Toxicity factors to assess the ecological risk for soil microbial communities.

The toxicity factor (TF), a critical parameter within the potential ecological risk index (RI), is determined without accounting for microbial factors. It is considerable uncertainty exists concerning its validity for quantitatively assessing the influence of metal(loid)s on microorganisms. To evaluate the suitability of TF, we constructed microcosm experiments with varying RI levels (RI = 100, 200, 300, 500, and 700) by externally adding zinc (Zn), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), cadmium (Cd), and mercury (Hg) to uncontaminated soil (CK). Quantitative real-time PCR (qPCR) and high-throughput sequencing techniques were employed to measure the abundance and community of bacteria and fungi, and high-throughput qPCR was utilised to quantify functional genes associated with CNPS cycles. The results demonstrated that microbial diversity and function exhibited significant alterations (p < 0.05) in response to increasing RI levels, and the influences on microbial community structure, enzyme activity, and functional gene abundances were different due to the types of metal(loid)s treatments. At the same RI level, significant differences (p < 0.05) were discerned in microbial diversity and function across metal(loid) treatments, and these differences became more pronounced (p < 0.001) at higher levels. These findings suggest that TF may not be suitable for the quantitative assessment of microbial ecological risk. Therefore, we adjusted the TF by following three steps (1) determining the adjustment criteria, (2) deriving the initial TF, and (3) adjusting and optimizing the TF. Ultimately, the optimal adjusted TF was established as Zn = 1.5, Cr = 4.5, Cu = 6, Pb = 4.5, Ni = 5, Cd = 22, and Hg = 34. Our results provide a new reference for quantitatively assessing the ecological risks caused by metal(loid)s to microorganisms.

Review of soil environment quality in India near coal mining regions: current and future predictions.

Production and utilization of coal are one of the primary routes of accumulation of Toxic Elements (TEs) in the soil. The exploration of trends in the accumulation of TEs is essential to establishing a soil pollution strategy, implementing cost-effective remediation, and early warnings of ecological risks. This study provides a comprehensive review of soil concentrations and future accumulation trends of various TEs (Cr, Ni, Pb, Co, Cu, Cd, Zn, Fe, Mn, and As) in Indian coal mines. The findings revealed that average concentrations of Cr, Mn, Ni, Cu, Zn, Pb, and Co surpass India's natural background soil levels by factors of 2, 4.05, 5.32, 1.77, 9.6, and 6.15, respectively. Geo-accumulation index values revealed that 27.3%, 14.3%, and 7.7% of coal mines are heavily polluted by Ni, Co, and Cu, respectively. Also, the Potential Ecological Risk Index indicates that Cd and Ni are primary contaminants in coal mines. Besides, the health risk assessment reveals oral ingestion as the main exposure route for soil TMs. Children exhibit a higher hazard index than adults, with Pb and Cr being major contributors to their non-carcinogenic risk. In addition, carcinogenic risks exist for females and children, with Cr and Cu as primary contributors. Multivariate statistical analysis revealed that TEs (except Cd) accumulated in the soil from anthropogenic sources. The assessment of future accumulation trends in soil TE concentrations reveals dynamic increases that significantly impact both the ecology and humans at elevated levels. This study signifies a substantial improvement in soil quality and risk management in mining regions.

Spatial and seasonal variations in trace metals in marine sediments from the Dubai coastal environment.

This study was conducted to assess sediment trace metals (Cd, Cr, Cu, Pb, Ni and Zn) contamination using a systematic approach by collecting sediment samples from 8 transects along the Dubai coastline, each 10 km long, and each transect included its nearshore sediment sampling station. Additionally, 10 sediment samples were collected from the Dubai creek and other potential sources of metal pollution. The sediment samples were collected in December and again in August. However, no significant difference in sediment metal concentration was found between the two sampling campaigns. The sediment trace metal concentrations (0.92-1.31 mg Cd/kg, 2.82-176.6 mg Cr/kg, 2.27-621.67 mg Cu/kg, 0.88-23.6 mg Pb/kg, 1.92-192.2 mg Ni/kg and 9.1-391.05 mg Zn/kg) showed considerable variability, except for Cd (1.08 ± 0.06 mg/kg, 5.55% variability). Despite this, no significant differences in sediment metal concentrations were found between the sampled transects. However, significant variations in Cr, Cu, Pb and Zn were evident between distances from the shoreline to offshore stations along the Dubai coast, and the nearshore locations presented clear evidence of elevated/maximum sediment metal concentrations. Most of the sediment trace metal concentrations, however, were found well within the sediment quality guidelines (SQGs) for nearshore sediments. Trace metal contamination hotspots, nonetheless, were identified at some nearshore stations as determined by metal level exceedance over the SQGs, background levels and the pollution load index, with limited potential ecological risk. Overall, the findings suggest that sediments in the Dubai coastal environment are mainly influenced by anthropogenic activities in stations located in the proximity of ship maintenance, ports, and industrial areas such as Dry Dock, Jaddaf, Jebel Ali Port, Wharfage, Hamriya and DUBAL.

Landscape transition-induced ecological risk modeling using GIS and remote sensing techniques: a case of Saint Martin Island, Bangladesh.

Uncontrolled human activity and nature are causing the deterioration of Saint Martin Island, Bangladesh's only tropical island, necessitating sustainable land use strategies and ecological practices. Therefore, the present study measures the land use/cover transition from 1974 to 2021, predicts 2032 and 2042, and constructs the spatiotemporal features of the Landscape Ecological Risk Index based on land use changes. The study utilized Maximum Likelihood Classification (MLC) on Landsat images from 1974, 1988, 2001, 2013, and Sentinel 2B in 2021, achieving ≥ 80% accuracy. The MLP-MC approach was also used to predict 2032 and 2042 LULC change patterns. The eco-risk index was developed using landscape disturbance and vulnerability indices, Bayesian Kriging interpolation, and spatial autocorrelations to indicate spatial clustering. The research found that settlements increased from 2.06 to 28.62 ha between 1974 and 2021 and would cover 41.22 ha in 2042, causing considerable losses in agricultural areas, waterbodies, sand, coral reefs, and vegetation. The area under study showed a more uniform and homogenous environment as Shannon's diversity and evenness scores decreased. The ecological risk of Saint Martin Island increased from 4.31 to 31.05 ha between 1974 and 2042 due to natural and human factors like erosion, tidal bores, population growth, coral mining, habitat destruction, and intensive agricultural practices and tourism, primarily in Nazrul Para, Galachipa, and Western Dakhin Para. The findings will benefit St. Martin Island stakeholders and policymakers by providing insights into current and potential landscape changes and land eco-management.

Ecological risk of mercury in bottom sediments and spatial correlation with land use in Neotropical savanna floodplain lakes, Araguaia River, Central Brazil.

The Araguaia River floodplain is an important biogeographic boundary between the two largest South American biomes: the Cerrado (Brazilian Savanna) and the Amazon rainforest. The large-scale degradation due to land use conversion experienced in the Araguaia River watershed represents a potential source of mercury (Hg) transport to aquatic ecosystems. However, more information is needed about the dynamics of Hg distribution in savanna floodplains, including the Araguaia River floodplain. We analyzed total mercury (THg) concentrations in the bottom sediments of 30 lakes connected to the Araguaia River and four tributaries, aiming to evaluate the environment's integrity based on the geoaccumulation index (Igeo) and the ecological risk index (ERI). The principal component analysis was applied to examine associations between Hg concentrations, environmental conditions, and land use intensity among lakes associated with different river systems. We used indicator cokriging to identify areas with a greater probability of Hg pollution and ecological risk associated with land use intensity. The land use data showed the predominance of areas used for pasture in the Araguaia River basin. THg concentrations in the sediments varied between 22.6 and 81.9 ng g-1 (mean: 46.5 ± 17.7 ng g-1). Sediments showed no significant pollution (Igeo: 1.35 - 0.50; Classes 1 and 2) and low to considerable ecological risks (ERI: 23.5-85.1; Classes 1 to 3). THg in bottom sediments was associated with land use, water turbidity and electrical conductivity, and sediment organic matter. The indicator cokriging indicates a moderate to strong spatial dependence between land use intensity and Hg, confirming the contribution of anthropic sources to the increment of ecological risk but also the influence of extrinsic factors (such as environmental conditions, geology, and hydrology). Integrating sediment assessment and land use indices with geostatistical methods proved a valuable tool for identifying priority areas for Hg accumulation at a regional scale.

Microplastic contamination in water and sediments of Mahanadi River, India: An assessment of ecological risk along rural-urban area.

Worldwide, environmental concerns about MPs pollution have increased. Microplastic contamination that pollutes the ocean is mostly caused by terrestrial transfer from close proximity locations. A study of MPs pollution near coastal locations becomes necessary to address the MPs transit, fate, and mitigation. In the current study MPs pollution in the surface water and sediment of the Mahanadi River estuary was assessed during Pre-MS and MS. The size, shape, and colour of the MPs were determined using a stereomicroscope, and the MPs polymer composition was identified by Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. The mean concentration of MPs that were potentially discovered in water was 16.6 ± 5.2 and sediments 197.3 ± 5.4 during Pre-MS. In the MS observed mean abundance of MPs was 15.1 ± 5.4 in water and 164.6 ± 76.9 in sediments. The highest abundant size was smaller than 1 mm; the most prevalent shape were fibers followed by film and fragments; black and white was a prominent colour in water and sediments respectively. Polyesters (PEs), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polyamide (PA), Polystyrene (PS), and Polycarbonates (PC) were found in the analysis of the chemical composition of MPs in water and sediments samples. The calculated PLI value shows pollution load at category I, with polymer hazard levels at categories III, IV, and V, indicating very high risk. The current research results show that river inflows and fishing-related actions are probably the main causes of MPs pollution.

Ecological footprint model of heavy metal pollution in water environment based on the potential ecological risk index.

Social heavy metal pollution poses a significant threat to aquatic ecosystems. Heavy metals are easily adsorbed by sediments and have cumulative effects on aquatic organisms, which is different with the hypothesis of the conventional ecological footprint model that the pollutants are independently degraded by water bodies. To solve this problem, an ecological footprint for heavy metal pollution (EFHM) is constructed based on the potential ecological risk index (PERI). EFHM is defined as the sediment area to control the cumulative ecological risk of heavy metals within the allowable limit. And then, EFHM uses ecological footprint index (EFI) and ecological footprint contribution rate (EFCR) to quantify the hazard of social heavy metal load and recognize the key risk factor. EFHM is applied for assessing the heavy metal pollution of Central China. The results show that (i) the EFHM model can effectively evaluate the cumulative ecological hazards of heavy metals in sediment. (ii) The EFHM values of Central China in 2015 and 2020 are 20,764.56 and 17,358.59 km2, respectively. (iii) Compared with 2015, the EFI values of Hunan Province and Jiangxi Province in 2020 decrease from 1.53 to 0.87 to 1.23 and 0.39, respectively, both of which are improved by one grade. The EFI values of Hubei Province increases from 0.42 to 1.34, which is deteriorated by one grade. (iv) In 2020, both of the key risk factors of Hunan Province and Hubei Province are Hg, and the crucial hazard source of Jiangxi Province is Cd. (v) The mine pollution control in Central China should be further consolidated, and the wastewater treatment of electronics and machinery industries should be strengthened.

The new era hypothesis of coastal degradation: G(s) elements-gallium, gadolinium, and germanium.

Mining of precious metals contributes to environmental pollution, especially in coastal areas, and conventional treatment methods are not always effective in removing metal contaminants. Some of these metals, such as gadolinium, germanium and gallium, have caused increasing concern worldwide, as little is known about their current concentrations in the aquatic environment and their biological significance. Therefore, the aim of this study was to determine for the first time the variation of average G(s) concentrations (gallium, gadolinium and germanium) by month/season/site differences along the coast of Istanbul. The ecological risk index was calculated to assess the contamination of seawater and to serve as a diagnostic tool for the mitigation of water pollution. The average distribution G(s) in seawater was in the following order: Ga > Gd > Ge. In addition, the potential ecological risk in the sampling areas ranged from 68 to 1049. Of the three metals, Gd poses the highest ecological risk (grade III). In the spatial distribution of ecological risks, Gd mainly originated from discharges from wastewater treatment plants. Therefore, the sources of the anthropogenic Gd anomaly in wastewater should be identified, as this indicates the possibility of human exposure to potentially harmful anthropogenic compounds.

Heavy metal(loid)s contaminations in soils of Pakistan: a review for the evaluation of human and ecological risks assessment and spatial distribution.

Heavy metal(loid)s (HM) contaminations in the soil poses threats to the human and ecological community due to their bioaccumulation, toxicity, and persistent nature in the ecosystem. This review was designed to know about the HM contamination in soils, ecological risk, distribution, and potential health risks. Soil HM concentrations published in the last 30 years were collected from Springer, Science Direct, Willey, Mendeley, ResearchGate, Google Scholar, etc. HM concentrations were used for the geo-accumulation index (Igeo), contamination factor, as well as integrated indices such as spatial distribution of ecological risk index. Similarly, the Igeo pattern was observed in Sindh > Baluchistan > Punjab > Khyber Pakhtunkhwa > Gilgit-Baltistan > Islamabad. Moreover, the high ecological risk mean values ranged (160 < ERI < 320) due to cadmium (Cd) was exhibited in the Punjab and Khyber Pakhtunkhwa provinces and Islamabad. Non-carcinogenic risk like hazard quotient was found higher for children (1.59) of Punjab due to arsenic (As) ingestion, whereas the lower risk was observed due to Zn (2.5E-08) for adults of Punjab province via inhalation pathway. Similarly, the health index (HI) from exposure to As (1.61) in soil was higher than the rest of the HM. Moreover, cancerous risk was determined and found in the tolerable range (10-4-10-6). This study recommended that HM contaminants in the soil need to be monitored on regular basis, especially in Baluchistan, Gilgit-Baltistan, and Sindh provinces.

Radiological and environmental hazards of granitic rocks in Wadi Faliq El Sahl and El Waar area, North Eastern Desert, Egypt.

Chronologically, the main exposures in the study area include; tonalite, granodiorite, adamellite, Hammamat Sediments, monzogranite, syenogranite, rapakivi syenogranite, alkali feldspar granite and dykes. This work aims to determine the suitability of the granitic rocks for using as ornamental stones through detecting their radiological and ecological impacts. The studied samples were measured radiometrically by using Na-I detector for determination of 226Ra, 232Th and 40K concentrations. External hazard indices (Hex) in some samples are more than unity, also, the (Raeq) are higher than the exemption limits (370 Bq.kg-1) exceeds the upper limit of exposure. The hierarchical cluster analysis (HCA) was applied to investigate the correlation between the radionuclides and the corresponding radiological hazard variables. Based on the statistical analysis, 232Th and 226Ra mainly contribute to the radioactive risk of the studied rocks. Regarding ecological indices, 42.1% of younger granite samples have Pollution load index values greater than 1, indicating deterioration, while the majority of older granite samples are lower than 1 suggesting perfection samples. Where, some sample from the older granitoids and younger granites have many radiological and ecological parameters greater than the recommended international limits, so, these samples should not be used in construction for safety reasons.

Distribution characteristics and potential ecological risk assessment of heavy metals in soils around Shannan landfill site, Tibet.

At present, sanitary landfill is mainly used for domestic waste treatment in Shannan City, Tibet. However, there are few studies on heavy metals in the soil around the landfill in Shannan city. Therefore, the surrounding soil of Luqionggang landfill in Shannan City, Tibet Autonomous Region, is taken as the research object. In the study, the geo-accumulation index method, Nemerow comprehensive pollution index method and potential ecological risk index method are mainly used to evaluate the pollution and risk of heavy metals in the soil around the landfill site. The main results are as follows: The average pH value of the soil around the landfill site is 9.37, belonging to the strong alkaline range. The average values of heavy metals Hg and Ni in soil exceeded the background content, and the average contents of other heavy metals Cu, Pb, Zn, Cr, As and Cd did not exceed the background content. The average content of these eight heavy metals did not exceed the screening value of the national soil environmental quality standard. In the horizontal direction, the average content of heavy metal elements Cu, Cr, Cd, Hg and Ni is relatively high in the west. The average content of heavy metals As, Zn and Pb in the north, east and south is slightly higher than that in the west. And the farther away from the landfill, the less the soil is affected by heavy metals. The evaluation results of geo-accumulation index show that heavy metal Hg is the most affected. The average value of the comprehensive pollution index is 2.969, which is between 2 and 3, belonging to the moderate pollution level. And the west side of the landfill (downstream area) is greatly affected. The evaluation results of potential ecological hazard pollution index show that the potential risk index of single pollutants of heavy metals Cu, Pb, Zn, Cr, Ni, As and Cd belongs to low ecological hazard level, and the potential risk index of single pollutants of heavy metal Hg belongs to relatively heavy ecological hazard level. On the whole, the total potential risk coefficient belongs to medium pollution hazard degree. According to the correlation analysis, there is no significant correlation between heavy metal elements As and Hg and the other six heavy metal elements. In addition, the pollution source of heavy metal As may be mainly soil forming factors and the pollution source of Hg may be mainly human factors.

Microplastics in the marine environment of St. Mary's Island: implications for human health and conservation.

Microplastics have now been identified as a class of emerging pollutants and is considered as a threat to aquatic organisms. This baseline paper investigated the distribution, composition, and potential ecological risks of microplastic (MP) pollution on St. Mary's Island, revealing an average abundance of 0.218 particles/L in water samples. Blue fibres and white foams were the primary MPs identified, and fishing activities and packaging were the main sources of pollution. Six types of polymers were identified: low-density polyethylene (LDPE), polystyrene (PS), polyamide (PA), polypropylene (PP), polyethylene (PE), and high-density polyethylene (HDPE). The Polymer Hazard Index (PHI) and Potential Ecological Risk Index (PERI) indicated a medium environmental risk for the island. Additionally, it was discovered that MPs' surfaces contained dangerous substances that could endanger aquatic life. The research emphasizes the significance of implementing measures such as responsible disposal, management, elimination, regulatory policies, and local administration techniques to mitigate the impact of MP pollution on the island's shores and marine biota. This research provides a baseline for monitoring MP contamination and underscores the need for continuous investigation to assess their impacts on marine life.

Evaluating heavy metal pollution risks and enzyme activity in soils with intensive hazelnut cultivation under humid ecological conditions.

In order to promote sustainable agriculture and ensure food security, it has become more vital to identify the causes of soil pollution in agricultural areas. This study was carried out in order to determine the danger of heavy metal contamination in hazelnut production areas and to take the appropriate actions in accordance with the study's findings. In this context, the main objectives of this study were to (i) determine some physical, chemical, and biological properties and heavy metal concentrations of different soils in intensive hazelnut cultivation areas under humid ecological conditions; (ii) reveal the heavy metal pollution risks of these areas by their enrichment factor, contamination factor, geo-accumulation index, degree of contamination, pollution load index, and potential ecological risk index; (iii) analyze the quality of soils contaminated with heavy metals by their total enzyme activity index and the geometric mean of enzymatic activities; and (iv) explore the correlation between heavy metals and soil enzyme activity indices. According to our results, the average concentrations of heavy metals in the study area ranked as Fe > Mn > Zn > Cr > Ni > Cu > Co > Pb > Cd. Based on EF, the area was evaluated as between deficiency to low enrichment and moderate enrichment for all elements except for Cd. When the parameters used to assess the risk of heavy metal contamination were evaluated, it was determined that the risk of contamination of other elements in the study area, except Cd, was low. Finally, analyzing the heavy metals and soil enzyme activity indices shows that there is a negative correlation between Ni and GMea and TEI.

Assessment of seasonal variation in distribution, source identification, and risk of polycyclic aromatic hydrocarbon (PAH)-contaminated sediment of Ikpoba River, South-South Nigeria.

The study aims to assess the seasonal variation in distribution, source identification, and risk of 20 polycyclic aromatic hydrocarbons (20 PAHs) in the sediment of the Ikpoba River, south-south Nigeria. The PAHs were extracted in an ultrasonic bath with a mixture of n-hexane and dichloromethane (1:1 v/v). The extract was cleaned by silica-alumina gel mixed with anhydrous Na2SO4 in a chromatography column, eluted by n-hexane, and analysed by gas chromatography-mass spectrometry. The range of the average PAHs in mg.kg-dw was 0.15 (Nap)-0.54 (Acy) and 0.13 (D.al.P)-0.99 (Acy) in wet and dry periods correspondingly, indicating an increase in concentration from wet to dry period. However, the rings of the average concentration of the PAHs show 6 and 3 rings to be the highest values during the wet and dry seasons, respectively. Based on the human health risk analysis, the hazard quotient (HQ) and hazard index (HI), and carcinogenic risk indices showed low non-carcinogenic and carcinogenic risk for both seasons. The ecological risk analysis showed the mean effect range median quotient (mERMQ) recorded a medium-low effect on the biota of the locations, except in AS3 during the wet season and also in WS8 and WS9 during the dry season. The minimum value of the toxic equivalent quotient (TEQ) was > 0.2 mg/kg, which indicated a recommendation for the clean-up of the Ikpoba River. The isomer ratio and the principal component analysis (PCA) revealed the sources of the PAHs to be majorly combustion, followed by pyrolytic and petrogenic sources for both seasons.

Spatial and temporal distribution of heavy metals pollution and risk indices in surface sediments of Gomal Zam Dam Basin, Pakistan.

Sediments were considered a sink and potential source of heavy metals in the aquatic system. For this purpose, the present study examined surface sediments for spatial and temporal variation of heavy metals pollution and risk indices in the Gomal Zam Dam Basin (GZDB), Pakistan. Sediment samples (n = 20) were collected from the GZDB, i.e., Gomal Zam Dam, its inlets, and outlets in the winter and summer seasons of 2020, and examined for heavy metals such as zinc (Zn), nickel (Ni), manganese (Mn), lead (Pb), chromium (Cr), copper (Cu), iron (Fe), and cobalt (Co) concentrations. Among GZDB, results showed that the Zhob River Inlet had a higher levels of heavy metals in both seasons. The results revealed that pollution load index values were < 1, observing no pollution in the aquatic system. The risk indices values revealed that sampling sites showed no or very low risk during the summer, 84% of samples showed no or very low risk during the winter, and the rest noted with reasonable risks. Winter season showed higher average values of contamination and risk indices than summer. Statistical analyses revealed that the heavy metals contaminations were mainly due to geogenic sources of rock weathering and ore deposits, with minor contributions from anthropic activities. This study recommends regular monitoring of temporal studies on heavy metals contamination in the water of the GZDB.

Urbanization-driven soil degradation; ecological risks and human health implications.

Urban soils contaminated with heavy metals and pesticide residues are of great concern because of their adverse impact on human health. A total of 66 agricultural topsoil samples (15 cm) were collected to represent the study area and determine how anthropogenic activities adversely affect soil quality and human health. Sampling was conducted in the summer, when it was dry and hot, and in the winter, after atmospheric deposition. Seventeen potentially hazardous metals/metalloids (Ag, As, Al, B, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Mo, Pb, Se, Zn, and V) were measured in the soils. The mean concentrations of metals ranged between 0.05 and 8080 mg/kg, and their distribution was site-specific, with high pollution at the sampling sites owing to proximity to human activities. In agricultural areas, the greatest arsenic concentration was recorded at 48 mg/kg. The potential ecological risk index (PERI) and health hazard index (HI) were calculated, as well as metal contamination indices including contamination factor (Cf), geo-accumulation index (Igeo), and pollution load index (PLI). The mean PLI was calculated to be 4.89, indicating that the area is highly polluted. The potential ecological risk index showed remarkably high risks for As, Cd, and Hg, and moderate risks for Ni and Pb. The arsenic hazard index (HI) was greater than one (2.41) in children, indicating a risk of exposure through ingestion. Pesticide residue analyses were performed in areas where the metal intensity was high. Banned or restricted organochlorine pesticide (OCPs) residues, including, dieldrin, endrin ketone, endosulfan I, II, heptachlor, heptachlor epoxide, lindane (γ-HCH), PP-DDD, and methoxychlor, were detected between 0.002 and 1.45 mg/kg in the soil samples.

Spatial Distribution of Heavy Metal Contamination in Road Dust Samples from an Urban Environment in Samsun, Türkiye.

Road dust is an environmental pollution indicator created by human activities for urban land use. This study aimed to determine the spatial distribution pattern and degree of trace metals in road dust samples collected from 5 different areas in Samsun city center. The trace metals of Mn, Co, Cd, Cr, Cu, Ni, Pb, and Zn are the most examined contaminants in road dust because their hot-spot areas were mainly associated with high traffic density. Factors governing potential contamination index range values of Co, Cr, and Ni were 0.34-0.62, 0.23-0.78, and 0.24-0.48 as the lowest contamination. However, potential contamination index values of Cu, Pb, and Zn in the main road site were 1.80, 2.32, and 2.84 suggesting that relatively high values were uncontaminated to moderately. Pollution assessment methods were applied to toxic metals and revealed that Samsun city had been affected as uncontaminated to moderately contaminated by anthropogenic emission of heavy metals.

Global ambient air quality monitoring: Can mosses help? A systematic meta-analysis of literature about passive moss biomonitoring.

Surging incidents of air quality-related public health hazards, and environmental degradation, have prompted the global authorities to seek newer avenues of air quality monitoring, especially in developing economies, where the situation appears most alarming besides difficulties around 'adequate' deployment of air quality sensors. In the present narrative, we adopt a systematic review methodology (PRISMA, Preferred Reporting Items for Systematic reviews and Meta-Analyses) around recent global literature (2002-2022), around moss-based passive biomonitoring approaches which might offer the regulatory authorities a complementary means to fill 'gaps' in existing air quality records. Following the 4-phased search procedure under PRISMA, total of 123 documents were selected for review. A wealth of research demonstrates how passive biomonitoring, with strategic use of mosses, could become an invaluable regulatory (and research) tool to monitor atmospheric deposition patterns and help identifying the main drivers of air quality changes (e.g., anthropogenic and/or natural). Besides individual studies, we briefly reflect on the European Moss Survey, underway since 1990, which aptly showcases mosses as 'naturally occurring' sensors of ambient air quality for a slew of metals (heavy and trace) and persistent organic pollutants, and help assessing spatio-temporal changes therein. To that end, we urge the global research community to conduct targeted research around various pollutant uptake mechanisms by mosses (e.g., species-specific interactions, environmental conditions, land management practices). Of late, mosses have found various environmental applications as well, such as in epidemiological investigations, identification of pollutant sources and transport mechanisms, assessment of air quality in diverse and complex urban ecosystems, and even detecting short-term changes in ambient air quality (e.g., COVID-19 Lockdown), each being critical for the authorities to develop informed and strategic regulatory measures. To that end, we review current literature and highlight to the regulatory authorities how to extend moss-based observations, by integrating them with a wide range of ecological indicators to assess regional environmental vulnerability/risk due to degrading air quality. Overall, an underlying motive behind this narrative was to broaden the current regulatory outlook and purview, to bolster and diversify existing air quality monitoring initiatives, by coupling the moss-based outputs with the traditional, sensor-based datasets, and attain improved spatial representation. However, we also make a strong case of conducting more targeted research to fill in the 'gaps' in our current understanding of moss-based passive biomonitoring details, with increased case studies. Supplementary Information: The online version contains supplementary material available at 10.1007/s10668-023-03043-0.

Provincial and seasonal influences on heavy metals in the Noyyal River of South India and their human health hazards.

This study was carried out to evaluate the heavy metals (Lead (Pb), Nickel (Ni), Chromium (Cr), Copper (Cu), Cadmium (Cd) and Zinc (Zn)) pollution in the Noyyal River of South India by collecting 130 river water samples (65 each in pre- and post-monsoon). The heavy metals were measured using Atomic Absorption Spectrophotometer (AAS). The data were used to calculate the associated health hazards for the inhabitants consume river water. Correlation analyses and average concentration of heavy metals denoted that post-monsoon metal concentrations were lesser compared to the pre-monsoon due to dilution effect. Modified Contamination Degree (MCD) indicated that 45% of pre-monsoon and 25% of post-monsoon samples were classified under extremely polluted category. Heavy metal pollution index (HPI) showed that all the regions fall under highly polluted category except 'Region I' where 20% of samples were under safe category during the pre-monsoon, whereas 9%,28%, 17% and 26% of samples in Regions I, II, III and IV were highly polluted during the post-monsoon season, respectively. Ecological Risk Index (ERI) revealed that high risks attained in Regions II (78%) and III (82%) during pre-monsoon, and reduced risks found in Regions II (28%) and III (45%) during post-monsoon season due to dilution by monsoon rainfall. Non-carcinogenic risks as inferred by the Hazard Index (HI) indicated that 78% and 52% of samples for infants, 75% and 49% of samples for teens and 71% and 45% of samples for adults exceeded the threshold limits of USEPA (HI > 1) and possessed risks during pre- and post-monsoon, respectively. The cancer risk assessment based on ingestion of heavy metals indicated that the order of risk is Ni > Cr > Cu. The HI for infants and teens was notably high to that of adults in both the seasons. This study will be useful to develop effective strategies for improving river water quality and to reduce human health hazards.

Multivariate geo-statistical perspective: evaluation of agricultural soil contaminated by industrial estate's effluents.

Present study was carried out to explore heavy metals pollution and potential ecological risk factors associated with agriculture soil irrigated with industrial effluents of Hayatabad industrial estate, Peshawar (HIEP) and Gadoon industrial estate, Sawabi (GIES) of Khyber-Pakhtunkhwa, Pakistan through multivariate geo-statistical tools. Diverse statistical tools like cluster analysis (HC) and principal component analysis (PCA), along with geo-statistical approaches were applied to highlight the geogenic and anthropogenic sources of pollution. The results indicated that concentration of heavy metals in target areas was significantly higher than control. Both soils had significant to moderate enrichment of heavy metals, while Gadoon soil had moderate to considerable ecological risk factor. The geo accumulation indices (Igeo) tendency for heavy metals in both target soil (Gadoon and Hayatabad) were the same. The Pb concentration of both target areas falls in the extremely severely polluted category because of the excessive presence of industries producing lead-containing products. Hence, this study indicated that the majority of toxic heavy metals contributed to soil pollution in the studied areas are coming from industrial and commercial activities.