Non-carcinogenic Hazard Index Research Articles

HEALTH RISK DUE TO HEAVY METAL(LOID)S EXPOSURE THROUGH FINE PARTICULATE MATTER AND SEDIMENTED DUST IN PEOPLE LIVING NEXT TO A BEACH CONTAMINATED BY MINE TAILINGS

The non-carcinogenic hazard index (HI) and the carcinogenic risk index (CRI) due to exposure to metal(loid)s were assessed in children and adults living adjacent to a beach contaminated with mine tailings. Chromium (Cr), nickel (Ni), cadmium (Cd), arsenic (As), zinc (Zn), copper (Cu), lead (Pb) and manganese (Mn) were determined in fine particulate matter (PM2.5) and sedimented dust (SD) in school and residential microenvironments. The HI in children was 13.8, 8.1, 5.4, 2.4, 2.3 and 1.8-times greater than the safety threshold (1.0) for Cr, As, Pb, Mn, Cu, and Cd, respectively; 84.1 % explained by dermal contact and 10.9 % by ingestion of SD. The CRI for Cr and As was 3.7 and 3.2 times above the acceptable risk (> 1 × 10–4), explained by the inhalation of PM2.5 and SD, respectively. In adults, the CRI for As and Cr was 46.0 and 2.8 times greater than 1 × 10–4; As risk is explained by dermal contact and inhalation of SD, and Cr by inhalation of PM2.5. This study reports a high risk of potential adverse health effects on children and adults due to exposure to these elements present in the particles and dust studied.

Cadmium, Lead and Zinc in the Soil-Plant-Alpaca System and Potential Health Risk Assessment Associated with the Intake of Alpaca Meat in Huancavelica, Peru

The consumption of contaminated natural pastures with highly dangerous and toxic heavy metals such as cadmium (Cd) and lead (Pb) by Andean camelids could cause harmful effects on the health of people exposed via consumption of contaminated alpaca meat. The concentration of Cd, Pb and Zn in the soil-plant-alpaca system was determined and the potential health risk associated with the intake of alpaca meat was evaluated. Soil and grass samples were collected in grazing areas of the South American camelid, and in the Municipal Slaughterhouse of Huancavelica, 30 samples of alpaca pectoral muscle were collected. The concentrations of Cd in the soil, grass and alpaca muscle exceeded the threshold values of national and international standards. Bioaccumulation factor (BAF) values of the three elements studied was less than 1, Cd was the element with the highest bioavailability and mobility in the soil-plant-alpaca muscle system. The mean concentration of Cd in muscle was 0.335 ± 0.088 mg/kg which exceeded the maximum level allowed by the FAO/WHO and the European Commission, the concentration of Pb and Zn did not exceed the regulated limits. No significant differences were detected in accumulation according to sex. The non-carcinogenic hazard index (HI) values for the studied metals indicated that there is no adverse health risk (HI <1) for children and adults from alpaca meat intake, but they could experience carcinogenic risk (CR) from prolonged exposure to Cd, and for exceeding the 1x10-4 limit threshold. It is recommended to conduct further studies on the accumulation of potentially toxic elements in alpaca tissues in order to determine the possible total risk of heavy metals in consumer’s health.

Bioavailability, distribution and health risk assessment of arsenic and heavy metals (HMs) in agricultural soils of Kermanshah Province, west of Iran.

Kermanshah Province as an agricultural hub exports food crops to neighboring countries. In this study, contamination status, bioavailability, spatial distribution, and ecological and human health risk of arsenic and heavy metals (HMs) in soil were investigate. For this purpose, 121 agricultural soil samples were collected and analyzed using ICP-MS. The data were studied by calculating some geochemical indices, and using geographical information system and statistical analysis. Results showed that Cd has the highest bioavailability, following by Cu and As. Also, Cu was severely associated with organic matter. Enrichment factor (EF) followed the order of As > Cu > Pb > Se > Cd > Zn > Ni > Cr, and the soil pollution index (SPI) ranged from 0.82 to 2.65. Low potential ecological risk was measured for most of the samples. However, Kermanshah County and Eastern parts of the Province showed the highest HMs enrichment and ecological risk. Moreover, high carcinogenic risk of Cr and Ni threatens the children. Cr showed also high non-carcinogenic hazard index (HI) for children. Principal component analysis (PCA) indicated the anthropogenic origins for As, Cd, Cu, Pb, Se and Zn, while Cr and Ni originated mainly from a geogenic source. Furthermore, Kruskal-Wallis H test revealed that As, Cd, Cr, Cu, Ni, Pb, Se and Zn concentrations were significantly different (p < 0.05) between 16 Counties of the Kermanshah Province. Overall, the management of urban and industrial contamination sources is required to minimize the concentration of bioavailable portion of HMs and preventing residents of the area from being exposed to contaminants.

Environmental and health risks of metal-contaminated soil in the former tannery area of Hazaribagh, Dhaka

Soil and plant samples collected from Hazaribagh, the former tannery area in Dhaka, Bangladesh, were analyzed for heavy metals (Cr, Pb, Ni, Zn, Cd, and Cu). The pollution and health risks of the metals were assessed with commonly used indicators. The mean soil Cr concentration was 4321 mg/kg (range 294–23,148 mg/kg). Most sites had a moderate to high degree of contamination and were classified as extremely polluted (Pollution Load Index > 1). The non-carcinogenic hazard index was greater than 1 for Pb and Cr for both children and adults, which indicates considerable non-cancer health risk. The combined cancer risks for Pb and Cr exceeded the allowable range of 1 × 10−6–1 × 10−4 for most sites (8 out of 11 sites in the case of adults, all sites in the case of children) with Cr being the dominant contributor and oral ingestion the primary pathway. The cancer and non-cancer risks for children were 26- and 3-fold higher, respectively, than for adults. Among all heavy metals, Pb and Zn were the most susceptible to leaching and becoming mobilized in groundwater. Concentrations of Pb, Cr, and Zn in edible parts of vine spinach (Basella alba) exceeded safe limits. However, Pb and Cu showed significant accumulation in plants (Mean Transfer Factor of 1.064 and 0.94, respectively, for Pb and Cu), while Cr exhibited relatively lower bioavailability. The spatial distribution of heavy metal contamination and associated risks presented in this study will allow policymakers to pinpoint areas of intervention for remediation.

Spatial distribution of pollution characteristics and human health risk assessment of exposure to heavy elements in road dust from different functional areas of Zhengzhou, China.

Road dust from different sources directly contacts the human body and has potential effects on public health. In this study, a total number of 87 road dust samples were collected at 29 sampling sites from five different functional areas (commercial area (CA), residential area (RA), educational area (EA), industrial area (IA), and park area (PA)) in Zhengzhou to study the contamination status, distribution, source identification, ecological risk assessment, and spatial distribution of human health risks due to eight heavy elements. The geo-accumulation index (Igeo) and pollution index (PI) revealed that there was very high contamination with Cd and Hg caused by atmospheric deposition, which should be paid special attention. Additionally, the source identification indicated that Cr, Ni, Cu, Zn, Cd, and Pb originate from anthropogenic activities related to traffic, and Hg can originate from medical equipment and agricultural chemicals, while the extremely low level of pollution with As could be explained by geographic sources. Moreover, the calculated ecological risk index values were increased in the order of CA > RA > EA > IA > PA in different functional areas. According to the human health risks of the whole city, children exposed to Pb have the highest health risk, especially for CA and IA, as calculated by the noncarcinogenic hazard index (HI). For adults and children, health risks caused by Cu, Zn, and Pb were higher in the CA, RA, and PA of the downtown area, whereas Cr and Ni had the highest noncarcinogenic exposure risk in northwestern Zhengzhou due to point source pollution. Calculations of the carcinogenic risk (CR) values for Cr, Ni, As, and Cd indicate that the value of Cr is highest (1.17 × 10-7), especially inside the industrial area (8.55 × 10-7), which is close to the lower limit of the threshold values (10-6 to 10-4). These results can provide a theoretical basis and data support for air treatment, pollution control, and the implementation of public prevention in different functional areas of Zhengzhou.

Evaluation of metal aerosols in four communities adjacent to metal recyclers in Houston, Texas, USA

ABSTRACT The metal recycling industry provides jobs, generates revenue in local communities and conserves energy and resources. Nonetheless, possible negative impacts of metal recyclers (MRs) include the potential for emissions of metal aerosols and other dusts, noise, traffic and fire during operations. In Houston, Texas, there were more than 180 resident complaints about air quality related to MRs from 2006 to 2011 that were reported to the city’s 311 call system. As a part of a community-based participatory research study, Metal Air Pollution Partnership Solutions (MAPPS), we evaluated the impact of metal emissions from MRs on air quality over two years in four environmental justice communities. We simultaneously collected samples of inhalable particles (aerodynamic particle size less than 10 µm, PM10) using a sampling strategy to capture emissions from the MRs while they were in operation at four locations within each community: an upwind location, the fence line of MR and two downwind locations and analyzed the samples for 10 metals. The highest values of iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), arsenic (As) and chromium (Cr) were detected at the fence lines of MRs. The normalized ratios of these metals at near and far neighborhood locations were 0.01 to 0.64 and 0.01 to 0.34, respectively, as compared with the metals at the fence line. The concentrations of metals rapidly decreased by 57–70% within 100 meters and reached similar levels at upwind (background) locations at approximately 600 meters. After adjusting the measured data for wind direction, rain and operating hours, we calculated non-carcinogenic hazard index values and carcinogenic risks for adult residents from breathing metals emitted from the facilities. Estimated inhalation cancer risks ranged from 0.12 case to 24 cases in 1 million people and the hazard index values ranged from 0.04 to 11. Implications: In Houston, Texas, residents complained about air quality related to metal recyclers from 2006 to 2011. Using a community-based participatory research method, metal emissions were characterized at four environmental justice communities. The results indicate that metal concentrations were the highest at the fence line and decreased by 57–70% within 100 meters and reached similar levels of background at 600 meters. After adjusting the measured data for meteorological parameters and operating hours, estimated inhalation cancer risks ranged from 0.12 cases to 24 cases in 1 million people and hazard index values ranged from 0.04 to 11.

Spatial distributions and probabilistic risk assessment of exposure to heavy metals in groundwater in a peri-urban settlement: case study of Atonsu-Kumasi, Ghana

Heavy metal contamination has been of major concern at local, regional, and global scales due to its direct effect on human health. In this study, physico-chemical parameters and heavy metals (Cr, Cd, Fe, Zn, Pb, Cu, Zn and Mn) concentration in drinking water comprising of 12 mechanized boreholes (MBH) and 44 hand dug wells (HDW) in Atonsu, a suburb of Kumasi, Ghana were assessed. Carcinogenic and non-carcinogenic health risk assessments, sensitivity and uncertainty analysis for children and adults were carried out using Monte Carlo simulations technique. The results showed that, the chemical composition of the groundwater varies over a wide range both in salinity and ionic composition but lowly mineralized (TDS« 1000 mg/L). All the physic-chemical parameters were below their respective guideline values. However, about 21% of HDW had NO3− values above the guideline value of 50 mg/L. Co, Cr, Cu and Cd were below the detection limit of the instrument used for the analysis. Mn and Zn showed appreciable levels in some wells but below their respective guideline limits. However, 88.63% and 83.33% of the hand dug wells and boreholes had Pb above the guideline values. The non-carcinogenic hazard index (HI) for adult and children with respect to Fe and Mn were >1 signifying some level of risk. However, the carcinogenic HI with respect to Pb was <1. A sensitivity analysis for the oral and dermal exposure pathways for both adults and children indicated that the most important factors in the risk model are (1) the amount of the heavy metal consumed, (2) exposure duration and (3) ingestion rate. To protect public health, reduction of the metal's concentrations, proper construction of the wells to prevent runoff seepage and comprehensive water quality monitoring program are recommended to avoid/minimise the potential risk to the population.

Simultaneous Health Risk Assessment of Potentially Toxic Elements in Soils and Sediments of the Guishui River Basin, Beijing.

Simultaneous ecological and health risk assessments of potentially toxic elements in soils and sediments can provide substantial information on their environmental influence at the river-basin scale. Herein, soil and sediment samples were collected from the Guishui River basin to evaluate the pollution situation and the ecological and health risk of potentially toxic elements. Various indexes were utilized for quantitatively assessing their health risks. Pollution assessment by geo-accumulation index showed that Cd had “uncontaminated to moderately polluted” status in the soils and sediments. Potential ecological risk index showed that the Guishui River basin was at low risk in general, but Cd was classified as “moderate or considerable ecological risk” both in the soils and sediments. Health risk assessment calculated human exposure from soils and indicated that both non-carcinogenic and carcinogenic risks of the selected potentially toxic elements were lower than the acceptable levels. Health risks posed by potentially toxic elements bio-accumulated in fish, stemming from sediment resuspension, were also assessed. Non-carcinogenic hazard index indicated no adverse health effects on humans via exposure to sediments; however, in general, Cr contributed largely to health risks among the selected potentially toxic elements. Therefore, special attention needs to be paid to the Guishui River basin in the future.

Metal (Pb, Cu, Cd, and Zn) Transfer along Food Chain and Health Risk Assessment through Raw Milk Consumption from Free-Range Cows.

Background: Metal transfer along the food chain has raised concerns about impacts on human health due to dietary exposure to low but chronic concentrations. Soil–forage–milk–consumer is a short food chain through which metals are able to reach an organism. Methods: Pb, Cu, Cd, and Zn were determined in water, soil, forage, and milk samples collected from free-range cattle farms situated near Baia Mare, Romania. The soil-to-forage (TFsf) and forage-to-milk (TFfm) transfer factors for metals and the health risk for three population groups (females, males, and children) through the consumption of milk containing low levels of metals were assessed. Results: TFsf indicated that the uptake capabilities of the metals from soil to forage were in the following order: Zn > Cd > Cu > Pb. TFfm indicated a lack of metal accumulation through forage ingestion. Estimated daily (EDI) and provisional tolerable weekly (PTWI) intake values revealed a minimal exposure of the population to those metals through milk consumption. A noncarcinogenic hazard index indicated that milk consumption from local markets does not pose any risk for human health; however, the average cancer risk showed a high potential carcinogenic risk. Conclusions: The consumption of milk produced by small local farmers does not pose noncarcinogenic risks. More extended studies should be carried out in order to identify the potential carcinogenic risk caused by the low levels of metals in the milk consumed.

Environmental and human health risks from metal exposures nearby a Pb-Zn-Ag mine, China

Metal contamination in mining areas, where mining and farming coexist, is of great concern worldwide. Nevertheless, a disconnection exists between those risks to environmental and human health. In this study, an integrated approach was used to connect the environmental and human health risks from metal exposures nearby a Pb-Zn-Ag mine. The field survey showed metal contamination in soils and crop plants as well as variation in soil microbial community in mining region relative to the reference site. Together with non-carcinogenic and carcinogenic risk assessment with a probabilistic approach, Cd and Cr were identified as the priority contaminants. Further, consumption of contaminated food crops was a significant pathway of human exposure. Especially, children were susceptible to metal contamination with non-carcinogenic hazard index (0.45 for soil ingestion and 1.19 for dietary intake) and carcinogenic risk index (3.47 × 10−4 for soil ingestion and 5.10 × 10−3 for dietary intake) at the 50th percentile. These findings facilitate the priority actions on mitigation strategies to minimize the environmental and health risks. Also, the potential environmental and human health consequences due to uncontrolled mining in this region serve as a case study for other regions involved in mining activities.

Risk-based exposure assessment for multiple toxic elements encountered by children in school playgrounds and parks in the southwest region of Saudi Arabia.

Children are in direct contact with surface soil and may inadvertently ingest and inhale toxic contaminants while playing; hence, special attention should be given to playgrounds regarding toxic contaminants. The concentrations of ten toxic metals were determined in soil samples collected from school playgrounds and children's parks from the southwest region of Saudi Arabia. The soils were moderately alkaline (pH 7.6-8.8), the texture was dominated by sand particles (54-88%), and the organic matter was in the range of 2.06 to 4.82%. Analytical solutions were prepared by microwave-digestion using a HNO3/H2O2 mixture, and the concentrations of toxic elements were measured by inductively coupled plasma mass spectrometry (ICP-MS). Metal concentrations were recorded in the range of 0.014-0.087, 1.14-3.54, 0.85-23.29, 0.77-36.32, 312.6-2065.7, 285.3-822.6, 75.4-240.8, 0.00-53.12, 0.52-6.80, and 1.25-92.12 mg/kg dry soil for Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn, respectively. The levels of heavy metals in the studied playgrounds were below the permissible limits, indicating insignificant influence of anthropogenic activities and can be considered as unpolluted soil. Values of the enrichment coefficient (EC) and contamination factor (CF) were found to be less than one, suggesting that the source of these elements is mainly the local soil, with the exception of Ni and Zn in certain playgrounds (CF > 1), which indicates a possible contamination from external sources. The non-carcinogenic hazard index calculated for all of the metals was below one, indicating that the exposure to heavy metal through playground soil is unlikely to produce any adverse health effect in children playing in the playgrounds.

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

Influencing factors and health risk assessment of microcystins in the Yongjiang river (China) by Monte Carlo simulation.

The Yongjiang river is a large, shallow, hyper-trophic, freshwater river in Guangxi, China. To investigate the presence of microcystin-RR, microcystin-LR, and microcystin-YR (MC-RR, MC-LR, and MC-YR) in the Yongjiang river and describe their correlation with environmental factors, as well as, assess health risk using Monte Carlo simulation, 90 water samples were collected at three sample points from March to December 2017. Results showed that during the monitoring period, total concentrations of MC-RR (TMC-RR), MC-YR (TMC-YR), and MC-LR (TMC-LR) varied from 0.0224 to 0.3783 μg/L, 0.0329 to 0.1433 μg/L, and 0.0341 to 0.2663 μg/L, respectively. Total phosphorus (TP) content appeared to be related to TMC-LR and the total concentrations of microcystins (TMCs), while pH and total nitrogen (TN)/TP ratio appeared to be related to TMC-RR and TMC-YR, respectively. Using the professional health risk assessment software @Risk7.5, the risks of dietary intake of microcystins (MCs), including the carcinogenic risk and non-carcinogenic risk, were evaluated. It was found that the carcinogenic risk of MC-RR from drinking water was higher than MC-LR and MC-YR, and the presence of MCs would lead to high potential health risks, especially in children. The carcinogenic risk of MC-RR to children was >1 × 10−4, the maximum allowance level recommended by the US Environmental Protection Agency; as for adults, it was >5 × 10−5, the maximum allowance level recommended by the International Commission on Radiological Protection. The non-carcinogenic hazard index (HI) of MC-RR, MC-YR, and MC-LR increased successively, indicating that MC-LR was more hazardous to human health than MC-YR and MC-RR, but its HI was <1. This suggests that MCs pose less risk to health. However, it is necessary to strengthen the protection and monitoring of drinking water source for effective control of water pollution and safeguarding of human health.

Short-term degradation of air quality during major firework events in Delhi, India

The effect of firework events on air quality was assessed from ambient fine particulate matter (PM2.5) collected during the Diwali period in two consecutive years, i.e., November 2015 and October 2016. The extensive firework activities led to the short-term degradation of air quality during the Diwali days. PM2.5 samples were chemically characterised for elements, water-soluble ionic species, organic carbon (OC) and elemental carbon (EC). Ba, K, Sr, S, Mg and Na showed significant increases in concentration on Diwali days compared to pre-Diwali days which revealed their association with firecrackers. Concentration of SO42−, NO3−, Cl−, K+ and NH4+ ions contributed to the increases in PM2.5 concentration on Diwali days. Higher OC/EC ratios indicated the formation of secondary organic carbon during the Diwali period. This study concludes that the high PM2.5 level during Diwali 2016 was a result of contribution from fireworks on the Diwali night, trans-regional movement of pollutants due to crop residue burning, low wind speed (0.15 m s−1), and high humidity. It was observed that short-term exposure to Diwali is plausible to generate 1.3% increase in non-carcinogenic hazard index due to elements Al and Ba during Diwali 2016, whereas no significant variation was observed for the carcinogenic risk due to Pb. However, in 2015, the increase in non-carcinogenic hazard index was appreciably lower as compared to 2016.

A human health risk assessment of heavy metals in agricultural soils of Yanqi Basin, Silk Road Economic Belt, China

ABSTRACTA total of 195 farmland soil samples were collected in Yanqi Basin, Xinjiang, northwest China, and the concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn were analyzed for their concentrations and pollution levels using the Nemerow comprehensive index. The health risk assessment model introduced by USEPA was utilized to evaluate the human health risks of heavy metals. Results indicated that the average concentrations of these seven metals were lower than the allowed soil environmental quality standards of China, while the average concentrations of Cd, Cr, Ni, Pb and Zn exceeded the background values of irrigation soils in Xinjiang. The average contamination factor (CF) for Pb indicated the heavy pollution, whereas the CF for Cd, Zn, Ni, Cu and Cr indicated the moderate pollution. The average PLI of heavy metals indicated the low pollution. The non-carcinogenic hazard index were below the threshold values, and the total carcinogenic risks due to As and Cr were within the acceptable range for both children and adults. As and Pb were the main non-carcinogenic factors, while As was the main carcinogenic factor in the study area. Special attentions should be paid to these priority control metals in order to target the lowest threats to human health.

Occurrence and Distribution of Arsenic, Antimony and Selenium in Shallow Groundwater Systems of Ibadan Metropolis, Southwestern Nigerian.

Background.Arsenic, antimony and selenium contamination of groundwater is of great concern due to the potential detrimental effects to human health.Objectives.This study investigates the occurrence and distribution of arsenic, antimony and selenium in the shallow groundwater system of Ibadan metropolis, southwestern Nigeria.Methods.A total of 210 groundwater samples were collected from 35 shallow wells (3.15–7.86 m) within the residential, commercial, industrial and agricultural areas of the metropolis during the dry and wet seasons. The average daily dose intake (ADD), hazard quotient (HQ) and hazard index (HI) of arsenic, antimony and selenium exposure in groundwater were calculated from these four studied areas for children and adults.Results.Average concentrations of arsenic, antimony and selenium in groundwater ranged between 2.17±3.49 to 33.8±37.2 μg/L, 13.5±15.0 to 33.2±36.8 μg/L and 7.33±6.22 to 46.3±22.4 μg/L, respectively. A corresponding analysis relay plot showed the order of occurrence of these trace metals in groundwater to be antimony>selenium>arsenic. The principal component analysis biplot showed that arsenic, antimony and selenium were fairly distributed in all of the study areas, suggesting the influence of geogenic factors. A total of 74.3% of sampling locations had antimony levels slightly above the World Health Organization (WHO) safe limit of 20 μg/L. Statistical t testing (0.05 confidence limit) showed a significant difference in seasonal levels of groundwater antimony concentration, with the dry season recording significantly higher levels with 100% of samples exceeding WHO safe limits. The chemical of highest potential human health concern is antimony, with a non-carcinogenic HQ risk factor >2 for both age groups. The overall non-carcinogenic HI was highest in the commercial area, 4.1989 for adults and 5.2487 for children.Conclusions.Antimony in groundwater within the Ibadan metropolis raises health concerns and a concerted effort is needed to identify its sources to avoid the risk of antimony toxicity.

Health risk assessment of some heavy metals in urban community garden soils of Baghdad City, Iraq

ABSTRACTThe objective of this study is the evaluation of health risk of heavy metals in soils of urban community gardens of Baghdad City in Iraq. The soil samples were collected from 14 community gardens and analyzed for Cd, Cr, Cu, Ni, Pb and Zn. The non-carcinogenic hazard index (HI) and carcinogenic risk index (RI) were utilized to evaluate human health risk of heavy metals. The health hazard evaluation showed that there is no non-carcinogenic hazard in light of the fact that the HI values were beneath the threshold value (HI < 1). The HI for children and adults has a descending order of Cd < Cr < Cu < Ni < Pb < Zn. The carcinogenic RI values for Cd, Cr and Ni were over the unacceptable threshold value (RI < 1 × 10−4), demonstrating that there is a serious carcinogenic risk for children and adults in the study area. The carcinogenic RI for children and adults has a descending order of Cr < Cd < Ni. These findings give environment administrators and leaders data on whether therapeutic activities are required to decrease exposure.

Multielemental Analysis of Gold Ore Samples from Underground Artisanal Gold Mines in Tongo, Upper East Region of Ghana: Implications of Occupational Exposure

Background: The presence of gold deposits discovered in rural areas in Ghana has attracted a lot of unemployed youth and smallscale mining ventures to the rural communities. The activities of illegal small-scale gold mining (locally referred to as “galamsey”) in the community is causing serious environmental havoc and destruction. The results of heavy element profiling of gold ores associated with the underground artisanal gold mining activities of the Tongo mines in the Upper East Region of Ghana have been reported in this paper. The analysis was made to assess the occupational exposure of the miners as well as to investigate the environmental impact of toxic heavy metals. Results: Gold ores from seven artisanal gold mines were sampled and analysed for heavy elemental content using Atomic Absorption Spectroscopy technique. The ranges of major elements detected were: Pb (14.16-37.00 mg/kg); Co (6.40-31.52 mg/kg); As (25.08-27.36 mg/kg); Hg (5.04-6.16 mg/kg); Ni (69.44-332.40 mg/kg); Mn (259.04-528.64 mg/kg) and Cd were Below Detectable Limits (BDL). The potential health risk assessment calculated for a lifetime of exposure for ingestion, inhalation and dermal contact were determined as the cumulative carcinogenic risk for children and adults. Risk assessment indicated that the carcinogenic risk is completely insignificant but the cumulative non-carcinogenic Hazard Index recorded alarming values of 4.55E+00 to 4.15E+01 and 8.53E-01 to 3.43E+01 for children and adults respectively. Conclusions: The investigations show that the concentrations of Pb, As and Ni which are known carcinogens presents no significant carcinogenic lifetime risk due to ingestion, inhalation and/or dermal contact but the non-carcinogenic risk, expressed as the Hazardous Index (HI), is not so benevolent; the cumulative index for all elements exceeding 1 and should be of concern, particularly in cases of the exposure of children. Capsule abstract: The concentrations of elements ranged from 5.04 mg/kg for Hg to 528.64 for Mn with highest Hazard Index being 4.55E+00 to 4.15E+01 and 8.53E-01 to 3.43E+01 for children.

Health-Based Risk Assessment of a Simple Landfilled Sludge Site

Based on the methods of health-based risk assessment of contaminated sites and the analysis of heavy metal pollution in a simple landfill sludge site, we assessed the integrated human health risk of soil contamination. It is concluded that the main pollutant is heavy metal. There are three exposure pathways identified: workers inside the site, residents working on the farmland and those living down of the site. This assessment indicates that workers would suffer non-carcinogenic impacts with total multi-pathways non-carcinogenic hazard index for heavy metal being 0.397,and the carcinogenic impacts being 2.2×10-7. The residents working on the farmland would suffer non-carcinogenic impacts with total multi-pathways non-carcinogenic hazard index for heavy metal being 0.788, and the carcinogenic impacts being 4.5×10-7. The residents living downslope of the site would suffer non-carcinogenic impacts with total multi-pathways non-carcinogenic hazard index for heavy metal being 6.22 for adults and 1.25 for children, and the carcinogenic impacts being 3.4×10-6 for adult and 7.5×10-7 for children. Non-carcinogenic index of the site and farmland areas are less than 1, while the non-carcinogenic health risk is negligible. Their carcinogenic index is less than 10-6, and the cancer health risk is small. The adults living downslope of the site have a greater risk of non-carcinogenic and carcinogenic risk. The children have non-carcinogenic risk and dont have carcinogenic risk.

A methodological approach for assessing indoor occupational risk from odor perception

This paper combines risk assessment principles with odor measurement concepts to develop a risk management tool that assists water reclamation plants’ administrators to identify, predict, and interpret the magnitude of risk associated with occupational odor perception. Analogous to the noncarcinogenic hazard index, an Odor Hazard Index (OHI) was formulated based on an Odor Reference Concentration (ORfC), which is a new concept similar to the widely used Reference Concentration (RfC) for inhalation exposures to chemicals. The OHI equals to the ratio of observed odor concentration over the ORfC, and sets a new acceptable level of odor perception, which specifies that 80% of building occupants do not perceive the odor. As the OHI approaches unity, concern about negative responses to odor perception increases. The OHI was estimated using a database generated in the dewatering building of a large water reclamation plant and was applied to evaluate odor levels and their perception at conditions with and without an odor control strategy. The control strategy was assessed using AERMOD model estimations of H2S outdoor concentrations to assure that it did not impact surrounding residential areas. The OHI responds to research limitations of odor risk assessment and management, and helps determine if a particular control strategy reduces indoor odors to acceptable levels. The risk management component of this study verified that outdoor acute and long-term ambient H2S standards are not violated as a result of the control strategy implemented by this work.