Average Concentrations Of Heavy Metals Research Articles

Investigation of Bioaccumulation and Human Health Risk Assessment of Heavy Metals in Crayfish (Procambarus clarkii) Farming with a Rice-Crayfish-Based Coculture Breeding Modes.

Due to the rapid development of the crayfish (Procambarus clarkii) industry in Chinese catering, people are paying more attention to the bioaccumulation of heavy metals in crayfish. To evaluate the health risks associated with the consumption of crayfish, nine types of heavy metals in both crayfish and abdominal muscles of crayfish were investigated. Crayfish samples were collected from rice-crayfish-based coculture breeding modes from different areas located in the middle and lower reaches of the Yangtze River. The average concentrations of heavy metals in the whole crayfish were much higher than the abdominal muscle of crayfish. The estimated daily intake (EDI) of heavy metals in the abdomen of crayfish was calculated to assess the noncarcinogenic risk and the overall noncarcinogenic risk including the target hazard quotient (THQ), the hazard index (HI) and carcinogenic risk (CR). The results of the present study showed that the consumption of crayfish may not present an obvious health risk to human associated with heavy metals. However, the THQ values of As in the abdominal muscles of crayfish for adults in EnShi (ES) and children in JiaYu (JY) should be of concern due to the higher contribution to the potential health risks of crayfish compared to other metals. Through X-ray photoelectron spectroscopy (XPS) detection of heavy metal As, it is found that As in crayfish culture environment mainly exists in the form of As3+.Therefore, the quality and quantity of crayfish consumption should be moderated to prevent the bioaccumulation of As. The results indicate that crayfish cultured in different areas may have similar pollution levels and/or emissions from the same pollution sources.

Characteristics and Risk Assessment of Heavy Metals in Urban Soils of Major Cities in China

The rapid urbanization in China may lead to heavy metal pollution in urban soil, threatening the health of residents. By collecting literature data published in the last 15 years, the characteristics and risks of heavy metals in the urban soils of 52 cities in China were analyzed. The results showed that the average ω(Pb), ω(Cd), ω(Cu) and ω(Zn) in the urban soils of China were 58.5, 0.49, 42.1, and 156.3 mg·kg-1, respectively, and the average Igeo values were ordered as follows Cd(1.10) > Zn(0.36) > Pb(0.28) > Cu(0.13). The high concentrations of heavy metals in the urban soils were mainly found in cities located in coastal economically developed provinces (such as Jiangsu, Zhejiang, etc.) and resource-based provinces (such as Hunan, Henan, Inner Mongolia, etc.). The cities of Kaifeng, Yangzhou, Hohhot, Taiyuan, and Xiangtan had relatively high Igeo values for heavy metals in the soils. The concentrations of heavy metals in soils from industrial areas and roadsides were significantly higher than those from residential areas and parks, suggesting that heavy traffic and developed heavy industry were the main causes of heavy metal accumulation in the urban soils. No significant correlations between the average concentrations of heavy metals in urban soil and urban economic and environmental indicators[such as permanent population, GDP, ρ (PM10), ρ(PM2.5), and SO2 emissions] were found. The concentrations of heavy metals in urban soils showed large spatial heterogeneity, and hence the average concentrations may not reflect the overall accumulation level in a city. The non-carcinogenic risks for children posed by heavy metals in urban soils were generally low, and the main risk contributor was Pb. However, the exposure to heavy metals in soils in cities with developed smelting industries is worthy of attention.

Fish diversity and heavy metal accumulation of Pb, Cu and Zn after Mount Sinabung Eruption in Benuken River, North Sumatra, Indonesia

Abstract. Pebriani MA, Barus TA, Ilyas S. 2021. Fish diversity and heavy metal accumulation of Pb, Cu and Zn after Mount Sinabung Eruption in Benuken River, North Sumatra, Indonesia. Biodiversitas 23: 187-194. The Benuken River is a river that has been affected by the volcanic ash eruption of Mount Sinabung, one of the active volcanoes in Indonesia. This study further examines the diversity of fish species and the analysis of their tissues with regard to the heavy metal content of each species in the Benuken River, Berastepu Village, Karo Regency after the eruption of Mount Sinabung using atomic absorption spectroscopy (AAS). The fish and water sampling were carried out in March 2019 with two sampling points using the electrofishing technique. Furthermore, four species were documented, including Spotted barb (Puntius binotatus), River loaches (Homaloptera nebulosa), Mahseer (Tor soro), and Striped snakehead (Channa striata). The diversity index of the fish community from two study sites ranged between 0.012<H' <0.023 or was categorized as very low in diversity. Meanwhile, the heavy metals concentrations of Cu, Pb and Zn in the water of Benuken River were below tolerance level based on the Governmental Regulations No. 82 year 2001. The average heavy metal concentrations in fish tissue were also safe for consumption based on the standard quality by FAO/WHO (2004) with 0.0049 ppm, 0.0056 ppm and 0.3852 ppm of Pb, Cu and Zn, respectively.

ASSESSMENT OF TEMPORAL VARIATION OF HEAVY METALS IN SEDIMENTS OF WARRI RIVER, SOUTHWESTERN NIGERIA

Contaminated sediment poses a serious environmental problem, therefore knowledge of the concentration of heavy metals in stream sediments is very important because of their significance to aquatic life and human health. The concentration of heavy metals (Cd, Pb, Cr, As, Ni, Zn, Fe and Cu), in stream sediments of some parts of Warri River, Southwestern Nigeria were examined during the rainy and dry seasons using Atomic Absorption Spectrophotometer, in order to assess their contamination levels using the environmental contamination indexes; Geoaccumulation Index, Enrichment Factor (EF), and Contamination Factor (CF). For both the rainy and dry seasons, the results revealed average heavy metal concentrations obtained in all samples in the study area in the order As>Cd>Pb>Ni>Cr>Zn>Cu>Fe. The trend in mean Igeo values was as follows: As (-0.66) > Zn (-4.93) > Cu (-5.8) > Fe (-5.31) > Cd (5.76) > Pb (-6.35) > Ni (11.25), showing that River Warri’s sediments were not polluted by heavy metals. Cu= Zn (0.08), Cd (0.34), Pb (0.02), As (0.01), and Ni (0.00) were the mean CF values across all measured locations, indicating a low contamination factor. The average EFs for the sediments were As (1.09) > Cd (1.10) > Cu (1.46) > Zn (1.61) > Pb (1.09) > Ni (1.09) > Fe (0.83), showing low enrichment (<2). Evaluation of enrichment factor, geo-accumulation index and contamination factor values showed that the stream sediments of the study area were unpolluted. Heavy metals in the sediments were found to be linked to anthropogenic activities in the study region, according to the results of the hierarchical cluster analysis (HCA). The metal concentrations in the sediment were found to be elevated at some sampled points, it is therefore recommended that annual monitoring of the stream sediments of the study area is undertaken. Also, sustainable practices should be employed in order to conserve the resources of the Warri River.

Heavy Metals in Agricultural Soils of National Capital Region, Delhi: Levels and Ecological Risk

This study was conducted to assess heavy metals concentrations in agricultural soils in the National Capital Region, Delhi. A total of 84 soil samples were collected from selected agricultural areas located near industries, national highways, state highways, Yamuna floodplain, residential complexes, and wastewater irrigated soils. Heavy metal concentrations, pH, and organic carbon (%) were analyzed in the collected soil samples. The average value of pH, and organic carbon (%) in the soil samples were 7.79±0.49 and 0.53±0.17 percent respectively. Average concentrations of heavy metals (mg kg-1) in the agricultural soils were found in the order of Fe > Al > Mn > Zn > Ni > Cr > Cu > Pb > Co > Cd with value as 14916.92, 13538.87, 277.16, 74.53, 35.34, 33.68, 22.94, 18.45, 1.88, and 0.92 . The concentrations of Zn, Ni, and Mn reported in the present study were several times higher than their concentration in Indian natural background soils. A significant potential ecological risk has been noticed in nearly all the agricultural soil samples except for the samples collected nearby residential areas. The contamination factor has shown that most of the soil samples were moderately contaminated with Mn, Ni, Fe, and Cr and some soil samples were considerably to strongly contaminated with Zn, Pb, Cd, and Ni. Wastewater irrigated soils showed a moderate to a strong degree of accumulation of Zn, Cd, and Ni.

Heavy Metal Levels in the Beyler Dam Lake, Kastamonu (Turkey)

In this study, some heavy metal concentrations (Cu, Cd, Pb, Cr, Mn and Zn) were seasonally determined in water to evaluate of the quality of the Beyler Dam Lake. The average concentrations of heavy metals analyzed in water samples for cold and hot season were Cu: 11.53, 13.23; Cd: 0.85, 0.97; Pb: 13.77, 16.26; Cr: 2.88, 3.48; Mn: 1.94, 1.71; and Zn: 7.57, 8.20 ppb, respectively. The annual average (AA) concentrations of heavy metals were Cu: 12.38; Cd: 0.91, Pb: 15.01, Cr: 3.18; Mn: 1.82; and Zn: 7.88 ppb. In general, the heavy metal concentrations were found to be higher in hot season than the cold season. It was observed that none of the heavy metals assessed exceeded the limits specified in the Turkish Water Pollution Control Regulation. The Beyler Dam Lake was classified as Class I for all the heavy metals except Pb for which it was classified as Class II. These results indicate that the lake is not polluted by the heavy metals. However, relatively high Pb levels seek further research to identify the source. The lake water can be used for agricultural activities but should continue to be monitored.

Assessment of the heavy metal sources and concentrations in the Nador Lagoon sediment, Northeast-Morocco

This study investigates the heavy metals (HM) and sulfurs concentration, enrichment level and potential sources in the bottom sediments of Nador lagoon, North-East Morocco. 50 samples of sediments from Nador lagoon heavy metals were analyzed by ICP-MS, while their spatial distribution and source identification were evaluated by Enrichment Factor (EF), QGis Inverse Distances Weighted (IDW) interpolation models, multivariate statistical techniques (Principal Component Analysis - Agglomerative Hierarchical Clustering - Pearson correlation matrix), Positive matrix factorization (PMF model) and grain size/organic matter analysis. The average heavy metal concentrations in the sediments are in the decreasing order: Sr > Ba > V > Zr > Zn > Cr > Rb > La > Cu > Pb > Ni > Ce > Nd > Co > Sc > Nb > Ga > Th > Y > Hf, and the Sulfurs. The results showed that the average concentrations of the S, Sr, Pb, and Nd in bottom sediments were higher than their background contents. The EF values demonstrated that HM contents were enriched by anthropogenic activities, especially for Sr and S, and secondly for Th, V, Ce, Nd, and Pb. The potential HM and sulfurs identified sources showed that: 1) Ga, Y, Hf, Nb, Rb, Sc, Zr, Nb, Co, Zn, Th, Ni, V, Ba, Cr, and Cu were derived industrial activities related to stealing and mining; 2) Wastewater treatment station and lagoon watershed were the main sources of Sr in the lagoon; 3) Zn, Cu, and Pb also linked to sulfurs, mostly origin from agriculture inputs and mining activities; 4) Ce, Cr, and Ni linked to sulfurs, mainly origin form metallurgical activities and solid wastes. The results suggest that heavy metal concentrations were significantly affected anthropogenic activities. Severe enrichment of Sr was found in the lagoon ecosystem with no correlation with carbonates, with four sources of heavy metals apportioned by Geostatistics and Positive matrix factorization. Solid waste, water waste and industrial activities were the main anthropogenic source. Lutite fraction and organic matter show a high accord with heavy metals concentration distribution.

Effects of long-term agricultural activities on the availability of heavy metals in Syrian soil: A case study in southern Syria

Agricultural soil pollution has attracted the attention of scientists and agricultural managers because of its importance to food security worldwide. In Syria, limited studies have been conducted to determine heavy metals (HMs) concentrations in arable lands. The objective of this study was to investigate the concentration of HMs in the southern part of Syria, and to identify the potential sources HMs. To achieve the study goals, 38 soil samples (0–25 cm) were collected and analysed for physical and chemical soil properties, while the DTPA (Diethylenetriamine pentaacetate) method was to extract HMs from soil. The results of this study showed that the average concentration of HMs in the study area are 2.00; 12.70; 8.56; 4.37; 0.12; and 0.12 ppm for Cu; Fe; Mn; Zn; Cd; and Pb, respectively. A multivariate statistical analysis showed that Cu, Fe, and Mn originated from parent material (natural resources), while Zn and Cd were related to agricultural activities (anthropogenic one) and Pb was relatively related to industrial activities. Interestingly, the spatial distribution indicates that Cu, Fe, and Mn distributed in the southern and eastern part of the study area, while Pb and Zn were dominant in the western and northern part. In addition, Cd was observed in the central part of the study area. We conclude that human activities are the main contributor of HMs accumulation in soil. The distribution of these HMs could affect the safety of agricultural product in the future.

Heavy Metal Concentrations and Human Health Risk Assessment of Selected Wild and Cultured Fishes of Bangladesh

This study was conducted to estimate the concentration of selected heavy metals such as chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) as well as the possible risk to consumer health from the flesh of three wild and cultured fishes (Labeo rohita, Mystus cavasius, and Heteropneustes fossilis) collected from the Meghna river, Narayangonj and Rajoir fish farm, Madaripur district respectively. Heavy metal concentrations were determined using Atomic Absorption Spectrometric method. The average concentration of heavy metals were found in the wild fish samples in the range as Cr (0.295-1.647), Mn (0.900-1.294), Ni (0.063-0.198), Cu (0.179-0.529), Zn (5.487-8.343), Cd (0.004-0.009) and Pb (0.193-0.290) mg/kg dry weight while in the cultured fish samples in the range as Cr (0.043-0.315), Mn (0.975-2.36), Co (BDL), Ni (0.005-0.095), Cu (0.238-0.978), Zn (5.487-8.305), Cd (0.004-0.009), and Pb (0.238-0.286) mg/kg dry weight respectively. The hierarchy of mean concentration of heavy metals in wild fishes was Zn> Mn> Cu> Pb> Cr> Ni > Cd and in the cultured fishes, the order was found Zn> Mn> Cr> Pb> Cu> Ni > Cd. The present study showed that the wild fish accumulated higher concentration of heavy metals in their muscles than the cultured fish. The analyzed Ni, Cu, Zn, Cd, and Pb were below the allowable level specified by international agencies (FAO, WHO, EU, CE, USEP). In order to assess the human health risk, the Target Hazard Quotient (THQ), Hazard Index (HI), and Target carcinogenic Risk (TR) were calculated. The TR values suggested that the fishes posed low to moderate carcinogenic risk from Cr, Ni and Cd. Consequently, continuous and excessive consumption of these fish species over a lifetime will increase the possibility of causing cancer. Bangladesh J. Zool. 49 (2): 189-203, 2021

Mapping heavy metals contamination and eco-risk along Mediterranean Sea coast, Egypt

The study was selected according to its variability in resources and its important location parallel to an important protectorate. This coastal zone is characterized by different land use/cover activities (water, industrial site, agricultural areas, bare land, vegetative areas, fish farms, and sabkha). Twelve sites were selected along this part of the Mediterranean deltaic coast, each distance between every site is nearly 5 km. water and sediment samples were collected for the determination of these metal ions (Fe, Mn, Zn, Cu, Ni, Pb, Cd, and Co). The average concentrations of heavy metals are 56.50, 2.53, 24.77, 4.28, 0.88, 18.37, 0.97 and 0.06 µg/l in water and 7284.58, 132.60, 13.52, 2.99, 8.36, 4.84, 0.36 and 4.32 µg/g in sediments for Fe, Mn, Zn, Cu, Ni, Pb, Cd, and Co, respectively. The concentrations of these metals (Zn, Cu, Ni, Pb, and Cd) are within the Australian guideline of marine sediments, but Zn, Cu, and Cd in water exceed these limits. Cadmium was the most abundant element in the coastal marine sediments. The heavy metal pollution index for marine water of the study area is within the normal limits except for site 12. The risk index of metals gives a low-risk category. The principal component analysis indicated that site 11 was related by dissolved Pb in seawater and Fe in sediments, this is maybe interpreted by the nature of sediment texture and different shipping activities. Mapping the spatial distribution of metals and their risk categories is an aid in monitoring environmental problems and quantifying their magnitudes.

Functional Trait Responses of Macrobenthos to Anthropogenic Pressure in Three Temperate Intertidal Communities

With the increasing impact of human activities on marine ecosystems, there is a growing need to assess how the components of marine ecosystems (e.g., macrobenthos) respond to these anthropogenic pressures. In this work, the trait-based approach was used to assess the effects of anthropogenic pressures represented by the area of land-based aquaculture pond (Pond Area) and heavy metals on the macrobenthic communities in three intertidal zones[Aoshan Bay (AO), Wenquan River and Daren River (RW), and Xiaodao Bay (XD)] of Laoshan Bay, Shandong Peninsula, China. Compared with RW and XD, AO was under more pressure in terms of the average concentrations of heavy metals and total organic carbon (TOC) in sediments and also in the Pond Area. Fuzzy correspondence analysis (FCA) showed that there were significant differences in the composition of functional traits among the three regions (PERMANOVA; p < 0.05). In the highly polluted area, macrobenthic communities exhibited a combination of traits, such as relatively short life span, weak mobility, feeding on deposits, and more tolerant to organic matter, whereas in a less polluted area, they exhibited a combination of traits, such as relatively long life span, relatively high mobility, and more sensitivity to organic matter. The RDA results showed that the distribution of the trait modalities was significantly affected by heavy metals (Hg and Cd), TOC, Pond Area, and sampled location. Variation partitioning analysis (VPA) indicated that the shared influence of sediment-related pollution factors and Pond Area contributed most to the variance of the functional traits, which implied that human activities directly and/or indirectly lead to changes in functional traits of macrobenthic communities in the intertidal zones.

Analysis and Prediction of Health Risk from Heavy Metals in Drinking Water Sources Based on Time Series Model

Health risk analysis can predict and control the risks posed by heavy metals, especially in drinking water, which is a highly sensitive environmental receptors. In order to evaluate heavy metal pollution in drinking water, the monthly average concentrations of As, Cd, Cu, Hg, Ni, and Zn were used to assess the health risk between January 2015 and December 2018 in a drinking water source. Furthermore, Spearman rank correlation coefficient and the ARIMA model were used to analyze temporal variations. The results showed that the monthly average concentrations of heavy metals exceeded the class Ⅲ values as specified by Chinese environmental quality standard for surface water(GB 3838-2002), especially Hg with a minimum monthly average four times more than that set by the standard limits. Overall, the order of carcinogenic risk of As and Cd was decreased; the non-carcinogenic risk of Zn, Cu, Ni, Pb, and Hg was increased. Further, the comprehensive non-carcinogenic risk for adults was lower than 1 throughout the study period except February 2015, when the comprehensive non-carcinogenic risk for children was lower than or close to 1 after October 2017, and the comprehensive carcinogenic risk for children was more than 10-4. Meanwhile, the children's health risks are higher than that for adults, with the main health risk characteristic factors of As, Cd, and Hg. The Spearman rank correlation coefficient were -0.714069, -0.773122, and -0.62234, indicating the significant downward trend from 2015 to 2018. However, the children's comprehensive carcinogenic risk, whose average value was 0.000234 much more than 10-4, had significant upward trend in 2018 with Spearman rank correlation coefficient 0.902098. The ARIMA(3,1,3) model was able to predict the comprehensive carcinogenic risk for children from heavy metals in drinking water, and the result indicated the children comprehensive carcinogenic risk should be monitored to ensure levels between 0.000200 and 0.000302. The study has positive significance for risk warning and environmental management compared to the analysis and prediction of health risk from heavy metals in drinking water sources based on time series models.

Spatial Distribution and Pollution Assessment of Dissolved Heavy Metals in Chaohu Lake Basin During the Wet Season

The spatial distribution characteristics of the mass concentration of V, Cr, Mn, Ni, Cu, Zn, Pb, Cd, Fe, and Sb in the Chaohu Lake basin and ten surrounding rivers during the wet season were explored. The results showed that the average mass concentration of heavy metals in the western and northwestern Chaohu Lake surrounding rivers was higher than that in the central and eastern regions. The correlation analysis showed a significant positive correlation between the concentrations of Cu, Ni, Zn, Pb, and Cd, which indicated a similarity of spatial distribution among the five elements. The single-factor pollution index evaluation results classified Cr in the ten surrounding rivers as Grade I based on the Environmental Quality Standards for Surface Water. Pb was classified as Grade Ⅰ-Ⅱ; Cu and Zn as Grade Ⅰ-Ⅴ; Fe, Sb, and V were far below the standard limit; Ni slightly exceeded the standard at some sampling points of the Nanfei River; Mn slightly exceeded the standard at some points of the Shiwuli and Pai River; Cd exceeded the standard at some points of the Nanfei River. Except Mn at one point of the Tangxi River, V, Cr, Ni, Cu, Zn, Pb, and Fe were all<1, which indicated clean and pollution-free level. The integrated pollution index of the rivers surrounding the lake in the northwestern part was the highest compared to the southwestern, central, and eastern parts.

Pollution monitoring, risk assessment and target remediation of heavy metals in rice from a five-year investigation in Western Fujian region, China

Recently, rice contamination by heavy metals (HMs) has become a severe problem. Taking the Western Fujian region as an example in this study, a total of 1311 rice samples containing eight HMs were collected from 2015 to 2019, then used to explore their pollution characteristics, health risks, and Spatio-temporal variations, finally derive the target remediation areas of the key pollutants. The results showed that average concentrations of all the HMs had not reached the limits of the National Standards of Food Safety, but pollution indexes of As (0.783) and Cu (0.665) were at accumulation level (>0.6), which posed high pollution risks. Furthermore, locations of higher HMs concentrations coincided with those of higher pollution estimation probabilities. The non-carcinogenic risk (4.150, 2.434) and carcinogenic risk (4.96 × 10−3, 2.92 × 10−3) for children and adults cannot be negligible, As and Cd were the largest contributors. Children were more susceptible than adults due to the metal concentrations and rice intake rate. The spatio-temporal changes indicated that a decreasing trend in average concentrations of HMs (except Cr), but As (0.37%−0.88%) contents increased in the west and northeast parts, and so did Cd (1.92%−5.11%) in the central region during monitoring. For the target remediation, particular regions in the western and eastern were used as risky areas of As and Cd, respectively. Our results will provide theoretical support for the pollution management of HMs in rice.

Arsenic geochemistry of the sediments of the shallow aquifer and its correlation with the groundwater, Rangpur, Bangladesh

The geochemical analysis of the shallow aquifer sediments of the area of investigation reveals that they are acidic in nature. The mean electrical conductivity of the deposits is 1.16 dS/m that indicates very low or negligible effects of salinity of the sediments of the Rangpur division. The median values of the concentrations of total organic carbon, total nitrogen and sulphur are 0.20%, 0.02% and 58.68 mg/kg, respectively. The trend of the average heavy metal concentrations of the investigated area can be shown as Fe > As > Cu > Zn. The average concentrations of arsenic of the sediments of the study area are 3.52 mg/kg. Sulphur is significantly, positively correlated with copper and zinc (p < 0.05) and insignificantly and positively correlated with arsenic content of the sediments that indicates that the copper and zinc occur as sulphide minerals. The mean concentrations of arsenic in the groundwater are 1.1793 μg/L. The concentration of all the water samples is below the permissible limit of World Health Organization (10 μg/L). The arsenic content of groundwater shows the positive correlations with the arsenic, iron and copper concentrations of the sediments. This implies that the arsenic of groundwater derived from the geogenic source, like the dissolution of arsenic bearing minerals of the aquifer sediments—pyrite and arsenopyrite. The acidic nature, texture and minor quantities of total organic carbon are the factors that also influence the low arsenic enrichment in the investigated sediments and its release to the groundwater. The contemporary arsenic specification research works showed that As(III) the most common species in natural water and foodstuffs and the arsenic is inorganic from source in Bangladesh.

Human Health Risk Assessment of Heavy Metals in the Urban Road Dust of Zhengzhou Metropolis, China

The goal of this research is to assess hazardous heavy metal levels in PM2.5 fractioned road dust in order to quantify the risk of inhalation and potential health effects. To accomplish this, Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) was used to determine concentrations of eight heavy metals (Cr, Cu, Ni, Zn, Cd, As, Pb, and Hg) in the PM2.5 portion of road dust samples from five different land use areas (commercial, residential, industrial, parks, and educational) in Zhengzhou, China. The following were the average heavy metal concentrations in the city: Cr 46.26 mg/kg, Cu 25.13 mg/kg, Ni 12.51 mg/kg, Zn 152.35 mg/kg, Cd 0.56 mg/kg, As 11.53 mg/kg, Pb 52.15 mg/kg, and Hg 0.32 mg/kg. Two pollution indicators, the Pollution Index (PI) and the Geoaccumulation Index (Igeo), were used to determine the degree of contamination. Both PI and Igeo indicated the extreme pollution of Hg and Cd, while PI also ranked Zn in the extreme polluted range. The US Environmental Protection Agency (USEPA) model for adults and children was used to estimate health risks by inhalation. The results identified non-carcinogenic exposure of children to lead (HI &gt; 0.1) in commercial and industrial areas. Both children and adults in Zhengzhou’s commercial, residential, and park areas are exposed to higher levels of copper (Cu), lead (Pb), and zinc (Zn).

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.

Levels, Inventory, and Risk Assessment of Heavy Metals in Wetland Ecosystem, Northeast China: Implications for Snow Cover Monitoring

Snow cover is a unique environmental medium in cold regions that can cause potential risks to the ecological environment, due to the release of pollutants that are stored in it. In this study, the Qixing River wetland, located in the Sanjiang Plain of China, was taken as the target research area. Heavy metals in snow cover, including Cu, Ni, Cr, Cd, Pb, and Zn were measured at 19 sampling sites. The results showed that the average concentrations of heavy metals were: Zn (103.46 ± 39.16) &gt; Pb (13.08 ± 4.99) &gt; Cr (11.97 ± 2.82) &gt; Ni (9.55 ± 4.96) &gt; Cu (6.19 ± 1.79) &gt; Cd (0.55 ± 0.25) μg·L−1. Cr and Zn were between Class I and Class II in the “Environmental Quality Standards for Surface Water” of China (GB3838-2002). Pb in snow exceeded the upper limit of Class II, and was significantly higher than concentrations measured in water samples from the Qixing River wetland (p &lt; 0.05), indicating that atmospheric deposition during winter was the major source of Pb. The water pollution index (WPI) indicated that 61.0% of samples could be considered of “clean” status, while the contribution of Zn, Pb, and Cr to WPI were 33.3%, 21.0%, and 19.3%, respectively. A preliminary evaluation of heavy metal inventory in snow cover showed that the residue level of Zn was the highest (2313.57 ± 1194.67 μg·m−2), while Cd was the lowest (13.91 ± 10.45 μg·m−2). The areas with high residues of heavy metals were all located near the buffer zone of the wetland (except for Zn), where snow depth tended to be greatest. Exposure analysis indicated that the risks to winter resident birds from snow ingestion was minimal, but it should be noted that the exposure risk was higher in birds with lower bodyweights. This study provides important information and scientific knowledge on the pollution characteristics and residue inventory of heavy metals in wetland ecosystems, while the results can also provide a monitoring method, reflecting atmospheric environmental quality at a local or regional scale.

Geology and distribution of heavy metals in topsoil, Kuala Krai, Kelantan

The study for geology of Guchil, Kuala Krai, Kelantan was carried out approximately 25 km2 in and around Guchil. Preliminary research and field studies conducted to produce geological map of Guchil, Kuala krai, Kelantan. Based on the field study carried, carbonaceous mudstone interbedded with greywacke sandstone, shale and ignimbrite distribution of rock found in this study. Meanwhile, investigation on distribution and potential heavy metals (Cu, Fe, Mn, Pb and Zn) in topsoil Guchil, Kuala Krai, Kelantan was conducted. Total of nine soil sample in and around Guchil undergo soil digestion and analyzed by Inductively Coupled Plasma Spectroscopy (ICP-OES). The heavy metals concentration in the topsoil was varied between 21176-138962; 649-8411; 11-505; 43-455; and 11-115 mg/kg for Fe, Pb, Mn, Zn and Cu respectively. The average concentration of heavy metals in this study followed the order of Fe > Pb > Mn > Zn > Cu. The spatial distribution pattern shows similar distribution pattern of heavy metals in residential area. The concentration of Cu, Fe, Mn, Pb and Zn from the soil samples compared with naturally occurring value of contaminated land management and control guidelines of Department of Environment Malaysia (DOE), 2009 and Barceloux (1999) as well as with permissible limit values in soil of Polish Ministry of the Environment, 2002. From this assessment method, highly potential element was Pb followed by Zn and Cu. Besides that soil characteristic of this study shows that soil pH which is acidic condition with low total organic matter. The soil fractions tend to dominated by clay fraction in topsoil.

Pollution Distribution and Ecological Risk Assessment of Heavy Metals in River Sediments from the Ancient Town of Suzhou

The contents of heavy metals (Cd, Cu, Cr, As, Mn, Ni, Pb, and Zn) in sediments from 20 representative sections of the ancient town of Suzhou were analyzed to determine the pollution degree and potential ecological risk, and pollution sources were identified. The results showed that the average concentrations of Cd, Cu, Cr, As, Mn, Ni, Pb, and Zn in river sediments from the ancient town of Suzhou were 1.1, 142.6, 90.2, 17.2, 800.1, 63.3, 199.1, and 384.2 mg·kg-1, respectively, and the proportions of sampling points that exceeded the soil background value of Jiangsu Province were 100%, 100%, 65%, 95%, 70%, 100%, 95%, and 100%, respectively. The geo-accumulation index indicated that the pollution degree of heavy metals followed the order of Pb > Cd > Cu > Zn > Cr > Ni > As > Mn. In general, high Pb pollution, moderate Cd, Cu, Zn, and Cr pollution, slight Ni and As pollution, and no Mn pollution were observed. The potential ecological risk index for heavy metals was determined to follow the order of Cd > Pb > Cu > As > Ni > Zn > Cr > Mn. Generally, Cd, Pb, and Cu presented moderate potential ecological risk, and the others presented low potential ecological risk. The average concentration of heavy metals, geo-accumulation index, and potential ecological risk index of river sediments in the northern and southern of ancient town were all higher than that of Ganjiang River and Huancheng River, indicating that the control of heavy metals should focus on the inner part of the ancient town. According to correlation analysis and principal component analysis, Cd, Cu, Cr, As, Ni, Pb, and Zn might be derived from man-made factors such as fertilizer, road aging, tire wear, exhaust emissions and so on, which Mn was mainly derived from natural factors.