/0.1, 1/1/0.3, and 1/1/0.5 for SP/Ch/Mag) were prepared, characterized and used as adsorbents for the removal of As and Pb from artificially contaminated water samples. Adsorption isotherm experiments of As and Pb onto the beads were conducted and single-solute adsorption isotherm models such as the Langmuir, Freundlich, Dubinin–Radushkevich (DR), and dual mode (DM) models were fitted to the experimental data to analyze the adsorption characteristics. The maximum adsorption capacities of the SCM beads were 75.7 and 232.8 mmol/kg for As and Pb, respectively, which were 40 and 5.6 times higher than that of SP according to the Langmuir model analyses. However, the DM model had the highest determinant coefficient (R2) values for both As and Pb adsorption, indicating that the beads had heterogenous adsorption sites with different adsorption affinities. These magnetic beads could be utilized to treat contaminated groundwater.

Evaluation of Dispersion of Lead-Bearing Mine Wastes in Kabwe District, Zambia

Dispersion of lead (Pb) in mine wastes was simulated for reproducing Pb contamination of soil in Kabwe District, Zambia. Local weather data of year 2019 were monitored in situ and used for the simulations. The plume model, weak puff model, and no puff model were adopted for calculation of Pb dispersion under different wind conditions. The results showed that Pb dispersion from the Kabwe mine was directly affected by wind directions and speeds in the dry season, although it was not appreciably affected in the rainy season. This may be because the source strength is lower in the rainy season due to higher water content of the surface. This indicates that Pb dispersion patterns depend on the season. In addition, the distribution of the amount of deposited Pb-bearing soils around the mine corresponded to the distribution of Pb contents in soils. These results suggest that Pb contamination in soils primarily results from dispersion of fine mine wastes.

Spatial Variation in Microbial Community in Response to As and Pb Contamination in Paddy Soils Near a Pb-Zn Mining Site

Mining activity is a growing environmental concern as it contributes to heavy metals (HMs) pollution in agricultural soils. Microbial communities play an important role in the biogeochemical cycling of HMs and have the potential to be used as bioindicators. Arsenic (As) and lead (Pb) are the most hazardous HMs and are mainly originated from mining activities. However, spatial variation in microbial community in response to As and Pb contamination in paddy soils remains overlooked. In this study, the biological and chemical properties of sixteen soil samples from four sites (N01, N02, N03, and N04) near a Pb-Zn mining site at different As and Pb levels were examined. The results showed that soil pH, total As and Pb, bioavailable As and Pb, nitrate-nitrogen (NO3−-N) and ammonia-nitrogen (NH4+-N) were the most important factors in shaping the bacterial community structure. In addition, significant correlations between various bacterial genera and As and Pb concentrations were observed, indicating their potential roles in As and Pb biogeochemical cycling. These findings provide insights into the variation of paddy soil bacterial community in soils co-contaminated with different levels of As and Pb.

Restoration and risk reduction of lead mining waste by phosphate-enriched biosolid amendments

Lead (Pb) contamination in environment has been identified as a threat to human health and ecosystems. In an effort to reduce the health and ecological risks associated with Pb mining wastes, a field study was conducted to stabilize Pb using phosphate (P)-enriched biosolid amendments in the contaminated mining wastes (average of 1004 mg Pb kg−1) located within the Jasper County Superfund Site, southwest Missouri. Experiments consisted of six biosolid amendment treatments, including Mizzou Doo compost (MD); Spent mushroom compost (SMC); Turkey litter compost (TLC); Composted chicken litter (CCL); Composted sewage sludge (CSS); and Triple superphosphate (TSP). Kentucky tall fescue seeds were planted following the treatments, and soil and plant samples were collected and analyzed 8–10 years post treatment. Results indicated that, in all cases, the biosolid treatments resulted in significant reductions in bioaccessible Pb (96.5 to 97.5%), leachable Pb (95.0 to 97.1%) and plant tissue Pb (45.5 to 90.1%) in the treated wastes, as compared with the control. The treatments had no significantly toxicological effect to soil microbial community. Analysis of the Pb fractionation revealed that the Pb risk reduction was accomplished by transforming labile Pb fractions to relatively stable species through the chemical stabilization reactions as induced by the treatments. The solid-phase microprobe analysis confirmed the formation of pyromorphite or pyromorphite-like minerals after the treatment. Among the six biosolid amendments examined, SMC and MD treatments were shown most effective in the context of Pb stabilization and risk reduction. This field study demonstrated that the treatment effectiveness of Pb stabilization and risk reduction in mining wastes by P-enriched biosolid amendments was long-term and environmental-sound, which could be potentially applied as a cost-effective remedial technology to restore contaminated mining site and safeguard human health and ecosystems from Pb contamination.