Health Risks Of Heavy Metals Research Articles

Spatial Distribution, Source Analysis and Health Risk Study of Heavy Metals in the Liujiang River Basin in Different Seasons

Three high-frequency sampling and monitoring experiments were performed at the Lutang and Luowei transects of the Liujiang River entrance and at the southeast exit of the Liuzhou during 2019 for the purpose of assessing physico-chemical variables and human health hazards of water heavy metals in different rainfall processes. There were significant seasonal variations in concentrations of 11 heavy metals and most variables showed higher levels during the dry season. The distribution of heavy metals in the Liuzhou area varied significantly by region. Pollution source analysis indicated distinct seasons of wetness and dryness. The dry season is dominated by anthropogenic activities, while the wet season is dominated by natural processes. The results of hazard quotient (HQ) and carcinogenic risk (CR) analysis showed that the health risk of non-carcinogenic heavy metals in the wet season is slightly higher than that in the dry season. Seasonal changes in carcinogenic risk are the opposite; this is due to the combined influence of natural and human activities on the concentration of heavy metals in the river. Among them, Al was the most important pollutant causing non-carcinogenic, with As being a significant contributor to carcinogenic health risk. Spatially, the downstream Luowei transect has a high health risk in both the dry and rainy seasons, probably due to the fact that the Luowei transect is located within a major industrial area in the study area. There are some input points for industrial effluent discharge in the area. Therefore, high-frequency monitoring is essential to analyze and reduce the heavy metal concentrations in the Liujiang River during dry and wet seasons in order to protect the health of the residents in the area.

Contamination and Probabilistic Ecological-Health Risk of Heavy Metal(loid)s in Urban Topsoil of Mianyang, SW China.

Heavy metal(loid) (HM) pollution in urban topsoil seriously endangers the health of urban residents and urban sustainable development. Compared with large cities, the research on the HM pollution of topsoil in emerging medium-sized industrial cities is quite limited. This study focuses on topsoil HM contamination in Mianyang, which is a representative moderate emerging industrial city in Southwest China. The results indicate that Ba, Cr, Cu, and Zn in the samples were much higher than their background values. The hot spots of Ba, As, Cu, Pb, Co, Cr, and Zn showed an obvious enrichment trend. The potential ecological risk of HMs showed a low ecological risk, which was mainly caused by As. The investigated HMs presented no significant non-carcinogenic hazard to local adult residents, but there were three sampling sites which presented a non-carcinogenic hazard to children; the carcinogenic risks of As, Cr, Co, and Ni were acceptable. In this study, a mixed source of industry and traffic was identified to be the priority anthropogenic source, and Cr and As were identified as the priority elements for further risk control. The findings of our study could be beneficial to decision-makers with regard to taking appropriate measures to control and reduce HM pollution in the Mianyang urban area.

Human Exposure Assessment to Air Pollutants in AC Filters from Agricultural, Industrial, and Residential Areas

High levels of potentially toxic metals and microbes in the atmosphere, especially indoor air, may severely threaten human health. Therefore, the concentration and associated health risks of heavy metals (Cd, Cr, Pb, Cu, Fe, Mn, and Zn), biological pollutants, and their risk to human health were assessed using air condition (AC) filter dust samples. Samples were collected from five locations representing agricultural, industrial, and residential settings of the Eastern Province, Kingdom of Saudi Arabia. The levels of trace metals varied considerably among sampling areas, with the highest levels of Cr and Cd recorded in the industrial area sites, followed by the agricultural and residential sites. The highest levels of Pb and Fe were found in the agricultural area sites, followed by the industrial and residential area sites. Among all the metals Cd, Cr, and Pb, showed a considerable health risk through a dermal pathway, and health risks for children from indoor dust exposure were higher compared to adults. Among the sites, the highest hazard quotient for these metals was found for Al-Qatif industrial area sites, and among the metals, it was the highest for Cd. The cancer risk from the metals contained in AC filter dust was negligible. Samples collected from agricultural and industrial area sites were substantially contaminated with bacteria and fungi, respectively. Bacterial contaminants were mostly Gram-negative, with considerable antibiotic resistance and hemolytic activity. Thus, indoor air quality assessed by AC filter dust depicted that the trace heavy metals and microorganisms could pose a considerable health risk for long-term exposure. Furthermore, this study demonstrated that AC filter dust could be a unique and reliable test sample for indoor environment assessment.

Risk Assessment of Heavy Metals Contamination in Soil and Two Rice (Oryza sativa L.) Varieties Irrigated with Paper Mill Effluent

Heavy metal pollution from industrial wastewaters has become an issue of global concern. These wastewaters are frequently used for inland irrigation which possess a serious risk of heavy metal contamination of both soil and cultivated crops. The problem is more common in developing countries like India where industrial wastewaters are often discharged without appropriate treatments. Therefore, this study aimed at assessing the impact of paper mill effluent for irrigation on the growth, productivity, and heavy metal accumulation potential of two rice (Oryza sativa L.) varieties (PB-1121 and PR-121). Water, soil, and rice crop samples were obtained from the vicinity of Saharanpur city, Uttar Pradesh, India, and subsequently analyzed for selected physicochemical and heavy metal parameters. Results showed that paper mill effluent and nearby Kali River water had significant (p < 0.05) loads of pollutants that impacted the soil properties. Moreover, the maximum plant height (123.48 ± 4.86 and 98.83 ± 2.02 cm); total chlorophyll (6.70 ± 0.25 and 6.64 ± 0.17 mg/g); leaf carotenoids (0.67 ± 0.08 and 0.63 ± 0.05 mg/g); starch content (71.08 ± 2.05 and 72.60 ± 1.63%); amylose content (25.10 ± 1.32 and 20.28 ± 1.24%); crop yield (4270.20 ± 75.12 and 5830.58 ± 63.10 kg/ha); and straw yield (5472.05 ± 93.90 and 6683.76 ± 61.26 kg/ha) of PB-1121 and PR-121, respectively, were observed using Kali River water irrigation source as compared to paper mill effluent and borewell water. The order of heavy metal accumulation in rice straw and grain followed: Fe > Mn > Zn > Cu > Cr > Cd. Similarly, the bioaccumulation factors for heavy metals in rice straw and grain were observed as >1 and <1, respectively. Moreover, the target hazard quotient (THQ) showed that there was no potential health risk of heavy metal in rice irrigated with contaminated water supply except for the PR-121 variety irrigated with Kali River water where the health risk index (HRI) value exceeded the limit (>1). As a result, the findings of this study provide useful information about the current state of heavy metal pollution and the health risks associated with rice crops irrigated with contaminated water sources.

Distribution, source apportionment, and risk analysis of heavy metals in river sediments of the Urmia Lake basin

The anthropogenic heavy metal dissemination in the natural environment through riverine sediments is a major ecological and public health concern around the world. This study gives insight into the source apportionment and potential ecological and health risks of heavy metals in river sediments of the Urmia Lake basin, a natural world heritage located in northwestern Iran. A comprehensive sediment sampling was conducted in seven major rivers feeding the basin during the summer and winter of 2021. Samples were analyzed for zinc (Zn), copper (Cu), cadmium (Cd), lead (Pb), and nickel (Ni) contents and a suite of chemical and physical properties. Subsequently, Pollution Index (PI), Pollution Load Index (PLI), Ecological Risk (ER), Hazard Quotients (HQ), Hazard Index (HI), and Carcinogenic Risk (CR) indices were determined. The mean concentration of heavy metals in all rivers’ sediments exhibited the descending order of Ni > Zn > Pb > Cu > Cd during both summer and winter. Multivariate analysis suggested that Zn was primarily initiated from natural processes, Cd and Pb were affected by human activities, and Cu along Ni were derived from natural and anthropogenic factors. The PI unveiled that most sediment samples were unpolluted to slightly polluted by Zn, Cu, and Pb, and slightly to moderately polluted by Cd. PLI and ER indices demonstrated that the sediment poses non to moderate pollution and low to moderate ecological risk, respectively. Using a human health risk approach, we found that the HI values of all heavy metals and THI were less than one for children and adults implying non-carcinogenic risk in the analyzed sediments. Carcinogenic effects of Cd and Pb at all rivers sediments via ingestion, inhalation, and dermal contact were almost within tolerable risks (1 × 10−6 to 1 × 10−4) for children and adults. PI, PLI, ER, HQ, HI, and CR index values of sediment samples during the summer were higher than those during the winter. This is attributed to the greater heavy metal concentrations and the lower water flow during summer. Our results provide practical information for better management and control of heavy metal pollution in aquatic-sedimentary ecosystems.

Distribution and Human Health Risk Assessment of Heavy Metals in Tissues of Callinectes sapidus from Iko River, Akwa Ibom State, Nigeria

This study investigates the accumulation of heavy metals in the tissues of Callinectes sapidus (blue crab) in the study area and evaluating the human health risk of their consumption. The tissues of concern were the gills, muscles and hepatopancreas in the male and female crab species, while the heavy metals assessed were Cd, Ni and Pb. Heavy metals levels in the tissues of Callinectes sapidus ranged as follow: Ni: hepatopancreas (182.97–313.53 mg/kg), gills (129.93–192.14mg/kg), muscles (93.09–165.84 mg/kg); Pb: hepatopancreas (22.86–39.65 mg/kg), gills (13.46–21.35 mg/kg), muscles (2.73 – 6.32 mg/kg); Cd: hepatopancreas (2.04 –9.03 mg/kg), gills (0.12–4.995 mg/kg), muscles (0.105–2.835 mg/kg), respectively. The highest metal concentrations were observed in the hepatopancreas tissue and in the female of the crab species. Furthermore, the metals’ levels were generally higher than the permissible level by FAO/WHO in seafood. To assess the heavy metals health risk to the inhabitants of the study area, the daily intake of metal (DIM) and total hazard Quotient (THQ) were estimated and were found to exceed the recommended values. The results reflect the risk of exposure for the period of life expectancy considered, and revealed that the inhabitants of the study area are highly exposed to the health risks associated with these metals.

Contamination and Health Risk Assessment of Heavy Metals in Soil and Ditch Sediments in Long-Term Mine Wastes Area.

The ecological and health risks posed by wastes discharged from mining areas to the environment and human health has aroused concern. 114 soil samples were collected from nine areas of long-term mine waste land in northwestern Yunnan to assess the pollution characteristics, ecological and health risks of heavy metals. The result revealed that the geo-accumulation indexes were Cd (4.00) > Pb (3.18) > Zn (1.87) > Cu (0.25). Semi-variance analysis revealed that Cd and Cu showed moderate spatial dependency, whereas Pb and Zn showed strong spatial dependency. Cd posed an extreme potential ecological risk. Slopes and ditches were extreme potential ecological risk areas. Non-carcinogenic risk to children from Pb and Carcinogenic risk to adult and children from Cd was non-negligible and direct ingestion was the major source. This study provided a scientific basis for policymakers in management and exposure reduction.

Source-specific health risk assessment of PM2.5 bound heavy metal in re-suspended fugitive dust: A case study in Wuhan metropolitan area, central China

To more accurately assess the health risk of heavy metals (HMs) from PM2.5 re-suspended fugitive dust (RFD2.5), it is necessary to understand the main source of health risk from different types of RFD2.5. For this purpose, the HMs (As, Cd, Co, Cr, Mn, Ni, Pb, V, and Zn) in five types of RFD2.5 from the Wuhan metropolitan area, which was prepared with a homemade suspension chamber, were comprehensively measured. A method combining the positive matrix factorization with the health risk assessment model was used to quantify the source-specific health risks. Results indicate that traffic-related activities contributed the most HMs to RFD2.5 at 61.18%, followed by nature sources (21.58%), fossil fuels emission (9.32%), and local deposition (3.92%). Although the non-carcinogenic risk of HMs had not been found from RFD2.5 through inhaling, cancer risks from Cr exceed the safety threshold. Moreover, traffic-related activities were also the main reason to cause carcinogenic risk of Cr from RFD2.5 in the Wuhan metropolitan area, especially in Wuhan. Besides that, developing characteristics would affect the carcinogenic risk level from RFD2.5, such as citizens in high-speed economic development or tourist cities would face relative high carcinogenic risks of Cr from traffic-relate activities in RFD2.5, while in green economic transition or small-scale city such risks were shown as relatively low. The investigation improves the understanding of the source of HMs health risk in different types of RFD2.5 and the results provide valuable information on health risk mitigation strategies for environmental managers.

Spatially Resolved Distribution, Sources, Exposure Levels, and Health Risks of Heavy Metals in

In the present study, a total of 64 road dust samples were collected from five different functional areas (residential, commercial, parks, high-traffic, and industrial) in urban Lucknow to assess the accumulation, distribution, and health risk of heavy metals (HMs) (i.e., Fe, Mn, Zn, Cu, Pb, Cd, As, Cr and Ni). Acid digestion methods were used to analyze HMs, followed by inductively coupled plasma-mass spectrometry (ICPMS). The ascending frequency of HMs was Cd < As < Ni < Cr < Pb < Cu < Zn < Mn < Fe for all different functional areas. Almost all HMs exceed the limits of Indian natural soil background values (INSB) across all functional areas. The pollution assessment results reveal that the urban road dust of Lucknow is highly enriched with Zn and Pb, causing deterioration of dust quality. The spatial distribution of HMs shows that road dust found in the central and southwestern zones of the Lucknow urban area are more contaminated than in other areas. The ecological risk assessment demonstrates that Cd was the highest risk contributor, followed by Pb, Zn and Cu. The result of the health risk assessment i.e., the cumulative hazard index (HI) and the cumulative lifetime cancer risk (LCR), reveal that children (mean HIchildren = 1.26, LCRchildren = 0.000187) are more vulnerable to HM exposure than adults (HIadults = 0.14, LCRadults = 0.0000804). For carcinogenic and non-carcinogenic risk, ingestion appears to be the major pathway of HM exposure in both age groups. It is alarming that all studied four carcinogenic HMs were found in concentrations higher than 1 × 10−6 (the permissible limit for humans). This indicates slight chances of developing cancer for both age groups in all functional areas.

Enrichment Factors, Health Risk, and Source Identification of Heavy Metals in Agricultural Soils in Semi-arid Region of Hainan Island

To understand the enrichment factors and pollution levels of heavy metals in agricultural soils in the semi-arid region of Hainan island, 1818 surface soil samples were collected in Gancheng Town and analyzed for their heavy metal contents and physicochemical composition. Correlation analysis was used to determine the heavy metal enrichment factors. The geo-accumulation index (Igeo), comprehensive ecological risk index (RI), and hazard index (HI), as well as carcinogenic risk (CR), were used to assess the degree of pollution and health risk. Positive matrix factorization (PMF) was used to determine the primary sources of pollution and priority sources. The average values of heavy metal contents in the topsoil were 22.7, 0.128, 33.4, 14.5, 0.032, 9.32, 32.5, and 43.3 mg·kg-1 for As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn, respectively. With the exception of Zn, the concentrations of other heavy metals in the topsoil were higher than the soil background values of Hainan, showing different degrees of heavy metal accumulation effect. The Igeo revealed that the major pollutant element in soils was As, followed by Cd and Cu. The RI showed that the proportion of soil samples that were high-risk level or worse was 29.4% of the total number of samples, among which As was the major source of risk. The health risk assessment results indicated that As, Cr, and Ni exposure presented carcinogenic risk for children with high CR values. Based on PMF, four major sources of heavy metals were identified in the study area. Hg was derived mainly from industrial sources, and As was closely associated with agricultural activities. Ni, Cu, Cr, and Zn were related to soil parent materials. Pb and Cd were associated with agricultural activities and traffic emissions. The PMF models combined with correlation analysis were useful for estimating the source apportionment of heavy metals in soils.

Health risks of industrial wastewater heavy metals based on improved grey water footprint model

The Belt and Road Initiative (B&RI) promotes cooperation among participating countries from multiple perspectives, especially infrastructure construction and investment, which is a critical driving force for industrial activities. The accelerated industrial development would inevitably cause environmental consequences in participants, in which pollution and related health risks caused by industrial heavy metal emissions were among the most concerned. In this study, an improved grey water footprint of industrial heavy metal emissions (GWFHMs) was proposed from the perspective of health risks to address the limitation of conventional GWF in reflecting their properties and impacts of pollutants, such as the health toxicity of heavy metals. Meanwhile, the water pollution level of GWFHMs (WPLHMs) was estimated to reveal the degree of aquatic industrial heavy metal pollution concerning health risks. We use China, the B&RI member with severe heavy metal pollution, as a case. The spatial distribution of GWFHMs (at the resolution of 1 km × 1 km) and WPLHMs (at the watershed level) monthly during 1998–2015 were uncovered. Results show that the GWFHMs of China have significantly decreased in this period, but WPLHMs in some regions are still high due to cyclical fluctuations in heavy metal emissions and water runoffs. The middle reaches of the Yangtze River had the highest GWFHMs but relatively low WPLHMs due to abundant water runoffs. In contrast, the Liaohe watersheds in north China had the highest WPLHMs due to water shortage, especially in dry seasons (from December to February). This study reveals critical periods and hotspot regions for heavy metal pollution, which would support decision-making for delicacy industrial heavy metal control measures concerning human health in B&RI countries. In addition to direct emission control, production activities and the following industrial wastewater emissions should also consider the time variation of water runoffs in each region, which would contribute to keeping the health risks of industrial heavy metal emissions within acceptable limits.

Spatial distribution and source identification of heavy metals in European mountain beech forests soils

The main objectives of this research were to (i) investigate the concentration; (ii) characterize the distribution; (iii) determine the sources apportionment; (iv) estimate environmental and health risks of heavy metals in soil from mountain beech forest. A total of 76 soil samples from 20 pure beech forest stands from Bosnia and Herzegovina (BA), Bulgaria (BG), Check Republic (CZ), Germany (DE), Italy (IT), Poland (PL), Romania (RO), Serbia (RS), Slovakia (SK), Slovenia (SL), and Spain (ES) were collected. The content of major elements was measured by X-ray fluorescence spectroscopy (XRF). The content of heavy metals was measured by inductively coupled plasma–optical emission spectrometry (ICP/OES). Heavy metals had a specific concentration range, which followed in soil samples from depth 0–40 cm the common order (low to high): Hg < Cd < As < Co < Pb < Ni < Cu < Cr < Zn, and from depth 40–80 cm: Hg < Cd < As < Pb < Co < Ni < Cu < Cr < Zn. The grouping of the examined parameters according to rock types, soil types, and localities indicated the separation of carbonate rocks from other substrates, luvisol, and rendzina from other soil types, and samples from BA, SL, and IT from other localities. According to sources apportionment As, Pb and Zn are of anthropogenic origin, Cd, Co, Cr, and Ni are of geogenic origin, while the middle position of Cu and Hg indicates a combined contribution of both sources. Elements Cd and Hg indicated severe to extremely severe enrichment with a mean value of 24.3 and 70.6, respectively. Based on the determined values Ni, Cr, As and Cd do not pose a health risk.

Remediation via biochar and potential health risk of heavy metal contaminated soils

Remediation via biochar and potential health risk of heavy metal contaminated soils

Occurrence and Health Risks of Heavy Metals in Drinking Water of Self-Supplied Wells in Northern China.

Self-supplied wells, an important water resource in remote and scattered regions, are commonly deteriorated by environmental pollution and human activity. In this study, 156 self-supplied well-water samples were collected from remote and scattered areas of Inner Mongolia (NMG), Heilongjiang (HLJ), and the suburbs of Beijing (BJ) in Northern China. Twenty-four heavy metals were identified by using the inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES), and the associated human health risks were assessed by using standards of the US Environmental Protection Agency (US EPA). The concentrations of four heavy metals (As, Fe, Mn, and Tl) in HLJ, one heavy metal (Tl) in BJ, and ten heavy metals (Al, As, B, Cr, Fe, Mn, Mo, Se, Tl, and Zn) in NMG exceeded the limits set by China or the World Health Organization (WHO). The total carcinogenic risk (TCR) and total non-carcinogenic risk (THQ) exceeding set limits mainly occurred in NMG, compared to HLJ and BJ. Moreover, As accounted for 97.87% and 60.06% of the TCR in HLJ and BJ, respectively, while Cr accounted for 70.83% of the TCR in NMG. The TCR caused by Cd in all three areas had a negligible hazard (<10−4). As accounted for 51.11%, 32.96%, and 40.88% of the THQ in HLJ, BJ, and NMG, respectively. According to the results of the principal component analysis, heavy metals in well water from HLJ and NMG mainly originated from mixed natural processes and anthropogenic sources, whereas, in BJ, most heavy metals probably originated from natural sources. In the future, long-term monitoring of heavy metals in water from self-supplied wells should be conducted for an extensive range of well-water sites, and well water with high As contamination should be monitored more and fully assessed before being used as a drinking-water source.

Spatial Distribution, Pollution Characteristics, and Health Risk Assessment of Heavy Metals in Soils from a Typical Agricultural County, East China

This study collected 1135 topsoil samples of cultivated land in Laiyang County, eastern China, to analyze the distribution, pollution and health risks of heavy metals (As, Cd, Cu, Cr, Hg, Ni, Pb and Zn). The results show that: (1) the levels of eight heavy metals at some sites were higher than the risk screening values in China, and there was heavy metal pollution. (2) An improved geoaccumulation index was used to evaluate soil pollution. The average value of Igeo before and after improvement was 0.32 (Iml, no pollution to medium pollution) and −0.04 (Iol, no pollution), respectively. (3) Hg and Cd were identified as the main contributors to ecological risk in this study, with a cumulative ecological risk contribution percentage &gt; 65%. The results of the potential ecological risk index (PERI) show that 9.3% of the sampling sites were considered to have moderate ecological risk. (4) As, Pb, Ni and Cu made a contribution of &gt;95% in terms of non-carcinogenic risk to adults and children through different exposure routes, and different soil intake routes posed no non-carcinogenic risk to adults; there was a sampling site with HQChildren &gt; 1, which was consistent with the non-carcinogenic risk site, indicating that children in this location and surrounding areas are more likely to face dual health risks. Therefore, it is necessary to promote the risk management of heavy metals in the study area in order to safely use soil resources.

Spatial-temporal distribution and pollution indices of heavy metals in the Turnasuyu Stream sediment, Turkey.

The potential contamination levels and human health risk of heavy metals in sediment of the Turnasuyu Stream in Ordu, Turkey, were evaluated comprehensively by taking seasonal samples from three different locations. The order of the mean heavy metals (HMs) concentrations (mg/kg) were as follows: Fe > Al > Mn > Pb > Zn > Cu > Co > Cr > Ni > Cd > As. All HM levels, except Cd and Pb, were in the minimum enrichment range as assessed by the sediment enrichment factor (EF). Similar low contamination levels for all HM, except Pb and Cd, were also observed when the contamination factor (CF) and geo-accumulation index (Igeo) were taken into account. The low risk of the study area has also been confirmed by the ecological risk index (Eri) values. The probable human health risk assessment has been performed, and the lifetime cancer risk (LCR) values for adults were found as negligible with values below 10-6. In addition, the hazard index (HI) and total hazard index (THI) results were both higher in children than in adults. The Pearson correlation coefficient (PCC) revealed the highest correlation between Cd and Pb (0.85). When the ecological indexes and statistical results are evaluated together, it is thought that the presence of HMs in the sediment may be due to lithological reasons as well as anthropogenic activities such as quarrying, municipal, agricultural, and domestic discharges in the region. Mitigation measures should be taken in accordance with the standards within the river basin to prevent the potential risks of pollution.

Heterogeneous changes of chemical compositions, sources and health risks of PM2.5 with the “Clean Heating” policy at urban/suburban/industrial sites

China has enacted the “Clean Heating” (CH) policy in north China. The domain-specific impacts on PM2.5 constituents and sources in small cities are still lacking, which obstruct the further policy optimization. Here, we performed an intensive observation covering the heating period (HP) and pre-heating period (PHP) in winter of 2017 at urban (UR), industrial (IS), and suburban (SUR) sites in one of the “2 + 26” cities. The mean PM2.5 concentrations at UR and IS decreased by 15.2 % and 4.6 %, while increased by 9.8 % at SUR in the HP compared with the PHP, indicating the heterogeneous responses. The lowest contribution percentages of coal combustion (14.6 %) and industrial emissions (17.1 %) to PM2.5 at UR in the HP implied the CH policy played more effective role. The most increase in NO3−/SO42− ratio by 26.8 % and the highest NO3− concentration at UR in the HP were linked mainly with the thermal-NOx emitted from natural gas (NG) burning in view of NOx emission reductions from other sources. The highest concentrations of OC, SO42−, K+, and Cl−, and contribution percentages of biomass burning (20.0 %) and coal combustion (24.8 %) to PM2.5 at SUR in the HP evidenced the enhanced usage of biomass/coal. Coal banning in the HP at IS and UR led to the obvious decreases in OC, SO42−, As, and Sb. Secondary nitrate became the largest PM2.5 source at IS and UR in the HP. Coal banning, emission control on large-size enterprises and ignored control on small-size enterprises efficiently modified the concentrations and health risks of heavy metals. The lowest carcinogenic risks moved from SUR in the PHP to UR in the HP. The policies on de-NOx of NG-burning related enterprises, reduction of biomass/coal usage in suburban area, and strict regulation of small-size enterprises were urgently need to further improve the air quality.

Determination of Aflatoxin and Heavy Metal Levels in Some Spices Sold as Unpackaged in Van Province and Health Risks Assessment of Heavy Metals

Aim: This study aimed to determine the aflatoxin and heavy metal levels in the samples of unpackaged red pepper, black pepper and cumin sold in Van and to estimate the health risks of heavy metals. Materials and Methods: In 60 samples (20 of each spice sample) obtained from herbal shops and markets, aflatoxin analysis was done with HPLC device and heavy metal analysis was done with ICP-MS device. Results: Although AFG1 and AFG2 were not detected in all spice samples, AFB1 and AFB2 were not detected in all cumin samples, AFB1 was detected in all red pepper samples and only one black pepper samples, and AFB2 in 18 red pepper samples. As a result of heavy metal analysis, the average concentration of Ni, Cd, Pb and Al were 5.08, 0.35, 2.47, 392.45 ppm in black pepper, 9.12, 0.20, 1.40, 514.4 ppm in cumin and 8.95, 0.06, 0.11, 33.75 ppm in red pepper, respectively. Arsenic was detected only in cumin and its average concentration was 0.06 ppm. Conclusion: In 90% (18 samples) of red pepper samples, AFB1 was detected above the permisisble limit value in Turkish food codex. The Cd level in black pepper samples and Ni levels in all spice samples determined in this study were above the limit values. According to daily intake tolerance limits, although Ni, As, and Cd levels in spices do not pose any risk, Al in all spice samples and Pb levels in black pepper samples are above the daily intake tolerance limits. Spice samples do not pose risk of non-carcinogenic effects, as THQ exposure values are less than 1.

Health ecological risk assessment of natural radionuclides and heavy metals in some sediment at Red Sea coast, Egypt

ABSTRACT The main objective of this study was to evaluate the health and ecological risks of natural radionuclides and heavy metals based on 23 sediment and water samples collected from some sediment at the Red Sea Coast in Egypt. The studied area is characterised old harbour used for shipping and processing phosphate ore. The results revealed that Cd and Zn contents in some water and sediment samples exceeded the standard limit, their concentrations reached (0.027–0.09) mg/L in water and (4.5–236) mg/Kg in sediment samples respectively. While the other analysed trace elements Fe, Mn, Ni, pb and Cu remain below permissible limits. The estimated contamination degree varied from low to considerable while the ecologic risk indices revealed that sediment ranged 10.8 to 466.6 as from low to moderately contaminate with trace elements. The average activity concentrations of 238U, 232Th, and 40K were 3.4, 0.83 and 5.5 Bq/L in water and 63.5, 16.5 and 556 Bq/Kg in sediment samples which were below the recommended limits except for the activity concentrations of 238U and 40K in some water and sediment samples above the permissible limits. The total annual effective dose rates from the exposure pathway were 0.09 to 0.26 mSv y−1. The estimated excess lifetime cancer risk values for workers were slightly higher than that of the sediment world average.

Pollution, sources, and human health risk assessment of heavy metals in urban areas around industrialization and urbanization-Northwest China

Heavy metal pollution in urban soils and dust is mostly caused by extensive anthropogenic activity during urbanization and industrialization. In this research study, the pollution characteristics, sources, ecological and human health risks of heavy metals in urban soil, and dust have been thoroughly evaluated. The research findings demonstrate that dust has a higher level of contamination than urban soil, such as Pb, Cu, and Zn metals are more contaminated in both urban soil and dust throughout the city, and Hg and As are also found in locations with a high concentration of heavy industrial companies. This implies that traffic emissions are still a significant source of metals in urban areas, though industrial companies also contribute. The health risk assessment model used to calculate human exposure revealed that the non-carcinogenic and carcinogenic risks of selected metals in soil and dust were generally in the low range, except for the carcinogenic risk from Cr in children. Statistical analysis revealed that Cr and Ni concentrations were mainly of natural origin, Cu and Zn have been sourced from traffic, whereas Pb, Hg, and As have been sourced from industrial activities. The overall recommendation is that the road traffic environment and municipal construction facilities need to be improved to ensure the sustainable development of the city's environment, while pollution from industrial waste is strongly controlled.