Carcinogenic Health Risk Assessment Research Articles

Non-carcinogenic and carcinogenic health risk assessment of pesticides and metals in spice samples from Iran

The extensive use of pesticides in agricultural practices along with metal contaminations has led to a global health concern. In this study, levels of 22 pesticides and 6 metals in 138 packaged and unpackaged spice samples (turmeric, black pepper, red pepper, cinnamon, ginger, and garlic powder spice) were determined and the risk of oral exposure to this mixture was assessed for Iranian consumers. Pesticides and metals mean levels differed between packaged and unpackaged samples. In both packaged and unpackaged samples, fenitrothion was the most frequently found pesticide. The greatest total mean concentration of metals was observed in unpackaged red and black peppers and in packaged turmeric ones. Mean percentages of recoveries for pesticides were 92.5–99.5 % (associated relative standard deviation (RSD) ≤7.1 % and limits of detection and quantification (LOD and LOQ, respectively) respectively 0.0001–0.0032 and 0.0003–0.01 mg/kg). Mean percentages of recoveries for metals ranged were 91.5–98.5 % (associated RSD ≤7.4 % and LODs and LOQs respectively 0.001–0.003 and 0.003–0.021 mg/kg). Total hazard index (HI) for pesticides in both packaged and unpackaged spices at the 50th, 80th, and 95th centiles was 0.0017, 0.0026, and 0.0032, respectively, reflecting di minimis risk. For the non-carcinogenic metals, the HI values in unpackaged spices at these centiles were 0.0058, 0.0074, and 0.0118, respectively, while for packaged spices were 0.0018, 0.0023. and 0.0038, respectively. For carcinogenic metals, incremental lifetime cancer risks (ILCRs) were <10−6 at these centiles, representing no health risk under both scenarios. In conclusion, no risk of carcinogenicity or non- carcinogenicity was found.

Non-carcinogenic and carcinogenic health risk assessment of heavy metals in cooked beans and vegetables in Punjab, North India.

Beans and vegetables are consumed with cereals in India on daily basis. The aim of the study was to assess carcinogenic and non-carcinogenic risk of heavy metals in cooked beans and cooked vegetables consumed by adults (18-59 years) and elderly (≥60 years) subjects from two districts (Ludhiana and Bathinda) of Punjab. A total of 150 households were selected from 30 different locations covering both rural and urban areas. The mean daily consumption of beans and vegetables in Ludhiana was recorded as 35.09 and 215.93 g, respectively. The corresponding figures in Bathinda were observed as 26.85 and 230.54 g. The average amounts of arsenic, cadmium, lead, and mercury were 1.44 × 10-5, 8.21 × 10-5, 1.30 × 10-3, and 2.61 × 10-7 mg/kg for cooked vegetables in urban households of Ludhiana district, respectively. The corresponding values for rural households were 1.53 × 10-5, 5.58 × 10-5, and 2.98 × 10-4 mg/kg while mercury was not detected. The mean chronic daily intake (CDI) of arsenic from cooked beans was significantly (p ≤ .001) higher in urban adult males of Ludhiana (7.74 × 10-9 mg/kg/day) and Bathinda (5.31 × 10-9 mg/kg/day) compared to their rural counterparts. Similar trend was observed in CDI of heavy metals from vegetables. The mean CDI of cadmium from cooked vegetables in urban adult females of Ludhiana (3.76 × 10-7 mg/kg/day) was significantly (p ≤ .001) higher than their rural counterparts and both urban and rural adult females of Bathinda. The study concluded that the subjects of both districts were found safe from non-carcinogenic and carcinogenic risk associated with heavy metals present in cooked beans and vegetables, except for urban subjects and rural adult subjects of Ludhiana district who had cancer risk due to cadmium present in cooked vegetable samples.

Spatial Patterns, Possible Sources, and Risks Assessment of Soil Potentially Toxic Elements in an Open Pit Coal Mining Area in a Typical Arid Region

Intensive mining activities in large-scale opencast coal mines have had a significant impact on the local environment. Elements that are potentially harmful to the environment are brought to the surface from deep underground, altering the geochemical conditions for their transport and redistributing them to the surface, causing serious local pollution. However, in-depth studies of toxic metal contamination in soils of arid coal mining areas have not yet received the attention they deserve. Although previous studies have conducted a great deal of research on heavy metal elements in surface coal mine soils, there are few studies related to the more seriously polluted surface coal mines in the arid regions of Northwest China, and there are no in-depth studies on the ecology of soil heavy metal contamination, health risks and source analysis according to the authors’ knowledge. To make up for this shortcoming, the present study takes Zn, Cu, Cr, Pb, Hg, and As in the surroundings of the tertiary coal mines in the Hongsachuan Mining Area (northern Xinjiang, China) as an example. The health, ecological risks, and pollution sources of heavy metal elements in surface coal mine soils were comprehensively analyzed. The results showed that the average concentrations of Cr, Hg, and As in the soils of open-pit coal mines greatly exceeded the corresponding provincial background values, with the Cr content exceeding China’s soil environmental quality standard Ⅰ and the As content even higher than standard Ⅱ (GB15618-1995). Geostatistical and multivariate statistical results showed that the six metals analyzed in this study can be divided into four groups, as follows. Group 1 included Zn and Cu and was mainly controlled by natural sources related to soil parent materials. Group 2 consisted of Cr and Hg and was associated with industrial practices. Group 3 was explained by As and was mainly from coal combustion during the mining activities. Group 4 was Pb and was dominantly from natural sources, together with vehicular emission during the mining activities, indicating a mixed source. Potential ecological risk index (PER) values exhibited low ecological risk in contaminated soils with Zn, Cu, Pb, and Cr, and only 10% of As samples exhibited moderate risks, while 77% of Hg samples posed ecological risks at different level, implying that Hg was the main contributor for comprehensive risk index (RI). Regardless of non-carcinogenic and carcinogenic health risk assessment, As was the primary risk element followed by Cr, and children tended to have a higher health risk than adults. In this paper, statistical methods, pollution assessment methods, and potential ecological risk models are skillfully combined, and relevant conclusions are drawn based on the human and economic geographical background information of the study area. The results can provide references for the investigation and evaluation of soil heavy metals and quantitative analysis of pollution sources in the same type of areas. In order to grasp the pollution level of potential toxic elements in the soil of large open-pit coal mines in arid areas, effective source-cutting measures are taken to provide data support the sustainable management of coal mines and local soil safety utilization measures.

Exposure Factors in Health Risk Assessment of Heavy Metal(loid)s in Soil and Sediment

Heavy metal(loid)s (HMs) play an important role in economic development since they are used in various branches of industry. However, all industrial activities emit HMs into the environment, where they are no longer useful but potentially toxic. It has been observed that HMs enter the soil and sediment, and potential human health risk may arise due to their excessive accumulation. Having in mind the importance of assessing the risk due to HMs in these media, we analyzed published works in the last decade and created a summary of exposure factors in health risk models for HMs in soil and sediment. This analysis revealed a remarkable increase in the number of publications about health risk assessment of HMs, especially in the last few years. Since many differences in the values of the exposure factors and their distributions were noted, this study focused on elucidating these differences. Non-carcinogenic and carcinogenic health risk assessment models were evaluated through a deterministic approach that is prevalent in use, and a probabilistic one, which is gaining more and more attention in research. In the end, guided by the studied literature, we propose the values and distributions for the exposure factors.

Ecological and health risk assessments of rare earth elements in soil from gold mining areas in Sudan

The increasing demand for rare earth elements (REE) has led to increased mining activities, which may result in potential ecological and health risks. Our objective was to evaluate the potential ecological and analyze the health risks associated with REE in soil samples obtained from the gold mining region, employing neutron activation analysis (NAA). The pollution load index (PLI) was carried out to evaluate the REE contamination. The findings indicated that the soils in gold mining regions were generally uncontaminated, with the exception of two specific locations. The correlation among of the REE with Au were carried out taking into account the chemical weathering indices (CIA). The potential ecological risk was calculated to conduct an ecological risk assessment of REE in the soil. The outcomes revealed that the RI values for the soil samples gathered from the mining area were within safe limits, signifying a low ecological risk, With the exception of Lutetium in three specific sample sites, suggesting a low to moderate level of ecological risk. Also, non-carcinogenic and carcinogenic health risk assessment was conducted in order to investigate potential adverse health risks. The hazard quotient values for both adults and children remained below 1, indicating that there were no significant non-carcinogenic risks to the inhabitants associated with all REE in the soil through ingestion, dermal contact, and inhalation pathways.

Source, toxicity and carcinogenic health risk assessment of heavy metals.

Heavy metals are chemical elements with unique properties that are toxic even in low concentrations and affect human health with different functions. Agricultural and industrial activities, improper disposal of household solid waste and residues related to industrial producers, discharge of household wastewater and agricultural fertilizers are the most important ways in which toxic heavy metals enter the environment, which harms human health and life. A narrative review of the literature was done from 2000 to 2022 based on searched databases included Google Scholar, PubMed, Springer, Web of Science, and Science Direct (Scopus). All relevant studies published 2000 until 2022 gathered. According to the databases, 820 articles were retrieved. 186 and 50 articles were found and selected based on records identified through database searching and additional records identified through other sources. In thenext stage, 97 studies were screened after review and 64 full-text articles entered into the analysis process. Finally, 45 articles were selected in this study. Adverse effects of heavy metals on various conditions in the body depend on a number of factors, including dose, route of exposure and chemical species, as well as age, sex, genetics, nutritional status, and duration of exposure to the heavy metal. The existence of significant relationships between long-term and short-term exposure to toxic heavy metals and their adverse effects, including carcinogenicity, has been extensively studied and proven through numerous experiments. However, the mechanisms associated with this complication have not been properly identified, so in future research, there is a great need for comprehensive studies on the carcinogenicity of heavy metals.

Groundwater characterization and non-carcinogenic and carcinogenic health risk assessment of nitrate exposure in the Mahanadi River Basin of India

Agriculture is the mainstay of India's economy and chemical fertilizers have been extensively used to meet increasing demands. Anthropogenic interventions at the soil surface, especially the application of nitrogenous fertilizers in agricultural fields, provide essential nutrients but become major pollutant sources in terrestrial ecosystems and aquatic environments. Groundwater samples from phreatic aquifers of the Mahanadi River Basin, Chhattisgarh, India, showed that the Ca2+-Mg2+-HCO3ˉ freshwater type dominates, followed by the Ca2+-Mg2+-Clˉ and Na+-HCO3ˉ types. Increasing trends in the ionic ratios of (NO3ˉ+Clˉ)/HCO3ˉ over TDS and of NO3ˉ/Clˉ over Clˉ indicated the significant impact of anthropogenic pollution on groundwater contamination. Deterministic and probabilistic approaches were used to assess the non-carcinogenic and carcinogenic health risks of nitrate to children and adults. Both approaches produced the same results and indicated children were more prone to non-carcinogenic health risk than adults. An excess gastric cancer risk (ER) exposure model showed that approximately 42% of the groundwater samples had a non-negligible ER (1.00 × 10−4 to 1.00 × 10−5). Sensitivity analysis indicated groundwater nitrate concentration, ingestion rate, and the percentage of nitrite from nitrate were the most significant variables in determining HI and ER. It is suggested to adopt proper management of control policies for reducing the elevated groundwater nitrate concentration in the present study area.

Distribution, Source Apportionment and Health Risk Assessment of Organochlorine Pesticides in Drinking Groundwater

Groundwater samples of Ile-Ife, Osun State, Nigeria were investigated for their organochlorine pesticides (OCPs) levels. Probable sources of the OCPs and health risks associated with their consumption along with the water were determined in order to establish the potability of the groundwater samples. Quantitative determination of the OCPs was carried out by Gas Chromatography coupled with Electron Capture Detector (GC-ECD) after liquid–liquid extraction with dichloromethane (DCM). Results indicated that all the analyzed OCPs except p,p´-dichlorodiphenylethane were detected with high concentrations in the groundwater. Hepachlor (14.60 ± 3.60 µg/L) and methoxychlor (12.60 ± 2.20 µg/L) showed dominant concentrations that were higher than 0.02 ng/L maximum residue levels (MRLs) recommended by the European Union. Levels of the OCPs in the samples followed the decreasing trend: cyclodienes > diclorophehylethanes > chlorinated cyclohexanes, while the predominant source of the analyzed pesticides could be ascribed to aerial transportation from fresh applications in homes within the community. The carcinogenic health risk assessment also revealed consistent higher values of HQ and CR in children as opposed to adults, indicating that children are the more vulnerable population to the analyzed environmental contaminants.

Determination of some heavy metals levels in the meat of animal species (sheep, beef, turkey, and ostrich) and carcinogenic health risk assessment in Kurdistan province in the west of Iran.

Heavy metals accumulation in food products as a result of industrialization is one of the main potential threats to public health. This study was aimed to evaluate the concentrations of heavy metals in the meat of some prevalent farm animal species including sheep, beef, turkeys, and ostriches in Sanandaj (one of the strategic cities in Kurdistan province, Iran). In this study, the contents of some heavy metals (selenium, lead, cadmium, arsenic, cobalt, zinc, nickel, copper, and chromium) were assessed in 170 meat samples collected from meat distribution centers in Sanandaj, Kurdistan province. The ICP-MS method was used to assess the levels of these elements in the meat of beef, sheep, turkey, and ostrich as the main consumed meats in this region. Statistical analysis was performed by ANOVA and one-sample t-test, and the correlation coefficient of the concentrations of metals was also calculated. The results showed that there were no significant differences in the average contents of selenium, nickel, cobalt, and chromium among various meats (P > 0.05). However, the amounts of lead, cadmium, arsenic, zinc, copper, chromium, and nickel were meaningfully different to maximum permissible limits (MPL) (P < 0.05). In addition, a significant negative correlation was found between arsenic and selenium in meats. Except for cobalt, the concentrations of other metals were higher than MPL in the evaluated meats. Despite the target hazard quotient (THQ) for cadmium in sheep and beef meats being higher than their MPL (> 1), its target risk of cancer (TR) was acceptable. It can be concluded that monitoring and elimination of heavy metals pollution are essential because of their high accumulation in the meat of main farm animal species in Sanandaj, Kurdistan province.

Environment impact and probabilistic health risks of PAHs in dusts surrounding an iron and steel enterprise

Dust can be regarded as environmental medium that indicates the level and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) coming from different pollution sources. In this study, samples including road dust, roof dust, and bare soil near an iron and steel enterprise (ISE) in Laiwu city of North China were collected. To assess the environment impact, atmosphere particulates and one flue dust from a coking plant were simultaneously sampled. Sixteen USEPA PAHs were detected quantitatively by Gas Chromatography Mass Spectrometry (GC–MS). A laser particle size analyzer was used to obtain the grain size of the dust particle samples. The results showed that PAH concentrations displayed great variability in the dust samples. The ∑16PAHs concentration was found to be between 0.460 and 46.970 μg/g (avg ± sd 10.892 ± 1.185 μg/g) in road dust, between 0.670 and 17.140 μg/g (avg ± sd 6.751 ± 0.692 μg/g) in roof dust, and 13.990 ± 1.203 μg/g in bare soil. In the environment atmosphere sites, the ∑16 PAHs value in PM2.5 constituted a very large proportion of PM10, indicating that PAHs in finer particle sizes should be given greater emphasis. The ∑16PAHs concentration was relatively high in the area close to the ISE because of the great impact of the ISE industrial activities. PAH concentration curves were similar, and the most abundant individual PAHs in the atmosphere sites were BbF, BkF, and Flu, and BbF, BkF, and Chry in dusts. Toxicity analysis revealed that PAHs with four rings, including carcinogenic PAHs, were the dominant pollutants in the studied area. The toxic equivalency value (TEQBaP), the carcinogenic health risk assessment value recommended by the US EPA, was calculated for seven carcinogenic PAHs, revealing that they account for more than 93.0% of the total TEQBap of the 16 PAHs and indicating the major toxic equivalent concentration contributor. Incremental lifetime cancer risk (ILCR) estimation results showed that PAHs tended to bring about great health risks through skin contact, followed by ingestion and inhalation. By comparison, road dust exhibited greater carcinogenic risks than roof dust, and bare soil may undergo heavier pollution. Therefore, the results of this study would be helpful in the effort to understand the PAHs pollution from the steel industry, which will provide some guidance for the probabilistic assessment of local health risks.

Heavy metal and metalloid contamination and health risk assessment in spring water on the territory of Belgrade City, Serbia.

The aim of this research was to examine the content of heavy metals and metalloids in the spring water on the territory of Belgrade City and their health risk. This paper presents results of the content and non-carcinogenic health risk assessment of aluminum, iron, chromium, manganese, nickel, copper, zinc, arsenic, cadmium, mercury and lead, as well as carcinogenic health risk assessment of arsenic, in untreated spring water on the territory of Belgrade City. 23 out of 30 registered and controlled springs in Belgrade City were sampled and examined. The analysis of all samples was done using an ICP-MS. Descriptive and multivariate statistical analysis of data was done, and based on Shapiro-Wilk test of normality, all data sets, from which mean values of heavy metals and metalloids were calculated, have normal distribution. Pearson's correlation coefficient for the examined elements was determined too, as well as spatial distribution and cluster analysis with dendrogram. Based on heavy metal and metalloid concentrations, the health risk assessment (HQ) was calculated. Although the concentrations of certain heavy metals and metalloids in untreated water were in a wide range of values and differed significantly, in a large number of springs concentrations of most of the investigated heavy metals and metalloids were lower than the maximum permissible concentrations prescribed by the legislation of the Republic of Serbia and do not show unacceptable non-carcinogenic and carcinogenic health risk.

Spatial, temporal variability and carcinogenic health risk assessment of nitrosamines in a drinking water system in China

Nitrosamines, as a class of emerging frequently detected nitrogenous disinfection byproducts (N-DBPs) in drinking water, have gained increasing attention due to their potentially high health risk. Few studies focus on the occurrence variation and carcinogenic health risk of nitrosamines in drinking water systems. Our study aimed to investigate the spatial and temporal variability of nitrosamines in a drinking water system and to conduct a carcinogenic health risk assessment. Three types of water samples, including influent water, treated water and tap water, were collected monthly during an entire year in a drinking water system utilizing a combination of chlorine dioxide and chlorine in central China, and 9 nitrosamines were measured. The nitrosamine formation potentials (FPs) in influent water were also determined. N-nitrosodimethylamine (NDMA) was the most prevalent compound and was dominant in the water samples with average concentrations ranging from 2.5 to 67.4 ng/L, followed by N-nitrosodiethylamine (NDEA) and N-nitrosopiperidine (NPIP). Nitrosamine occurrence varied monthly, and significant seasonal differences were observed in tap water (p < .05). There were decreasing mean NDMA, NDEA and NPIP concentrations from influent water to treated water to tap water, but no significant spatial variability was observed within the water distribution system (p > .05). The average and 95th percentile total lifetime cancer risks for the three main nitrosamines were 4.83 × 10−5 and 4.48 × 10−4, respectively, exceeding the negligible risk level (10−6) proposed by the USEPA. Exposure to nitrosamines in drinking water posed a higher cancer risk for children than for adults, and children aged 0.75 to 1 years suffered the highest cancer risk. These results suggest that nitrosamine occurrence in tap water varied temporally but not spatially. Exposure to drinking water nitrosamines may pose a carcinogenic risk to human health, especially to children.

Hydrochemical characteristics and a health risk assessment of the use of river water and groundwater as drinking sources in a rural area in Jiangjin District, China

To determine the hydrochemical characteristics and health risks associated with their use as drinking water, 54 river water and 44 groundwater samples were collected and analyzed in a rural area of Jiangjin District, Chongqing City. The concentration of solutes in river water and groundwater showed significant spatial variability in the region. A number of dissolved chemical constituents including nitrate (NO3−), nitrite (NO2−), aluminum (Al), arsenic (As), boron (B), barium (Ba), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and selenium (Se) exceeded their respective recommended drinking water limits at some locations. Ternary plots of cations, anions and silica indicated that carbonate weathering was the primary source of major ions in water, followed by silicate weathering. Elevated concentrations of some chemical constituents including NO3− and chloride (Cl−) were found in water samples in areas with the most intensive agricultural land use activities. A health risk assessment indicated that Cl− and NO3− were the most important chemical constituents that were a non-carcinogenic health concern. A carcinogenic health risk assessment indicated that chromium (Cr) and As were the chemical constituents of most concern in water from the area that might be used as a drinking water source. The average annual carcinogenic risks for Cr in drinking water were determined to be in the range of 3.14E−05 and 7.90E−05 for adults and children, respectively. Similarly, the average annual carcinogenic risks for As in drinking water for adults and children were calculated to be in the range of 4.43E−07 and 1.11E−06, respectively. These values are within the risk values of 10−6 to 10−4, which generally indicate that there are health concerns that need to be addressed in more detail. The highest values of carcinogenic risk for drinking water were mainly located in the northern part of the study area where there are industrial activities that are potential sources of arsenic and chromium in surface water and groundwater.

Potential carcinogenic and non-carcinogenic health hazards of metal(loid)s in food grains.

Metal(loid) contamination of vital food grains such as wheat and rice is a very serious problem throughout the world because consumption of such contaminated food can lead to severe health effects in humans. Metal(loid) contamination of food crops can occur from different sources such as contaminated soil, irrigation water, and aerial deposition. Therefore, the present study was conducted to analyze potential non-carcinogenic and carcinogenic health impacts posed by different metal(loid)s (As Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, and Zn) via consumption of wheat and rice grown on metal(loid)-contaminated soils in areas around rivers (Beas and Sutlej) of Punjab, India. Among the metal(loid)s analyzed in wheat and rice samples, contents of As, Cd, Cr, Ni, and Pb were found to be above the international (FAO/WHO and EU) maximum permissible limits. The non-carcinogenic and carcinogenic health risk assessment of individual metal(loid)s revealed that As posed highest risk followed by Cd, Cu, Fe, Mn, and Pb. The values of indices calculated for analysis of combined non-carcinogenic, i.e., (hazard index; range 3.49-15.94) and carcinogenic (total carcinogenic risk index; range 8.30 × 10-4-131.62 × 10-4) risks for both crops were found to be many fold higher than the prescribed limits of 1.0 and 1.0 × 10-4, respectively. Thus, the analysis of combined risks posed by metal(loid)s indicated that human population consuming wheat and rice from the study area faced both non-carcinogenic and carcinogenic health risks. Therefore, immediate steps must be taken to reduce the levels of metal(loid)s in wheat and rice from the study area.

Size-fractionated Particulate Matter in Indoor and Outdoor Environments during the 2015 Haze in Singapore: Potential Human Health Risk Assessment

Landscape fires in Indonesia during the 2015 resulted in large-scale emissions of airborne particulate matter (PM) that degraded ambient air quality of several countries in Southeast Asia (SEA) including Singapore. During this transboundary haze episode, the general public was advised to remain indoors as much as possible in order to mitigate their exposure to high concentrations of PM in the outdoor environment. To understand the quantitative relationship between outdoor and indoor air quality, we measured PM2.5 as well as the size-fractionated PM (coarse, accumulation and quasi-ultrafine (q-UF) particles) simultaneously inside and outside a naturally ventilated apartment and studied the potential health risk associated with exposure to PM of different sizes under the three levels of smoke haze (light, moderate and severe). PM mass concentrations increased with a decrease in particle size, and the q-UF particles (diameter ≤ 250 nm) were observed to be as high as 80 to 85 µg m–3 both indoors and outdoors. Estimation of PM deposition patterns along the human respiratory tract revealed that q-UF particles were mainly deposited in the deeper alveolar region, thereby posing severe health threats. Potential human health risk assessment results based on bioavailable concentrations of toxic elements in PM raised further concerns about health impacts of q-UF particles deposited in the alveolar region. Moreover, uncertainty analysis of exposure parameters used in potential carcinogenic health risk assessment model indicated much higher exceedance of potential health risk than the threshold limit for 95th percentile values of the health risk (11.5 times higher for PM2.5) during severe-haze episodes. The potential health risk estimated in this study indicates the need to conduct further studies focused upon mitigation of human exposure to achieve health benefits during haze episodes.

Hazardous metals levels in groundwater from Gokana, Rivers State, Nigeria: Non-cancer and cancer health risk assessment

ABSTRACTThis study investigated heavy metals concentration in groundwater in six coastal communities in Gokana, Rivers State, namely, Gbe, K-Dere, B-Dere, Mogho, Kpor and Bodo City and the human health risk posed to the local populace via ingestion and dermal contact using non-carcinogenic and carcinogenic health risk assessment. The mean values of the heavy metals ranged between 0.02–0.86, 0.16–0.19, 0.03–0.10, 0.02–0.03 and 0.01–0.17 for Mn, Ni, Pb, Cd and Cr, respectively. The heavy metals were above the drinking water quality recommended limits in all the study sites. Estimations of average daily dose (ADD) and dermal absorbed dose (DAD) health risk indicates that Mn, Ni and Pb posed human health risk via ingestion contact pathway. However, hazard index (HI) values of Cd and Cr for ingestion pathway were >1.0 and the estimated Lifetime of Carcinogenic Risks (LTCR) for Ni, Cd and Cr exceeded the predicted lifetime risk for carcinogens of 10−6 from ingestion pathway. Furthermore, there were more appreciable risk from Ni and Cr in the study sites as LTCR value in most sites were >10−4. This study indicates possible non-carcinogenic and carcinogenic human health hazard from groundwater consumption in Gokana via oral ingestion.

Chemical characterization and health risk assessment of soil and airborne particulates metals and metalloids in populated semiarid region, Agra, India.

Rapid industrialization and urbanization have contaminated air and soil by heavy metals and metalloids from biogenic, geogenic and anthropogenic sources in many areas of the world, either directly or indirectly. A case study was conducted in three different microenvironments, i.e., residential sites, official sites and official sites; for each sites, we choose two different locations to examine the elemental concentration in fine particulate matter and soil and health risk assessment. The concentration values of heavy metals and metalloid in the air and soil in the Agra region were measured using inductively coupled plasma-atomic emission spectrophotometry. The exposure factor and health risk assessment for carcinogenic and non-carcinogenic effects due to heavy metals and metalloid contaminants have been calculated for both children and adults by following the methodology prescribed by USEPA. For the elements As, Cr, Cd, Ni and Pb selected for the carcinogenic health risk assessment, the calculated results lie above the threshold ranges. We observed the lifetime exposure to heavy metals through mainly three pathways, ingestion, inhalation and dermal contact of soil and air from that particular area. Therefore, the overall hazard quotient (HQ) values for children are more than that of adults. The assessment of health risk signifies that there were mainly three exposure pathways for people: ingested, dermal contact and inhalation. The major exposure pathway of heavy metals to both children and adults is ingestion. The values of HQ are higher than the safe level (=1), indicating a high risk exists in present condition. Meanwhile, HQs value for children is higher than that for adults, indicating that children have higher potential health risk than adults in this region.

Non-carcinogenic and carcinogenic health risk assessment of selected metals in soil around a natural water reservoir, Pakistan

Contaminants in surface soil can directly pose significant human health risks through oral ingestion, dermal contact and particle inhalation, especially for children. Both non-cancer and cancer risks associated with selected metal levels (Cd, Cr, Cu, Fe, Mn, Pb and Zn) were evaluated in surface soil around Mangla Lake during summer and winter. The results based on average pseudo-total metal concentrations followed the decreasing order: Fe (4038mg/kg)>Mn (394mg/kg)>Zn (40mg/kg)>Pb (17mg/kg)>Cr (21mg/kg)>Cu (15mg/kg)>Cd (1.3mg/kg) during summer and Fe (3673mg/kg)>Mn (407mg/kg)>Zn (30mg/kg)>Cr (26mg/kg)>Pb (26mg/kg)>Cu (14mg/kg)>Cd (1.8mg/kg) during winter. Present metal levels in the soil were also compared with other studies and guideline values which showed significant increase in the metal concentrations in this study. The metal levels also showed considerable spatial variations around the lake. The correlation study and multivariate principal component analysis revealed significant anthropogenic contributions of the metals in soils. Aqua-regia extractable (pseudo-total) contents were used as the reference to establish the percentage of bioavailability. After considering the bioavailability (Cd>Pb>Cr>Zn>Cu>Fe>Mn during both seasons), the non-cancer and cancer risks posed by Cd, Pb and Cr was relatively higher than rest of the metals, though the overall hazard index (HI) and cancer risk levels were within the safe limits (1.0 and 1.0E-06, respectively). The overall cancer risk to the adults based on pseudo-total metal concentrations exceeded the target value (1.0E-06), mainly contributed by Cr. A method considering bioavailability is suggested to produce a more realistic estimation for human health risks of trace metals contamination in soil.