Pb Contamination Research Articles

Chemical fractionations and mobilization potentials for some trace metals in reef sediments and corals of Qeshm Island, the Persian Gulf

The bioavailability of trace metals in coral skeletons and sediment samples from Larak and Qeshm Islands in the Persian Gulf was investigated using the sequential extraction technique (SET), bioaccumulation measurement and risk assessment indices. The fractionation results and risk assessment indices indicated that Pb at the Qeshm Station and Cd and Zn at both Stations could have adverse biological effects due to high bioavailability. The bioaccumulation rate of metals in different reef species and at different Stations was not significant. The studied coral reefs showed a high tendency for Pb adsorption, so they could be an efficient bioindicator of Pb contamination. Statistical analysis showed that Pb and Zn were mainly from anthropogenic contamination sources, while the other metals were primarily of natural origin. The results indicated that further studies are needed to make a realistic assessment of the discharge of trace metals to the Persian Gulf.

Effect of stagnation period and flow rate on soluble and particulate Pb leaching in copper pipe water distribution systems

Extremely high lead level in tap water caused by particulates has attracted increasing attention in recent years. Despite extensive research on the role of particulate Pb in water supply systems with lead service lines, little information is available on the role of particulate Pb in copper (Cu) water distribution systems. In this study, the dissolved, colloidal, and particulate lead and copper concentrations in representative prototype copper pipe water distribution systems with leaded solder joints and brass fixtures are measured. The effects of flow rate and stagnation time on metal fractionation are investigated. For each experimental scenario, all the water that stagnated inside the system is sampled to have a comprehensive understanding of lead contamination. Sampled at flow rates of 200–250 mL/s, the soluble lead and copper make up 60–96 % of the total concentration in the samples after hours of stagnation. More than half of the Pb and Cu particles are larger than 0.8 μm. Higher flow rates result in substantial increases in particulate metal concentrations but have no apparent effect on dissolved metals. The soluble and particulate copper concentrations (∼ 100–250 μg/L) both increase with stagnation time. For the case of Pb, while the particulate concentration increases (up to ∼ 40 μg/L after 12 h), the soluble concentration does not change significantly beyond 4 h; this can be attributed to the different solubilities of Pb (∼ 20 μg/L) and Cu (∼ 200 μg/L) in tap water. The results also show that particulates suspended by clean “once through” water (without prior stagnation) can lead to high levels of Pb contamination (> 10 μg/L).

Spatial geochemical structure of soft sediment on shallow littoral of the Gulf of Antalya, the eastern Mediterranean Sea

The concentrations of heavy metals in soft sediments of the Manavgat and Lara regions in Antalya, Türkiye were investigated to assess contamination levels and their potential sources, followed by multivariate statistical analysis and generation of spatial distribution maps. Results showed low contamination levels for As, Zn, and Cu, moderate contamination for Pb, Ni, and Mn, and very high accumulation for Co and Cr. Geoaccumulation index (Igeo) and contamination factor (CF) analyses revealed moderate enrichment for Mn and low enrichment for As, indicating no human-induced contamination in Cu, Pb, Zn, Mn, and As, while Ni, Co, and Cr originated mainly from agriculture. The maximum modified degree of contamination (mCd) value was at an extreme high level, with an average mCd of 4.12 indicating high contamination. Maximum pollution load index (PLI) value was 3.13, indicating high-grade pollution and an average value of 1.7 indicating moderate pollution.

Spatial and temporal variations in the environmental and biological characteristics of the Turyanchay River basin, Azerbaijan

This is the first comprehensive examination of the Turyanchay River in Azerbaijan, focusing on water quality (WQ), contamination, and biodiversity at four different locations: Gabala, Agdash, Udjar and Zardab. The study analysed nutrient (nitrate, ammonium, phosphate) and metal/metalloid (Pb, Cu, Ni, Zn, Mn, Cr, Cd, Fe and Al) contamination levels, as well as the diversity of macrozoobenthos in the river, birds and vegetation. The chemical and biological oxygen demands (COD and BOD), including WQ index (WQI) were also determined for the river. The results showed no significant difference in the levels of nutrients, metal/metalloid, COD, BOD, WQI and macrozoobenthos diversity across different locations (p > .05). However, they revealed temporal fluctuations, with their highest levels being recorded during the warmer months (July and August) and the lowest during the colder months (March and November). The estimated WQI, ranging from 19.6 to 43.6, indicated that the water in the Turyanchay River is safe for household and consumption purposes. Up to 83 species of macrozoobenthos were identified, with Hydropsychidae and Chironomidae showing the highest species richness, followed by Coenagrionidae, Psychomyiidae, Ceratopogonidae, Baetidae, Naididae and Gammaridae. Eighteen bird species, consisting of 11 terrestrial and 7 aquatic birds, were recorded, with eight of these species belonging to the Order Charadriiformes. A total of 42 different plant species belonging to 17 families were identified in the Turyanchay River basin, with Fabaceae being the most widely distributed, followed by Asteraceae and Typhaceae. This study provides important baseline data for the Turyanchay River, offering insights into its freshwater environment and biodiversity, and should support future monitoring efforts.

Isotopic signatures unveil the lead sources and migration in surface mangrove sediments

Mangrove sediments act as both sinks and secondary sources for lead (Pb), yet the sources, migration, and transformations of Pb in mangrove environments are poorly understood. In this study, Pb concentration in three mangrove sediments adjacent to different land-use types was evaluated. The Pb sources were quantitatively identified using Pb isotopes. Our data indicated minor Pb contamination in the mangrove sediments, possibly due to the relative lack of developed industry in this region. The Pb isotopic ratios suggested, on average, natural sources, coal combustion, agricultural activities, and traffic-related emissions respectively contributed approximately 61.4 %, 18.8 %, 14.0 %, and 5.8 % of the Pb accumulation in the mangrove sediments, suggesting that coal combustion and agriculture were important anthropogenic Pb sources. Significant relationships were observed between the 206Pb/207Pb ratios and total organic content (TOC) in mangrove sediments, which implied contrasting Pb cycling in two mangrove environments. We further suggested that organic matter and sulfur content significantly reduced Pb mobility and bioavailability in mangrove sediments. Our study provides isotopic method to investigate the Pb sources and migration in the mangrove environment.

S-Nitrosoglutathione (GSNO)-Mediated Lead Detoxification in Soybean through the Regulation of ROS and Metal-Related Transcripts.

Heavy metal toxicity, including lead (Pb) toxicity, is increasing in soils, and heavy metals are considered to be toxic in small amounts. Pb contamination is mainly caused by industrialization (e.g., smelting and mining), agricultural practices (e.g., sewage sludge and pests), and urban practices (e.g., lead paint). An excessive concentration of Pb can seriously damage and threaten crop growth. Furthermore, Pb adversely affects plant growth and development by affecting the photosystem, cell membrane integrity, and excessive production of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) and superoxide (O2-). Nitric oxide (NO) is produced via enzymatic and non-enzymatic antioxidants to scavenge ROS and lipid peroxidation substrates to protect cells from oxidative damage. Thus, NO improves ion homeostasis and confers resistance to metal stress. In the present study, we investigated the effect of exogenously applied NO and S-nitrosoglutathione in soybean plants Our results demonstrated that exogenously applied NO aids in better growth under lead stress due to its ability in sensing, signaling, and stress tolerance in plants under heavy metal stress along with lead stress. In addition, our results showed that S-nitrosoglutathione (GSNO) has a positive effect on soybean seedling growth under lead-induced toxicity and that NO supplementation helps to reduce chlorophyll maturation and relative water content in leaves and roots following strong bursts under lead stress. GSNO supplementation (200 µM and 100 µM) reduced compaction and approximated the oxidative damage of MDA, proline, and H2O2. Moreover, under plant stress, GSNO application was found to relieve the oxidative damage by reactive oxygen species (ROS) scavenging. Additionally, modulation of NO and phytochelatins (PCS) after prolonged metal reversing GSNO application confirmed detoxification of ROS induced by the toxic metal lead in soybean. In summary, the detoxification of ROS caused by toxic metal concentrations in soybean is confirmed by using NO, PCS, and traditionally sustained concentrations of metal reversing GSNO application.

A case study of environmental pollution by pathogenic bacteria and metal(oid)s at Soran Landfill Site, Erbil, Iraqi Kurdistan Region.

Environmental pollution is a serious issue all around the world, especially when it is caused by metal(oid)s and pathogenic microorganisms. This study reports here for the first time on the contamination of soil and water with metal(oid)s and pathogenic bacteria directly resulting from the Soran Landfill Site. Soran landfill is a level 2 solid waste disposal site that lacks leachate collection infrastructure. The site is potentially an environmental and public hazard caused by metal(oid)s content and significantly dangerous pathogenic microorganisms through leachate release into the soil and nearby river. This study reports on the levels of the metal(oid)s content of As, Cd, Co, Cr, Cu, Mn, Mo, Pb, Zn, and Ni obtained by inductively coupled plasma mass spectrometer in soil, leachate stream mud, and leachatesamples. Five pollution indices are used to assess potential environmental risks. According to the indices, Cd and Pb contamination is significant, whereas As, Cu, Mn, Mo, and Zn pollution is moderate. A total of 32 isolates of bacteria were defined from soil, leachate stream mud, and liquid leachate samples: 18, 9, and 5, respectively. Moreover, 16s rRNA analysis suggested that the isolates belong to three enteric bacterial phyla of Proteobacteria, Actinobacteria, and Firmicutes. The closest GenBank matches of 16S rDNA sequences indicated the presence of the genera: Pseudomonas, Bacillus, Lysinibacillus, Exiguobacterium, Trichococcus, Providencia, Enterococcus, Macrococcus, Serratia, Salinicoccus, Proteus, Rhodococcus, Brevibacterium, Shigella, Micrococcus, Morganella, Corynebacterium, Escherichia, and Acinetobacter. The identity percentage was mostly between 95%-100%. The results of this study show the levels of microbiological and geochemical contamination of soils, surface and potentially ground water with harmful microorganisms and toxic metal(oid)s originating specifically from Soran landfill leachate which subsequently incorporated into the surrounding environment, creating thus a considerable health and environmental risk.

Reagentless Dissolution and Quantification of Particulate Lead in Tap Water via Membrane Electrolysis.

The presence of particulate Pb in tap water has been a limiting factor in the design of accurate and portable platforms for quantifying this toxic metal. Convenient and affordable electrochemical techniques are blind toward particulate species and thus require addition of reagents and additional chemical processing such as sample acidification. This study describes the fundamentals and the first use of membrane electrolysis for the reagentless sample preparation of tap water for the detection of particulate Pb contaminants. Membrane electrolysis allows for the in-situ generation of nitric acid, which, in combination with anodic stripping voltammetry, provides a powerful tool for the accurate and reagent-free detection of Pb2+. The configuration of the setup allows for its semi-autonomous operation and requires minimal attention, making electrochemical methods more suitable and accessible for continuous measurements of particulate contaminants in tap-water. The voltammetric response is linear in the range of 24.1-398 nM of Pb, which covers the action level of 48 nM suggested by the World Health Organization.

Multiregional Pb isotopic linear patterns and diagenesis: Isotopes from ancient animal enamel show Native American “foreign war trophies” are local ancestors

Skull burials are found all over the world and often are interpreted to be foreigners, sacrifices, or victims of warfare. The cause of ancient Native American skull deposits often leads to disagreement among scholars torn between warfare and ancestor veneration. Most previous research suggested a Caddo skull-and-mandible deposit (consisting of clusters of skulls and clusters of isolated mandibles) in southwest Arkansas, USA contained foreign victims of interregional warfare, representing at least 352 people (1253–1399 CE). While Sr isotopes are commonly used in archaeology to investigate such issues, they did not provide a conclusive answer to the geographic origin of the remains. This study advances the biologically available Pb method by constructing a large-scale multiregional Pb isotopic background with ancient animal tooth enamel and uses their associated linear patterns to evaluate human geographic origins. Evaluation of Pb contamination through diagenesis in human tooth enamel is evaluated and advanced using correlation analysis of trace elemental data from teeth and burial soil. A total of 180 animal teeth were processed from 28 ancient sites in the southcentral USA. Combining Pb isotopic linear patterning analysis with the Sr isoscape allows us to establish that the skulls and mandibles are local to southwest Arkansas and indicate or strongly suggest they are non-local to all other tested regions. This illustrates the importance of Pb isotopes in studies of human geographic origins. It also provides one cautionary tale that interpretations about violence related to detached skulls should be evaluated with appropriate methods and evidence and with a critical eye for other explanations. This study was conducted in collaboration with the Caddo Nation of Oklahoma and provided both the descendant community and researchers with answers to the questions surrounding the remains, serving as one example of how stakeholders can come together and produce positive outcomes.

In vitro study on antidiabetic and antihypertensive activities of ethanolic extract of propolis of Indonesian stingless bee Tetragonula sapiens

The stingless bee, Tetragonula sapiens, is one of the species producing propolis in Indonesia. To date, there is still limited information about the standard characteristics and biological activity of propolis. This study investigated the standardized extract of Indonesian propolis in terms of its potency for controlling diabetes and high blood pressure in vitro, in accordance with its standard parameters. Three types of extracts; i.e., ethanolic extract of propolis (EEP), spray-dry propolis without wax (SDPNW), and spray-dry propolis with wax (SDPW); were prepared from T. sapiens stingless bees collected in South Sulawesi, Indonesia. The ethanolic extractable, loss on drying, ash, and water content parameters of EEP, SDPNW, and SDPW met the natural extract requirement. There is no significant value for their residual solvent levels (<0.54%), heavy metals (the absence of As, Cd, Pb, and Hg contamination), or the absence of microbial contamination. ACE inhibition activity on captopril, EEP, SDPNW, and SDPW had IC50 values of 5.97, 115.06, 112.93, and 116.70 ppm, respectively. While the IC50 values of acarbose, SDPNW, EEP, and SDPW for antidiabetic activity of α-glucosidase inhibition were 53.34, 56.48, 60.09, and 68.28 ppm, respectively. The TFC and TPC content of SDPNW were higher than EEP and SDPW, with values of 1.59% and 1.93%, respectively. It can be said that Indonesian propolis extract meets the standards for an extract and has the potential to reduce diabetic and hypertensive diseases. Further preclinical and clinical studies are needed to develop standardized propolis extract as an anti-diabetic and antihypertensive agent.

Roman-era alluvial waste in the Vistre de la Fontaine (Nîmes, southeast France): from a sacred spring to a contaminated river

AbstractThe excavation of a palaeochannel at the Vistre de la Fontaine 2-2 archaeological site, 3 km downstream from the ancient city of Nîmes (southeastern France), provided an accumulation sequence covering the last 2,500 years. Trace metal analyses of these alluvial sediments disclosed lead (Pb) contamination during the Early Roman Empire, with concentrations close to 1,000 ppm, a factor of 100 above the local geochemical background. This excess of Pb shows a uniform isotopic signature that may reflect unchanged ore sources, perhaps from the Massif Central or from Great Britain. The Pb peak accompanied visible waste that was transported in the sediments of the Vistre de la Fontaine at the time of the development of the Nîmes urban water supply and drainage network during the Early Roman Empire. This research shows the bimillennial persistence of palaeo-contamination in a peri-urban alluvial plain and the relevance of fluvial sedimentary archives in documenting ancient waste.

The Effect of Geomembrane Plastic Usage on Microplastic and Heavy Metal Contamination in Salt Field

Seawater is used to produce salt. For 10–15 years, geomembrane plastic has been used in salt fields in Indonesia to prevent contamination and increase quality and productivity. However, it is unfortunate that currently, seawater has been polluted by plastic waste, which has degraded gradually into small pieces about <5 mm in size called microplastics. In addition to microplastics, seawater is also polluted by heavy metals. Previous research indicated that the north coast of Central Java has been polluted by heavy metals whose content exceeded the threshold. The aim of this study was to analyze the amount of microplastic (MPs) and heavy metal contamination in salt. A microscope was used to measure the amount of MPs and AAS was used to measure the concentration of heavy metals. Variables that were conducted included sampling location (4 locations) and crystallization process (with and without using geomembrane). The results showed that the amount of MPs salt with a geomembrane was higher than without a geomembrane, at 337 and 326 particles/kg, respectively. The average is 332 particles/kg. Salts that use geomembranes have more contamination than salts without geomembranes. Heavy metal contamination of Pb, Cd, Hg, As, all of which were still within the threshold. The average Pb and Cd concentration in salts with and without geomembranes were 4.11 mg/kg and 4.14 mg/kg; 0.65 and 1.05, respectively. Meanwhile, the average of Hg and As concentrations for both were below than 0.001 and 0.005 mg/kg, respectively.

Investigating Heavy Metal Contamination Extent of Soil and Plant from Urban Gardens in Jinju

In Korea, 90% of the population lives in urban areas, so urban agriculture is commonly carried out. However, research on the safety of urban soils for growing food still needs to be done. Thus, this study was conducted to evaluate the suitability of urban soil for crop cultivation by investigating the heavy metal concentration of soil and plant from urban gardens in Jinju. Soils and crop leaves were collected from 23 urban gardens, and the concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn were analyzed. The average concentrations of garden soils in Jinju were As 5.31, Cd 0.59, Cr 30.09, Cu 33.05, Ni 21.14, Pb 23.28, and Zn 121.68 mg kg-1, which did not exceed the Korean guidelines except for Zn in one study site. Geoaccumulation Index, calculated using the background values of heavy metals in Korean soil, showed that contamination of Cd, Cu, Pb, and Zn was in progress. The inflow of Cu and Zn into the garden soils would be from the atmosphere and direct entry into the soil by adding livestock manure. Differently, the other elements were more predominantly introduced from the atmosphere. Particularly, a significant amount of Pb was introduced into the soils from the atmosphere in a couple of gardens. Overall, the results from this study indicated that continuous monitoring for heavy metals in urban garden soils is required for food safety.The number of urban gardens at each level of soil contamination by Geoaccumulation Index. Level of soil contamination As Cd Cu Ni Pb Zn Practically uncontaminated 19 1 1 12 12 1 Uncontaminated to moderately contaminated 3 12 10 8 8 12 Moderately contaminated 1 10 9 3 2 8 Moderately to heavily contaminated 0 0 3 0 1 2 More than heavily contaminated 0 0 0 0 0 0

12 Years of honey surveys in northern Italy: How anthropic activities can influence honey quality

Bees and hive products, such as honey, can act as indicators of environmental quality. Our research aimed to evaluate historical data of honey quality in Lombardy (Northern Italy) and consider the possible sources of air contamination that can influence it. We collected analytical data from the local Health Protection Agency on residues of 57 honey samples from 2011 to 2022, comparing a rural area and an industrial area. At the same time, we consulted estimated air emissions in the same areas through the INEMAR database used by the local Environmental Protection Agency. Data revealed antibiotic contamination in one case and, regarding heavy metals, lead contamination in several samples in the industrial area. Pb contamination could derive from multiple sources. The INEMAR database permitted us to hypothesize that combustion in industry and road transportation could have a role in honey contamination, being among the main sources of Pb emission in that area.

Hexaploid Salix rehderiana is more suitable for remediating lead contamination than diploids, especially male plants

Willows are promising candidates for phytoremediation, but the lead (Pb) phytoremediation potential of different willow ploidy and sex has not yet been exploited. In this study, the Pb uptake, translocation and detoxification capacities of hexaploid and diploid, female and male Salix rehderiana were investigated. The results showed that Pb treatment inhibited biomass accumulation and gas exchange, caused ultrastructural and oxidative damage, and induced antioxidant, phytohormonal and transcriptional regulation in S. rehderiana. Absorbed Pb was mainly accumulated in the roots with restricted root-to-shoot transport. Despite lower biomass, greater transpiration, phytohormonal and transcriptional regulation indicated that hexaploid S. rehderiana had higher tissue Pb concentration, total accumulated Pb amount (4.39 mg, 6.19 mg, 6.60 mg and 10.83 mg in diploid and hexaploid females and males, respectively) as well as bioconcentration factors and translocation factors (0.412, 0.593, 0.921 and 1.320 for bioconcentration factors in roots, and 0.029, 0.032, 0.035 and 0.047 for translocation factors in diploid and hexaploid females and males, respectively) than diploids. Higher soil urease and acid phosphatase activities also favored hexaploids to use more available N and P than diploids in Pb-contaminated soils. Additionally, hexaploid S. rehderiana had stronger antioxidant, phytohormonal and transcriptional responses, and displayed less morphological and ultrastructural damage than diploids after Pb treatment, suggesting that hexaploids have greater Pb uptake, translocation and detoxification capacities than diploids. Moreover, S. rehderiana males had greater Pb uptake and translocation abilities, as well as stronger antioxidant, phytohormonal, and transcriptional regulation mediated Pb detoxification capacities than females. Therefore, hexaploid S. rehderiana are superior to diploids, and males are better than females in Pb phytoremediation. This study provides novel and valuable insights for selecting better willow materials to mitigate Pb contamination.

Comprehensive assessment on groundwater quality, pollution characteristics, and ecological health risks under seasonal thaws: Spatial insights with Monte Carlo simulations

Groundwater pollution is a major environmental concern and may persist under diverse ecological conditions. This study describes the seasonal impacts on pollution characteristics coupled with the degree of human health risks in groundwater. For this purpose, a highly populated city of Pakistan, Lahore was planned and about 50 groundwater samples were collected during the summer and winter seasons in 2021 and 2022. Various physiochemical parameters (pH, EC, TDS, and hardness), cations, anions, and toxic metals (As, Cd, Co, Cr, Mn, Ni, and Pb) were analyzed to evaluate the seasonal impacts on the groundwater quality. Besides, a Monte Carlo simulation model and sensitivity analysis were performed to obtain a high-level accuracy in cancer risk estimation. Results revealed that physiochemical parameters, cations, and anions in most of the samples were within the WHO limit. However, the heavy metals concentration was higher in winter than in summer season. Most metals showed a significant spatial variability were found in older settlements and densely populated areas of the city for both seasons. Factor analysis (FA) and cluster analysis (CA) revealed a significant anthropogenic contribution to Ni, Co, Cd, Cu, Cr, and Pb contaminations in groundwater. Drinking water quality indices (DWQI) and heavy metal pollution indices (HMEI) points in both seasons revealed a poor to moderated pollution pattern. Pollution load index (PLI) and potential ecological risk index (PERI) indicated the medium pollution with low risks. Through Monte Carlo simulation at 95% confidence level revealed that carcinogenic risks associated with As, Cr, Cd, and Ni has exceeded from safer limits. Consequently, winter season was perceived more sensitive owing to the substantial increase of pollutants proclamation in groundwater and posturing a serious threat to humans. Hence, instant remedial actions are suggested to ensure safe drinking water.

Perception and legacy of soil chromium and lead contamination in an operational small-scale coal mining community.

Operational small-scale coal mining (OSCM) is one of the most significant sources of chromium (Cr) and lead (Pb) pollution in Bangladesh. Attempts to minimize or lessen the use of Cr and Pb in OSCM have shown unsatisfactory results, mainly because they need to address the sociotechnical complexity of pollution concerns in OSCM. This research adopts a multidisciplinary, sociotechnical approach to addressing Cr and Pb problems, coupling soil sampling for Cr and Pb with questionnaires of miners' and inhabitants' perceptions of pollution and its distribution. The study was undertaken in the Barapukuria coal basin in northwest Bangladesh. Except for mining areas (average of 49.80 ± 27.25mg/kg), Cr levels in soils exceeded the world average in the periphery (73.34 ± 24.39mg/kg, ~ 1.2 times) and residential areas (88.85 ± 35.87mg/kg, 1.5 times the world standard of 59.5mg/kg). Pb levels in soils exceeded national and global averages in mining (53.56 ± 37.62mg/kg, ~ 1.9 times), periphery (35.05 ± 21.77mg/kg, ~ 1.3 times), and residential areas (32.14 ± 26.59mg/kg, ~ 1.2 times) when compared to Bangladesh and global standards of 20 and 27mg/kg. Pb levels were highest in mining areas, while Cr concentrations were highest in residential areas. The questionnaire findings indicated that miners and inhabitants did not correctly assume that the highest levels of Cr and Pb pollution would be found in these areas. Among all respondents, 54% are unaware of the health impacts of prolonged Cr and Pb exposure. They face respiratory problems (38.6%), skin diseases (32.7%), and other health issues. A large number of people (66.6%) agreed with the fact that Cr and Pb contamination has an impact on drinking water. Cr and Pb pollution has caused 40% crop loss and a 36% decrease in productivity in the agricultural sector. However, respondents underestimated the level of Cr pollution in mining areas, and most assumed that only individuals working directly with mines were impacted by the Cr and Pb content. Participants also rated the reduction of Cr and Pb contamination as of low importance. There is less awareness of Cr and Pb pollution among miners and inhabitants. Sincere efforts to reduce Cr and Pb pollution will likely be met with extra attention and hostility.

X-ray fluorescence analysis of coastal sediments of Tamil Nadu with a statistical approach

X-ray fluorescence spectroscopy is applied to determine the concentration of essential and toxic heavy metals such as silicon (Si), potassium (K), calcium (Ca), titanium (Ti), iron (Fe), copper (Cu), zinc (Zn), nickel (Ni), and lead (Pb) in the sediments of Kovalam coastal area, Tamil Nadu, India. Fe (599280 ppm), an essential heavy metal/mineral shows the highest average concentration, followed by Si (181593 ppm), Ca (130913 ppm), K (99673 ppm), Ti (77620 ppm), Cu (64 ppm), Ni (43 ppm), Pb (20 ppm), and Zn (8 ppm). Heavy metal contamination was assessed using various pollution indicators such as the geo-accumulation index (Igeo), contamination factor (CF), pollution load index (PLI), and enrichment factor (EF). Si, K, Ca, Ti, Fe, Cu, Ni, Pb, and Zn had mean Igeo values of −1.29, 1.54, 1.07, 3.59, 3.19, 0.64, −1.14, −0.22, and −3.70, respectively. Except for Ti (19.36) and Fe (13.87), the average CF value for determined heavy metals was significantly low. The PLI value ranges from 1.47 to 2.46. Heavy metal EF values are greater than 1 in all sampling locations. Multivariate statistical analyses such as Pearson correlation analysis, cluster analysis, and principal component analysis are performed to identify the sources of heavy metals in the studied sediment samples. The findings indicate that anthropogenic sources such as boating and tourism activities have a probable contribution on the enrichment of K, Ca, Ti, Fe, Cu, and Pb in sediments, necessitating more attention in monitoring of toxic heavy metals (such as Pb) contamination in the coastal environment.

Chemically Catalyzed Phytoextraction for Sustainable Cleanup of Soil Lead Contamination in a Community Garden in Jersey City, New Jersey

Soil lead (Pb) contamination in Pb paint-contaminated homes is a serious health risk in urban areas. Phytoextraction is a green and sustainable technology for soil Pb remediation, but its efficiency depends on the geochemical partitioning of Pb in soil. Following successful laboratory, greenhouse, and panel experiments, a field study was conducted to demonstrate the effectiveness of a chemically catalyzed phytoextraction model for Pb removal. A biodegradable chelating agent, ethylenediaminedisuccinic acid (EDDS) was applied during Pb phytoextraction by vetiver grass (Chrysopogon zizanioides) in a Pb-contaminated community garden in Jersey City, New Jersey. Results showed that soil Pb concentration was reduced from 1144 to 359 mg/kg in 3 years, despite ongoing Pb input to the field plots from a nearby construction site. EDDS was effective in converting non-plant-available forms of Pb (i.e., carbonate-bound, oxide-bound, and organic-bound forms) to plant-available forms (i.e., water-soluble and exchangeable forms). With EDDS application, vetiver roots accumulated 532, 231, and 401 mg/kg of Pb in Years 1, 2, and 3, respectively, which were higher than the values obtained without EDDS applications (228, 154, and 214 mg/kg). This field study demonstrated the effectiveness of a chemically catalyzed phytoextraction model for Pb removal from urban soils.

Effects of atmospheric deposition on heavy metals accumulation in agricultural soils: Evidence from field monitoring and Pb isotope analysis

Atmospheric deposition is an essential pathway of heavy metals (HMs) from the atmosphere to soils, while few studies assess the effects and contributions of atmospheric deposition on HMs accumulations in agricultural soils from the field and regional scales. In this study, eleven representative field monitoring sites from industrial areas, agricultural areas, and reference site in a typical rapid industrial development region were selected to determine the effects of atmospheric deposition on soil HMs accumulation. Industrial activities significantly increased the deposited particles flux from atmospheric deposition, with annual particles fluxes in industrial areas being 1.83 and 1.90 times higher than in agricultural areas and reference site, respectively. Although the HMs deposition fluxes had decreased significantly with time by literature comparison, the deposition fluxes of Cd and Pb were still at high levels in this study area. Precipitation was the key factor affecting seasonal variations of atmospheric HMs deposition. Lead isotope analysis indicated that atmospheric Pb originated from coal combustion, and atmospheric deposition was the primary source of Pb contamination in agricultural soil adjacent to industries. This study provided insight into the effects of atmospheric deposition on agricultural soil HMs accumulations at the regional scale and an important theoretical basis for source-preventing soil HMs contamination in industrial developed and other similar areas.