Nemerow Pollution Index Research Articles

Evaluation and prediction of water quality in the dammed estuaries and rivers of Taihu Lake.

Proper evaluation of water quality is pertinent to estuarine habitat restoration. Identifying the degrading factors of the water environment and predicting the trend of eutrophication are key to restore the habitat. Through trophic level index (TLI), water quality index (WQI), modified Nemerow pollution index (NPI), and the Random Forest (RF) model, water samples collected from various estuaries of Taihu Lake from 2017 to 2019 were evaluated. To predict the water quality development, four scenarios were set viz. S1: add or remove an ecological buffer, S2: increase or reduce the external nutrients, S3: open or close the dam/gate, and S4: increase or decrease the internal release. In Wuli Lake, the nutrient concentrations in the river regions were higher than in the lake regions, while a contrary trend was observed in Gonghu Bay. The estuarine water quality in the dry season (WQI = 40.91, NPI = 1.73) was merely worse than that in the wet season (WQI = 47.27, NPI = 1.67). On the other hand, the eutrophic status in the wet season (TLIWet = 57.93) was worse than that in the dry season (TLIDry = 57.23). The estuarine water quality of Taihu Lake has improved from 2017 to 2019 but still belongs to medium level. The principal component analysis (PCA) revealed that dam construction, land use types, unstable hydrodynamic conditions, and trumpet-shaped estuary were the main factors that aggravated the water quality degradation. The RF model has strong forecasting capabilities for estuarine water quality. When the estuaries are close to residential and industrial districts, controlling the surface runoff and improving sewage treatment efficiency are the most effective measures to improve the water quality. In the estuaries, the sediments are usually disturbed by the wind-waves. Conclusively, reducing sediment disturbance and internal contamination accumulation via biological and engineering measures is the key to estuarine restoration.

Soil Quality Assessment of Salinized Farmland Neighboring a Chinese Oil Exploitation Area

Industrial intensification in salinized areas poses a risk of farmland soil degradation. Limited research has been carried out on comprehensive assessment of both soil fertility and polycyclic aromatic hydrocarbon (PAH) contamination. In this study, we performed a soil quality assessment to consider soil fertility and PAH contamination, with quantification of 13 indicators of soil physicochemical and biological properties and 16 PAHs in the Yellow River Delta (YRD) of China. The soil fertility level in this area was moderate according to the minimum data set (MDS), which consisted of pH, soil organic carbon (SOC), microbial quotient, total nitrogen, phosphorus, potassium, sand, and salinity level. Soil salinity was identified as the primary limiting factor in the study area. In addition, according to the Nemerow pollution index (NPI), the farmland soils were seriously contaminated by PAHs. Comprehensive assessment revealed that the soil quality belonged to moderate to low grades. Pearson correlation analysis showed that the soil quality index scores had significantly negative correlation with the NPI (p < 0.01) and significantly positive correlation with the soil fertility index (p < 0.05). This study demonstrates that pollution control and fertility improvement (e.g., soil salinity, SOC, nitrogen, and phosphorus) are crucial in managing soil quality of salinized farmlands neighboring an oil exploitation area in the YRD. The results will help different stakeholders to better understand the status of soil quality and the importance of pollution remediation in the YRD.

Comprehensive assessment of water quality of ten rivers in Zhengzhou main urban area

In order to clarify the water quality characteristics and provide reference for the overall control and prevention of the rivers in Zhengzhou, the comprehensive pollution index method and the Nemerow pollution index method were used to evaluate the water quality of ten rivers in Zhengzhou main urban area. The results show that the water quality of ten rivers in Zhengzhou is worse than that of Class III before February 2018. After that, the water quality was improved and basically reached Class III water quality. Suggestion: the main prevention and control work in Zhengzhou is to control the discharge of pollutants, especially chemical oxygen demand and ammonia nitrogen pollutants.

黄河三角洲石油化工区农田土壤-玉米体系PAHs的分布特征及风险评价

PDF HTML阅读 XML下载 导出引用 引用提醒 黄河三角洲石油化工区农田土壤-玉米体系PAHs的分布特征及风险评价 DOI: 10.5846/stxb202003270714 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2016YFC0503604） Distribution characteristics and risk assessment of polycyclic aromatic hydrocarbons in farmland soil-corn system from oil mining area of Yellow River Delta Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为明确黄河三角洲石油开采区表层土壤和玉米中多环芳烃（PAHs）的含量及其污染水平，采集农田土壤和玉米各71个样品，检测农田土壤和玉米各部位中16种PAHs含量，并采用内梅罗指数法和健康风险评价模型评估了农田土壤中多环芳烃的生态健康风险。结果表明，农田土壤、玉米根、茎和叶中多环芳烃的含量分别为256.6-1936、291.4-680.9、324.9-527.9、289.5-2400 μg/kg。农田土壤中多环芳烃以4-6环为主。多环芳烃在玉米根茎叶富集系数大小排序为：叶 > 茎 > 根。玉米不同组织中PAHs浓度与相应农田土壤中PAHs浓度的进行相关分析结果表明，农田土壤中PAHs含量与玉米根、茎中PAHs含量均存在极显著正相关关系，相关系数分别为0.98（P<0.01）、0.98（P<0.01），表明玉米根和茎的多环芳烃主要来源于农田土壤中，农田土壤中PAHs的含量影响着PAHs在玉米根茎中的积累和分布。玉米叶中PAHs含量与农田土壤中PAHs含量与玉米根、茎中PAHs含量不存在相关关系，表明玉米叶中多环芳烃并非来自土壤中PAHs的迁移，可能来源于大气。内梅罗指数结果表明，农田土壤PAHs达到了中度污染，其中BaA、Pyr和BbF达到了偏重污染；健康风险评价结果表明，农田土壤PAHs对儿童和成人的平均非致癌风险分别为0.44和0.12（均小于1），表明农田土壤多环芳烃对成人和儿童的非致癌风险是可接受；农田土壤PAHs对儿童和成人的平均致癌风险分别为3.6×10-5、9.0×10-6，没有超过致癌风险水平上限（10-4），致癌风险尚在可接受范围内。3种暴露途径中，皮肤接触是土壤PAHs的最主要暴露方式，其次是经口摄食，吸入暴露途径甚微，可忽略不计。PAHs对儿童健康的威胁风险要大于成人，所以应尽可能避免儿童直接接触或误食土壤等其他介质的污染物。 Abstract:To investigate the residual levels of polycyclic aromatic hydrocarbons (PAHs) in topsoil and corns in the Yellow River Delta oil extraction area, total 71 samples of farmland soils and 71 samples of corns were collected. The content of 16 PAHs in soils and spinach were detected. The Nemerow pollution index method and the health risk assessment model were used to assess the ecological health risks of PAHs in farmland soil. The results showed that the contents of PAHs in farmland soil, corn roots, stems, and leaves were 256.6-1936 μg/kg, 291.4-680.9 μg/kg, 324.9-527.9 μg/kg, and 289.5-2400 μg/kg, respectively. The results showed that PAHs in farmland soils were dominated by 4-6 rings. The order of PAHs enrichment coefficients in root, stem and leaf was leaf > stem > root. The correlation analysis results of the PAHs concentration in different corn tissues and the PAHs concentration in the corresponding farmland soil showed that there was very significantly positive correlation between the PAHs content in the farmland soil and the PAHs content in the corn root and stem, and the correlation coefficients were 0.98 (P<0.01), 0.98 (P<0.01), respectively. It indicates that the PAHs of corn roots and stems are mainly from farmland soil, and the content of PAHs in farmland soil affects the accumulation and distribution of PAHs in corn roots and stems. There is no correlation between PAHs content in corn leaves and PAHs content in farmland soil and PAHs content in corn roots and stems, which indicating that PAHs in corn leaves do not come from the migration of PAHs in soil, but may come from the atmosphere. The Nemerow index results showed that the PAHs in farmland soils have reached moderate pollution, and BaA, Pyr, and BbF have reached heavy pollution. The health risk assessment results showed that the average non-carcinogenic risk of PAHs in farmland soils to children and adults was 0.44<1, 0.12 <1, indicating that the non-carcinogenic risk of PAHs in farmland soils is acceptable for adults and children. The average carcinogenic risk of PAHs in farmland soils for children and adults was 3.6×10-5 and 9.0×10-6, respectively, which was less than the upper limit of acceptable cancer risk of 10-4. Among the three exposure routes, skin contact is the most important way of exposure to soil PAHs, followed by oral ingestion, and the inhalation exposure route is negligible. The risk of PAHs to children's health is greater than that of adults, so it is necessary to avoid children's direct contact with or ingestion of soil and other pollutants by mistake. 参考文献 相似文献 引证文献

Sediments quality assessment in terms of single and integrated indices from Romanian MONITOX network (2019 – 2020)

The assessment of sediments quality from Romanian part of MONITOX Network was performed using both single indices - Single Ecological Risk Index (ErMe), Contamination Factor (CF Me), Enrichment Factor (EF Me), Geoaccumulation Index (Igeo Me) - and integrated indices - Ecological Risk Index (RI), Global Pollution Index (PLI), Nemerow Pollution Index (PI N), Degree of Contamination (mCd), Probability of Toxicity (MERMQ), Contamination Security Index (CSI) - considering the heavy metals concentrations. The sediments were collected in 2019 and 2020 from 32 sampling points in the system of Danube river – Danube Delta - Black Sea, as follows: Lower Danube RO-BG (1), Lower Danube RO (10), Lower Prut RO-MD border (2), Danube Delta RO-UA border (7), Danube Delta –RO (2), Black-Sea area-RO (10). The selected heavy metals investigated in this work by ICP-MS technique are: Cd, Cr, Cu, Pb, Zn, Mn. For the evaluation of defined indices, the standard quality levels and background concentrations corresponding to the selected heavy metals were used. At the individual and integrated levels, it was observed an annual decreasing trend. The sediments from the Black Sea area are much less contaminated with heavy metals than those from the Lower Danube (Romania), attributed to the historical pollution resulting from anthropogenic activities. CSI – an index that includes the biological effects – shows values indicating that in 2019 and 2020 the sediments were unpolluted with heavy metals; however, the CSI value for both years (0.402 for 2019 and 0.398 for 2020) is very close to 0.5, the limit which separates the two quality classes/risk levels for heavy metals in sediments - uncontaminated and very low contaminated.

Validation of Hydrocharis morsus-ranae as a possible bioindicator of trace element pollution in freshwaters using Ceratophyllum demersum as a reference species.

The assessment of trace metal pollution in aquatic environments remains a challenge. Chemical methods are insufficient and bioindicators seem to be the most promising alternative. Finding an adequate species is important to ensure accurate data. The combined use of several bioindicators may help to overcome the limitations of species' spatial distribution and specific reactions. The aims of the present study were to compare the contents and bioaccumulation capability of 11 trace elements in Ceratophyllum demersum and different organs of Hydrocharis morsus-ranae and to validate H.morsus-ranae as a bioindicator of pollution in aquatic reservoirs using C.demersum, an established bioindicator, as a reference species. The application of several statistical techniques allowed us to identify similarities in accumulation patterns and concentration gradients between the two species. The results showed that concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb, Rb, Zn, V in C.demersum and roots of H.morsus-ranae were similar and mostly higher than in the leaves and stems of H.morsus-ranae. The contents of Cd, Co, Cr, Li, Mn, Ni, Rb, V, Zn were positively correlated. The inner transport of metals in H.morsus-ranae was limited (TF<1). Both species are accumulators (BF>103) of Ni and Zn, and H.morsus-ranae also of Cu and Pb. Frog-bit roots were chosen to be most promising in bioindication. Major axis regression analysis showed that the uptake of Cd, Cr, Co, Li and Pb was similar in the two species. Neural networks demonstrated substantial uniformity in responses of C.demersum and roots of H.morsus-ranae to the type of anthropogenic activity and land use and similar spatial distributions of Cd, Cr, Co, Li and Pb. When Nemerow Pollution Index was applied, both species showed congruent gradients of contamination. Thus, H.morsus-ranae was validated as a reliable bioindicator of trace metal pollution in freshwater.

Estimation of heavy metal contamination in the Hindon River, India: an environmetric approach

The Hindon River is a major freshwater resource predominantly for the rural population of the western region in Uttar Pradesh, India. The river receives industrial wastewaters having heavy metals concentration at potentially toxic levels. The focus of this study is to estimate the heavy metals (such as Fe, Cu, Zn and Cr) contamination in the Hindon River using Nemerow pollution index followed by environmetrics to identify their pollution source. The water samples are collected from 28 industrial discharge sites in the river to analyze metals concentration during pre- and post-monsoon months. The estimated Nemerow pollution index value is more than 3 indicating severely contaminated river water. Principal component analysis results confirm that Fe and Cu are the major contaminants in the river, which indicates the direct input of wastewater from electroplating industries. Therefore, it is suggested that a strategic eco-conservation plan should be formulated and implemented in advance to prevent the deterioration of the water quality and aquatic life.

Comparison of Pollution Indicies in Assessing the Heavy Metal(loid)s Pollution of Arable Soils Adjacent to Industrial Complex in Gyenggi-do

Soils adjacent to the industrial complexes are known to be vulnerable to pollution with the diverse pollutant sources. This research assessed pollution level in the arable soils located nearby industrial complexes using different pollution indices. Both surface (0 - 15 cm) and subsurface (15 - 30 cm) soil samples were taken from 150 agricultural fields located nearby 15 industrial complexes. Total concentrations of As, Cd, Cu, Ni, Pb, Zn, and Hg in soils were determined after extracting with aqua regia and mostly were lower than the pollution threshold criteria for the agricultural soil designated by the Korean Soil Environment Conservation Act. The calculated PI values for As indicated the unpolluted status but those for all other metals were in the ranges of low to moderately polluted. The Igeo values for Cd and Zn indicated soils were in the unpolluted to moderately polluted ranges, but those for other metals were unpolluted. The Igeo evaluated the pollution level lower than PI due to the geochemical correction factor. The average PINemerow values for surface soil and subsurface soils were 1.26 and 0.73, respectively, indicating a higher pollution in surface soil than subsurface soil. Ranges of PINemerow values showed a wide spectrum of pollution level from clean to heavy pollution, depending on soil sampling sites. All pollution indices indicate that levels of pollution for Cd were higher than other metals. Also four pollution indices exhibited different levels of pollution, even though they are equally based on the total concentrations of heavy metals in soil. This discrepancy might be derived from the fact whether a pollution index considers the geochemical background level, an individual metal or overall metals. The results suggest that a suitable pollution index for the pollution assessment cannot be specified based on the total concentrations of metal in the arable soil. Pollution assessments of the arable soils using (A) single pollution index and (B) geoaccumulation index for each heavy metals, and (C) Nemerow pollution index for the integrated heavy metals in each industrial complex.

Integrating entropy-weighted water quality index and multiple pollution indices towards a better understanding of drinking water quality in Ojoto area, SE Nigeria

The integration of multiple approaches often presents a better and valid interpretation of water quality. In the present study, multiple water quality indices were integrated with multiple pollution indices to ascertain the quality status of drinking water sources (streams, springs, dug wells and boreholes) in Ojoto area, SE Nigeria. Water samples were tested for physicochemical properties such as pH, Na+, K+, Mg2+, Ca2+, Cl–, SO42–, HCO3–, NO3–, Fe, Zn, Ni, Cr, and Pb. Several pollution indices (e.g., Nemerow pollution index, geoaccumulation index, enrichment factor, and modified heavy metal pollution index) utilized in this study revealed that some water samples have high metal pollution, and hence pose high environmental risks. Modified water quality index indicated that the water quality is threatened with conditions departing from natural or desirable levels. However, entropy-weighted water quality index showed that about 57%, 8%, 4%, 4% and 25% of the samples are of excellent, good, average, poor, and extremely poor qualities, respectively. Pollution index of groundwater (PIG) confirmed that 25% of the samples were very highly polluted, and thus unsuitable for drinking purpose. Quantification of contamination (QoC) and the PIG models were successfully utilized in demarcating the proportions of contribution by geogenic and human activities in the pollution of the drinking water sources. However, both models revealed that the deterioration in the water quality is mostly influenced by anthropogenic inputs. Therefore, change in lifestyle pattern and adoption of adequate water management policy are advised.

Heavy metals and major anion content in groundwater of Tamoios coastal district (Rio de Janeiro/Brazil): assessment of suitability for drinking purposes and human health risk

ABSTRACT The coastal environment of Tamoios District (Rio de Janeiro State, Brazil) has been extensively modified by anthropogenic interference. Activities such as agriculture, livestock, and domestic wastewater discharge, expose groundwater to several toxic chemical elements. Some of these elements may accumulate and affect the potability of the water, making it unsafe for human consumption. Thus, hydrochemical characterisation of Tamoios groundwater was carried out with a variety of methods of representation (Piper Diagram, Hierarchical Clustering Analysis, Spearman’s correlation matrix, and groundwater suitability assessment), comparing six water quality standards and applying Nemerow Pollution Index (NPI). Human health risk assessment of eleven metals (Ba, Co, Cu, Cr, Sr, Mn, Mo, Ni, Zn, Al and V) and two anions (NO3 − and F−) was calculated by the Hazard Index, a tool developed by the United States Environmental Protection Agency to establish the potential health risk via chemical exposure in drinking water for adult and child population. Results showed that the concentration of Mn, NO3 −, Al and Cr were above the water quality standards for human ingestion. NPI classification defined 20% of the samples as slightly polluted and 40% as severely polluted. The spatial distribution of NPI values demonstrated that the samples neighbouring the coastline did not show excessive levels of heavy metals, NO3 − and F−. For both child and adult population, concentration of Co and NO3 − represented a risk to health. In addition, Cr and F− also represented heath risks to child population, the most vulnerable residents. Health risk for heavy metals and anions showed different spatial distribution trends. Poor quality groundwater and simultaneous exposure to different chemical compounds represented a health risk for both child and adult population in the study area.

Environmental Health and Ecological Risk Assessment of Soil Heavy Metal Pollution in the Coastal Cities of Estuarine Bay-A Case Study of Hangzhou Bay, China.

Shanghai is the major city on the north shore of Hangzhou Bay, and the administrative regions adjacent to Hangzhou Bay are the Jinshan district, Fengxian district, and Pudong new area (Nanhui district), which are the main intersection areas of manufacturing, transportation, and agriculture in Shanghai. In this paper, we collected a total of 75 topsoil samples from six different functional areas (agricultural areas (19), roadside areas (10), industrial areas (19), residential areas (14), education areas (6), and woodland areas (7)) in these three administrative regions, and the presence of 10 heavy metals (manganese(Mn), zinc(Zn), chromium(Cr), nickel(Ni), lead(Pb), cobalt(Co), cadmium(Cd), mercury(Hg), copper(Cu), and arsenic(As)) was investigated in each sample. The Nemerow pollution index (NPI), pollution load index (PLI), and potential ecological risk index (PERI) were calculated to assess the soil pollution levels. The hazard quotient (HQ) and carcinogenic risk (CR) assessment models were used to assess the human health risks posed by the concentrations of the heavy metals. The CR and HQ for adults and children in different functional areas descended in the following order: industrial areas > roadside areas > woodland areas > residential areas > education areas > agricultural areas. The HQ of Mn for children in industrial areas was higher than 1, and the risk was within the acceptable range.

Trace elements in Gobi soils of the northeastern Qinghai-Tibet Plateau

ABSTRACT This study investigated the pollution, potential ecological risks, and possible sources of trace elements in Gobi soils of the northeastern Qinghai-Tibet Plateau. Contents of Hg in soils were below the detection limit. The average contents of the remaining trace elements in soils ranged from 0.21 (Cd) to 2360.82 (As) mg/kg. Multiple methods were used to evaluate the soil pollution of the study area. Pb posed the most serious pollution based on geo-accumulation index evaluation. As showed the strongest enrichment feature according to enrichment factor method. Compared with pollution load index and modified contamination degree, Nemerow pollution index results obtained the most serious evaluation on pollution that 10% and 40% of sampling sites possessed moderate and high pollution, respectively. Trace elements in soils posed high ecological risks in 20% of sampling sites. Pearson’s correlation matrix and principal component analysis were used to determine that anthropogenic activities such as industrial and mining activities might be the main source for several trace elements. This study will provide important information on soil quality control in the northeastern Qinghai-Tibet Plateau, especially the area with little vegetations.

Application of electrical resistivity tomography and hydro-chemical analysis for an integrated environmental assessment

Municipal solid waste disposal sites generate groundwater contamination through leachate release to the surrounding environment, causing various harmful and deleterious effects. Thus, an integrated assessment of landfilling impact on the environment via the combination of electrical resistivity tomography (ERT) and hydro-chemical analysis from existing wells was undertaken to ascertain the contamination of both surface and groundwater near the Bizerte landfill site, northeastern Tunisia. The ERT measurement indicated a polluted depth of over 20 m beneath the surface which coincides with marly substratum.Similarly, hydro-chemical analysis showed that continuous leachate generation obviously affected chemical properties of surface and groundwater, especially an increase in heavy metals contents (lead, cadmium and nickel contents). The results also indicated significant microbiological contaminations of the water samples. Nemerow pollution index (WQI) for water classification indicated that all sites had clean water with respect to metal contamination, except for R1 and R2 (surface water), which have WQI values of 2.5 and 2.1, respectively. Based on those results, it is recommended to strictly monitor leachate generation, surface water and groundwater quality in the Bizerte landfill for an integrated sustainable environmental assessment.

Ecological Effects of Heavy Metal Pollution on Soil Microbial Community Structure and Diversity on Both Sides of a River around a Mining Area.

The objectives of this study were to understand the characteristics of heavy metal pollution caused by mining activities on the two sides of the Shun’an river and the response of soil microorganisms to the habitats by different contamination levels and vegetation. This paper selected soil samples from the banks of the Shun’an River near the Shizishan mining area, which is at the left of the river, in Tongling, Anhui Province, China. Using Illumina MiSeq 2500 technology, we analyzed the relationship between environmental factors and microbial communities. As the distance from the mining area increased, the heavy metal comprehensive pollution and potential risk value decreased. Additionally, the pollution severity and risk value of the left bank, where the mining area lies, were generally higher than those of the right bank. Because the symmetric sampling points on both banks of the river had similar planting types, their environmental factors and microbial community structure were similar and clustered. However, under different vegetation, the paddy soils tended to have a higher nutrient content and community richness and diversity than the vegetable fields or the abandoned land. It was found that soil microbial communities in this area were mostly affected by pH and Nemerow pollution index (PN). The pH significantly affected the abundance and structure of most microorganisms. In addition, Proteobacteria, Acidobacteria, and Bacteroidetes had significant tolerance to Zn, Pb, and Cd. By exploring the potential use of these tolerant microorganisms, we seek to provide strains and the theoretical basis for the bioremediation of areas contaminated by heavy metal.

Variability of water quality and metal pollution index in the Ganges River, Bangladesh.

The Ganges River is one of the biggest transboundary streams in the Indian sub-continent. The significant part of this waterway channel drains one of the most densely populated areas on the planet so it is unequivocally influenced by human activities. Unprecedented high-temporal-resolution samples were collected for investigating the seasonal variability of water quality. Water quality index (WQI) reveals large seasonal variation among three major seasons and also indicates that the river water is not suitable for drinking and other household uses. The dominant water facies is bicarbonate (HCO3-). The water quality indices, %Na, Kelley's ratio (KR), sodium adsorption ratio (SAR), and magnesium adsorption ratio (MAR), reveal that the water is appropriate for irrigation. The permeability index (PI) indicated that the water is moderate to poorly useable for agricultural purposes. Heavy metals concentrations demonstrated significant seasonal variations with high concentrations during the monsoon due to flushing of pollutants from catchment areas by intense monsoonal precipitations. In addition, local activities such as oil spills from the boat, vehicle washing water, and agricultural runoff may also added pollutants. The single-factor pollution index (Ii) and Nemerow pollution index (Ni) exhibits minor pollution. The values of heavy metal pollution index (HPI) are far below than the critical limit (100) for the studied month, although relatively higher HPI values found for April, August, and November than other months might come from domestic wastes and agricultural activities. The heavy metal evaluation index (HEI) values of all the months indicated a low degree of pollution. Even though the river water pollution level is low, the authority should take proper management and monitoring strategy for sustainable use.

Characteristics and sources of heavy metal pollution in desert steppe soil related to transportation and industrial activities.

A study area was selected from the industrial region of Gaoshawo Town, Yanchi County, Ningxia, to explore the level of heavy metal pollution in desert grasslands due to industrial activities. A total of 82 surface soils were collected, and the concentration of heavy metals, namely, Cu, Cd, Cr, Pb, Zn, Mn, and Co, was determined by ICP-AES (atomic emission spectrometer) (HK-8100); the average values were 21.64 ± 3.26, 0.18 ± 0.02, 44.99 ± 21.23, 87.18 ± 25.84, 86.63 ± 24.98, 570.49 ± 171.57, and 17.96 ± 9.96mgkg-1. The single-factor, Nemerow pollution, and potential ecological risk index methods were used to evaluate the status of soil heavy metal pollution and the contribution from the major sources identified by the receptor model. The results showed that 9.09% of the samples were slightly polluted, 32.47% of the samples were moderately polluted, and 58.41% of the samples were heavily polluted. The comprehensive potential ecological risk index indicated that 90.79% of the samples had moderate ecological risk. It was verified from the models and spatial distribution maps that Cr, Co, Zn, and Mn are mainly contributed by the industrial sources that account for 55.04%, 92.13%, 50.05%, and 48.77% of these heavy metals, respectively. The heavily contaminated areas are distributed around the industrial park. A total of 70.63% and 77.83% of Cu and Pb are contributed by transportation sources, respectively, with the concentrations decreasing from southwest to northeast. The contribution from agricultural activities to Cd is 77.02%, with concentrations largely distributed in the north of the highway. This study showed that the existence of the Gaoshawo Industrial Zone and the corresponding industrial and transportation activities have a significant impact on the grassland soil environment.

Heavy metal pollution and the risk from tidal flat reclamation in coastal areas of Jiangsu, China

Tidal flat is an important supplementary land resource. However, increasing tidal flat reclamation in China has resulted in severe environmental issues. Using single-metal pollution index and multi-metal Nemerow pollution index, this study aimed to evaluate the risks of heavy metal pollution among different tidal flat use types, including fish farm, farmland, pastoral land, industrial land, forest and unutilized land. The results indicated that, concentrations of all elements were higher than geochemical values; Cd posed the highest risk, followed by As and Ni. Fish farm created the highest risk, followed by farmland. Every one year increase in fish farming led to increases in sediment concentrations of Cu, Cr, Ni, Pb, Zn and As by 0.73, 1.25, 0.68, 0.41, 1.22 and 0.20 mg.kg−1, respectively. Tidal flat reclamation in Jiangsu Province creates the risk of heavy metal pollution, and specific attention should be paid to the fodders and additives used in fish farming.

Accumulation of Heavy Metals and As in the Fern Blechnum orientale L. from Guangdong Province, Southern China

Blechnum orientale L. is a traditional, medicinal fern found in China. To assess the characteristics of heavy metals and As accumulation, the fronds, roots, and the rooting soils of this fern were sampled from urban, suburban, and rural woodlands across Guangdong Province in southern China. The concentrations of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn in both the fern and its rooting soils were separately detected by ICP-MS. Contamination levels of woodland rooting soils were also assessed using both a single pollution index and the Nemerow pollution index. Both the metal concentrations and the pollution index showed that soils from urban, suburban, and even rural woodlands were adversely contaminated by As, Cd, Hg, and Pb. Based on transfer factor, B. orientale had good translocation of As, Hg, and Mn, but poor translocation of Cd, Cr, Ni, Cu, Ni, Pb, and Zn from the roots to the fronds. This result suggests that this fern could be an excluder to latter metals. Despite the significantly higher levels of metals in the roots as compared with the fronds, the low bioaccumulation factor suggests that this fern has a weak capacity for metal accumulation.

Spatial and seasonal variations and risk assessment for heavy metals in surface sediments of the largest river-embedded reservoir in China.

The sediment acts as not only sink but also source of heavy metals in aquatic environment, which may cause the endogenous pollution in drinking water reservoirs. In this work, we collected the surface sediments from Qingcaosha Reservoir, the largest river-embedded reservoir in China, and investigated the spatial distribution, risk, and sources of heavy metals in four seasons. Significant spatial and seasonal heterogeneity could be found in the distribution of five heavy metals (Cr, Cu, Mn, Zn, and Ni) in the surface sediments. The highest concentrations of the five metals were detected in the sediments from the reservoir downstream, especially in summer and next spring. The geo-accumulation index (Igeo) and enrichment factor (EF) suggest that the sediment pollution caused by single metal was heavier in summer than in other seasons. Also, the Nemerow pollution index (PIN) manifests that the synergetic pollution induced by five metals was most serious in summer, followed by next spring. However, the potential ecological risk index (PERI) indicates that none of these metals caused potential ecological risk in four seasons. Comprehensive analysis demonstrates that the sediment pollution gradually increased from autumn to winter and then to next spring. Principal component analysis shows that the main pollution source of five heavy metals may come from industrial wastewater and domestic sewage, which was almost independent of seasons. This work can provide data support for the subsequent seasonal optimization of drinking water quality and reservoir management.

Application of Definite Indices For Assessment of Some Heavy Metals Pollutants in surrounding Soils of Metal Recycling Companies in Sulaimani Governorate

This study was conducted to apply some indices assessment methods for heavy metal pollution in the soil as well as to study the variation in physicochemical characteristics of the soil samples taken from different sites around scrap metal recycling companies in the township of Bazian behind Bibijak village, Sulaimani Governorate. Physicochemical parameters results indicated relatively high variation along with the ranges of the specified distances from the companies, directions, and depths as well as between the companies even though the two companies are adjacent to each other. Additionally, correlation analysis approved the significant effect (at p ≤ 0.05) of some soil physicochemical properties on the concentrations of the investigated heavy metals in the studied soils. In general, the concentration of all the investigated metals were mostly higher in surface soils (D1) samples rather than the subsoil (D2) samples at all the distances ranges and directions of the sampling sites. The spatial occurrence of the studied metals followed the order of; Fe &gt; Mn &gt; Ni &gt; Cr &gt; V &gt; Co, and this may be in a sequence that agrees with the trend of main scrap metals components. Results of the simple Geoaccumulation index (Igeo) for Fe, Co, Cr, Mn, Ni, and V indicated that the soil qualities were generally in unpolluted status, but limited sampling sites fell in class one which characterized by uncontaminated to moderately polluted. On the contrary, the comparative integrated pollution load indices (PLI) and Nemerow Pollution Index (PINemerow) showed that most of the studied sampling sites around the scrap metal recycling companies were slightly polluted according to PLI, but they were in warning limit (precaution domain) according to PINemerow in consequence of the industrial activity of Sulaimani Steel and Super Steel at all the four main directions, and all distances ranges.