Health Risk Assessment Of Metals Research Articles

Children Health Risk Assessment of Metals in Total Suspended Particulate Matter (TSP) and PM1 in Kindergartens during Winter and Spring Seasons

This study evaluates the health risks related to heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Se, Zn, and metalloid As) in the indoor dust samples of total suspended particles (TSP) and particles with diameter <1 μm (PM1). The samples were collected during 5-day periods during the spring and winter seasons in the Upper Silesia region, Poland. The highest concentration among determined trace elements revealed Fe. The greatest concern expressed the concentration of carcinogenic Cd in PM1 (from 6.7 to 9.7 ng/m3), exceeding the permissible value 5 ng/m3 (for PM10). The carcinogenic and non-carcinogenic health risks were assessed for three exposure pathways (inhalation, ingestion, and dermal contact) for preschool children. None of the single trace elements obtained the Hazard Quotient Index (HQ > 1) or carcinogenic risks above the upper acceptable limit (1 × 10−4). However, the cumulative HQ values (ΣHQ) for three exposure pathways were greater than the safe level. The highest cumulative non-carcinogenic risk presented the TSP in rural kindergartens (2.0 × 10−4). In the same location as the TSP, the highest carcinogenic risk was also observed (9.1 × 10−4). High carcinogenic risks (>10−4) were found for the ingestion pathway of TSP inside urban and rural kindergartens and of PM1 in urban ones. A comparative evaluation shows that the health risks of trace elements in airborne particles in Polish kindergartens bring high risk.

Human health risk assessment of metals and anions in surface water from a mineral coal region in Brazil.

Coal mining releases high concentration elements to the environment, which can be deposited in surface water, causing several human health problems. Candiota mine in the south of Brazil is the largest coal reserves in the country, representing approximately 40% of total national coal reserves. Therefore, the present study aimed to estimate the chronic daily dose and the non-carcinogenic risk index for metals and anions in surface waters of Candiota Region, using the USEPA protocols for Human Health Risk Assessment. A total of eight water samples were collected over a distance of up to 15km from the emission sources of the thermal power generation companies, then the Chronic Daily Intake (CDI), Hazard Quotient (HQ), Hazard Index (HI), and sum of Hazard Index (ΣHI) were calculated. All the elements and anions evaluated showed natural concentrations for continental fresh waters according to Brazilian legislation, except Pb. Individually, none of the metals Pb, As, Cd, Ni, and Se or anions F- and NO3- showed an HI value greater than 1. However, the sum of HI (ΣHI) (five metals and two anions) by sample point showed values close to 1, for one of the eight points analyzed. Pb and Fe were the elements that most contribute to the risk values in the sample points of the study area. Although, there is no human health risk in this scenario, this investigation highlight priority elements to future investigations in coal mine areas. In the current region, Pb and F- as priority elements for future studies.

Chemical characterization and Health Risk Assessment of metals associated to airborne particulate matter PM2.5 in Saltillo, México

This study was carried out from September to December 2012 and January-February 2013, in the Faculty of Chemical Sciences of the Autonomous University of Coahuila, in total 13 samples were taken. On that period, dry weather predominated, with an average temperature of 17.0 °C, relative humidity of 52.0% and wind speed of 3.5 m s-1. The mean concentration for PM2.5 was 36.0 μg m-3. The most abundant metal in PM2.5 was Fe, with an average concentration of 1386.4 ng m-3 and the lowest concentration was obtained for Cd with 4.1 ng m-3. On the other hand, within the ionic species the most abundant were sulfates (3569.0 ng m-3), while ammonium was the least abundant species (490.9 ng m-3). The ion balance indicated that during the study period the suspended particles had acidic characteristics, which means that the amount of cations was not sufficient to neutralize the sulfates, nitrates and chlorides. Finally, the risk assessment indicates that of heavy metal in the PM2.5, represent a potential danger for the health of the population exposed to the inhalation of breathable suspended particles.

Distribution characteristics, chemical speciation and human health risk assessment of metals in surface dust in Shenyang City, China

Surface dust samples were collected in 2018 at 30 different sites in Shenyang City, China. Concentrations of chromium (Cr), arsenic (As), cupper (Cu), lead (Pb), zinc (Zn), nickel (Ni), mercury (Hg) and cadmium (Cd) were determined, and chemical speciation of metals were analyzed. Mean metal concentrations followed the order Zn > Cu > Pb > Cr > Ni > As > Cd > Hg. Although concentrations of metals in dust samples were lower than previously reported, a measurable metal pollution signature in dust still exists. Metals (except for As), are influenced by anthropogenic activities. Spatial variation in mean metal dust concentrations and speciation varied significantly and were influenced by land-use and industrial activities. Source appointment Results revealed that pollution of surface dust was derived from three main source profiles (industrial and traffic pollution, coal combustion, and urban pollution), contributing to 90.7% of the variance. Health risk assessment indicated that risks were low, but children were susceptible to metals in surface dust. Results indicated oral ingestion was the dominant exposure pathway. Non-carcinogenic Cr and Pb and carcinogenic As were the main metal contaminants in surface dust.

Concentrations, sources, and health risk assessment of metals in indoor dust collected from visual arts studios of selected tertiary institutions in Southern Nigeria

This study provides data on the concentrations and occupational risk of Cd, Pb, Cr, Ni, Cu, Co, Mn, Zn, and Fe in indoor dust from visual arts studios of nine tertiary institutions in southern Nigeria. The dust samples were digested in aqua regia and their metal concentrations were quantified by atomic absorption spectrometry. The concentrations of metals in dust from visual arts studios ranged from not detected (nd) to 91.5 mg kg−1 Cd, 4.5 to 540 mg kg−1 Pb, 0.10 to 1,100 mg kg−1 Cr, 0.50 to 1,150 mg kg−1 Ni, 10 to 15,600 mg kg−1 Cu, 0.5 to 146 mg kg−1 Co, 3.0 to 3,680 mg kg−1 Mn, 93.5 to 9,600 mg kg−1 Zn, and 853 to 237,000 mg kg−1 Fe. The degree of contamination of the dust particles by metals was assessed by making use of the contamination/pollution index, geoaccumulation index and enrichment factor. These indices suggested that dusts from these visual arts studios were impacted with Cd, Pb, Cu, and Zn. The hazard index (HI) and cancer risk values relating to adults’ exposure to metals in dust from these arts studios were within safe limits. Principal component analysis indicated that the sources of metal contamination in dust from these visual arts studios were related to inputs from constituents of the artist’s materials and vehicular emissions.

New Insights into Health Risk Assessments for Inhalational Exposure to Metal(loid)s: The Application of Aqueous Chemistry Modelling in Understanding Bioaccessibility from Airborne Particulate Matter

Aqueous modelling of chemical speciation in simulated lung fluid (SLF) enables a better understanding of the underlying chemical factors that influence metal(loid) inhalation bioaccessibility from airborne particulate matter. Such an approach can be used to supplement experimental techniques that are integral to the health risk assessment of metal(loid) exposure by inhalational routes. In this paper, we modelled the aqueous chemistry of airborne particulate-bound metal(loid)s (As, Cu, Mn, Pb and Zn) in a SLF based on Gamble’s solution (neutral pH). The modelling was performed using two software packages (Geochemist’s Workbench 14 and OLI Studio 9.5) and a total of five thermochemical databases (GWB Thermo, MINTEQ, PHREEQC, WATEQ4F and the default database for OLI Studio). Modelled results were compared with experimentally determined bioaccessibilities for the NIST 2710a standard reference material (SRM) and with literature-reported bioaccessibilities for NIST 1648a and BCR 038 SRMs. Whilst the models correctly describe the observed increase in bioaccessibility for more dilute solid/liquid extraction ratios, the performance of the models against the fractional bias of the mean (FBmean) and the normalised mean square error (NMSE) statistical metrics was generally outside the acceptance criteria. Findings from an analysis of the main aqueous chemical species predicted to be present in SLF indicate that carbonate and chloride complexes of Cu, Mn, Pb and Zn predominate, whilst free cations (for Cu, Mn and Zn) and hydroxides (for Cu) also play a role in solubilisation. Arsenic is not predicted to form significant complexes with the SLF components and is present in solution mainly as the HAsO42− ion and its conjugate acid, H2AsO4−. For modelled runs where glycine and citrate were present, significant increases in the bioavailability of Cu and Zn were predicted as a result of complexation with these ligands. An additional finding from our experimental bioaccessibility results for NIST 2710a was that the inclusion of the lung fluid surfactant dipalmitoylphosphatidylcholine (DPPC) in the SLF did not significantly affect the bioaccessibility. Our study provides useful insights into the likely aqueous- and solid-phase speciation of metal(loid)s in SLF and highlights that future developments in this area should consider the role of mineralogy and surface interactions.

Spatial distribution, pollution index, receptor modelling and health risk assessment of metals in road dust from Lagos metropolis, Southwestern Nigeria

This study assessed the spatial distribution, pollution index, receptor modelling and health risk of metals in road dust samples from Lagos metropolis, Southwestern Nigeria. Paved and unpaved road dust samples were collected from twenty locations for three consecutive months. Seventy two samples (including control soils) were collected and analysed for metals using inductively coupled plasma - optical emission spectrophotometry. Dust and control soil data were manipulated for descriptive and inferential statistics. Road dusts and control soil revealed high concentrations of Ca (758-2509 mg kg−1), Mg (693-1461 mg kg−1), Fe (583-2493 mg kg−1), Ti (189-785 mg kg−1) and Zn (42-1255 mg kg−1). The geospatial map identified pollution hotspots for Ca, Cd, Cr, Cu, Fe, Mg and Mn at the mainland parts of Lagos state. The receptor models (positive matrix factorization and principal component analysis) identified emission sources from steel industry, traffic emission, crustal matter and combustion processes. The pollution assessment (pollution index, ecological risk index, Nemerov integrated pollution index and enrichment factor) indicated high contamination levels for As, Cd, Pb and Zn in dust/soil. The health risk of metals evaluated for non-carcinogenic [average daily dose (ADD), hazard quotient (HQ), hazard index (HI)] and cancer risk (CR) revealed the HQs greater than 1.0 for As and Ca, an indication of adverse health effects. The CRs of As, Cr, Cd and Ni were higher than the acceptable limit of 1.0 × 10−4, suggesting probable development of cancer.

Ecological and human health risk assessment of metals leached from end-of-life solar photovoltaics

Photovoltaic industry has shown tremendous growth among renewable energy sector. Though, this high installation rate will eventually result in generation of large volume of end-of-life photovoltaic waste with hazardous metals. In present study, reported leached metal contents from different photovoltaics in previous investigations were utilized for (i) potential fate and transport analysis to soil and groundwater and, (ii) estimating ecological and human health risks via dermal and ingestion pathways for child and adult sub-populations. The results indicate that the children are at highest risk, mainly due to lead (hazard quotient from 1.2 to 2.6). Metals, such as cadmium, lead, indium, molybdenum and tellurium pose maximum risks for child and adult sub-populations via soil-dermal pathway followed by soil-ingestion pathway. This is further proved by calculated high values of contamination factor and geo-accumulation index for cadmium (102.4), indium (238.9) and molybdenum (16.12). The estimated soil contamination is significant with respect to aluminium, silver, cadmium, iron, lead, however, groundwater contamination was insignificant. Exposure to polluted soils yields an aggregate hazard index (for non-cancer effects) > 1 for all four pathways, with soil dermal pathway as the major contributor. Lead poses significant cancer risk for all scenarios (average risk: 0.0098 to 0.047 (soil) and 2.1 × 10−5 to 3.5 × 10−5 (groundwater)), whereas acceptable non-cancer risk was observed for other metals from groundwater exposure. Further, variance contribution and spearman correlation coefficient analysis show that metal concentration, exposure frequency and ingestion rate are the main contributors towards overall uncertainty in risk estimates. More detailed assessment for environmentally-sensitive metals should be carried out by considering other field breakage scenarios also, although the assessment suggests low risk for majority of metals examined.

Selected Mollusks from Pujada Bay, Philippines: Heavy Metal Health Risk Assessment and Antibacterial Activities

Selected Mollusks from Pujada Bay, Philippines: Heavy Metal Health Risk Assessment and Antibacterial Activities

Bioaccessibility and health risk assessment of trace metals in soils of greenhouse vegetable production near the industrial areas of the Yangtze River Delta, China.

As a common environmental problem in China, trace metal accumulation and contamination in soils of greenhouse vegetable production (GVP) may pose significant health risk via oral ingestion, inhalation, and dermal contact to vegetable farmers and children playing in greenhouse fields. Thus, bioaccessibility and health risk of Cr, Ni, Cu, Zn, Cd, and Pb in GVP soils collected from 13 GVP farms or bases near industrial areas of the Yangtze River Delta, China, were investigated as a case study. The results suggested that both GVP and industrial discharges contributed a lot to accumulation or contamination especially of Zn and Cd in soil, which subsequently increased their bioaccessible concentrations. In addition, soil acidification caused by GVP also increased bioaccessible Cr and Ni concentrations in soil of the Anthrosols study area. However, the health risk assessment of metals in GVP soil through inhalation and oral ingestion considering metal bioaccessibility suggested no non-carcinogenic and carcinogenic risks to both farmers and children. In contrast, there was potential carcinogenic risk within acceptable level posed by Cr in GVP soil through dermal contact to farmers and children. This indicates that both GVP and industrial activities had limited effect on health risk of trace metals in GVP soil via ingestion, inhalation, and dermal contact. However, the carcinogenic risk posed by Cr, which mainly originated from natural sources, still cannot be negligible. Overall, the results will provide valuable information for decision-makers to develop reasonable strategies and guidelines for risk management of trace metals in GVP soil.

Pollution assessment and spatial distribution of trace elements in soils of Arak industrial area, Iran: Implications for human health

Emerging industrial hubs have resulted in soil and dust pollution by trace elements, being a potential source and pathway for human exposure to nearby cities. The aim of this study was to determine the spatial distribution, levels, sources and health risk assessment of metals and arsenic in soils of Arak industrial area, Iran. A total of 235 topsoil (0–5 cm) samples were collected from the vicinity of Arak, and the concentrations of As, Zn, Ni, Pb, Cu and Cd were 152, 104, 93, 38, 14 and 1.2 mg kg−1, respectively, and exceeded the background values, with the exception of Cu. Values of pollution indexes revealed that most of the soils are especially enriched by As and Cd. Multivariate statistical analysis showed that Pb and Zn originated from common anthropogenic sources related to industrialization and mining, whereas Cu and Ni are probably associated with geological sources. Cd was mainly derived from the input of agricultural and industrial activities, and As should be attributed to residues in mining. Spatial risk maps showed the high risk of trace elements pollution in the order of As (100%) > Cd (62%) > Ni (12%) > Pb (5%) > Zn (4%) > Cu (0%). The results of the noncarcinogenic risk assessment showed that chronic daily intake in children and adults for ingestion pathway was higher than for dermal contact and inhalation. Values of hazard index (HI) for trace elements were below the safe level (HI ≤ 1), indicating that no noncarcinogenic risk threaten children and adults. Likewise, the total carcinogenic risk of Cd in both groups is less than the EPA threshold (1 × 10−6), indicating a low carcinogenic risk, however As (1 × 10−6 to 1 × 10−4) indicates an acceptable risk.

Health Risk Assessment of Metals (Cu, Pb, Zn, Cr, Cd, As, Hg, Se) in Angling Fish with Different Lengths Collected from Liuzhou, China.

Wild fish caught by anglers (WFAs) were confirmed to be usually contaminated with metals, and the contamination status is radically affected by the growth and length of the fish. To determine the contamination levels of metals and health risks in WFAs with different length ranges of fish, this study ascertained the concentration of eight metals, including Cu, Pb, Zn, Cr, Cd, As, Hg and Se, in 171 wild fishes collected from the watershed of Liujiang River. The assessment of metal pollution and health risks from the consumption of these fishes with seven length ranges were accomplished. The obtained results implied a relatively high concentration of Zn, Cr, and Cd up to 109.294 mg/kg, 4.226 mg/kg, and 0.196 mg/kg (wet weight), respectively, which exceed the corresponding Maximum Residue Limit (MRL). The negative correlation between Cu, Zn, Cr, and Cd was observed to be significant with fish length, signifying a possible occurrence of biological dilution on these metals. The WFAs were mostly contaminated with Cr and Cd irrespective of the length ranges of fish, which were denoted by the average pollution index (Pi) of Cr and Cd and were commonly found to be beyond 0.2. Based on the results of health risk assessment analysis, most of the target hazard quotient (THQ) values of Cr were below 1, implying that the consumption of wild fish for adults has insignificant health risk. For children, the total target hazard quotient (TTHQ) values of beyond 1 were found in fishes with the length range of <25 cm, particularly a TTHQ value 1.627 in the range of 10–15 cm, indicating that children are being prone to serious health risks owing to the consumption of WFAs. The weekly recommended consumption of WFAs with the length range of 10–15 cm for adults and children was 0.298 kg/week and 0.149 kg/week, respectively. These are substantially lower than the current rate of fish consumption (0.42 kg/week), and therefore, the wild fish with the length range of 10–15 cm should be avoided for consumption.

Health risk assessment of metals in wheat grown in municipal solid waste amended soil

Health risk assessment of metals in wheat grown in municipal solid waste amended soil

Health risk assessment of metal(loid)s in soil and particulate matter from industrialized regions: A multidisciplinary approach

In this study, samples of soil and particulate matter obtained from the highly industrialized region of Ostrava, Czech Republic, are used for the toxicity evaluation of the selected metal(loid)s (Cd, Cr, Cu, Ni, Pb, Zn, As). We investigated the samples from sites supposedly affected the most by the local pollution sources using mineralogical techniques (XRD, SEM/EDS) to understand the solid speciation of the contaminants as the crucial factor affecting their release. Although the bulk composition was defined by common silicates and oxides that are rather resistant to leaching, the presence of tiny Ni, Pb, and/or Zn sulfate-like droplets indicated a potential increase of the solubility of these metals. In vitro tests simulating gastric and lung fluids were used to assess the exposure risk for humans, as well as metal(loid) bioaccessibility. Based on the results, the potential risk for the observed age group (3-year-old children) could be recognized, particularly in the cases of As, Pb and Cd for both oral and inhalation exposure. Arsenic exhibits high bioaccessibility (7.13–79.7%, with the median values of 10.6 and 15.6 for SGL and SLF, respectively), high daily intake (1.4- to 8.5-fold higher than the tolerable daily intake) and high concentrations in atmospheric PM10 (2.5 times the tolerable concentration in air). In contrast, Ni exceeded tolerable concentrations in the atmosphere up to 20-fold, but its bioaccessibility remained relatively low (0.1–22%), and Ni did not pose a major threat to human health. Cadmium, Pb and As originating from industrial activities and domestic heating have been suggested to be the most important pollutants (tolerable daily intake was exceeded by up to 74-, 34- and 8-fold for Cd, Pb and As, respectively).

Health Risk Assessment of Metals in Selected Drinks from Abeokuta, Southwestern Nigeria.

The present study assessed the human health risk of metals in selected drinks from Abeokuta, southwestern Nigeria. Fifteen different brands of drinks (alcoholic, non-alcoholic, herbal and non-herbal) were purchased from notable markets in Abeokuta between June and August, 2018. A total of sixty drink samples were analysed for metals using atomic absorption spectrophotometry. Data were subjected to descriptive and inferential statistics. Human health risks were assessed for cancer risk (CR) and non-carcinogenic indices of hazard quotient (HQ) and hazard index (HI). Results showed acidic medium for most of the samples ranging from 3.12 ± 0.29 to 6.14 ± 0.17. The highest concentrations of Fe (5.53 ± 2.81mg/L) and Mn (6.63 ± 8.33mg/L) were found in Kunnu and Zobo, respectively. The HQ and HI values of Cu in bottled water indicated non-carcinogenic adverse effects, while the CR of Co in bottled water and bitters demonstrated carcinogenic effects. Regular monitoring of metals in drinks from the study area is recommended.

Heavy Metals Health Risk Assessment through Consumption of Baobab Leaf Cultivated in Katsina State, North West Nigeria

Vegetables play important roles in human nutrition and health. They can also contain some undesirable components that can be harmful, e.g. Pesticides and heavy metals. The objectives of the study were mainly to detect the presence of heavy metals (Cr, Cd, Fe, Ni, Mn, Pb and Zn) in sampled Baobab leaf in Katsina state Nigeria and assessed the human health risks associated with the consumption of the Baobab leaves. The content of these metals was assayed by the AAS method. The health risk to the local inhabitants was evaluated by estimating daily heavy metal intake and computing the Incremental Lifetime Cancer Risk (ILCR) and the Target Hazard Quotient (THQ) for cancer and non-cancer risks. The results were compared with the safety standards established by the WHO/FAO and USEPA. With the exception of the heavy metal Pb (0.526-0.981) the mean concentration (mg/kg) range values of Cr (0.116-0.352), Cd (0.041-0.054), Fe (1.016-1.951) and Zn (0.940-1.229) in the samples were generally lower than the USEPA, WHO/FAO maximum permissive limits. The risk level of Target Hazard Quotient (THQ &lt; 1) was observed for all the evaluated heavy metals for both adults and children. The THQ for the samples was in the decreasing order Zn&gt;Fe&gt;Pb&gt;Cr&gt;Cd, for all the baobab leaf samples respectively. All the studied samples showed the risk level (HI &lt; 1). ILCR for Cd violated the threshold risk limit (&gt;10−4) and ILCR for Pb reached the moderate risk limit (&gt;10−3) for cancer in all the studied samples in adults, While in children ILCR for Pb in samples from Dabai and Daura have reached the moderate risk limit (&gt;10−3), while the ILCR for Pb in rest of the samples and ILCR for Cd of all the samples are beyond the moderate risk level (&gt;10−2). The consumption of the Baobab leaf sample may contribute to the population cancer burden.

Pollution characteristics and chronic health risk assessment of metals and metalloids in ambient PM2.5 in Licheng District, Jinan, China.

PM2.5 samples were collected at the Wangsheren primary school site in Licheng District of Jinan, China, during 2016. Eleven metals and metalloids including Al, As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sb and Se in PM2.5 were measured by inductively coupled plasma-mass spectroscopy. The annual average mass concentration of PM2.5 was found to be 88.7μgm-3. The highest PM2.5 concentrations were obtained during the heating seasons of winter and spring. The concentrations of metals and metalloids in PM2.5 were in a descending order of Al, Pb, Mn, As, Se, Cr, Sb, Ni, Cd, Hg and Be. The enrichment factors showed that Pb, Mn, As, Se, Cr, Sb, Ni, Cd, Hg originated from anthropogenic sources. Factor analysis indicated that the main sources of the metals were coal combustion dust, soil dust, metallurgical industry, brake abrasion of vehicles and other mixed sources. Coal combustion dust was the primary source of metal pollution in PM2.5. Non-carcinogenic risks associated with exposure through the respiratory system were between 6.30 × 10-4 and 7.62 × 10-1, which were lower than the safe limit (1). The carcinogenic risks of Cr, As and Cd were 3.17 × 10-5, 1.52 × 10-5, 2.22 × 10-6, respectively, which were higher than the precautionary criterion (10-6/year). This study indicates that the air pollution of PM2.5 is of public health concern in Licheng District of Jinan, particularly related to potential carcinogenic metals of As, Cr and Cd. Intervention action is needed to reduce the emission sources of these elements, especially coal combustion in winter heating season.

Bioaccessibility and human health risk assessment of metal(loid)s in soil from an e-waste open burning site in Agbogbloshie, Accra, Ghana

Environmental pollution and human health issues due to unrestricted electronic waste (e-waste) recycling activities have been reported at a number of locations. Among different e-waste recycling techniques, open burning of e-waste releases diverse metal(loid)s into the environment, which has aroused concern worldwide. In human health risk assessments (HHRAs), oral ingestion of soil can be a major route of exposure to many immobile soil contaminants. In vitro assays are currently being developed and validated to avoid overestimation of pollutants absorbed by the human body when calculating total pollutant concentrations in HHRAs. In this study, Cu, As, Cd, Sb, and Pb bioaccessibility in polluted soils (n = 10) from e-waste open burning sites at Agbogbloshie in Accra, Ghana, was assessed using an in vitro assay, the physiologically based extraction test. A bioaccessibility-corrected HHRA was then conducted to estimate the potential health risks to local inhabitants. The in vitro results (%) varied greatly among the different metal(loid)s (Cu: 1.3–60, As: 1.3–40, Cd: 4.2–67, Sb: 0.7–85, Pb: 4.1–57), and also showed marked variance between the gastric phase and small intestinal phase. The particle sizes of soil samples and chemical forms of metal(loid)s also influenced bioaccessibility values. Using these bioaccessibility values, both the hazard index and carcinogenic risk were calculated. The hazard index was above the threshold value (>1) for 5/10 samples, indicating a potential health risk to local inhabitants.

Trace metal levels in castor plants growing on refuse dumpsites in wukari metropolis, Nigeria

A preliminary survey of the risk assessment of selected trace metal (Cd, Cr, Cu, Pb and Zn) levels of castor (Ricinus communis L.) plant growing on refuse dumpsites in Wukari Metropolis, Taraba State was investigated. Duplicate samples each of whole castor plants and decomposed remains of the refuse dumpsites were collected from three locations namely Kwararafa 1(Abo prisoners), G.R.A (Barikr) and Marmara 1(Abattior) based on population density and out of the 10 locations surveyed. Triplicates pH readings of the decomposed refuses at the three locations were recorded. Trace metal levels and pH were determined by the flame AAS using acetylene/air and pH meter respectively. Selected risk assessment techniques such as soil-plant transfer coefficient (TC), plant uptake factor (PUF) and translocation factor (TF) were worked out for the castor plants. Results revealed a high TC value (1.405) for whole castor plant above the permissible limits (value &gt;1) than PUF and TF with less than unity value revealing the potential possible transfer of metals into the plant body. Higher levels of Zn and Cd were evident, followed by Cu according to the Joint FAO/WHO Food standards 2006. Health risk assessment of metals from refuse dumpsites is a good technique for predicting potential threat to life.

Distribution, pollution levels, toxicity, and health risk assessment of metals in surface dust from Bhiwadi industrial area in North India

To understand distribution, toxicity, and health risk assessment of Cu, Ni, Cr, Pb, Zn, Fe, and Mn, 33 surface dust samples were collected during June 2015 from Bhiwadi Industrial Area (BIA) in north India. Average metal concentrations exceeded their corresponding values in upper continental crust depending upon metal(s) and sampling site(s). Industrial emissions resulted in high contamination factors and high pollution load index for metals. The BIA falls under least to moderately for Mn, unpolluted to heavily and extremely for Ni and Cu, Pb, and Zn and moderately to extremely polluted region for Cr. Inter-metal correlations and PCA indicated common and mixed sources for metals such Ni–Cr electroplating and alloys, battery recycling, stainless-steel, electrical wires, galvanizing, vehicular emissions, and wear and tear of vehicle parts. Non-carcinogenic health risk due to metals in surface dust was high in children compared to adults and major pathways were ingestion followed by dermal and inhalation. Surface dust in BIA falls under hazardous category as metals leached in toxicity characteristics leaching procedure and waste extraction test exceeded their prescribed regulatory limits. Leaching of metals can cause contamination of surface water, groundwater, and soils in surrounding areas, and can pose risk to human health and ecology.