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High lead (Pb) levels in agricultural soil and wastewater threaten ecosystems and organism health. Microbial remediation is a cost-effective, efficient, and eco-friendly alternative to traditional physical or chemical methods for Pb remediation. Previous research indicates that micro-organisms employ various strategies to combat Pb pollution, including biosorption, bioprecipitation, biomineralization, and bioaccumulation. This study delves into recent advancements in Pb-remediation techniques utilizing bacteria, fungi, and microalgae, elucidating their detoxification pathways and the factors that influence Pb removal through specific case studies. It investigates how bacteria immobilize Pb by generating nanoparticles that convert dissolved lead (Pb-II) into less harmful forms to mitigate its adverse impacts. Furthermore, the current review explores the molecular-level mechanisms and genetic engineering techniques through which microbes develop resistance to Pb. We outline the challenges and potential avenues for research in microbial remediation of Pbpolluted habitats, exploring the interplay between Pb and micro-organisms and their potential in Pb removal. [ABSTRACT FROM AUTHOR]

Malang City, located in Java, Indonesia, faces significant anthropogenic pressures but remains an important habitat for the endangered Java sparrow (Lonchura oryzivora). Understanding how Java sparrows adapt to environments with high levels of human activity is essential for their conservation. This study focused on identifying the distribution of Java sparrows and investigating their habitat selection within Malang City. The bird positions were recorded within the tree canopy, and the frequency of canopy use by the birds was determined. Living in the middle of the city impacts the metabolism of birds, as indicated by taking samples and measuring the levels of lead found in their droppings and vegetation used. Encounters near the center of human activity show they can utilize buildings and vegetation they utilize. The Java sparrows predominantly utilize plant parts at the tree level, particularly focusing on the middle canopy part of the edge (TTt) and the middle part (TT). Laboratory tests revealed that the plants utilized by the Java sparrow contain high lead levels. Therefore, to conserve the Java sparrow, it is crucial to improve the quality of their habitat to make it more natural and conduct regular health monitoring to ensure their well-being. [ABSTRACT FROM AUTHOR]

The environmental justice literature demonstrates consistently that low‐income and minority communities are disproportionately exposed to environmental hazards. In this case study, we examined cumulative multipollutant, multidomain, and multimatrix environmental exposures in Milwaukee County, Wisconsin for the year 2015. We identified spatial hot spots in Milwaukee County both individually (using local Moran's I) and through clusters (using K‐means clustering) across a profile of environmental pollutants that span regulatory domains and matrices of exposure, as well as socioeconomic indicators. The cluster with the highest exposures within the urban area was largely characterized by low socioeconomic status and an overrepresentation of the Non‐Hispanic Black population relative to the county as a whole. In this cluster, average pollutant concentrations were equivalent to the 78th percentile in county‐level blood lead levels, 67th percentile in county‐level NO2, 79th percentile in county‐level CO, and 78th percentile in county‐level air toxics. Simultaneously, this cluster had an average equivalent to the 62nd percentile in county‐level unemployment, 70th percentile in county‐level population rate lacking a high school diploma, 73rd percentile in county‐level poverty rate, and 28th percentile in county‐level median household income. The spatial patterns of pollutant exposure and SES indicators suggested that these disparities were not random but were instead structured by socioeconomic and racial factors. Our case study, which combines environmental pollutant exposures, sociodemographic data, and clustering analysis, provides a roadmap to identify and target overburdened communities for interventions that reduce environmental exposures and consequently improve public health. Plain Language Summary: Our study focused on Milwaukee County, Wisconsin, where we examined how people in this region were exposed to different types of pollutants. We found that areas with the highest levels of pollution (e.g., lead, nitrogen dioxide) had a higher proportion of Black residents and residents that experienced social and economic challenges (e.g., unemployment, poverty, and low education). Our work adds to the growing evidence that patterns of pollution and economic challenges are not random, but rather, racially and socially structured. By understanding these patterns, we can develop policies that reduce pollution in these areas and improve the health for residents in these overburdened communities. Key Points: We examine cumulative exposures to multiple pollutants and their association with socioeconomic and racial disparities in Milwaukee CountyWe highlight census block groups that are most vulnerable to pollution and low socioeconomic status (SES), which can be prioritized for regulatory interventionsPeople of color in Milwaukee County are not just exposed to high pollution, they are often exposed within the context of low SES [ABSTRACT FROM AUTHOR]

High lead (Pb) levels in agricultural soil and wastewater threaten ecosystems and organism health. Microbial remediation is a cost-effective, efficient, and eco-friendly alternative to traditional physical or chemical methods for Pb remediation. Previous research indicates that micro-organisms employ various strategies to combat Pb pollution, including biosorption, bioprecipitation, biomineralization, and bioaccumulation. This study delves into recent advancements in Pb-remediation techniques utilizing bacteria, fungi, and microalgae, elucidating their detoxification pathways and the factors that influence Pb removal through specific case studies. It investigates how bacteria immobilize Pb by generating nanoparticles that convert dissolved lead (Pb-II) into less harmful forms to mitigate its adverse impacts. Furthermore, the current review explores the molecular-level mechanisms and genetic engineering techniques through which microbes develop resistance to Pb. We outline the challenges and potential avenues for research in microbial remediation of Pb-polluted habitats, exploring the interplay between Pb and micro-organisms and their potential in Pb removal.

Organic materials, such as straw, animal manure, and their processed product biochar, are known to exhibit agronomic effects and the ability to remediate heavy metal contamination. However, knowledge regarding the relative effects of different organic amendments in soils on heavy metal immobilization and phytoavailability remain limited. Consequently, the effects of maize straw (MS), chicken manure (CM), mushroom cultivation waste (MW), and sawdust biochar (SB) on the immobilization and phytoavailability of lead (Pb) in wheat plants were investigated in this study using pot experiments. The results showed that the artificial application of Pb reduced soil pH, while increasing the total organic carbon (TOC) and cation exchange capacity (CEC) to various extents. Furthermore, the Pb treatment increased the adsorption of Pb by wheat grains (0.83 mg∙kg−1), resulting in decreased above-ground dry biomass (43.16 g∙pot−1) during the maturity growth period when compared with the control check (CK) treatment. The MS + Pb and CM + Pb treatments increased the exchangeable Pb fractions in the soil, but had a limited effect on Pb accumulation in wheat grains compared with the Pb treatment. In contrast, the SB + Pb treatment effectively increased soil pH and TOC, while decreasing the fraction of exchangeable Pb forms and increasing the oxidizable and residual Pb fractions, compared with the Pb treatment. Moreover, the MW + Pb treatment also increased the soil pH and CEC, displaying the potential to increase soil TOC, in addition to substantially modifying the portioning of Pb from exchangeable forms to less bioavailable fractions. Both the MW and SB amendments significantly reduced Pb concentrations in wheat grains (0.49 and 0.70 mg∙kg−1,∙respectively), resulting in increased above-ground dry biomass (51.59 and 54.12 g∙pot−1, respectively). In summary, the application of organic amendments, especially MW, could be an effective measure for enhancing Pb immobilization in polluted soils, thereby reducing its uptake and translocation to crops. [ABSTRACT FROM AUTHOR]

Abstract The environmental justice literature demonstrates consistently that low‐income and minority communities are disproportionately exposed to environmental hazards. In this case study, we examined cumulative multipollutant, multidomain, and multimatrix environmental exposures in Milwaukee County, Wisconsin for the year 2015. We identified spatial hot spots in Milwaukee County both individually (using local Moran's I) and through clusters (using K‐means clustering) across a profile of environmental pollutants that span regulatory domains and matrices of exposure, as well as socioeconomic indicators. The cluster with the highest exposures within the urban area was largely characterized by low socioeconomic status and an overrepresentation of the Non‐Hispanic Black population relative to the county as a whole. In this cluster, average pollutant concentrations were equivalent to the 78th percentile in county‐level blood lead levels, 67th percentile in county‐level NO2, 79th percentile in county‐level CO, and 78th percentile in county‐level air toxics. Simultaneously, this cluster had an average equivalent to the 62nd percentile in county‐level unemployment, 70th percentile in county‐level population rate lacking a high school diploma, 73rd percentile in county‐level poverty rate, and 28th percentile in county‐level median household income. The spatial patterns of pollutant exposure and SES indicators suggested that these disparities were not random but were instead structured by socioeconomic and racial factors. Our case study, which combines environmental pollutant exposures, sociodemographic data, and clustering analysis, provides a roadmap to identify and target overburdened communities for interventions that reduce environmental exposures and consequently improve public health.

Abstract Lead (Pb) pollution is a major concern in many developing nations of the world. Hence, there is a need for the development of an environmentally safe and cost-effective method for the clean-up of contaminated environments. The present study investigated the tolerance of presumptively identified fungal species isolated from 5 different dumpsite soils to Pb concentrations 200, 400, 600, 800, 1000, 1500, 5000, and 10000 mg/L. The identity of strains exhibiting outstanding tolerance was confirmed using molecular technique, and their biosorption capacity at 10000 mg/L was evaluated. FTIR and SEM analyses were performed on the Pb2+ untreated and treated fungal biomasses. A total of 17 fungal isolates belonging to the genera Aspergillus Alternaria, Chrysosporium, and Penicillium were obtained. All the fungi were resistant to the test concentrations of Pb2+ except Chrysosporium sp. (at 5000 mg/L and 10000 mg/L) and Alternaria sp. (at 1500 mg/L, 5000 mg/L, and 10000 mg/L). Four isolates molecularly identified as A. awamori OP341445 and OP341446 and A. niger OP342447 and OP341448 recorded outstanding tolerance (> 1). Biosorption capacity was at its peak on day 5 except in OP34148, day 10 with a value of 97.82 mg/g. The Pb2+ removal rate was at equilibrium on day 5 (≈86%) except for OP41447 and OP41448 (≈87%) on day 15. FTIR analysis reveals the involvement of functional groups O-H, C-H, N-H, O=C=O, C≡C, N=C=S, C=C, N-O, C-N, and S=O in the biosorption process. SEM showed distortion in the cellular structure of the fungi. These results indicated the lead remediation potential of the fungal strains.

Our objective was to determine the effect of lead (Pb) on the behavior of the Mexican mojarra, which is native to the Balsas River basin, and the convict cichlid, which is an exotic invasive there. Both fish species were exposed to Pb, followed by Pb depuration, to evaluate its impacts on behavior. We evaluated swimming activity, predation attempts, prey consumed, foraging efficiency, and aggressive behaviors. The behavioral effects of Pb differed between the two species. While swimming activity decreased in both species during Pb exposure, swimming activity recovered during the Pb depuration period in the convict cichlid, but not in the Mexican mojarra. In both species, the total predation attempts and prey consumed increased during exposure to Pb and remained elevated during Pb depuration. Pb did not affect the foraging efficiency or number of aggressive behaviors of the convict cichlid. In contrast, the foraging efficiency of the Mexican mojarra decreased with Pb exposure and remained low during Pb depuration, and the number of aggressive behaviors increased under Pb exposure and remained elevated during Pb depuration. Pb exposure affected Mexican mojarra more strongly than the convict cichlid, which could induce changes in the ecological relationships between these species. [ABSTRACT FROM AUTHOR]

Lead (Pb) pollution is a major concern in many developing nations of the world. Hence, there is a need for the development of an environmentally safe and cost-effective method for the clean-up of contaminated environments. The present study investigated the tolerance of presumptively identified fungal species isolated from 5 different dumpsite soils to Pb concentrations 200, 400, 600, 800, 1000, 1500, 5000, and 10000 mg/L. The identity of strains exhibiting outstanding tolerance was confirmed using molecular technique, and their biosorption capacity at 10000 mg/L was evaluated. FTIR and SEM analyses were performed on the Pb2+ untreated and treated fungal biomasses. A total of 17 fungal isolates belonging to the genera Aspergillus Alternaria, Chrysosporium, and Penicillium were obtained. All the fungi were resistant to the test concentrations of Pb2+ except Chrysosporium sp. (at 5000 mg/L and 10000 mg/L) and Alternaria sp. (at 1500 mg/L, 5000 mg/L, and 10000 mg/L). Four isolates molecularly identified as A. awamori OP341445 and OP341446 and A. niger OP342447 and OP341448 recorded outstanding tolerance (> 1). Biosorption capacity was at its peak on day 5 except in OP34148, day 10 with a value of 97.82 mg/g. The Pb2+ removal rate was at equilibrium on day 5 (≈86%) except for OP41447 and OP41448 (≈87%) on day 15. FTIR analysis reveals the involvement of functional groups O-H, C-H, N-H, O=C=O, C≡C, N=C=S, C=C, N-O, C-N, and S=O in the biosorption process. SEM showed distortion in the cellular structure of the fungi. These results indicated the lead remediation potential of the fungal strains. [ABSTRACT FROM AUTHOR]

Lead (Pb) pollution is a major concern in many developing nations of the world. Hence, there is a need for the development of an environmentally safe and cost-effective method for the clean-up of contaminated environments. The present study investigated the tolerance of presumptively identified fungal species isolated from 5 different dumpsite soils to Pb concentrations 200, 400, 600, 800, 1000, 1500, 5000, and 10000 mg/L. The identity of strains exhibiting outstanding tolerance was confirmed using molecular technique, and their biosorption capacity at 10000 mg/L was evaluated. FTIR and SEM analyses were performed on the Pb2+ untreated and treated fungal biomasses. A total of 17 fungal isolates belonging to the genera Aspergillus Alternaria, Chrysosporium, and Penicillium were obtained. All the fungi were resistant to the test concentrations of Pb2+ except Chrysosporium sp. (at 5000 mg/L and 10000 mg/L) and Alternaria sp. (at 1500 mg/L, 5000 mg/L, and 10000 mg/L). Four isolates molecularly identified as A. awamori OP341445 and OP341446 and A. niger OP342447 and OP341448 recorded outstanding tolerance (> 1). Biosorption capacity was at its peak on day 5 except in OP34148, day 10 with a value of 97.82 mg/g. The Pb2+ removal rate was at equilibrium on day 5 (≈86%) except for OP41447 and OP41448 (≈87%) on day 15. FTIR analysis reveals the involvement of functional groups O-H, C-H, N-H, O=C=O, C≡C, N=C=S, C=C, N-O, C-N, and S=O in the biosorption process. SEM showed distortion in the cellular structure of the fungi. These results indicated the lead remediation potential of the fungal strains. [ABSTRACT FROM AUTHOR]

Phytoremediation of lead (Pb) in contaminated soils using hyper-enriched plants is an important task. It is a green and sustainable measure. Studies have revealed that three ornamental plants, Tagetes patula (T. patula), Solanum nigrum (S. nigrum), and Mirabilis jalapa (M. jalapa), have the ability to enrich for Pb; however, studies on difference between them and root morphology and the relationship between tolerance and capacity are lacking. The ability of three lead-enriching plants, T. patula, S. nigrum, and M. jalapa, to cope with Pb stress was assessed in hydroponic experiments using five Pb stress concentrations (0–1000 mg/L). Under different Pb stress conditions, the growth of the shoots and roots of three tested ornamental plants was inhibited to varying degrees. In the three tested ornamental plants, Pb mainly accumulated in the roots, and the highest levels of Pb observed in the shoots of T. patula, S. nigrum, and M. jalapa were 1074.1 mg/kg, 958.7 mg/kg, and 975.3 mg/kg, respectively. All plants reached a critical level of Pb hyperaccumulation. Redundancy analysis showed that changes in the root architecture of the three tested ornamental plants were significantly and positively correlated with tolerance as well as the enrichment and transfer ability of the heavy metal Pb. Therefore, these three ornamental plants have the potential to remediate Pb-contaminated water and soil and can increase the tolerance and enrichment characteristics of Pb by regulating the root biomass and root length of the three test ornamental plants via various agronomic measures. In addition, more research should be conducted to assess their effectiveness as phytoextractants under field conditions. [ABSTRACT FROM AUTHOR]

With the rapid development of synthetic biology, various whole-cell biosensors have been designed as valuable biological devices for the selective and sensitive detection of toxic heavy metals in environmental water. However, most proposed biosensors are based on fluorescent and bioluminescent signals invisible to the naked eye. The development of visible pigment-based biosensors can address this issue. The pbr operon from Klebsiella pneumoniae is selectively induced by bioavailable Pb(II). In the present study, the proviolacein biosynthetic gene cluster was transcriptionally fused to the pbr Pb(II) responsive element and introduced into Escherichia coli. The resultant biosensor responded to Pb(II) in a time- and dose-dependent manner. After a 5-h incubation with Pb(II), the brown pigment was produced, which could be extracted into n-butanol. Extra hydrogen peroxide treatment during n-butanol extract resulted in the generation of a stable green pigment. An increased brown signal was observed upon exposure to lead concentrations above 2.93 nM, and a linear regression was fitted from 2.93 to 3,000 nM. Extra oxidation significantly decreased the difference between parallel groups. The green signal responded to as low as 0.183 nM Pb(II), and a non-linear regression was fitted in a wide concentration range from 0.183 to 3,000 nM. The specific response toward Pb(II) was not interfered with by various metals except for Cd(II) and Hg(II). The PV-based biosensor was validated in monitoring bioaccessible Pb(II) spiked into environmental water. The complex matrices did not influence the regression relationship between spiked Pb(II) and the dual-color signals. Direct reading with the naked eye and colorimetric quantification enable the PV-based biosensor to be a dual-color and low-cost bioindicator for pollutant heavy metal. [ABSTRACT FROM AUTHOR]

As agroecology deteriorates, agricultural production is threatened by the combined stressors of exposure to environmental pollutants and pathogenic microbes. Proper agronomic practices for crop growth management and fertilization require understanding plant tolerance strategies. Both rice blast and heavy metals substantially impair rice crops, while silicon (Si) is an effective amendment to alleviate the combined stressors. Herein, this study was conducted to investigate the rice physiology and pathology perspective on the mechanism of Si alleviation against both lead (Pb) toxicity and Magnaporthe oryzae infection, utilizing pot experiments with inoculation of the virulent Magnaporthe oryzae strain. Exogenous Si reduced the phyto-availability and plant absorption of Pb, resulting in a 73.5% reduction in exchangeable Pb concentration in soil and a 40.23% reduction in rice plants. Furthermore, Si addition boosted the plant antioxidant system by increasing the activities of related enzymes, as the activities of catalase, superoxide dismutase, and polyphenol oxidase were significantly improved while the activity of peroxidase in rice panicles decreased. As a result, an improvement in dry matter quantity by 19.19% was observed compared to treatments without Si application, and the panicle blast severity (PBS) was reduced by 0.4–37.52%. Notwithstanding the interaction between the combined stressors, this study revealed that the speciation of Pb formation in the rhizosphere was the primary contributor to the alleviation of abiotic stresses, whereas the regulation of oxidative stress by enzymatic antioxidants played a dominant role in alleviating Magnaporthe oryzae colonization and impairments. The regulation process may reveal the mechanism of siliceous fertilizer functioning in the paddy system. Thereby the role of exogenous Si in anti-fungal, heavy metal toxicology, and plant physiology needs further study to fully elucidate the role of Si amendment, which is proposed to be considered from the perspective of soil chemistry and plant physiology.

This study was conducted in order to study the effect of different concentrations of lead pollution on the photosynthetic characteristics and growth of Miscanthus floridulus, and to reveal its photosynthetic adaptability to lead stress. The differences of gas exchange parameters, chlorophyll fluorescence characteristics and photosynthetic pigment of two Miscanthus floridulus populations, one population from Boluo an uncontaminated site, and another population from Dabaoshan, a mine site, were compared and studied through nutrient solution culture experiments treated with heavy metal lead (Pb) in green house. The results showed that (1) under Pb stress, the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), intercellular carbon dioxide concentration (Ci), and chlorophyll content (Chl) of the leaves of the two populations decreased in different amplitude. Under moderate and severe Pb stress (80 mg·L−1, 120 mg·L−1, 240 mg·L−1), the plant biomass of non-mining population and mining population plants were 54.5%, 39.7%, 29.4% and 70.4%, 54.7%, 50.9% of the control, respectively. (2) Stomatal restriction was the main factor for the Pn's decrease in the leaves of the non-mine population under light Pb stress, while the non-stomatal restriction was the main factor for Pn's decrease in the leaves of the non-mine population under middle and high Pb stresses. (3) Under Pb stress, the maximum photochemical efficiency (Fv/Fm) and potential activity (Fv/Fo) of PS II reaction centers in the two populations of M. floridulus decreased. However, Fv/Fm and Fv/Fo showed a smaller decrease, but the capability to utilize light and the potential to activate PSII of the mine population remained higher than that of the non-mine population. The changes of photochemical quenching coefficient (qP) and non-photochemical quenching coefficient (NPQ) of PSⅡ showed that qP value decreased and NPQ value increased in the two populations under Pb stress. On the whole, the resistance mining area population had a low qP reduction and a large increase in NPQ. Electronic transfer rate (ETR) and PSII actual fluorescence efficiency (ΦPSII) of the mine population changed slightly under Pb stress. These results indicated that when under Pb stress, the electron transport activity and photosynthetic apparatus were damaged less in the mine population with high resistance than in the non-mine population with low resistance. Conclusion: the mining population of M. floridulus has strong tolerance to Pb, which is suitable for the pioneer species of gramineae in vegetation restoration construction in metal mining area. [ABSTRACT FROM AUTHOR]

Cow manure derived biochar (CMBC) can serve as a promising functional material, and CMBC can be regarded as an ecofriendly approach compared to conventional ones. CM bioadsorbent can be employed for heavy metal immobilization (such as for lead) as well as an amendment to increase soil fertility (e.g., phosphorus). Few studies have examined the surface interactions between pollutants and bioadsorbents when inherent nutrient release is present. In this work, CMBC was prepared and applied for Pb(II) removal, and the vital roles of released phosphorus from CMBC were comprehensively disclosed. Furthermore, CMBC could immobilize part of the Pb(II) in soil and promote plant growth. CM400 was an effective adsorbent whose calculated Qe reached 691.34 mg·g−1, and it rapidly adsorbed 98.36 mg·g−1 of Pb(II) within 1 min. The adsorption mechanisms of Pb(II) by CMBC include ion exchange, physical adsorption, electrostatic attraction, chemical precipitation, surface complexation, and cation–π bond interaction. Based on the residual phosphorus content and adsorption effect, complexation rather than the chemical precipitation had a greater contribution toward adsorption. Besides, as the concentration of Pb(II) increased, the main adsorption mechanisms likely transformed from chemical precipitation to ion exchange and complexation. CMBC not only had a good effect on Pb(II) removal in the solution, but also immobilized the Pb(II) in soil to restrain plant uptake as well as promote plant growth. The main novelty of this work is providing more insights to the cow manure bio adsorbent on Pb immobilization and phosphorus release. This study is expected to serve as a basis and reference for analyzing the release effects of inherent nutrients and the interfacial behaviors with heavy metals when using CMBC and other nutrient–rich carbon–based fertilizers for pollution control. [ABSTRACT FROM AUTHOR]

In this research, we collected 10 samples, 2 soil and 8 vegetables cultivated in orchard area allowing district agricultural land in Al-Khatib at a few distances from Kadhimiya district, and adjacent to the area Al-Huria samples are congested as in table 2 after the chemical digestion of the seamount by using the atomic absorption technique, we found the following results: The highest value of Cadmium in A5 sample was 0.0436 ppm and 0.026933 ppm, the highest value of Lead in the sample A1 (soil of Kadhimiya) was 0.07345 ppm average and the highest value of Brass in A2 was 1.1176 ppm and 0.1762 ppm. The highest value of Cadmium in B4 (Rashad) was 0.0514 ppm and 0.04303 ppm, and the highest value of Lead in B5 (Kirath) was 0.365 ppm and on average 0.2293 ppm, the value of Copper in B4 (Rashad) was 1.1491 ppm and 0.20185 ppm in seriously. The limits are permitted within the WHO (World Health Organization), and therefore, there is no contamination of these items in these regions A and B (allows bastinade Kadhimiya, Khatib) respectively.

Phytoremediation of lead (Pb) in contaminated soils using hyper-enriched plants is an important task. It is a green and sustainable measure. Studies have revealed that three ornamental plants, Tagetes patula (T. patula), Solanum nigrum (S. nigrum), and Mirabilis jalapa (M. jalapa), have the ability to enrich for Pb; however, studies on difference between them and root morphology and the relationship between tolerance and capacity are lacking. The ability of three lead-enriching plants, T. patula, S. nigrum, and M. jalapa, to cope with Pb stress was assessed in hydroponic experiments using five Pb stress concentrations (0–1000 mg/L). Under different Pb stress conditions, the growth of the shoots and roots of three tested ornamental plants was inhibited to varying degrees. In the three tested ornamental plants, Pb mainly accumulated in the roots, and the highest levels of Pb observed in the shoots of T. patula, S. nigrum, and M. jalapa were 1074.1 mg/kg, 958.7 mg/kg, and 975.3 mg/kg, respectively. All plants reached a critical level of Pb hyperaccumulation. Redundancy analysis showed that changes in the root architecture of the three tested ornamental plants were significantly and positively correlated with tolerance as well as the enrichment and transfer ability of the heavy metal Pb. Therefore, these three ornamental plants have the potential to remediate Pb-contaminated water and soil and can increase the tolerance and enrichment characteristics of Pb by regulating the root biomass and root length of the three test ornamental plants via various agronomic measures. In addition, more research should be conducted to assess their effectiveness as phytoextractants under field conditions.

Lead-contaminated water, soil, and air have been perceived as potential sources of lead exposure for a considerable length of time, which continues to threaten human health; particularly that of young children. An Integrated Exposure, Uptake, and Biokinetic (IEUBK) as a human health risk model were applied to predict the Blood lead levels (BLLs) in children. A variety of data for air, soil, and water were obtained from the industrial region in Al-Dorah city in Baghdad for the period 2012- 2014. The result found that the predicted BLLs value of 11.17 μg/dL obtained from the IEUBK model was exceeding the agency’s threshold of concern of 10 μg/jdL which was considered as the lowest level of concern for BLL in children, this result of the IEUBK model was in agreement with the actual value of BLLs which were taken from previous literature for 24 blood samples of school children matched for age curried out in the same Al-Dorah region. This technique propels logical comprehension of the connection between BLLs in children and environmental media in both air and soil for the pollute condition. It can control national health-based benchmarks for lead and related community public health decisions.

The study was carried out to investigate the remediative capacity of Eleusine indica in lead-polluted soil. Soil samples were collected near student hostel (hall 5) in the University of Benin. The soil samples were sun dried to constant weight and was pulverized with wooden roller and sieved with a hand sieve of 2 mm mesh size. The sieved soil was spiked with 0.625 g lead nitrate (PbNO3), lead sulphate (PbSO4), lead carbonate (PbCO3), lead acetetrahydrate (PbC2H6) and lead chloride (PbCl2) separately in three replicate using aqueous standard solutions. Tillers of Eleusine Indica were placed in the metal - polluted soil immediately and the experiment was allowed to stay for 15 weeks. The result showed that the uptake efficiency for Eleusine indica in both shoots and roots for lead nitrate was 0.016% and 0.8%, lead sulphate 0.016 % and 0.352 %, lead carbonate 0.064% and 0.496 %, lead acetetrahydrate 0.032 % and 0.688 %, and lead chloride 0.08 % and 0.72 % respectively, indicating that the plant might have sequestered the metal in the soil rather than accumulating it in the leaves. This was evident in the presentation of the metal sequestration factor of over 70 % irrespective of the nature of the metal. Microbial count of soil before and after contamination with lead nitrate was 1.9×104 and 0.4×104 cfu/g indicating a reduction. The study therefore revealed that Eleusine indica is a high efficient plant in sequestering lead in polluted soil. [ABSTRACT FROM AUTHOR]

Cow manure derived biochar (CMBC) can serve as a promising functional material, and CMBC can be regarded as an ecofriendly approach compared to conventional ones. CM bioadsorbent can be employed for heavy metal immobilization (such as for lead) as well as an amendment to increase soil fertility (e.g., phosphorus). Few studies have examined the surface interactions between pollutants and bioadsorbents when inherent nutrient release is present. In this work, CMBC was prepared and applied for Pb(II) removal, and the vital roles of released phosphorus from CMBC were comprehensively disclosed. Furthermore, CMBC could immobilize part of the Pb(II) in soil and promote plant growth. CM400 was an effective adsorbent whose calculated Qe reached 691.34 mg·g−1, and it rapidly adsorbed 98.36 mg·g−1 of Pb(II) within 1 min. The adsorption mechanisms of Pb(II) by CMBC include ion exchange, physical adsorption, electrostatic attraction, chemical precipitation, surface complexation, and cation–π bond interaction. Based on the residual phosphorus content and adsorption effect, complexation rather than the chemical precipitation had a greater contribution toward adsorption. Besides, as the concentration of Pb(II) increased, the main adsorption mechanisms likely transformed from chemical precipitation to ion exchange and complexation. CMBC not only had a good effect on Pb(II) removal in the solution, but also immobilized the Pb(II) in soil to restrain plant uptake as well as promote plant growth. The main novelty of this work is providing more insights to the cow manure bio adsorbent on Pb immobilization and phosphorus release. This study is expected to serve as a basis and reference for analyzing the release effects of inherent nutrients and the interfacial behaviors with heavy metals when using CMBC and other nutrient–rich carbon–based fertilizers for pollution control.

Tall fescue (Festuca arundinacea Schreb.) shows huge potential for lead (Pb) phytoremediation, while little is known on the molecular mechanisms involved in Pb tolerance and accumulation. Here, genetic engineering strategy was firstly used to investigate Pb tolerance and accumulation in tall fescue. The transgenic tall fescue overexpressing a class II (CII) sHSP gene FaHSP17.8-CII was generated. After exposure to 1000 mg/L Pb(NO3)2, two FaHSP17.8-CII overexpressing lines, OE#3 and OE#7, showed higher tolerance to Pb as illustrated by the reduced levels of electrolyte leakage (EL) and malondialdehyde (MDA) as compared to the wild-type (WT) plants under Pb stress. Moreover, the FaHSP17.8-CII overexpression lines, OE#3 and OE#7, exhibited 36.3% and 46.6% higher shoot Pb accumulation relative to the WT grasses. When the grasses were exposed to Pb stress, the two OE lines had higher CAT, POD and SOD activities as compared to WT. Additionally, overexpression of FaHSP17.8-CII improved the synthesis of chlorophyll and transcript abundance of FapsbC, FapsbD and FapsbE, and alleviated the photoinhibition of PSII in tall fescue under Pb stress. This study provides an initial genetic engineering strategy to improve Pb phytoremediation efficiency in tall fescue by FaHSP17.8-CII overexpression.

Lead (Pb) is one of the most common metal pollutants in soil, and phytoextraction is a sustainable and cost-effective way to remove it. The purpose of this work was to develop a phytoextraction strategy able to efficiently remove Pb from the soil of a decommissioned fuel depot located in Italy by the combined use of EDTA and endophytic bacteria isolated from indigenous plants. A total of 12 endophytic strains from three native species (Lotus cornicolatus, Sonchus tenerrimus, Bromus sterilis) were isolated and selected to prepare a microbial consortium used to inoculate microcosms of Brassica juncea and Helianthus annuus. As for B. juncea, experimental data showed that treatment with microbial inoculum alone was the most effective in improving Pb phytoextraction in shoots (up to 25 times more than the control). In H. annuus, on the other hand, the most effective treatment was the combined treatment (EDTA and inoculum) with up to three times more Pb uptake values. These results, also validated by the metagenomic analysis, confirm that plant-microbe interaction is a crucial key point in phytoremediation. [ABSTRACT FROM AUTHOR]

• The growth, biosynthesis of pigments and other macromolecules appeared to be strong predictors in appraisal of Pb tolerance/susceptibility in durum wheat. • Germplasm of CBD59, CBD63 and CBD66 can be exploited for future selection and breeding programs. • The bioaccumulation of metal in grains of some cultivars of durum wheat much below than permissible limits set by FAO/WHO is of great significance owing to its implications for food safety. Lead (Pb) pollution emerged as an international issue particularly during second and third industrial revolution and is of serious global concern. Cereal crops have shown different capabilities, innate variability and mechanisms to cope with heavy metals present in their environment. Keeping in view the perspectives of food security and safety with increasing demand for Triticum durum L. it becomes imperative to appraise sustainability potential of the crop for Pb contaminated soils. The current study was conducted to test the hypothesis that T. durum germplasm holds genetic variability to evolve under Pb contamination through modulations of morpho-biochemical parameters of selective advantage. The performance of nine T. durum L. cultivars (CBD25, CBD46, CBD58, CBD59, CBD63, CBD66, CBD68, CBD69 and CBD82) was evaluated following exposure to varying Pb levels (control, 10, 20 and 40 mg kg−1) in soil. Growth, biosynthesis of macromolecules and metal distribution in plant parts were assessed using valid procedures and protocols. The cultivars exhibited a differential degree of tolerance to Pb and among the tested germplasm, CBD59 performed better followed by CBD63 and CBD66 for their primary productivity traits, biosynthesis of pigments and other macromolecules (amino acids, proteins and sugar) along with resilience for Pb uptake and its consequent bioaccumulation in grains. The traits used in the study served as strong predictors to provide superior/selective ability to survive under contaminated environment. The study signified that metal tolerance/sensitivity in the cultivars is independent of magnitude of metal stress, growth responses and Pb accumulation in plant parts hence varied in space and time. The existence of genetic variability, which is a pre-requisite for selection can definitely be of great advantage for future breeding projects to develop high yielding varieties/ cultivars of durum wheat with Pb free grains to assure food security and safety. [ABSTRACT FROM AUTHOR]

Environmental degradation due to human economic activities is closely linked to poverty in developing countries and can have long-term effects on well-being and sustainable development. This study investigates the nexus between toxic pollution and poverty by examining the economic impacts of lead (Pb) exposure on household welfare in Kabwe, Zambia. Kabwe, once a lead and zinc mining center, is now one of the world's most polluted urban areas, with high soil and air lead levels posing substantial health risks. We conducted a household survey and collected blood samples, matching socioeconomic data with blood lead levels (BLLs). Our empirical strategy uses variations in soil lead concentration across Kabwe neighborhoods to assess the causal impact of lead exposure on household welfare dimensions, such as consumption, education, health, and labor supply. Results show that a 1% increase in adult BLLs reduces per capita household consumption by 0.1–0.2% and increases the probability of being below the poverty line. Additionally, BLLs negatively affect adult health and children's schooling, while healthcare costs and labor supply remain unaffected. These findings suggest that lead exposure exacerbates poverty, hinders human capital accumulation, and has long-lasting implications for sustainable development. • Investigates the nexus between toxic pollution and poverty in Kabwe, Zambia. • Uses soil lead concentration variations to assess the causal impact of lead exposure on household welfare. • A 1% increase in adult blood lead levels decreases per capita consumption by 0.1-0.2% and increases the poverty risk. • Lead exposure harms adult health and children's schooling, while healthcare costs and labor supply remain unaffected. • Highlights lead exposure's enduring effects on human capital and poverty. [ABSTRACT FROM AUTHOR]

Nanoscale zerovalent iron (nZVI) is efficient for removing Pb(2+) and nitrate from water. However, the influence of nitrate, a common groundwater anion, on Pb(2+) removal by nZVI is not well understood. In this study, we showed that under excess Fe(0) conditions (molar ratio of Fe(0)/nitrate>4), Pb(2+) ions were immobilized more quickly (

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Abstract Understanding the context from which evidence emerges is of paramount importance in reaching robust conclusions in scientific inquiries. This is as true of the present as it is of the past. In a trans‐disciplinary study such as More et al. (2017, https://doi.org/10.1002/2017GH000064) and many others appearing in this and similar journals, a proper analysis of context demands the use of historical evidence. This includes demographic, epidemiological, and socio‐economic data—common in many studies of the impact of anthropogenic pollution on human health—and, as in this specific case, also geoarchaeological evidence. These records anchor climate and pollution data in the geographic and human circumstances of history, without which we lose a fundamental understanding of the data itself. This article addresses Hinkley (2018, https://doi.org/10.1002/2018GH000105) by highlighting the importance of context, focusing on the historical and archaeological evidence, and then discussing atmospheric deposition and circulation in the specific region of our study. Since many of the assertions in Bindler (2018, https://doi.org/10.1002/2018GH000135) are congruent with our findings and directly contradict Hinkley (2018), this reply refers to Bindler (2018), whenever appropriate, and indicates where our evidence diverges.

Abstract Over the past four decades numerous studies of lake sediment, marine sediment, and peat from sites in close proximity to mining or metallurgical centers and in remote locations have detailed local and regional histories of lead (Pb) pollution in Europe. Contrary to More et al.'s (2017, https://doi.org/10.1002/2017GH000064) claim that “previous assumptions about preindustrial “natural” background lead levels in the atmosphere have been misleading,” these studies have clearly shown that true natural background conditions occurred more than 2,500 or even 3,500 years ago, and Pb pollution has proceeded uninterrupted since. The implications of this have been discussed within the context of environmental policy, for example, European Water Framework Directive. Though these records reflect a common European narrative of mining, metallurgy, and pollution, each reflects a combination of local and regional events, leading to differences in the timing and intensity of changes in each Pb record. No one record—ice or otherwise—fully represents the three millennia Pb pollution history in Europe. While the resolution of the ice record is impressive, there are questions about its interpretation. First, the authors discount local and regional Pb sources, whereas there is a close connection between the mining history in an area 40 km from the glacier and changes in a nearby lake Pb record; second, significant changes in ice chemistry cooccurring with the lowest Pb values are overlooked. A sharp increase in Ca/Fe ratios occurs precisely with the steepest Pb declines during the Black Death and mid‐1400s, suggesting additional processes influencing the Pb record.

Currently, the pollution of soils by heavy metals is a problem of paramount relevance and requires the development of proper remediation techniques. In particular, lead is a frequently detected soil contaminant that poses adverse effects to the environment and human health. In this review, we provide an overview of the bioremediation treatments promoted by plants (phytoremediation), fungi, or bacteria that could be applied to areas polluted by lead. These restoration processes have the advantage of being environmentally friendly and cost-effective solutions that exploit plants to immobilize and extract contaminants from soil and water, and fungi and bacteria to degrade them. Phytoremediation is an extensively studied and mature practice, with many in-the-field applications where numerous plant species have been employed. In contrast, bioremediation processes promoted by fungi and bacteria are very promising but, up to now, studies have been mostly performed at a laboratory scale with only a few implementations in real-world situations; therefore, further research is needed. [ABSTRACT FROM AUTHOR]

Lead (Pb) is one of the most common metal pollutants in soil, and phytoextraction is a sustainable and cost-effective way to remove it. The purpose of this work was to develop a phytoextraction strategy able to efficiently remove Pb from the soil of a decommissioned fuel depot located in Italy by the combined use of EDTA and endophytic bacteria isolated from indigenous plants. A total of 12 endophytic strains from three native species (Lotus cornicolatus, Sonchus tenerrimus, Bromus sterilis) were isolated and selected to prepare a microbial consortium used to inoculate microcosms of Brassica juncea and Helianthus annuus. As for B. juncea, experimental data showed that treatment with microbial inoculum alone was the most effective in improving Pb phytoextraction in shoots (up to 25 times more than the control). In H. annuus, on the other hand, the most effective treatment was the combined treatment (EDTA and inoculum) with up to three times more Pb uptake values. These results, also validated by the metagenomic analysis, confirm that plant-microbe interaction is a crucial key point in phytoremediation.

Lead (Pb2+) pollution is a serious food safety issue, rapid detection of Pb2+ residual in food is vital to guarantee food quality and safety. Here we proposed ratiometric aptamer probes, allowing robust Pb2+ supervision in food samples. Pb2+ specific aptamer can bolster a transition of G-quadruplex structural response to Pb2+; this process can be monitored by N-methyl mesoporphyrin IX (NMM), which is highly specific to G-quadruplex. Particularly, the utilization of G-quadruplex specific dye and terminal-labeled fluorophore allowed to endue ratiometric signal outputs towards Pb2+, dramatically increase the robustness for lead detection. The ratiometric G-quadruplex assay allowed a facile and one-pot Pb2+ detection at room temperature using a single-stranded DNA aptamer. We demonstrated its feasibility for detecting lead pollution in fresh eggs and tap water samples. The ratiometric G-quadruplex design is expected to be used for on-site Pb2+ testing associated with food safety.

One of methods to eliminate metals from water is the use of adsorption. Chitosal is a material with a biological origin and was chosen for this study. The material was extracted from shrimp shells. The final product of the extraction progress was chitosal gel with a diameter of 3.5 mm, 97% of purity and good solubility in 1% CH3COOH solution. Three adsorption columns were built with PVC plastic. Two experiments at lead concentration 6.98 mg/l and 15.7 mg/l were carried out with the flow from the top down, at different water retention times of 15 minutes, 30 minutes, 45 minutes, 60 minutes, 90 minutes, and 120 minutes. The results showed that at lead concentrations of 6.98 mg/l we did not find the optimum water retention time. However, in the second experiment with lead concentration of 15.7 mg/l we determined the optimal water retention time was 60 minutes for column h1 and the lead adsorption efficiency achieved was 30.44%; column h2, h3 were the same time (90 minutes) and the lead adsorption efficiency reached 44.71%; and 52.87% respectively.

Lead pollution in Arctic ice reflects large-scale historical changes in midlatitude industrial activities such as ancient lead/silver production and recent fossil fuel burning. Here we used measurements in a broad array of 13 accurately dated ice cores from Greenland and Severnaya Zemlya to document spatial and temporal changes in Arctic lead pollution from 200 BCE to 2010 CE, with interpretation focused on 500 to 2010 CE. Atmospheric transport modeling indicates that Arctic lead pollution was primarily from European emissions before the 19th-century Industrial Revolution. Temporal variability was surprisingly similar across the large swath of the Arctic represented by the array, with 250- to 300-fold increases in lead pollution observed from the Early Middle Ages to the 1970s industrial peak. Superimposed on these exponential changes were pronounced, multiannual to multidecadal variations, marked by increases coincident with exploitation of new mining regions, improved technologies, and periods of economic prosperity; and decreases coincident with climate disruptions, famines, major wars, and plagues. Results suggest substantial overall growth in lead/silver mining and smelting emissions--and so silver production--from the Early through High Middle Ages, particularly in northern Europe, with lower growth during the Late Middle Ages into the Early Modern Period. Near the end of the second plague pandemic (1348 to ~1700 CE), lead pollution increased sharply through the Industrial Revolution. North American and European pollution abatement policies have reduced Arctic lead pollution by >80% since the 1970s, but recent levels remain ~60-fold higher than at the start of the Middle Ages. [ABSTRACT FROM AUTHOR]

In this paper, the barrier mechanism of silico-alkaline sol-modified bentonite as cutoff wall materials for lead ions in lead‑zinc tailings ponds was investigated. Mechanical property tests, adsorption capacity tests, and permeability tests were conducted to assess the performance of the materials. The results indicated that the addition of silico-alkaline sol at a proportion of 20% by weight of bentonite improved the mechanical strength, anti-seepage ability, and adsorption capacity of the materials towards lead ions. The modification process of bentonite using silico-alkaline sol was confirmed through XED analysis. It was observed that silico-alkaline sol particles adsorbed onto the end face of montmorillonite crystal layer, altering its charge properties. This modification enhanced the adsorption capacity of bentonite towards metal cations. The interaction between the cutoff walls and lead ions was primarily governed by ion exchange. Through the utilization of CT and the finite element method (FEM), demonstrated the exiguity of connected flow lines in the vertical direction within the cutoff walls. Furthermore, column tests revealed that lead ions permeating through the cutoff walls gradually transformed into residuals and were immobilized within the wall. Visual Modflow analysis confirmed the effective application of the cutoff wall in remediating contaminated sites and the potential for practical implementation. • The materials for preparing cutoff walls. • Materials were analyzed by the pore-scale modeling. • The FEM was used to simulate the velocity field. • The control effect of the cutoff walls was simulated by Visual Modflow. [ABSTRACT FROM AUTHOR]

Lead (Pb) is one of the most hazardous heavy metal that caused serious problems for ecosystem at recent years. In this study, the effect of Pb on seed germination, incipient growth and antioxidant enzymes of six common used turfgrasses was investigated. The results showed that after implementation of different concentrations (0, 1000, 2000 and 3000 µM) of Pb, Agropyron elongatum exhibited the highest germination percentage (90%) under 3000 µM Pb, followed by Lollium perenne L. (85.56%). The lowest germination parameters including germination vigor, rate, index and germination percentage was found in Festuca ovina, which means it is the most sensitive species to Pb than the other studied turfgrasses. In contrast, F. rubra, F. ovina, A. elongatum and L. perenne had the most significant aerial growth and the lowest chlorophyll degradation even at high lead concentration. An increase in L. perenne and A. elongatum antioxidant enzymes activities as well as a decrease in F. ovina observed after exposure to 3000 µM Pb which correlated to their tolerance and sensitivity to Pb respectively. However, such increase in antioxidant activity was also found in F. Rubra and Poa pratensis but could not inhibit chlorophyll degradation and seedling growth retardation. It might support that there is suggesting the probable existence of a lead-injury mechanism rather than the oxidative stress. Overall, A. elongatum is introduced as the most tolerant turfgrass among studied ones, which could be cultivated in Pb-polluted sites.

Currently, the pollution of soils by heavy metals is a problem of paramount relevance and requires the development of proper remediation techniques. In particular, lead is a frequently detected soil contaminant that poses adverse effects to the environment and human health. In this review, we provide an overview of the bioremediation treatments promoted by plants (phytoremediation), fungi, or bacteria that could be applied to areas polluted by lead. These restoration processes have the advantage of being environmentally friendly and cost-effective solutions that exploit plants to immobilize and extract contaminants from soil and water, and fungi and bacteria to degrade them. Phytoremediation is an extensively studied and mature practice, with many in-the-field applications where numerous plant species have been employed. In contrast, bioremediation processes promoted by fungi and bacteria are very promising but, up to now, studies have been mostly performed at a laboratory scale with only a few implementations in real-world situations; therefore, further research is needed.

In recent times, there has been increased focus on a holistic approach to soil remediation with consideration of social, economic and environmental factors. Consequently, there is a demand from practitioners and regulators alike for suitable ways to measure ancillary outcomes, for example, effects on soil quality. Here we show that biochar, when applied to land to remediate lead (Pb)-contaminated soils, can lead to environmental improvements not realized by adding mined or manufactured phosphates. Here, we study a Pb-contaminated soil amended with two phosphate fertilizers (slow- and fast-release) and with biochars produced from poultry litter and from biosolids at three temperatures (300 °C, 400 °C and 500 °C). The results show that, unlike the fast-release P fertilizer, biochars did not result in an increase in the amount of leachable P that could be released into the environment. Biochars prepared at 500 °C presented a higher value of the integrative geometric mean of soil enzyme activity, compared to the P fertilizers. Overall, our research shows that biochars, particularly those prepared at the higher temperature tested, are a suitable alternative to P fertilizers as an integrative remediation strategy in Pb-contaminated soils, enabling soil biological restoration.

The Balkans are considered the birthplace of mineral resource exploitation and metalworking in Europe. However, since knowledge of the timing and extent of metallurgy in southeastern Europe is largely constrained by discontinuous archaeological findings, the long-term environmental impact of past mineral resource exploitation is not fully understood. Here, we present a high-resolution and continuous geochemical record from a peat bog in western Serbia, providing a clear indication of the extent and magnitude of environmental pollution in this region, and a context in which to place archaeological findings. We observe initial evidence of anthropogenic lead (Pb) pollution during the earliest part of the Bronze Age [~3,600 years before Common Era (BCE)], the earliest such evidence documented in European environmental records. A steady, almost linear increase in Pb concentration after 600 BCE, until ~1,600 CE is observed, documenting the development in both sophistication and extent of southeastern European metallurgical activity throughout Antiquity and the medieval period. This provides an alternative view on the history of mineral exploitation in Europe, with metal-related pollution not ceasing at the fall of the western Roman Empire, as was the case in western Europe. Further comparison with other Pb pollution records indicates the amount of Pb deposited in the Balkans during the medieval period was, if not greater, at least similar to records located close to western European mining regions, suggestive of the key role the Balkans have played in mineral resource exploitation in Europe over the last 5,600 years. [ABSTRACT FROM AUTHOR]

Lead pollution in Arctic ice reflects midlatitude emissions from ancient lead–silver mining and smelting. The few reported measurements have been extrapolated to infer the performance of ancient economies, including comparisons of economic productivity and growth during the Roman Republican and Imperial periods. These studies were based on sparse sampling and inaccurate dating, limiting understanding of trends and specific linkages. Here we show, using a precisely dated record of estimated lead emissions between 1100 BCE and 800 CE derived from subannually resolved measurements in Greenland ice and detailed atmospheric transport modeling, that annual European lead emissions closely varied with historical events, including imperial expansion, wars, and major plagues. Emissions rose coeval with Phoenician expansion, accelerated during expanded Carthaginian and Roman mining primarily in the Iberian Peninsula, and reached a maximum under the Roman Empire. Emissions fluctuated synchronously with wars and political instability particularly during the Roman Republic, and plunged coincident with two major plagues in the second and third centuries, remaining low for >500 years. Bullion in silver coinage declined in parallel, reflecting the importance of lead–silver mining in ancient economies. Our results indicate sustained economic growth during the first two centuries of the Roman Empire, terminated by the second-century Antonine plague. [ABSTRACT FROM AUTHOR]

Abstract: Understanding the context from which evidence emerges is of paramount importance in reaching robust conclusions in scientific inquiries. This is as true of the present as it is of the past. In a trans‐disciplinary study such as More et al. (2017, https://doi.org/10.1002/2017GH000064) and many others appearing in this and similar journals, a proper analysis of context demands the use of historical evidence. This includes demographic, epidemiological, and socio‐economic data—common in many studies of the impact of anthropogenic pollution on human health—and, as in this specific case, also geoarchaeological evidence. These records anchor climate and pollution data in the geographic and human circumstances of history, without which we lose a fundamental understanding of the data itself. This article addresses Hinkley (2018, https://doi.org/10.1002/2018GH000105) by highlighting the importance of context, focusing on the historical and archaeological evidence, and then discussing atmospheric deposition and circulation in the specific region of our study. Since many of the assertions in Bindler (2018, https://doi.org/10.1002/2018GH000135) are congruent with our findings and directly contradict Hinkley (2018), this reply refers to Bindler (2018), whenever appropriate, and indicates where our evidence diverges. [ABSTRACT FROM AUTHOR]

Abstract: Over the past four decades numerous studies of lake sediment, marine sediment, and peat from sites in close proximity to mining or metallurgical centers and in remote locations have detailed local and regional histories of lead (Pb) pollution in Europe. Contrary to More et al.'s (2017, https://doi.org/10.1002/2017GH000064) claim that “previous assumptions about preindustrial “natural” background lead levels in the atmosphere have been misleading,” these studies have clearly shown that true natural background conditions occurred more than 2,500 or even 3,500 years ago, and Pb pollution has proceeded uninterrupted since. The implications of this have been discussed within the context of environmental policy, for example, European Water Framework Directive. Though these records reflect a common European narrative of mining, metallurgy, and pollution, each reflects a combination of local and regional events, leading to differences in the timing and intensity of changes in each Pb record. No one record—ice or otherwise—fully represents the three millennia Pb pollution history in Europe. While the resolution of the ice record is impressive, there are questions about its interpretation. First, the authors discount local and regional Pb sources, whereas there is a close connection between the mining history in an area 40 km from the glacier and changes in a nearby lake Pb record; second, significant changes in ice chemistry cooccurring with the lowest Pb values are overlooked. A sharp increase in Ca/Fe ratios occurs precisely with the steepest Pb declines during the Black Death and mid‐1400s, suggesting additional processes influencing the Pb record. [ABSTRACT FROM AUTHOR]

High mountain areas are an appropriate indicator of anthropogenic lead (Pb), which can reach remote mountain ranges through long distance atmospheric transport. We compared the content of Pb in ecologically equivalent rodent species from Tian-Shan with European mountain ranges including the Tatra, Vitosha and Rila mountains. We used bone tissues from terminal tail vertebrae of small rodents for detection of Pb levels through electro-thermal atomic absorption spectroscopy (AAS). The tailbones of Tian-Shan rodents had significantly lower Pb levels than snow voles from the Tatra Mountains, but there was no significant difference in comparison with the Vitosha and Rila mountains. We can conclude that Tian-Shan shows lower pollution by Pb than the Tatras, which may be a result of prolonged industrialization of north-western Europe and strongly prevailing west winds in this region. [ABSTRACT FROM AUTHOR]

As agroecology deteriorates, agricultural production is threatened by the combined stressors of exposure to environmental pollutants and pathogenic microbes. Proper agronomic practices for crop growth management and fertilization require understanding plant tolerance strategies. Both rice blast and heavy metals substantially impair rice crops, while silicon (Si) is an effective amendment to alleviate the combined stressors. Herein, this study was conducted to investigate the rice physiology and pathology perspective on the mechanism of Si alleviation against both lead (Pb) toxicity and Magnaporthe oryzae infection, utilizing pot experiments with inoculation of the virulent Magnaporthe oryzae strain. Exogenous Si reduced the phyto-availability and plant absorption of Pb, resulting in a 73.5% reduction in exchangeable Pb concentration in soil and a 40.23% reduction in rice plants. Furthermore, Si addition boosted the plant antioxidant system by increasing the activities of related enzymes, as the activities of catalase, superoxide dismutase, and polyphenol oxidase were significantly improved while the activity of peroxidase in rice panicles decreased. As a result, an improvement in dry matter quantity by 19.19% was observed compared to treatments without Si application, and the panicle blast severity (PBS) was reduced by 0.4–37.52%. Notwithstanding the interaction between the combined stressors, this study revealed that the speciation of Pb formation in the rhizosphere was the primary contributor to the alleviation of abiotic stresses, whereas the regulation of oxidative stress by enzymatic antioxidants played a dominant role in alleviating Magnaporthe oryzae colonization and impairments. The regulation process may reveal the mechanism of siliceous fertilizer functioning in the paddy system. Thereby the role of exogenous Si in anti-fungal, heavy metal toxicology, and plant physiology needs further study to fully elucidate the role of Si amendment, which is proposed to be considered from the perspective of soil chemistry and plant physiology. [Display omitted] • Interaction of the combined stressors exacerbated rice impairment. • Si facilitates Pb formation speciation as an avoidance mechanism for stress mitigation. • Plant internal mechanism for alleviating M. oryzae infections by Si lies in the regulation of enzymatic antioxidants. [ABSTRACT FROM AUTHOR]

Phytotoxic effects of Pb as Pb(NO3)2 and silver nanoparticles on Mung bean (Vigna radiata) planted on contaminated soil was assessed in terms of growth, yield, chlorophyll pigments, phenol and flavonoid content at 120 ppm concentration. Experiments were carried out with 4 treatments in 10 days. Treatments were including (T1) control, (T2) silver nanoparticles (50 ppm), (T3) Pb as Pb (NO3)2 (120 ppm) and (T4) silver nanoparticles (50 ppm) plus Pb as Pb(NO3)2 (120 ppm). Regarding the pigment content, silver nanoparticles-treated plants showed a remarkable increase of chlorophyll. The loss of chlorophyll content was associated with disturbance in photosynthetic capacity which ultimately results in the reduction of Vigna radiate growth. Pb caused a fall in the total content of phenols, while the content of flavonoid not significantly changed. The minimum decrease in root length, weight of root fresh and stem fresh was observed in T4 group, but this factors increased in the other treatments. Also, length of stem and seedling height decreased in control group. Increase length and fresh weight of stem in Pb-treated plants suggest that compatible solutes may contribute to osmotic adjustment at the cellular level and enzyme protection stabilizing the structure of macromolecules and organelles.