Health risk assessment of heavy metals in soils and crops in a mining area(Au-Ag-Cutrona-oil et al.) of the Nanyang Basin, Henan Province, China

Heavy metal distribution in mining areas has always been a hot research topic due to the special environment of these areas. This study aims to explore the impact of heavy metal pollution on soils and crops in the study area, ensure the safety of local crops and the health of local residents, and provide a basis for the subsequent environmental restoration and the prevention and control of environmental pollution. Based on the analysis of the heavy metal concentrations in local soils and crops, the study investigated the spatial distribution, pollution degrees, and potential ecological risks of heavy metals in the farmland of a mining area in the southeastern Nanyang Basin, Henan province, China explored the sources of heavy metals and assessed the health risks caused by crop intake. The results of this study are as follows. The root soils of crops in the study area suffered heavy metal pollution to varying degrees. The degree of heavy metal pollution in maize fields is higher than that in wheat fields, and both types of fields suffer the most severe Cd pollution. Moreover, the root soils of different crops suffer compound pollution.The root soils in the maize fields suffer severe compound pollution at some sampling positions, whose distribution is similar to that of the mining area. Cd poses the highest potential ecological risks among all heavy metals, and the study area mainly suffers low and moderate comprehensive potential ecological risks. The principal component analysis(PCA) shows that the distribution of Zn, Cd, Pb, and As in soils of the study area is mainly affected by anthropogenic factors such as local mining activities;the distribution of Cr and Ni is primarily controlled by the local geological background;the distribution of Hg is mainly affected by local vehicle exhaust emissions, and the distribution of Cu is influenced by both human activities and the geological background. Different cereal crops in the study area are polluted with heavy metals dominated by Cd and Ni to varying degrees, especially wheat. As indicated by the health risk assessment results, the intake of maize in the study area does not pose significant human health risks;however, Cu has high risks to human health, and the compound heavy metal pollution caused by the intake of wheat in the study area poses risks to the health of both adults and children. Overall, the soils and crops in the study area suffer a high degree of heavy metal pollution, for which mining activities may be the main reason.

Pollution and health risk assessment of heavy metals in waters around mine sites of Elazig(Eastern Turkey)

Turkey’s Eastern Anatolia Region is the oldest known mineral mining area of Maden and Alacakaya.Chromite production in the Alacakaya field constitutes 50% of the country’s exports,and copper mines in the Maden region account for approximately 12% of the country’s copper production.There is a risk of water pollution due to significant mine waste which affects the Inci and Maden rivers.The water needs of many settlements are met from these streams,which run through these two mine sites.This study investigated the water pollution in the rivers.25 water samples were collected during the dry and rainy periods,and the Al,Cr,Cu,Fe,Li,Mn,Ni,Pb,Sr and Zn contents of these samples were examined in terms of health.Evaluation of element concentrations and creation of spatial distribution maps were performed using ArcGIS software.Spatial distribution maps,correlation and cluster analysis indicate that the source of heavy metals observed in waters is mine fields.The heavy metal content of the samples is higher in the dry period,the high concentration values are obtained from the mine sites,the decrease in the concentrations throughout the flow during the rainy period,are indicators of the effect of the mines on the water pollution.As a result of the comparison from the analysis results of water samples with World Health Organization(WHO),Environmental Protection Agency(EPA)and European Commission(EC)standards,the element values of Al,Cr,Fe,Mn,Ni and Pb exceeded the permissible values for health.The concentrations of these elements for dry period samples are:0-6.411 mg L^(-1),0.006-0.235 mg L^(-1),0-13.433 mg L^(-1),0-0.316 mg L^(-1),0-0.495 mg L^(-1),0-0.065mg L^(-1),and for rainy period samples are 0-1.698mg/L,0-0.2 mg L^(-1),0-9.033 mg L^(-1),0-0.173 mg L^(-1),0-0.373 mg L^(-1),0-0.034 mg L^(-1),respectively.Although the waters in the region are polluted by heavy metals,it has been determined that there is no noncarcinogenic hazard as a result of the calculation of the hazard index(HI<1)by ingestion and dermal contact within the scope of human health risk assessment.This study will be beneficial as it draws attention to the prevention of the negative effects of water pollution,which may cause serious health problems in the future as a result of mining activities in the region.

A land use-based spatial analysis method for human health risk assessment of heavy metals in soil and its application in Zhuzhou City, Hunan Province, China

A land use- and geographical information system-based framework was presented for potential human health risk analysis using soil sampling data obtained in Zhuzhou City, Hunan Province, China. The results show that heavy metal content in soil significantly differs among different land use types. In total, 8.3% of the study area has a hazard index(HI) above the threshold of 1.0. High HIs are recorded mainly for industrial areas. Arsenic((29)87%) and the soil ingestion pathway(about 76%) contribute most to the HI. The mean standardized error and root-mean-square standardized error data indicate that the land use-based simulation method provides more accurate estimates than the classic method, which applies only geostatistical analysis to entire study area and disregards land use information. The findings not only highlight the significance of industrial land use, arsenic and the soil ingestion exposure pathway, but also indicate that evaluating different land use-types can spatially identify areas of greater concern for human health and better identify health risks.

Health risk assessment of trace metal(loid)s in agricultural soils based on Monte Carlo simulation coupled with positive matrix factorization model in Chongqing, southwest China

This study aimed to investigate the pollution characteristics, source apportionment, and health risks associated with trace metal(loid)s(TMs) in the major agricultural producing areas in Chongqing, China. We analyzed the source apportionment and assessed the health risk of TMs in agricultural soils by using positive matrix factorization(PMF) model and health risk assessment(HRA) model based on Monte Carlo simulation. Meanwhile, we combined PMF and HRA models to explore the health risks of TMs in agricultural soils by different pollution sources to determine the priority control factors. Results showed that the average contents of cadmium(Cd), arsenic (As), lead(Pb), chromium(Cr), copper(Cu), nickel(Ni), and zinc(Zn) in the soil were found to be 0.26, 5.93, 27.14, 61.32, 23.81, 32.45, and 78.65 mg/kg, respectively. Spatial analysis and source apportionment analysis revealed that urban and industrial sources, agricultural sources, and natural sources accounted for 33.0%, 27.7%, and 39.3% of TM accumulation in the soil, respectively. In the HRA model based on Monte Carlo simulation, noncarcinogenic risks were deemed negligible(hazard index <1), the carcinogenic risks were at acceptable level(10^(-6)<total carcinogenic risk ≤ 10^(-4)), with higher risks observed for children compared to adults. The relationship between TMs, their sources, and health risks indicated that urban and industrial sources were primarily associated with As, contributing to 75.1% of carcinogenic risks and 55.7% of non-carcinogenic risks, making them the primary control factors. Meanwhile, agricultural sources were primarily linked to Cd and Pb, contributing to 13.1% of carcinogenic risks and 21.8% of non-carcinogenic risks, designating them as secondary control factors.

Distribution and risk assessment of heavy metals in surface sediments of coastal mudflats on Leizhou Peninsula,China

Mudflats play a vital role in maintaining the dynamic balance between sea and land.To understand the characteristics,sources,and pollution risks of six heavy metals(As,Cd,Cr,Cu,Hg,and Pb)in the coastal mudflats on the Leizhou Peninsula,257 surface sediment samples were studied using mathematical statistics,correlation analysis,and factor analysis.The results show that the overall concentrations of these heavy metals are low although there are several high abnormal points in the local areas.The strong correlation between these heavy metals indicates that the sources of some of the metals are similar,yet their elemental combinations in different cities(counties)varied.According to the calculated enrichment factor(EF),anthropogenic activity-induced heavy metals were determined in order of decreasing influence:As,Cd,Pb,Cr,Cu,and Hg.The low EF values of Hg indicate that it does not present as a contaminant in the study area,while low values of Cr and Cu from the Lianjiang City suggest that these two metals were also attributed to natural sources.The presence of As,Cd,Cr,Cu,and Pb from the remaining cities(counties)should be influenced by anthropogenic activities.The overall potential ecological risk index indicates that the ecological risks posed by the six analyzed heavy metals to the Leizhou Peninsula mudflats,in order of decreasing risk,are Cd,As,Hg,Pb,Cu,and Cr.It is noteworthy that only Cd in Lianjiang City demonstrated substantial ecological risk.Other examined heavy metals in other cities of the study area showed slight ecological risk.

Contamination and human health risk assessment of heavy metal(loid)s in topsoil and groundwater around mining and dressing factories in Chifeng,North China

Chifeng is a concentrated mining area for non-ferrous metal minerals,as well as a key prevention and control area for heavyduty enterprises.This situation necessitates an efective ecological and human health risk assessment of heavy metal(loid)s driven by the wide distribution of metal ore processing,mining,and smelting factories in Hexigten Banner and Bairin Left Banner.We conducted surveys to assess the levels of heavy metal(loid)s(Cr,As,Pb,Cd,and Hg)in the topsoil and groundwater of the areas.The results indicated that the concentrations of As,Cd,and Pb in partial soil samples exceeded the environmental quality standards of Grade II.Based on contamination assessments,such as geoaccumulation indices and pollution indices,we inferred that Cd,Pb,and As were primary pollutants in topsoil.Potential ecological risks when considered as part of the average risk indices(RI)are up to 1626.40 and 2818.76,respectively,in the two areas.Comparative analysis revealed that Cd posed a very high potential ecological risk,followed by As.Moreover,the evaluation showed that the three exposure pathways of carcinogenic and non-carcinogenic risk followed a descending order:inhalation>ingestion>dermal contact,except for Pb.Arsenic in topsoil posed a potential non-carcinogenic risk to human health,while there were no adverse efects of As in groundwater.In addition,the average total carcinogenic risk for As in the two areas,as well as the risk of Pb in the topsoil of Bairin Left Banner and all the fve heavy metal(loid)s in groundwater,exceeded human tolerance.Pb–Zn mines caused higher human health risks.In addition,the tandem contamination of heavy metal(loid)s in soil and groundwater was not obvious.This research study provides a basis for pollution remediation to control heavy industry-induced ecological and health risks of heavy metal(loid)s.

Multiple assessments, source determination, and health risk apportionment of heavy metal(loid)s in the groundwater of the Shule River Basin in northwestern China

Global ecosystems and public health have been greatly impacted by the accumulation of heavy metal(loid)s in water.Source-specific risk apportionment is needed to prevent and manage potential groundwater contamination with heavy metal(loid)s.The heavy metal(loid)s contamination status,water quality,ecological risk,and health risk apportionment of the Shule River Basin groundwater are poorly understood.Therefore,field sampling was performed to explore the water quality and risk of heavy metal(loid)s in the groundwater of the Shule River Basin in northwestern China.A total of 96 samples were collected from the study area to acquire data for water quality and heavy metal(loid)s risk.There was noticeable accumulation of ferrum in the groundwater of the Shule River Basin.The levels of pollution were considered to be moderately low,as evaluated by the degree of contamination,heavy metal evaluation index,heavy metal pollution index,and Nemerow pollution index.The ecological risks were also low.However,an assessment of the water quality index revealed that only 58.34%of the groundwater samples had good water quality.The absolute principal component scores-multiple linear regression model was more suited for this study area than the positive matrix factorization model.There were no obvious noncarcinogenic or carcinogenic concerns for all types of receptors according to the values of the total hazard index and total carcinogenic risk.The human activities and the initial geological environment factor(65.85%)was the major source of noncarcinogenic risk(residential children:87.56%;residential adults:87.52%;recreational children:86.77%;and recreational adults:85.42%),while the industrial activity factor(16.36%)was the major source of carcinogenic risk(residential receptors:87.96%;and recreational receptors:68.73%).These findings provide fundamental and crucial information for reducing the health issues caused by heavy metal(loid)s contamination of groundwater in arid areas.

Heavy metals and health risk analysis of arable farmlands in selected local government areas of Taraba State,Nigeria

The soil environment is a reservoir of nutrients as well as pollutants,and because of this,most of our food items are ladened with lots of pollutants ranging from fertilizers,pesticides,herbicides to heavy metals(HM).The consumption of these contaminated food items has serious implication on the health and economic status of the populace.These pollutants have also been implicated in causing several problems to plants.This study investigated heavy metals and health risk analysis of arable farmlands in selected Local Government Areas(Donga,Ussa and Takum)of Taraba state Nigeria.Samples obtained were processed and the concentration of following heavy metals(Pb,Cd,Cr,Hg,and As)were determined using Atomic Absorption Spectrophotometry(AAS).The results showed that Chromium had a very high concentration across all the study areas with values ranging from 1.40mg/kg to 2.30 mg/kg.The concentration of Cadmium and Arsenic were moderate,with values ranging from 0.03mg/kg to 0.08mg/kg while Lead and Mercury had the lowest concentration of less than 0.03mg/kg across the three LGAs respectively.The following ecological and health risk assessments parameters;Target Cancer Risk or Target Hazard Quotient(THQ),Hazard Index(HI)and Estimated Daily Intake(EDI)were determined to assess the carcinogenic health risks by consuming produce from such farmlands.Ussa LGA recorded the highest concentration of heavy metals,with the highest health risk index followed by Takum whereas Donga had the lowest risk factors from the analysis.The study showed bioaccumulation of toxicants from the soil to crops and grazing plants across the study areas which was as a result of chemical farming that polluted and contaminated the soil,thus posing risk to the populace.

Source, Contamination Assessment and Risk Evaluation of Heavy Metals in the Stream Sediments of Rivers around Olode Area SW, Nigeria

In order to investigate the source,contamination,and risk of heavy metals such as Pb,Zn,Cu,Ni,Co,Fe,Mn,and Cr,twelve(12)stream sediments and ten(10)rock samples were collected from pegmatite mining sites at Olode and its environs inside Ibadan,Southwestern Nigeria.The average values and order of abundance obtained followed the pattern:Mn(595.09)>Ba(80)>Cr(50.82)>V(45.09)>Zn(29.73)>Cu(13.82)>Co(13.82)>Sr(10.46)>Ni(9.73)>Pb(9.09)>Fe(1.59).These were greater than the background values,indicating that mining has a negative impact on the study area,as indicated by the high coefficient of variation and correlation values(>0.6)for Copper-Lead(0.929),Copper-Vanadium(0.970),Copper-Chromium(0.815),Lead-Vanadium(0.884),and others.On the basis of the enrichment factor(EF),the Olode sediments show extremely high enrichment for Mn and Ba in the research region.Cu and Ni are most likely to blame for the elevated contamination levels,according to CF values.The degree of contamination(CD),pollution load index(PLI),pollution index(PI),and modified pollution index(MPI)all revealed high levels of contamination in all stream sediment samples,whereas Igeo shows that the Olode stream sediments are“practically uncontaminated to extremely contaminated by Ni,Co,and Mn”.Ni and Cu are the major regulating factors that are most likely causing the possible Eri.As a result,these findings give important information for conducting appropriate ecological management research.

Health risk assessment of heavy metals in soils and vegetables from wastewater irrigated area,Beijing-Tianjin city cluster,China

The possible health risks of heavy metals contamination to local population through food chain were evaluated in Beijing and Tianjin city cluster, China, where have a long history of sewage irrigation. The transfer factors （TF） for heavy metals from soil to vegetables for six elements including Cu, Zn, Pb, Cr, As and Cd were calculated and the pollution load indexes （PLI） were also assessed. Results indicate that only Cd exceeded the maximum acceptable limit in these sites. So far, the heavy metal concentrations in soils and vegetables were all below the permissible limits set by the Ministry of Environmental Protection of China and World Health Organization. The transfer factors of six heavy metals showed the trend as Cd 〉 Zn 〉 Cu 〉 Pb 〉 As 〉 Cr, which were dependent on the vegetable species. The estimated dietary intakes of Cu, Zn, Pb, Cr, As and Cd were far below the tolerable limits and the target hazard quotient （THQ） values were less than 1, which suggested that the health risks of heavy metals exposure through consuming vegetables were generally assumed to be safe.

Contamination and health risk assessment of heavy metals in road dust in Bayan Obo Mining Region in Inner Mongolia, North China

The objective of this study was to investigate the concentration and spatial distribu- tion patterns of 9 potentially toxic heavy metal elements （As, Cd, Co, Cr, Pb, Cu, Z.n, Mn, and Ni） in road dust in the Bayan Obo Mining Region in Inner Mongolia, China. Contamination levels were evaluated using the geoaccumulation index and the enrichment factor. Human health risks for each heavy metal element were assessed using a human exposure model. Results showed that the dust contained significantly elevated heavy metal elements concen- trations compared with the background soil. The spatial distribution pattern of all tested met- als except for As coincided with the locations of industrial areas while the spatial distribution of As was associated with domestic sources. The contamination evaluation indicated that Cd, Pb, and Mn in road dust mainly originated from anthropogenic sources with a rating of ＂heav- ily polluted＂ to ＂extremely polluted,＂ whereas the remaining metals originated from both natural and anthropogenic sources with a level of ＂moderately polluted＂. The non-cancer health risk assessment showed that ingestion was the primary exposure route for all metals in the road dust and that Mn, Cr, Pb, and As were the main contributors to non-cancer risks in both children and adults. Higher HI values were calculated for children （H1=1.89）, indicating that children will likely experience higher health risks compared with adults （H1=0.23）. The cancer risk assessment showed that Cr was the main contributor, with cancer risks which were 2-3 orders of magnitude higher than those for other metals. Taken in concert, the non-cancer risks posed by all studied heavy metal elements and the cancer risks posed by As Co, Cr, Cd, and Ni to both children and adults in Bayan Obo Mining Region fell within the acceptable range.

Assessment of pollution levels and human health risk of heavy metals in dust deposited on Yerevan＇s tree leaves (Armenia)

The total concentrations of Cd,As,Pb,Cr,Ni,Co,Zn,Cu,Ag,Hg,and Mo were determined in the atmospheric dust of the city of Yerevan by atomic absorption spectrometry(AAnalyst PE 800).Heavy metal pollution levels were evaluated by calculating geo-accumulation(I_(geo)) and summary pollution(Z_c) indices.Potential human health risk was assessed using the United States Environmental Protection agency's human health risk assessment model.The results show that mean contents of all elements tested except Ni and Cr were substantially higher than local geochemical background values.According to the I_(geo),Yerevan territory is strongly-to-extremely polluted by As,Ag,Hg,Mo,and Cd.The Z_c assessment indicated that very high pollution was detected in 36%of samples,high in 32%,average in 12%,and low in 20%.The health risk assessment revealed a noncarcinogenic risk(HI >1) for children at 13 samplings sites and for adults at one sampling site.For children the risk was due to elevated levels of Mo,Cd,Co,and As,while for adults,only Mo.Carcinogenic risk(>1:1,000,000) of As and Cr via ingestion pathway was observed in 25 and 14 samples,respectively.This study,therefore,is the base for further detailed investigations to organize problematic site remediation and risk reduction measures.

PM_(2.5), PM_(10) and health risk assessment of heavy metals in a typical printed circuit noards manufacturing workshop

A typical Printed Circuit Board（PCB） manufacturer was chosen as the object of this study.During PCB processing, fine particulate matter and heavy metals（Cu, Zn, Pb, Cr, Cd and Ni）will be released into the air and dust, which then impact workers＇ health and the environment. The concentrations of total suspended particle（TSP）, PM10 and PM2.5in the off-site were 106.3, 90.0 and 50.2 μg/m3, respectively, while the concentrations of TSP, PM10 and PM2.5in the workshops ranged from 36.1 to 365.3, from 27.1 to 289.8 and from 22.1 to212.3 μg/m3, respectively. Almost all six of the heavy metals were detected in all of the particle samples except Cd. For each workshop, it was obvious that Zn was the most enriched metal in TSP, followed by Cu 〉 Pb（Cr） 〉 Ni 〉 Cd, and the same trend was found for PM10 and PM2.5. In the dust samples, Cu（which ranged from 4.02 to 56.31 mg/g） was the most enriched metal, followed by Zn, Cr, Pb, Ni and Cd, and the corresponding concentrations ranged from 0.77 to 4.47, 0.37 to 1.59, 0.26 to 0.84, 0.13 to 0.44 and nd to0.078 mg/g, respectively. The health risk assessment showed that noncancerous effects are unlikely for Zn, Pb, Cr, Cu, Cd and Ni. The carcinogenic risks for Cd and Ni were all lower than 10-6, except for Cr. This result indicates that carcinogenic risks for workers are relatively possible in the workshops. These findings suggest that this technology is advanced from the perspective of environmental protection in the waste PCB＇s recycling industry.

Source identification, contamination status and health risk assessment of heavy metals from road dusts in Dhaka, Bangladesh

In this study, concentrations of Cr, Mn, Ni, Cu, Zn, Cd and Pb were determined in road dusts collected from different locations in Dhaka to assess source, contamination status and health risk. Energy-dispersive X-ray fluorescence spectroscopy and energy-dispersive X-ray spectroscopy were used to determine Cr, Mn, Ni, Cu, Zn, Cd and Pb and their mean concentrations were 162.27 ± 29.46, 721.18 ± 180.14, 35.65 ± 12.55, 104.56 ± 128.33, 515.32 ± 321.90,BDL, and 342.82 ± 591.20 mg/kg, respectively. Among the heavy metals, highest concentrations of Cu, Zn and Pb were found at urban sites-7(municipal waste dumping) and 8(medical waste incineration). Highest concentration of Cr followed by Cu and Zn was found at site-5(Tejgaon, urban). Principal component analysis revealed that anthropogenic activities are the potential sources for Cr, Ni, Cu, Zn and Pb while earth crust for Mn. Pollution index and pollution load index results suggested that all the sites were contaminated and/or degraded by Cr, Cu, Zn and Pb except sites-9(urban), 10(sub-urban), 11(rural) while sites-7 and 8(urban) were extremely degraded. For noncarcinogenic health risk, hazard quotient values for dermal were higher compared to that of inhalation/ingestion. Though hazard index values were less than 1 at all the sites, these were at least one order of magnitude higher for children group than that of adult group, thus the children group may face more noncarcinogenic health risk at sites -7 and 8. Values of incremental lifetime cancer risk were from 10to 10showed no carcinogenic health risk by road dusts contaminated with the heavy metals.

Health Risk Assessment Due to Heavy Metals Exposure via Consumption of Bivalves Harvested from Marudu Bay, Malaysia

Concern over health risk from consumption of bivalves originating from Marudu Bay is escalating due to the rapid agricultural development surrounding the bay. This has motivated us to estimate the health risk index (HRI) of heavy metals from four commercially important and highly exploited bivalve species which are abundant in the bay. Samples (n = 30) of green mussel (Perna viridis), Asiatic hard clam (Meretrix meretrix), Pacific oyster (Crassosstrea gigas) and marsh clam (Polymesoda expans) were acquired from fishermen in Kg. Teritipan, Marudu Bay. These bivalves were analyzed for heavy metals content using the Inductively Couples Plasma-Optical Emission Spectroscopy (ICP-OES). The study found that the mean contents of Arsenic (As) and Manganese (Mn) in all analyzed bivalves exceeded the permissible limits as well as copper (Cu), lead (Pb) and zinc (Zn) in Pacific oyster, and Zn in marsh clam. It was also noticed that consumption of different bivalve species may bring about health risk from different metals as indicated by varied Total Hazard Index (THI) values. Consumption of the four bivalves was noticed to promote high health risk from As intoxication. Although metal pollution index (MPI) analysis revealed that the bivalves from the bay are currently not seriously impacted by heavy metal pollution, vigorous efforts should be taken to preserve the natural condition of the bay for years to come. There are several ways to minimize health issues from bivalve consumption which include keeping the bivalve natural habitat away from heavy metals pollution by strictly enforcing environmental laws and policies, establishing zones for bivalve fisheries, monitoring heavy metals concentration in bivalve on a regular basis and making depuration process a compulsory requirement in every seafood restaurant throughout the country.

Pollution and health risk assessment of heavy metals in soils of Guizhou,China

Mining of minerals in Guizhou,China,where it is enriched with reserves,may lead to soil contamination with heavy metals.We assessed the risk of eight typical heavy metals in Guizhou soils by collecting province-wide data available in the literature and using the geo-accumulation index method,the ecological risk assessment method,and the USEPA health risk assessment model.The concentrations of eight heavy metals,except for Pb and Cr,were above the background levels.Soil heavy metal pollution evaluation results showed that As,Cu,Zn,Pb,Cr,Cd,and Ni reached the pollution levels,while Hg fell into the category of moderate contamination.As,Cu,Zn,Pb,Cr,and Ni posed low potential ecological risk,while Cd and Hg demonstrated a considerable or a very high potential ecological risk.Totally,the integrated potential ecological risk was ranked“very high”.Regarding to health risk,the non-carcinogenic risks caused by heavy metals were insignificant,but the carcinogenic risk caused by As was significant.Consequently,there appeared serious soil contamination of Hg and As,with the latter also being the greatest potential risk to human health.Both Hg and As should stay at the highest priory for remediation efforts in Guizhou soils.

Mineral Uptake of Heavy Metals by Some Marine Organisms along the Limbe Coastline in Cameroon and Health Risk Assessment

This study aimed at investigating the content of heavy metals in some marine organisms of the Cameroon Atlantic coast and assessing the health risk due to their consumption by the population. Nine fish and one shrimp species were collected for this study. These fish species were Ethmolosa fimbriata, Drepane africana, Dentex moroccanus, Arius latiscotatus, Scarus hoefleri, Cynoglossus browni, Sardinella madorensis, Pseudotolithus elongatus, Pseudotolithus typus. The shrimp species was Macrobranchium macrobranchium. The elements investigated in this study were: Fe, Co, Cu, Cd and Pb. For seven fish species it was found that the concentration of heavy metals followed the order Fe > Co > Cd > Cu > Pb. For most fish species the Target Hazard Quotient (THQ) value calculated showed the following trend Cd > Co > Pb > Fe ≥ Cu. Cadmium was found to be the main contributor to health risk that may result from the consumption of the fish species under study. The THQ for this element was in the range 0.7 - 1.2 while the Target Cancer Risk (TR) due to ingestion of this metal was in the range (3 × 10-4 - 6 × 10-4). These values are slightly above the threshold limits established for both carcinogenic and non carcinogenic risks by the United States, Environmental Protection Agency. The estimated weekly intake of cadmium due to consumption of some fishes under study was greater or equal to the Provisional Tolerable Weekly Intake (PTWI) determined by Food and Agriculture Organization/World Health Organization.

Assessing the health risk of heavy metals in vegetables to the general population in Beijing,China

A systematic survey of As, Cd, Cr, Cu, Ni, Pb and Zn concentrations in vegetables from 416 samples （involving 100 varieties） in Beijing was carried out for assessing the potential health risk to local inhabitants. The results indicated that the metal concentrations in vegetables ranged from 〈 0.001 to 0.479 μg/g fresh weight （fw） （As）, 〈 0.001 to 0.101 μg/g fw （Cd）, 〈 0.001 to 1.04 μg/g fw （Cr）, 0.024 to 8.25μg/g fw （Cu）, 0.001 to 1.689 μg/g fw （Ni）, 〈 0.001 to 0.655 μg/g fw （Pb） and 0.01 to 25.6 μg/g fw （Zn）, with average concentrations of 0.013, 0.010, 0.023, 0.51, 0.053, 0.046 and 2.55 μg/g fw, respectively. The results showed that the concentrations of As, Cr, Cu, Cd, Pb and Ni in vegetables from open-fields were all significantly higher than those grown in greenhouses. In addition, in local-produced vegetables, all HMs except Zn were significantly higher than those in provincial vegetables. The estimated daily intake （EDI） of As, Cd, Cr, Cu, Ni, Pb and Zn from vegetables was 0.080, 0.062, 0.142, 3.14, 0.327, 0.283 and 15.7 μg/（kg body weight （bw）.d） for adults, respectively. Arsenic was the major risk contributor for inhabitants since the target hazard quotient based on the weighted average concentration （THQw） of arsenic amounted to 44.3% of the total THQ （TTHQ） value according to average vegetable consumption. The TTHQ was lower than 1 for all age groups, indicating that it was still safe for the general population of Beijing to consume vegetables.

Assessing the concentration and potential health risk of heavy metals in China's main deciduous fruits

To assess levels of contamination and human health risk, we analyzed the concentrations of the heavy metals lead （Pb）, cadmium （Cd）, chromium （Cr）, and nickel （Ni） in China’s main deciduous fruits-apple, pear, peach, grape, and jujube. The concentration order of the heavy metals was Ni〉Cr〉Pb〉Cd. In 97.5% of the samples, heavy metal concentrations were within the maximum permissible limits. Among the fruits studied, the heavy metal concentrations in jujube and peach proved to be the highest, and those in grape proved to be the lowest. Only 2.2% of the samples were poluted by Ni, only 0.4% of the samples were poluted by Pb, and no samples were poluted by Cd or Cr. Compared with the other fruits, the combined heavy metal polution was signiifcantly higher （P〈0.05） in peach and signiifcantly lower （P〈0.05） in grape. For the combined heavy metal polution, 96.9% of the samples were at safe level, 2.32% at warning level, 0.65% at light level, and 0.13% at moderate level. In the fruits studied, the contribution of heavy metals to the daily intake rates （DIR） folowed the order of Ni〉Cr〉Pb〉Cd. The highest DIR came from apple, while the lowest DIR came from grape. For each of the heavy metals, the total DIR from ifve studied fruits corresponded to no more than 1.1% of the tolerable daily intake, indicating that no signiifcant adverse health effects are expected from the heavy metals and the fruits studied. The target hazard quotients and the total target hazard quotients demonstrated that none of the analyzed heavy metals may pose risk to consumers through the fruits studied. The highest risk was posed by apple, folowed in decreasing order by peach and pear, jujube, and grape. We suggest that the main deciduous fruits （apple, pear, peach, grape, and jujube） of China’s main producing areas are safe to eat.

Soil Heavy Metal Pollution and Health Risk Assessment of Abandoned Land in Coal Mining Areas in Xingren County

Total contents of heavy metals （ Pb, Cr, Cd, Hg, As, Cu, Zn, and Ni） in 68 soil samples were determined to evaluate the contamination level of soil from five coal mine areas in Xingren County, Guizhou province. The pollution levels of heavy metals were characterized by anthro- pogenic influence multiple, and the pollution of heavy metal in soil was evaluated using geo-accumulation index. Based on the health risk models recommended by the U.S. Environmental Protection Agency （ US EPA）, the health risks of heavy metals in the soils were assessed. The results showed that the abandoned land in the five coal mining areas were contaminated by heavy metals, and the order of pollution levels of eight heavy metals was As 〉 Pb 〉 Cu 〉 Hg 〉 Ni 〉 Cr 〉 Cd 〉 Zn. The soils suffered moderate-heavy pollution from As and Pb, and the contents of As and Pb in the soils were 13.16 and 4.76 times higher than the background values of Guizhou Province, followed by Cu, Hg and Ni , while soil pollution from Cr, Cd and Zn was mild. The order of non-caminogenic risks of the heavy metals in the soils was As 〉 Pb 〉 Cr 〉 Ni 〉 Cu 〉 Hg 〉 Cd 〉 Zn, and the non-carcinogenic dsk value of As was higher than that its threshold value 1, which indicated that As had a high potential health risk to adults and children. The order of carcinogen risks of the four heavy metals was As 〉 Cd 〉 Cr 〉 Ni, and the carcinogenic risk value of As was higher than its threshold value, indicating that As had a high carcinogenic risk to adults and children. The carcinogenic risk values of other three heavy metals （ Cd, Cr and Ni） were lower than the threshold value, so they had no carcinogenic risk to human health. Moreover, children were more sensitively affect- ed by heavy metals from the abandoned land. Therefore, the health of children in such areas should be paid more attention to. The HI value of the eight heavy metals to children was seven times higher than that to adults. The contribution rate of HQAs to HI was about 88%, and the contribution rate of CRA, to TCR was about 98%, so As was the most crucial factor influencing non-carcinogenic and carcinogenic dsk in the abandoned soils.