Human Health Risks from Exposure to Heavy Metals of Suspended Particulate Matter around the Tongon Gold Mine, Côte d’Ivoire

The Tongon mine, the largest gold mine in C?te d’Ivoire, has been in operation since April 2010. However, to our knowledge to date, no study has been conducted on metallic contamination in suspended particulate matter (PM10 and PM2.5) where there is a lack of information on the carcinogenic and non-carcinogenic risk to human health associated with the exposure of populations in the Tongon area to these pollutants. The general objective of this study is to evaluate the level of contamination of PM10;PM2.5 by heavy metals and their impact on the health of populations exposed to these pollutants in the Tongon gold mine area. The sampling and measurement of suspended particulate matter (PM10 and PM2.5) were done using a MiniVol TAS passive air sampler. Heavy metal concentrations were determined by inductively coupled plasma mass spectroscopy (Nex ION 2000 ICP-MS, USA). The results indicate that the average concentrations of suspended particles (PM2.5 and PM10) obtained are all above the recommended exposure limits. In addition, among the heavy metals contained in the suspended particles, the concentrations of arsenic and nickel are high and all above the standard limit values. The assessment of the health risks related to the inhalation of PM10 particles reveals that their inhalation over a long period could cause a carcinogenic risk.

Fine Particulate Matter and Heavy Metals Pollution Status in Ambient Air of Some Selected Industrial Sites in Northern Nigeria

Fine particulate matter and eight heavy metals (Ni, Co, Cu, Pb, Cd, Cr, Mn, and Zn) concentrations were determined in air samples collected from three industrial sites in northern Nigeria using a Handheld Portable Particle Counter for PM2.5 and PM10 with model number CW-HAT 200 and a High Volume Respirable Dust Sampler (APM 460 NL) in conjunction with an Atomic Absorption Spectrophotometer (Serial No. AA0904M046) Flame Test. The results of the fine particulates ranged from 11.0 - 46.0 μg.m-3 for PM2.5 and 22.0 - 88 μg.m-3 for PM10 across all the industrial sites investigated. Most of these results exceeded the WHO permissible levels of 25.0 μg.m-3 and 50.0 μg.m-3 for PM2.5 and PM10 and thus pose threats to people living and working close to these sites. The concentration of the heavy metals studied were found to be within WHO/EU set standards except for the concentrations of Ni, Pb, and Cd that exceeded the set standard by WHO/EU with toxicity potential >1 in the Terytex industry, Kano and Grand Cereals, Jos. Strong positive correlations were found between the fine particulates concentrations and heavy metals in all the studied sites suggesting that common anthropogenic sources contributed to the fine particulates and heavy metals recorded from the industrial areas. We suggested the installation of electrostatic precipitators to combat fine particulates emission from the stack and also recommended a proper legislative framework by the government to regulate and control industrial fugitive emissions to protect human health.

Distribution and Concentrations of Heavy Metals in Tropospheric Suspended Particulate Matter (PM10) In Nairobi City, Kenya

Air pollution present the greatest threat to human health and welfare in urban environments. Population growth, industrial activities, expanded transport system, vehicular traffic, poor road planning, poor land use and traffic congestion contribute to the problem. Particulate matter (PM2.5 and PM10) has become the principal pollutants due to increased material use, energy demand and use as a result of global economic growth. This study assessed the levels of PM10 in ambient air and heavy metal composition in Nairobi city. Sampling sites were classified into three categories namely;controlled areas, industrial and residential areas as proscribed in the EMCA Air Quality Regulations, 2014. Portable Mini-Vol ambient air samplers were used for fine particulate monitoring. The concentrations of manganese, lead, and cadmium was determined in PM10 samples from all sampling sites. The lead concentration mean was 0.07 ± 0.06 μg/m3, 0.34 ± 0.35 μg/m3 and 1.10 ± 0.59 μg/m3 for residential, controlled and industrial areas respectively. Generally, all afternoons had high particulate matter while the lowest concentration levels of PM10 were recorded at night.

Spatial Variation and Risk Assessment of Arsenic and Heavy Metals in Surface Water and Suspended Particulate Matter in Tail Reaches of the Yellow River, China

To determine the pollution levels and potential toxic risks of arsenic(As) and heavy metals(Cr, Ni, Cu, Zn, Pb and Cd) in water and suspended particulate matter(SPM) in tail reaches(including freshwater reach and low-salinity reach) of the Yellow River as the Flow-Sediment Regulation Project(FSRP) has been carried out for approximately 15 yr, the surface water and SPM were sampled at pre-flood(April) and post-flood seasons(October). Results showed that similar changes of As and metal levels in water and SPM were observed along the tail reaches at pre-flood or post-flood season. Compared to pre-flood season, the levels of As, Cu, Cr and Ni in freshwater reach and the concentrations of Cr and Ni in low-salinity reach rose greatly at post-flood season. The levels of As and metals in SPM of freshwater reach or low-salinity reach at pre-flood season were significantly higher than those at post-flood season(P < 0.01).The pollutions of As and metals in surface water of tail reaches at pre-flood or post-flood season were not serious. The SPM in freshwater reach at pre-flood season were polluted by Cd, As, Cr, Cu and Ni while those in low-salinity reach were polluted by Cd and Cr. The SPM in freshwater reach at post-flood season were polluted by Cd and Pb while those in low-salinity reach were polluted by Cd and Cr.Cd was identified as heavy metal of primary concern at both pre-flood and post-flood seasons. Combined with the existed data reported in present research, this study found that the toxic risk of As and metals in SPM of tail reaches at pre-flood season was higher than that at post-flood season, implying that the implementation of FSRP during flooding season, to a great extent, reduced the toxic risk of these elements. With the long-term implementation of FSRP, the pollution levels of As and metals(particularly for Cd) in SPM of tail reaches might be elevated and the potential toxic risk primarily produced by Cr, Ni and As might be increased if effective measures were not taken in future.

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.

Magnetic properties and heavy metal contents of automobile emission particulates

Measurements of the magnetic properties and total contents of Cu, Cd, Pb and Fe in 30 automobile emission par-ticulate samples indicated the presence of magnetic particles in them. The values of frequency dependent susceptibility (χfd) showed the absence of superparamagnetic (SP) grains in the samples. The IRM20 mT (isothermal remanent magnetization at 20 mT) being linearly proportional to SIRM (saturation isothermal remanent magnetization) (R2=0.901), suggested that ferrimagnetic minerals were responsible for the magnetic properties of automobile emission particulates. The average contents of Cu, Cd, Pb and Fe in automobile emission particulates were 95.83, 22.14, 30.58 and 34727.31 mg/kg, respectively. Significant positive correla-tions exist between the magnetic parameters and the contents of Pb, Cu and Fe. The magnetic parameters of automobile emission particulates reflecting concentration of magnetic particles increased linearly with increase of Pb and Cu content, showed that the magnetic measurement could be used as a preliminary index for detection of Pb and Cu pollution.

Accumulation and Cycle of Heavy Metals in Sonneratia apetala and S. caseolaris Mangrove Community at Futian of Shenzhen, China

This paper reports the absorption,accumulation,distribution and cycle of Cu,Pb,Zn,Cr and Ni in S.apetala+S.caseolaris,mangrove community at Futian Mangrove Nature Reserve of Shenzhen,The Cu,Pb,Zn,Cr and Ni contents in forest soil increase from bottom to surface layers,and the storage of the five heavy metals in the surface layer(depth0-30cm)is Zn>Pb>Ni>Cr>Cu.The concentration ability is S.caseolaris>S.apetala>K.candel.The existing accumulation of Cu,Pb,Zn,Cr and Ni in the community is 23019.63μg/m^2,23429.66μg/m^2.177870.42μg/m^2,6835.80μg/m^2,and 12995.22μg/m^2,respectively.The annual absorption is 6592.57μg/m^2,2664.80μg/m^2,23123.56μg/m^2,853.24μg/m^2,and 1990.95μg/m^2,respectively.The annual return is 3179.50μg/m^2,1300.65μg/m^2,7401.31μg/m^2,398.99μg/m^2,and 646.20μg/m^2 respectively.The annual net retention accumulation of Cu,Pb,Zn,Cr and Ni in the community is 3413.07μg/m^2,1364.15μg/m^2,15722.25μg/m^2,454.25μg/m^2,and 1344.75μg/m^2,respectively,The turn over periods of Cu,Pb,Zn,Cr and Ni are 8,19,15,18and 21 years,respectively.

Heat shock proteins development in different stages of schistocerca gregaria as response to heavy metals intoxication

The induction of heat shock proteins in different stages of S. gergaria exposed to long and short term contamination with heavy metals, Cd and Pb in food was determined, revealing a prominent variable effect in response to the term of exposure and the type of contamination. HSP 70 was specially quantified and characterized to reveal the probability of using HSP as a biomarker for pollution.

重金属汞胁迫下菲律宾蛤仔GPx和GST基因表达分析

为研究重金属汞胁迫下菲律宾蛤仔谷胱甘肽过氧化物酶(glutathione peroxidase,GPx)和谷胱甘肽-S-转移酶(glutathione-S-transferase,GST)基因的表达情况,用汞对指示生物菲律宾蛤仔(Ruditapes philippinarum)进行单一慢性暴露试验,分别在0、12、24 h以及2、3、4、5、6、7和8 d时检测菲律宾蛤仔内脏团和鳃中GPx和GST基因的表达情况。结果表明,菲律宾蛤仔内脏团中GPx和GST基因的表达量都呈现波动变化趋势,分别在24和12 h时表达量最高(P<0.05),6 d时GPx基因表达量最低(P>0.05),3 d时GST基因表达量最低(P<0.05);GPx基因在鳃中的表达量在8 d时最高(P<0.05);鳃中GST基因的表达量在5 d时最高(P<0.05)。以上结果表明汞暴露在短期内能够诱导GPx和GST基因进行不同程度的表达,但其随着时间的延长呈明显的抑制作用。该研究结果为揭示重金属汞对菲律宾蛤仔的毒性机理提供了理论依据。

Molecular cloning and differential expression patterns of sigma and omega glutathione S-transferases from Venerupis philippinarum to heavy metals and benzo[a]pyrene exposure

Glutathione S-transferases (GSTs) are a class of enzymes that facilitate the detoxification of xenobiotics, and also play important roles in antioxidant defense. We identified two glutathione S-transferase isoforms (VpGSTS, sigma GST; VpGSTO, omega GST) from Venerupis philippinarum by RACE approaches. The open reading frames of VpGSTS and VpGSTO were of 612 bp and 729 bp, encoding 203 and 242 amino acids with an estimated molecular mass of 22.88 and 27.94 kDa, respectively. The expression profiles of VpGSTS and VpGSTO responded to heavy metals and benzo[a]pyrene (B[a]P) exposure were investigated by quantitative real-time RT-PCR. The expression of VpGSTS and VpGSTO were both rapidly up-regulated, however, they showed differential expression patterns to different toxicants. Cd displayed stronger induction of VpGSTS expression with an approximately 12-fold increase than that of VpGSTO with a maximum 6.4-fold rise. Cu exposure resulted in similar expression patterns for both VpGSTS and VpGSTO. For B[a]P exposure, the maximum induction of VpGSTO was approximately two times higher than that of VpGSTS. Altogether, these findings implied the involvement of VpGSTS and VpGSTO in host antioxidant responses, and highlighted their potential as a biomarker to Cd and B[a]P exposure.

Heavy metal removal from aqueous solution using carbonaceous K_2S-impregnated adsorbent

A novel carbonaceous adsorbent for heavy metal removal was prepared from raw coal by one-step simple sulfur impregnation using K2S. Raw coal was mixed with K2S powder and then heated at 800℃ for 30 min in nitrogen to produce K2S char. The sulfur content and form in K2S char were determined, and the ability of K2S char to adsorb Zn^2＋, Cd^2＋ and Pb^2＋ was examined. The K2S impregnation was effective at impregnating sulfur into coal, especially in the form of elemental, thiophenic and sulfatic sulfur. The sulfur content of K2S char was higher than those of raw coal and pyrolysis char. The Zn^2＋ removal in 2.4 mmol/L of Zn^2＋ solution by K2S char was higher than raw coal with the removal rate of 100%. K2S char adsorbed Pb^2＋ and Cd^2＋ in 24 mmol/L of Pb^2＋ and Cd^2＋ solution with the removal rate of 97% and 35%, respectively. The elution extents of adsorbed Pb^2＋ and Cd^2＋ were zero in distilled water and 27% in 0.1 mol/L HCl solution. These results indicated that an effective adsorbent for heavy metal ions was prepared from coal using K2S sulfur impregnation, and that the adsorbed metals were strongly retained in K2S char.

Microbial Remediation of Heavy Metal(loid)Contaminated Soil: A Review

Because of the rapid development of industrial processes, increased urban pollution and agricultural chemicals applied in recent years, heavy metal(loid) pollution in soil has been very serious, and there is an urgent need for fast and efficient removal of heavy metal(loid) pollution. Currently, environmental microorganisms are always used to perform biological alteration or improvement of soils and sewage. Using functional microorganisms that are resistant to toxic heavy metal(loid) ions for alteration and transformation of heavy metal(loid)s in ionic form is an effective measure for microbial remediation of heavy metal(loid)contaminated soil. This paper reviewed the microbial remediation mechanism of heavy metal(loid) contaminated soils, and the approaches for breeding bacteria those can be used for highly efficient removal of heavy metal(loid)s, as well as the application examples of microbial remediation and transformation of heavy metal(loid) contaminated soil, and finally described the future trends and further research work of heavy metal(loid) contaminated soils by microbial remediation.

Zinc and Chromium Load in Road Dust, Suspended Particulate Matter and Foliar Dust Deposits of Anand City, Gujarat

Anand, the milk capital of India, is a developing city with increasing vehicles and developmental activities going on at a fast pace. This study attempts to investigate the zinc and chromium concentration in street dust, suspended particulate matter and in foliar dust deposits. Ten sampling locations were selected based on the traffic density on the roads and different anthropogenic activity. Sampling was carried out in the dry months of January to March 2011. The range of Zn and Cr was 16.82 - 108.29 ppm and 118 - 151.5 ppm in the street dust respectively. Zn concentration in Suspended particulate matter lies in the range of 12.41 to 86 ppm and Cr concentration between 75 to 130 ppm. The range of Cr in foliar deposited dust varied from 79.54 ppm to 31 ppm. Whereas, for Zn maximum concentration was in S10 which is 42.34 ppm and minimum was in site S9, 23.73 ppm. ANOVA single factor showed that at 0.05 level of significance site wise variation of zinc and chromium concentration in SPM, Street dust and foliar deposited dust was not significant signifying similar source of contamination. Which is further strengthened by the good positive correlation found between the Zn and Cr concentration of street dust, leaf deposited dust and SPM. The Contamination Factor in the sites where metal concentration was high was 1.24 in S10 and 1.06 in S5 for Zn. For chromium the value of CF was 1.77 in S10 and 1.67 in S5. These values indicate that street dust is moderately contaminated with respect to zinc and chromium.

Spatial Analysis of Heavy Metal Emissions in Residential, Commercial and Industrial Areas Adjacent to a Scrap Metal Shredder in Winnipeg, Canada

A spatial analysis of air pollution in the South St. Boniface (SSB) and Mission Industrial Areas (MIA) of Winnipeg, in Manitoba, Canada, was conducted by mapping the results for 23 composite snow samples. Heavy metals were analyzed in the snow samples by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Higher concentrations closer to the shredder were significant for every metal, but, not for arsenic, in regression modeling R squared (0.585 for Cd, 0.462 for Pb, 0.423 for Zn, 0.343 for Cr, 0.343 for Ni, 0.244 for Mn, and 0.069 for As). Heavy metal concentrations were significantly higher in the industrial zone, with the next highest being the roadside zone, then the commercial zone and finally the residential/parkland zone, at p-value < 0.01 statistical significance levels according to the non-parametric Kruskal-Wallis H- test. The metals concentrations mapped on Arc-GIS with ArcMap 10.6 using kriging interpolation, display that all toxic metal concentrations, but particularly Pb, Ni, Zn, Cr, and Hg, are highest proximate to the scrap metal shredder. Furthermore, pollution indices, specifically contamination factor (CF), degree of contamination (DOC), and pollution load index (PLI), were undertaken registering high contamination. The CF registered high for lead, zinc, and nickel in all areas compared to the background levels, but the highest levels were nearby to the scrap metal shredder. The DOC values showed that the industrial contamination is nearly five times greater than that for the road or commercial areas and almost 20 times more contaminated compared to the residential/parkland. With PLI levels above 1 considered contaminated, the shredder (4.1), roadside (2.2), and commercial areas (1.9) were polluted. These findings point to the shredder as the cause of present-day contamination for all areas, including residential/parkland, traffic, and commercial areas. High levels of toxic metal air pollution emissions warrant further study of human exposure and health risk posed by multiple sources from the air, water, and land. Enforcement and enclosure of the outdoor shredder should be considered to reduce heavy metal exposure to the public.

Effect of cyclic drying and wetting on engineering properties of heavy metal contaminated soils solidified/stabilized with fly ash

团结 / 稳定(S/S ) 是重金属污染了土壤的处理的最有效的方法之一。在团结 / 稳定的污染土壤上的周期的弄湿并且弄干的效果被调查。一系列测试节目，自由压缩力量(UCS ) 测试， TCLP 沥滤测试和扫描电子显微镜学(SEM ) 测试，在污染的铅和锌上被执行土壤由苍蝇灰团结 / 稳定。UCS 和 S/S 的重金属离子的沥滤的特征污染了的测试结果表演玷污显著地随苍蝇灰内容的增加被改进。S/S 土壤的 UCS 第一随弄干并且弄湿周期的时间的增加增加，在到达山峰以后，它与它减少。当污染物质内容更低时(1 000 mg/kg ) ， TCLP 集中稍微首先在周期的弄干并且弄湿下面减少，然后增加，而是变化是次要的。TCLP 集中在 5 000 mg/kg 的一个高污染物质内容下面是更高的，并且随弄干并且弄湿周期的时间的增加增加。扫描电子显微镜学(SEM ) 的结果测试与 UCS 测试和 TCLP 沥滤测试一致，它揭示在弄干并且弄湿周期以后设计稳定的污染土壤的性质的变化的微观机构。

Chemical and Morphological Characteristics of Particulate Matter Suspended in the Air of the Dhaka University Area of Bangladesh

Total suspended particulate matter (SPM) in the urban atmosphere of Dhaka city was collected using a high volume sampling technique for a period of one month (August 2017-September 2017). Chemical characterization of particulate matter (PM) was investigated, and characterized concerning the size distribution, morphological features such as count, total area, average size, perimeter, circularity, aspect ratio (AR), roundness;equivalent spherical diameter (ESD), surface area and volume of PM. The results of elemental analysis showed that the presence of heavy metal in PM was ten to hundred times higher than the standard value prescribed by WHO and USEPA. Several morphological analysis indicated that particles varying in shape from nearly spherical to various irregular shape, had higher surface energy, higher content of Cl and S bearing particles and had a large surface area which can cause greater damage to lungs. The presence of various organic compounds containing functional groups like alcohols, ketones aldehydes, carboxylic acids as well as unsaturated and saturated carbon bonds was observed by FT-IR analysis. Scanning Electron Microscopy (SEM) was used to characterize the morphology of the PM. Agglomerates and shoots type particles were mostly seen in SPM.

竹笋重金属污染与膳食风险评估及有效阻控研究

重金属污染是全球公认的环境问题,重金属胁迫下农产品安全成为近些年的研究热点。竹笋作为一种健康食品,在世界范围内广受欢迎。此前,已经发表了许多关于竹笋重金属污染方面的论文,重金属污染已对竹笋安全构成威胁。该文主要综述了竹笋的重金属污染特征、膳食健康风险及阻控方法。结果表明,竹笋主要受Pb污染,毛竹冬笋重金属超标比其他竹笋严重,笋皮和笋根中富集系数较大,基于总量通过非致癌目标风险系数(target hazard quotient,THQ)评价重金属的健康风险,表明儿童的健康风险会比成人的高,但基于此评价尚存在不足,需进行下一步的生物可给性和建立细胞模型等进行健康风险的综合评估。在控制竹笋重金属污染上,可考虑土壤的理化性质,Ca肥、富Se肥或纳米材料可在未来加以应用,以期为竹笋安全生产提供参考。

刁江水体多相介质中As,Zn和Pb的空间和季节分布规律

调查了广西刁江河水中As,Zn和Pb的溶解态、悬浮颗粒态分布情况及季节变化,以及3种重金属在不同粒级沉积物中的分布情况.结果表明:刁江流域河水与沉积物中3种重金属污染在流域尺度上的分布存在差异,沉积物污染更为严重.与土壤污染一致,沉积物中3种重金属的污染范围扩散延伸到距离污染源近200 km的下游区域,其中车河矿区对As污染的贡献率明显高于大厂矿区,而对Pb污染的贡献率明显小于大厂矿区;不同重金属在水体中的赋存形态存在差异,河水中悬浮颗粒态Pb所占比例远高于As和Zn,这与3种重金属矿物的稳定性以及在不同粒级沉积物中的富集特征有关;河水中重金属的赋存形态存在季节差别,丰水期悬浮颗粒态重金属所占比例明显高于枯水期.