Non-carcinogenic Risk For Children Research Articles

Pollution characteristics of soil heavy metals around two typical copper mining and beneficiation enterprises in Northwest China.

In order to investigate the situation of heavy metal pollution in the heavy metal industry in Gansu Province, a large copper mining province, two large and typical copper mining and beneficiation enterprises with differences in topographic features, climatic conditions, and soil types were selected as the target of this study based on similar ore types and beneficiation processes. Around these two enterprises, geochemical baselines of the six heavy metals were established, while the degree of local soil heavy metal pollution and potential hazards to humans were assessed based on statistical analysis, single-factor and multi-factor index analysis, and health risk evaluation models. In addition, Spearman's correlation analysis and hierarchical cluster analysis were used to explore the intrinsic association between each heavy metal in the two mining industries to reveal the pattern of soil heavy metal pollution in the copper mining and beneficiation industry and to propose targeted measures to improve and prevent soil heavy metal pollution. The results showed that the heavy metal pollution in the soil around Shengxi Mining Co., Ltd. of Subei County (SX enterprise) was higher than that around Yangba Copper Co., Ltd. of Gansu Province (YB enterprise), but the two enterprises had similar patterns of pollution, with an overall medium level of pollution. The carcinogenic and non-carcinogenic risks for children and adults were within acceptable limits for both enterprises. Besides, the correlation between the different heavy metals to similarity in their sources of contamination and the different degrees of association between the soil heavy metals of the two enterprises due to their environmental characteristics.

Potentially Toxic Elements in Urban Soils from Public-Access Areas in the Rapidly Growing Megacity of Lagos, Nigeria.

Rapid urbanization can lead to significant environmental contamination with potentially toxic elements (PTEs). This is of concern because PTEs are accumulative, persistent, and can have detrimental effects on human health. Urban soil samples were obtained from parks, ornamental gardens, roadsides, railway terminals and locations close to industrial estates and dumpsites within the Lagos metropolis. Chromium, Cu, Fe, Mn, Ni, Pb and Zn concentrations were determined using inductively coupled plasma mass spectrometry following sample digestion with aqua regia and application of the BCR sequential extraction procedure. A wide range of analyte concentrations was found—Cr, 19–1830 mg/kg; Cu, 8–11,700 mg/kg; Fe, 7460–166,000 mg/kg; Mn, 135–6100 mg/kg; Ni, 4–1050 mg/kg; Pb, 10–4340 mg/kg; and Zn, 61–5620 mg/kg—with high levels in areas close to industrial plants and dumpsites. The proportions of analytes released in the first three steps of the sequential extraction were Fe (16%) < Cr (30%) < Ni (46%) < Mn (63%) < Cu (78%) < Zn (80%) < Pb (84%), indicating that there is considerable scope for PTE (re)mobilization. Human health risk assessment indicated non-carcinogenic risk for children and carcinogenic risk for both children and adults. Further monitoring of PTE in the Lagos urban environment is therefore recommended.

Distribution and human health hazard appraisal with special reference to chromium in soils from Peenya industrial area, Bengaluru City, South India.

Presence of heavy metals in Peenya industries is considered a major environmental and human health risk. The purpose of this research is to determine the concentrations of trace elements in urban industrial soils in north Bengaluru in order to assess the degree of soil pollution and to evaluate environmental and human health risk. Twelve soil samples during July-2016 were taken from Peenya industrial sites at different depth viz., 0-Hft., 1-3ft., and 3-5ft. heavy metals (As, Cd, Co, Cr+3, Cu, Fe, Mn, Pb, Sr, V, and Zn) were determined by inductively coupled plasma mass spectrometry (ICP-MS). Contamination Factor, Enrichment Factor, Pollution Index, Modified Pollution Index, indices of pollution, Toxic Unit (TU), Hazard Quotient (HQ), Hazard Index (HI), Total Hazard Index (THI), Cancer Risk (CR), and Lifetime Cancer Risk (LCR) were used to evaluate the environmental and potential health hazard risks of human beings. Results showed that Cr+3 concentration exceeded the threshold limit of 60mg/kg and 66.66%, 50%, and 41.66% showing more than the threshold limit at 0-1ft., 1-3ft. and 3-5ft. depth soil samples. Single pollution indices showed that the study site was contaminated with chromium concentration. Nemerow pollution index showed that majority of soil samples were in the very high level of pollution. THI values showing <1 indicating that there were non-carcinogenic risks for children and less risk for adults. Based on LCR for children, 100% of soil samples were at high risk. LCR for Cr+3 concentrations of the soils were found higher than the threshold value of 1.00E-04, indicating a significant carcinogenic risk. The study area is polluted, mainly with Chromium, whereas environmental risk is limited to a small part of it. This study can be used as a reference point to develop future long-term risk assessment plans on the probable movement of heavy metals in urban soils to human beings.

The preliminary survey on the concentration of potentially toxic elements (PTEs) in salt samples collected from Tehran, Iran: a probabilistic health risk assessment.

The present study aimed to assess the potentially toxic elements (PTEs), including copper (Cu), zinc (Zn), arsenic (As), lead (Pb), and mercury (Hg) in refined, rock, and sea salt samples collected (n=60) from Tehran's local market by the aid of an inductively coupled plasma-mass spectrometry (ICP-MS). Besides, the carcinogenic and non-carcinogenic risks for children and adults were estimated with the aid of the Monte Carlo simulation (MCS) method. The rank order of PTEs in refined salt was Pb (13.378 μg/g) > Cu (6.448 μg/g) > Zn (0.363 μg/g) > As (0.184 μg/g) > Hg (0.049 μg/g); in sea salt was Pb (22.972 μg/g) > Cu (3.963 μg/g) > Zn (0.986 μg/g) > As (0.387 μg/g) > Hg (0.224 μg/g); and in rock salt was Cu (31.622 μg/g) > Pb (22.527 μg/g) > Zn (0.638 μg/g) > As (0.235 μg/g) > Hg (0.095 μg/g). It was concluded that the average concentration of some of the investigated PTEs was higher than the national standard limits and Codex's guidelines. A significant non-carcinogenic risk (TTHQ > 1), except for adult consumers, was noted based on the health risk assessment who consume refined salt. All consumers were also at the threshold carcinogenic risk of As (between 10-4 and 10-6). Given the considerable health risks due to consumption (refined, rock, and sea salt), approaching effective monitoring plans to control the PTEs concentrations in salt distributed in Tehran are recommended.

Comparison of the Potential Ecological and Human Health Risks of Heavy Metals from Sewage Sludge and Livestock Manure for Agricultural Use.

Sewage sludge and livestock (chicken, swine and cattle) manure samples were collected from the Yanmenguan Cattle Herbivorous Livestock Area to compare the potential ecological and human health risks caused by heavy metals contained in them. In this study, the Class II level of Quality Control of Imported Organic Fertilizers is selected as the limit standard value of heavy metals. Based on the mean content values, no heavy metal in cattle manure was higher than the limit standard value; the content of Cu in swine manure was higher than the limit of Cu; the content of Zn in sewage sludge, chicken manure and swine manure were all higher than the limit of Zn; and the content of Cr in sewage sludge and chicken manure were all higher than the limit of Cr. Results indicated that sewage sludge and livestock manure all had high contents of Zn, Cu and Cr. The mean pollution index (PI) suggested that Cu, Zn, As and Cr in sewage sludge and livestock manures all induced potential ecological risks. According to the mean Nemerow’s synthetic pollution index (PN) values, swine manure had the highest potential ecological risk for agricultural use. Daily exposure to Cu, Zn and Cr was higher than other heavy metals from sewage sludge and livestock manures, and heavy metal exposure was always higher for children than adults, with ingestion as the main pathway. Non-carcinogenic risk was caused mainly by Cu and Cr, based on the higher hazard quotient (HQ) values for adults and children. There was no non-carcinogenic risk for all people, except exposure of Cu from swine manure for children, which was 1.76 times higher than the threshold value of 1. According to the mean hazard index (HI) values, only swine manure had a non-carcinogenic risk for children. As the carcinogenic risk index (Risk) values were continuously greater for As than Cd, As had a higher carcinogenic risk than Cd. There was no carcinogenic risk for any single heavy metal, although As exposure from sewage sludge was found to have an inapparent carcinogenic risk for both adults and children. Regarding the RISK value, sewage sludge had an unacceptable carcinogenic risk for adults and children, and swine manure had an unacceptable risk for children only. In general, for both non-carcinogenic and carcinogenic risks, ingestion was the main pathway, and children were more sensitive than adults. Comparing the four kinds of organic waste, cattle manure was the safest for agricultural use in terms of ecological and human health risks. In multiple comparisons, swine manure was significantly different regarding potential ecological risk and non-carcinogenic risk, and sewage sludge was significantly different regarding carcinogenic risk.

Human health risk assessment in aluminium smelting site: Soil fluoride bioaccessibility and relevant mechanism in simulated gastrointestinal tract

Incidental oral ingestion is considered to be an important exposure route for humans to soil contaminants, such as fluoride (F). For 25 soil samples containing 4000 mg F/kg from aluminium smelting site in southwestern China, this study investigated F bioaccessibility in the human gastrointestinal tract in vitro. Fluoride bioaccessibility (2.4–48.8%) in the gastric phase was primarily caused by the dissolution of F-Ca and F-Al compounds (assigned to residual phase), identified by X-ray photoelectron spectroscopy and sequential extraction. Following modification to the small intestinal phase, the variation in F bioaccessibility (2.5–38.8%) should be the result of concurrent processes, including the formation of F complexes and competitive adsorption, and inversely the precipitation of fluorite and surface adsorption of formed F–Al complexes. The colon incubation with human gut microbiota yielded a 1.3-fold increase in F bioaccessibility (3.9–45.7%), probably due to the dissolution of F bound to Fe (hydr)oxides. Bioaccessibility adjustment can reduce hazard quotient of fluoride, and non-carcinogenic risk for children should be noted that soil F intake contributed 21.7% on average, up to 76.6% of oral reference dose. This will result in better understanding of human health risk assessment associated with F exposures.

Source and Health Risk Assessment of PM2.5-Bound Metallic Elements in Road Dust in Zibo City

To study the pollution characteristics, sources, and ecological and health risk of PM2.5-bound metallic elements in road dust in Zibo City, a total of 97 dust samples were collected in eight districts between October 2016 and May 2017, and particles smaller than 2.5 μm were suspended filtered using a resuspension system. Inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES) were used to investigate 18 metal elements within the dust samples. The results showed that the mass fraction of Ca[ω(Ca)] was highest with an average of 120307.7 mg·kg-1, which was 7.2 times higher than the soil background values for Shandong Province. The mean values of ω(Zn), ω(Cu), ω(Sb), and ω(Cd) were 13.9, 11.7, 13.3, and 29.6 times higher than the background values, respectively. The geo-accumulation index (Igeo) indicated high levels of Cd, Zn, Cu, and Sb pollution, especially in winter. Enrichment factors (EFs) also indicated high concentrations of Cd, Zn, Sb, and Cu in the road dust, which were notably affected by human activities. Principal component analysis (PCA) showed that biomass combustion, coal burning, vehicle emissions, iron and steel smelting, and soil dust are the five main sources of metal elements in road dust in Zibo City. The potential ecological risk of Cd and the total potential risk were extremely high during three seasons and was highest in winter. Health risk assessment showed that As and Pb had a non-carcinogenic risk for children, while Cr presents a carcinogenic risk. In conclusion, pollution from PM2.5-bound metallic elements in road dust in Zibo City is derived from anthropogenic sources and is most severe during winter. Importantly, the levels of pollution detected represent potential ecological risk as well as some non-carcinogenic and carcinogenic risks for children. Therefore, the source control of road dust requires particular attention.

Pollution effect assessment of industrial activities on potentially toxic metal distribution in windowsill dust and surface soil in central China

Boundaries between industrial and urban areas in developing countries are not clearly defined, but pollution effect assessment of industrial activities on potentially toxic metal (PTM) distribution in these areas has rarely been investigated. Fifteen villages and eight communities surrounding the industrial areas from Anyang, China, were chosen as research objects in this study. A total of 78 windowsill dust and 78 surface soil samples were collected to determine the pollution levels, spatial distribution and risk indices of nine PTMs. PTM concentrations (expect Cr, Mn and Ni in surface soil) in the surveyed region were higher than the local soil background values. Amongst these PTMs, serious Cd and As pollution was discovered, and Cd and As in windowsill dust and surface soil exceeded the background value by 73.00 and 9.59, 9.74 and 10.92 times, respectively. Compared with the Igeo in surface soil, a large degree of variation in Igeo for the different PTMs was found in windowsill dust. The interpolated spatial distribution of dust Cr, Zn, Pb, Cd and soil Mn, Ni and Cu had a gradually decreasing pollution trend from the south to the north due to the prevailing wind directions in winter in the study area. Results of multivariate statistics reflected that industrial production and traffic emission affected the concentration of PTMs in windowsill dust and surface soil. The non-carcinogenic risks for children (soil: 12.4; dust: 19.2) were larger than those for adults (soil: 1.02; dust: 1.51). This finding suggested that industrial activities caused serious harm to the residents around industrial areas.

Concentration of Potentially Harmful Elements (PHEs) in Trout Fillet (Rainbow and Brown) Fish: a Global Systematic Review and Meta-analysis and Health Risk Assessment.

In this work, articles regarding the concentration on potentially harmful elements (PHEs) in fillet trout (rainbow and brown) fishes were retrieved from Cochrane, Scopus, and PubMed databases between 1 January 1983 and 30 April 2020. The pooled concentration of PHEs in fillet trout fishes was meta-analyzed using a random-effect model (REM) and following the non-carcinogenic and carcinogenic risks was calculated using the Monte Carlo simulation (MCS) method. The meta-analysis of 42 articles (43 data report) revealed that a sort of PHEs in fillet trout was 19,996.64μg/kg ww for Fe; 1834.75μg/kg ww for Co; 772.21μg/kg ww for Cu; 335.78μg/kg ww for Ni; 290.46μg/kg ww for Se; 226.20for Cr; 178.11μg/kg ww for Pb; 77.40μg/kg ww for Hg; 19.40μg/kg ww for Cd; and 3.66μg/kg ww for inorganic As. The non-carcinogenic risk assessment indicated that the lowest and highest hazard index (HI) in the adults was Pakistan (0.0012) and Turkey (0.2388), respectively, and in children was Pakistan (0.0057) and Turkey (1.114), respectively. The non-carcinogenic risk was acceptable for adult consumers in all countries (HI > 1 value) but non-carcinogenic risk for children was not acceptable in Turkey. The sort of countries based on carcinogenic risk in the adults due to inorganic As was China (1.44E-06) > Iran (9.14E-08) > Turkey (4.45E-08) > Portugal (9.04E-10). The carcinogenic risk was threshold for adult consumers in China (CR < 10-6). Consumption of fillet trout (rainbow and brown) content of PHEs in many countries cannot endanger the health of consumers.

Pollution Characteristics and Health Risk Assessment of Heavy Metals in Road Dust from Non-ferrous Smelting Parks

In order to explore the pollution characteristics and health risks of heavy metals in dust from roads around non-ferrous smelting activities in different regions, dust samples from urban roads, non-ferrous smelting industry park roads, and tunnel roads were collected from the Mengzi area of Yunnan Province. The dust samples were suspended on Teflon filters by re-suspension equipment to obtain PM2.5 and PM10 samples. Eight heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) were analyzed by ICP-MS. The results showed that the average content of the total heavy metals in PM2.5 was higher than that in PM10. The average contents of Pb, Cd, As, and Zn were highest in all three types of road dust, and the difference in the total average content in different types of road dust was ranked as:tunnel roads > non-ferrous smelting industrial park roads > urban roads. The average contents of Pb and As in PM2.5 from the tunnel road dust were higher than other heavy metals, and reached up to 92338.3 mg·kg-1 and 12457.7 mg·kg-1, respectively. The average contents of Pb and Zn in PM2.5 from the industrial park road dust were the highest of all heavy metals (4381.7 mg·kg-1 and 4685.0 mg·kg-1, respectively). The average content of Zn and Pb in PM2.5 were the highest of all the heavy metals in the urban road dust (1952.6 mg·kg-1 and 1944.8 mg·kg-1, respectively). The average contents of Cu, Zn, As, Cd, and Pb in the different types of road dust were all higher than their background values in Yunnan Province. The results of the enrichment factor analysis and principal component analysis indicated that Cu, Zn, As, Cd, and Pb were obviously enriched in all three types of road dust, which were significantly affected by the non-ferrous smelting industry and traffic sources. In contrast, Cr, Mn, and Ni were not obviously enriched in the three types of road dust and were less affected by anthropogenic sources. The results of the health risk assessment testified that ingestion was the main exposure route, and that the children's non-carcinogenic risk was higher than that of adults. In PM2.5, As, Cd, and Pb in all types of road dust were associated with non-carcinogenic risks for adults and children. In PM10, As, Cd, and Pb in dust from the non-ferrous smelting industry park roads and tunnel roads had non-carcinogenic risks for humans. As in PM10 from the urban road dust was associated with a non-carcinogenic risk for children, whereas As in dust from the tunnel roads had carcinogenic risks.

Interdisciplinary Approaches to Assessing the Health of People Living in Environmentally Adverse Conditions

The health status of the population of different ages was examined. Since children are very vulnerable to environmental factors, our goal was to examine their health status and compare them with those of the older population. Also one of the important tasks of our study was the installation of carcinogenic and non-carcinogenic risks for children and adults of different sexes. During our research, we calculated the air pollution index, investigated the incidence statistics of the population, and calculated the lifetime average daily dose (LADD). We investigated the content of sulfur dioxide, hydrogen sulfide, nitrogen oxide, ammonium and hydrogen carbonates and compared it with safe level of exposure. In Aktobe, the Republic of Kazakhstan the external environment is polluted with boron and chromium, and in Aktau - with organic hydrocarbons. High morbidity rates in adolescents were found for endocrine disorders, digestive system diseases, and musculoskeletal system disorders. Estimating the prevalence and incidence of newly diagnosed diseases among women in Aktau showed that the overall incidence rate, as well as the incidence of respiratory and skin diseases, declines with age. The incidence of the genitourinary system and the number of nervous disorders increase, and the number of neoplasms increases in men population. A study of carcinogenic risks showed that children with Aktau, especially boys, have the greatest risk of cancer. The conducted research shows that environmental factors have a big impact on the health of the population.

Assessment of human health risks and pollution index for heavy metals in farmlands irrigated by effluents of stabilization ponds.

Areas contaminated with heavy metals can pose major risks to human health and ecological environments. The aims of this study are to assess human health risk and pollution index for heavy metals in agricultural soils irrigated by effluents of stabilization ponds in Birjand, Iran. The results revealed that the levels of Cr, Mn, Zn, Fe, Cu, Cd, and Pb were in range of 70.3-149.65, 355-570, 31.15-98.45, 23,925-29,140, 22.75-25.95, 0.17-6.51, and 8.5-23.5mg/kg in topsoils, respectively. Total hazard index values from heavy metals through three exposure routes for adults and children were 9.13E-01 and 1.10, respectively, indicating that there was non-carcinogenic risk for children. The total risk of carcinogenic metals (Cr, Cd, and Pb) through the three exposure routes for adults and children was 1.06E-04 and 9.76E-04, respectively, which indicates that the metals in the soil will not induce carcinogenic risks to these age groups. Pollution levels of heavy metals in soil samples including enrichment factor (EF), contamination factor (CF), pollution load index (PLI), and geo-accumulation index (Igeo) showed heavy metal contamination of agricultural soils. The results of the present study provide basic information about heavy metal contamination control and human health risk assessment management in the study area.

Contamination, ecological and health risks of trace elements in soil of landfill and geothermal sites in Tibet

Due to the utilization of landfill technology and geothermal energy production in Tibet, the contamination of the soils and underground water by trace element has currently become a serious problem, both ecologically and to the human health point of view. However, relevant studies concerning this critical problem, particularly in the Tibet area has not been found. Therefore, this study investigated the soil contamination and the spatial distribution of the trace elements in the areas surrounding the Tibetan landfill sites (LS) and geothermal sites (GS) through several pollution evaluation models. In addition, the possible sources of trace elements and their potential impact on public health were also investigated. Results showed that the trace elements in soils nearby LS and GS had moderate to high contamination risk. In soils surrounding LS, mercury had the highest concentration of 0.015 mg/kg and was 6 times higher than the background value of 0.008 mg/kg while in GS, arsenic had the highest concentration of 66.55 mg/kg, and exceeded the soil contamination risk value of 25 mg/kg. Maizhokunggar LS was the most polluted site with an average pollution load index value of 2.95 compared to Naqu, Nyingchi, Shigatse, and Lhasa. 42% of LS were with considerable ecological risk, and all GS had low ecological risk. Both carcinogenic and non-carcinogenic risk for children and adults (male, female) were within the acceptable range. According to the source analysis, unscientific anthropogenic activities including accumulated MSW, industrial discharges, and vehicle emissions significantly contributed 51.83% to soil trace element contamination. Considering that Tibet is an environment-ecologically vulnerable region with very weak self-adjustment ability, accumulated municipal solid waste in the landfill sites should be well disposed of, and even soil remediation should be well implemented.

Heavy metal pollution and health risk assessment of agricultural soil near a smelter in an industrial city in China

ABSTRACTTo assess heavy metal pollution and human health risk, a total of 28 topsoil samples were collected during four seasons from seven agricultural soil sites near a famous smelter in Jiyuan, China. The maximum concentrations of Cd, Pb, Hg, As, Zn, Cu, Ni, and Cr were 26.00, 2601.00, 3.29, 65.00, 410.00, 156.30, 54.80, and 73.60 mg kg−1, respectively. Compared with the sampling site nearest to the smelter, the concentrations of six metals at the farthest site were decreased significantly (P < 0.05). All sites were heavily contaminated, with Nemerow index (P) >3.0, and all sites had very high ecological risks related to Cd and Hg. The non-carcinogenic risk for children (based on combined exposure to the eight metals) was above the safety level. The carcinogenic risk of As for adults (8.98 × 10–6) and children (1.49 × 10–5) exceeded the acceptable level (1 × 10–6). Results suggest a serious health risk in the polluted areas, particularly for children.Abbreviation Cd: Cadmium; Pb: Lead; Hg: Mercury; As: Arsenic; Zn: Zinc; Cu: Copper; Ni: Nickel; Cr: Chromium; P: Nemerow index; RI: Potential ecological risk index; Ei: Monomial potential ecological risk of a specific heavy metal; HI: non-carcinogenic hazard index; CR: Carcinogenic risk; TN: Total nitrogen; TP: Total phosphorus; OM: Organic matter; MC: Moisture content; ADD: Average daily dose

Human health risk assessment of groundwater arsenic contamination in Jinghui irrigation district, China

The groundwater is an important route of human exposure to kinds of contaminants. This study was carried out to investigate the occurrence and spatial distribution of groundwater arsenic in the Jinghui irrigation district in Shaanxi Province, China. The water contamination was assessed for drinking purposes by comparing it to national guidelines, and the impacts of arsenic on human health were quantified using the health risk assessment model recommended by the USEPA. The results show that the concentration of groundwater arsenic ranges from 0.0012 to 0.0190 mg/L (average 0.0054 mg/L), and 2.58% of groundwater exceed the national guidelines of 0.01 mg/L for drinking. The carcinogenic risk of arsenic affecting adults has reached 3.50 × 10−4, significantly exceeding the national guideline (1.00 × 10−4.) The health risks resulting from oral exposure are higher than those of dermal exposure. The carcinogenic risk for adults is higher than that for children, while the non-carcinogenic risk for children is higher than that for adults. The area ratio of the carcinogenic risk is 42.82%, and the area of the non-carcinogenic risk is 69.19%. Groundwater arsenic mainly originates from the discharge of industrial wastewater and the slowly release of natural sediments. The results of this study can help to set up suitable management strategies to guarantee water supply and health safety for local residents.

Multipotential Toxic Metals Accumulated in Urban Soil and Street Dust from Xining City, NW China: Spatial Occurrences, Sources, and Health Risks.

A total of 155 urban soil and 157 dust samples were collected from Xining city (NW, China) with the objective to systematically investigate the spatial occurrences, sources, and health risk status of potential toxic metals (PTMs) bound in urban soil and street dust. Results established by Geographic Information System tools with inverse distance weighted interpolation technique indicated that the spatial status of 24 multi-PTMs varied with their concentration levels in urban soils and street dusts in monitored local areas. However, they had the similar sources in soil and dust. It was found that Bi, Ga, Nb, Ni, Rb, Sr, Th, U, Y, Zr, As, Mn, Nb, Ti, and V would be possibly predominated by nature material, whereas contamination of Ba, Cr, Cu, Pb, and Zn was clearly related to traffic-related sources. Peculiar associations among Sb, Sn, Ce, and Co were possibly enriched in soil and dust very close to the industrial activities. It was noted that PTMs in urban soil was an important contributor to them in dust. Compared with the potential ecological risk index of all PTMs, Sb posed very high risk. The calculated hazard index and cancer risk of all PTMs suggested the acceptable range both to noncarcinogenic and carcinogenic risk to children and adults except for the case of Cr. However, the noncarcinogenic risk for children was usually higher compared with adults. Although the noncarcinogenic and carcinogenic risk were not significant, the risk of Cr above the threshold for children and adults were observed in most local sites, which should be given more attention.

Hydrogeochemistry and human health risks of groundwater fluoride in Jinhuiqu irrigation district of Wei river basin, China

This study was carried out to investigate the hydrogeochemistry and spatial distribution of groundwater fluoride in Jinghuiqu irrigation district of China and to identify the hydrogeochemical processes and factors that control fluoride concentration. Water quality was assessed by comparing with the Chinese national groundwater quality guidelines and World Health Organization (WHO) guidelines for drinking water quality. Human health risks of fluoride were also quantified based on the US Environmental Protection of Agency (USEPA) model. The results show that groundwater in the study area is hard and slightly alkaline. The groundwater quality is generally very poor with excessive TDS, TH, Na+, SO42− and F− at some locations. The fluoride concentration in the groundwater samples ranges from 0.34 to 2.55 mg/L with an average of 1.08 mg/L, and 15.2% of the samples containing fluoride exceed the WHO guidelines of 1.5 mg/L for drinking water. High-fluoride groundwater mainly distributes in the southeast of the study area. The trend of fluoride concentration is consistent with the flow direction of groundwater. Groundwater fluoride mainly originates from natural sources and is controlled by hydrogeochemical factors such as alkaline environment, ion exchange, dissolution and precipitation of minerals. Health risk assessment results show that the non-carcinogenic risk for children is higher than that for adults and the health impact on adults is ignorable. The results of this study may help to set up suitable management strategies to guarantee water supply and health safety for local residents.

PM2.5 Associated PAHs and Inorganic Elements from Combustion of Biomass, Cable Wrapping, Domestic Waste, and Garbage for Power Generation

ABSTRACT PM2.5 fractions were collected by re-suspension of the ashes derived from the incineration processes of peanut straw (PS), wheat straw (WS), garbage-fired power plant (GFPP), domestic garbage for volume reduction (DG), and workshop of cable combustion for metal reclamation (WCC) for the analysis of 16 PAHs and 26 elements to obtain the information about their composition profiles, toxicity of PAHs, and exposure risks posed by heavy metals (HMs) and As. GFPP possessed the highest Ʃ16PAHs, while the lowest value occurred at DG. HMW-PAHs dominated in GFPP, while LMW-PAHs were predominant in PS and WS. BaP was the top PAH in GFPP and GFPP possessed the highest TEQ values based on the 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and BaP associated TEFs, and followed by WCC > DG > WS > PS. Except for DG vs. WCC, the PAH-, and HM vs. As-profiles between any 2 out of 5 sources were different based on higher coefficients of divergence than 0.3. The sum of 10 HMs and As (∑11IEs) dominated in WCC due to high contents of Cu, Zn, and Pb, and followed by GFPP > DG > WS > PS. The most enriched HMs were Sb, Cu, and Pb for WCC, Sn for GFPP, and Cd for both GFPP and DG. The integrated carcinogenic risks (CRs) for children posed by both dermal adsorption (Derm) and ingestion (ING) were higher than those for adults. The CRs for children from all the 5 sources exceeded the acceptable level of 1 × 10–4. The non-carcinogenic risks (NCRs) for children posed by both ING and DERM for 5 sources were much higher than those for adults. The NCRs for children posed by ING significantly exceeded 1, which were 63.8, 10.9, 4.11, 3.58, and 2.19 for WCC, GFPP, WS, DG, and PS.

Ecological and human health risk assessment of toxic metals in street dusts and surface soils in Ahvaz, Iran.

This study aimed to examine the concentrations and environmental health risk of the potentially toxic metals including Pb, Zn, Cu, Cd, Cr, and As in street dusts and surface soils of Ahvaz, the capital of Khuzestan province, located in the southwest of Iran. To this end, a total of 81 street dusts and 96 surface soils were collected from Ahvaz urban areas. Toxic metals were measured by inductively coupled plasma-mass spectrometry and evaluated using enrichment factors, potential ecological risk index and human health risk assessment. Lead in street dusts and Pb and Cu in surface soil showed the highest enrichment factor. The results revealed that there are two major sources of toxic metals in Ahvaz, including industrial activities and road traffic emissions and also resuspension of soil and dust particles. Cu, Pb, Zn, and Cr in Ahvaz soil and dust particles are strongly influenced by anthropogenic activity, mainly industrial and traffic emissions, while As and Co originate from resuspension of soil natural parent particles. The potential ecological risk index (RI) values for dust samples indicated that 58.02% of all samples showed low potential ecological risk. Moreover, 33% and 9% of samples showed moderate and considerable ecological risk, respectively. In addition, the RI values for soil samples indicated that 57% and 40% of all samples had low and moderate ecological risk, respectively, and 3% had a high ecological risk. The hazard index (HI) values of studied potentially toxic metals showed that there is no non-carcinogenic risk for children and adults. Furthermore, the HI value for children was 2-7 times upper than those for adults, which confirm that children show more potential health risks for exposition to these potential toxic metals. Cancer risks of the studied potential toxic elements for both adults and children decreased in the following order Crdust > Crsoil > Cddust > Cdsoil > Asdust > Assoil > Pbdust > Pbsoil. The carcinogenic risk values of Cd, As, and Pb for adults and children was lower than 1 × 10-6, suggesting carcinogenic risk of potentially toxic metals in the street dust and surface soil could be neglected. On the other hand, the carcinogenic risk value of Cr was greater than 1 × 10-6 for both adults and children revealing that the carcinogenic risks of Cr essentially need more consideration for environmental management control.

Risk assessment of heavy metals in soil based on the geographic information system-Kriging technique in Anka, Nigeria

Soil contaminated with heavy metals from artisanal gold mining in Anka Local Government Area in Northwestern Nigeria was investigated to evaluate the human health risk as a result of heavy metals. Measured concentration of heavy metals and exposure parameters were used to estimate human carcinogenic and non-carcinogenic risk. GIS-based Kriging method was utilized to create a prediction maps of human health risks and probability maps of heavy metals concentrations exceeding their threshold limits. Hazard index calculation showed that 21 out of 23 locations are posing non-cancer risk for children. Adults and children are at high cancer risk in all locations as the total cancer risk exceeded 1×10−6 (the lower limit CTR value). Kriging model showed that only a very small area in Anka has a hazard index of less than unity and cumulative target risk of less than 1×10−4, indicating a significant carcinogenic and non-carcinogenic risks for children. The probability of heavy metals to exceed their threshold concentrations around the study area was also found to be high. Keywords: Carcinogenic, Heavy metals, Human risk assessment, Kriging, Non-carcinogenic