Mean Concentrations Of Zn Research Articles

Monitoring, Source Identification and Environmental Risk of Potentially Toxic Elements of Dust in Isfahan Province, Central Iran.

The aim of this study was to identify potentially toxic elements (PTEs) associated with airborne particulate matters (PMs) and their source identification and environmental risk in Isfahan Province, central Iran. Dust samples were collected from various locations included three urban and four rural locations. Results revealed the eastern part of the region as the main source of dust and showed that the highest monthly atmospheric dust deposition was in July (5.53g m-2). The mean concentrations of Zn, Pb, Cu and Cd were respectively 279, 63, 49 and 0.5mg kg-1 in dust samples, whereas Cd showed the highest ecological risk index. Dust samples of urban areas showed considerable and very high levels of pollution indices for Pb and Zn, respectively. Among the metals, Zn showed the highest enrichment factor (>5), mainly due to anthropogenic sources. The comprehensive ecological risk index of PTEs revealed the moderate and considerable risk of Isfahan and Najafabad cities, respectively.

Heavy metal profile in smoked Atlantic cutlass fish (Trichiurus lepturus, linnaeus 1758) from some major markets in Benin metropolis, Nigeria

The concentrations of heavy metals (Pb, Cd, Cu and Zn), in smoked Trichiurus lepturus (Trichiuridae) from some major Markets in Benin Metropolis, Nigeria, were determined employing Atomic Absorption Spectrophotometric technique, in order to ascertain their suitability for human consumption against the dearth of data regarding the metal content of such fish. The mean concentrations of metals in fish ranged from 0.118 mg/kg for Cd to 72.738 mg/kg for Zn. The mean concentration of Zn in fish ranged from 51.80 mg/kg at New Benin Market to 89.28 mg/kg at Ramat Market while the mean concentration of Cu ranged from 6.58 mg/kg at Oba Market to 9.29 mg/kg at Ramat Market. The mean concentration of Cd ranged from below detection limits at Oba and New Benin Markets to 0.31 mg/kg at Ramat Market while the mean the mean concentration of Pb ranged from 0.39 mg/kg at New Benin Market to 0.75 mg/kg at Uselu Market. There was no significant difference (P>0.05) in the mean concentrations of metals in fish between Markets. The toxicity quotient for heavy metals ranged from 0.271 for Cu to 2.425 for Zn. The mean concentrations of Zn, Cd and Pb in fish exceeded the Food and Agriculture Organization and Commission Regulation maximum limits for heavy metals in fish indicating that fish must be consumed with caution, to avert heavy metal poisoning.

Geochemistry of zinc and cadmium in coal waste rock, Elk Valley, British Columbia, Canada

Weathering of mine waste rock can result in high concentrations of zinc (Zn) and cadmium (Cd) in surface and ground water. Design and implementation of mitigation measures requires an understanding of the mineralogical occurrence of Zn and Cd within the waste rock as well as the subsequent weathering and leaching processes. Recent geochemical studies have focused on the characterization of selenium and arsenic leaching from sphalerite and pyrite in waste rock from coal mines in the Elk Valley, British Columbia, Canada. Data collected from these studies provide an opportunity to evaluate the distribution and behavior of Zn and Cd. The abundance and mineralogical association of Zn and Cd were determined in waste rock placed at different times in the dump and leaching of Zn and Cd at the dump-scale was estimated by analyzing porewater and effluent water samples in a rock drain. Mean contents of Zn and Cd in the waste rock samples (n = 260) were 152 mg/kg (range: 48.4–591 mg/kg) and 3.02 mg/kg (range: 0.97–7.56 mg/kg), respectively. Electron microprobe analysis showed Zn and Cd are present in rock samples as primary sphalerite and sorbed onto secondary Fe oxides. The mean concentrations of Zn and Cd in porewater in the dump (n = 121) were 231 μg/L (range: 4.27–1046 μg/L) and 0.61 μg/L (range: <0.01–6.85 μg/L), respectively. The sorption onto secondary Fe oxides is identified as the sink for aqueous Zn and Cd in the dump. Under the oxidizing conditions that exist throughout much of the dump, Fe oxides will likely be a long-term sink for aqueous Zn and Cd. Mean concentrations of Zn and Cd in the rock drain water were 56.4 μg/L (range: 1.2–523 μg/L, n = 213) and 1.53 μg/L (range: 0.004–3.92 μg/L, n = 209), respectively. As such, these low concentrations are attributed to dilution by drain waters sourced upstream of the dump and sorption of Zn and Cd onto secondary Fe oxides and calcite precipitated in the drain within 200 m after discharge from the dump. The relative increase of Cd concentration in rock drain water compared to porewater can be because of its lower affinity for the sorption onto secondary Fe oxides and calcite. This study suggests that the mobility of Zn and Cd from the weathering of any low sulfide – high carbonate waste rocks will be limited because the precipitation of secondary Fe oxides and calcite provide a strong internal geochemical control on Zn and Cd mobilization.

An Integrated Approach for Source Apportionment and Health Risk Assessment of Heavy Metals in Subtropical Agricultural Soils, Eastern China

Unreasonable human activities may cause the accumulation of heavy metals (HMs) in the agricultural soil, which will ultimately threaten the quality of soil environment, the safety of agricultural products, and human health. Therefore, the accumulation characteristics, potential sources, and health risks of HMs in agricultural soils in China’s subtropical regions were investigated. The mean Hg, Cu, Zn, Pb, and Cd concentrations of agricultural soil in Jinhua City have exceeded the corresponding background values of Zhejiang Province, while the mean concentrations of determined 8 HMs were less than their corresponding risk-screening values for soil contamination of agricultural land in China. The spatial distribution of As, Cr, Ni, Cu, and Pb were generally distributed in large patches, and Hg, Zn, and Cd were generally sporadically distributed. A positive definite matrix factor analysis (PMF) model had better performance than an absolute principal component–multiple linear regression (APCS-MLR) model in the identification of major sources of soil HMs, as it revealed higher R2 value (0.81–0.99) and lower prediction error (−0.93–0.25%). The noncarcinogenic risks (HI) of the 8 HMs to adults and children were within the acceptable range, while the carcinogenic risk (RI) of children has exceeded the safety threshold, which needs to be addressed by relevant departments. The PMF based human health risk assessment model indicated that industrial sources contributed the highest risk to HI (32.92% and 30.47%) and RI (60.74% and 61.5%) for adults and children, followed by agricultural sources (21.34%, 29.31% and 32.94% 33.19%). Therefore, integrated environmental management should be implemented to control and reduce the accumulation of soil HMs from agricultural and industrial sources.

Assessment of the potential environmental and ecological risks associated with traffic induced heavy metal contamination in country parks of Hong Kong

Hong Kong is a densely populated area with a limited area, so most country parks are adjacent to busy traffic roads and town activities. The soil in country parks may be contaminated by heavy metals emitted by traffic activities. During the holidays, most people go to country parks to play. It is very important to assess the potential risks of residents, especially children. So far, data on pollution in Hong Kong’s country parks is very limited. The heavy metals arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), silver (Ag) and zinc (Zn) were collected in the Kam Shan (KS), Plover Cove (PC), Sai Kung West (SK) and Lion Rock (LR) country parks. The mean Zn concentration in KS Country Park was more than three times higher than the background concentration in Dutch soil standard, while Cu and Pb were more than 1.6 times higher. The average pollution index (PIave) of KS Country Parks was classified as high, and the potential ecological risk index (RI) was classified as moderate. Country parks should pay special attention to heavy metal pollution in order to continue further research and remedial measures.

Physiological and biochemical responses of Lawsonia inermis L. to heavy metal pollution in arid environments

Trace metal pollution is increasing worldwide due to human activities. In this study, we investigated the physiological and biochemical effects of heavy metals on henna plants (Lawsonia inermis L.) grown in oases situated at various distances from an industrial complex in arid southern Tunisia. Our results showed that leaves had higher mean Zn and Cu concentrations than roots, while the reverse was true for Pb and Cd. Such metal immobilization in root cells is related to an exclusion strategy. The biological concentration factor (BCF) of Cu was > 1 at all studied sites, indicating the potential of henna plants to accumulate Cu from the soil. Heavy metals affected various physiological parameters of henna, including water status, macronutrient content, and photosynthetic activity, and increased the rate of hydrogen peroxide (H2O2) production and lipid peroxidation in leaves and roots, indicating oxidative stress. Deleterious heavy metal effects induced biochemical mechanisms in henna plants by accumulating proline and soluble sugars and activated the antioxidant system by enhancing the activities of superoxide dismutase, catalase, and glutathione peroxidase. The magnitude of accumulation and activation was proportional to the concentration of heavy metals in the plant tissues. The stimulation of enzymatic and non-enzymatic antioxidant systems reflects the ability of henna plants to survive in highly polluted environments.

Probabilistic risk assessment of soil contamination related to agricultural and industrial activities

Soil contamination related to industrial and agricultural activities were associated with many adverse health effects and climate change could exacerbate this effect. However, the evidence on this topic in low and middle-income countries (LMICs) is still scarce. We, therefore, aimed to investigate the heavy metals (HMs) concentrations in topsoil around Lake Urmia (which dried about 50 % of it in recent years). Accordingly, 96 surface soil samples were collected from an area of about 4000 km2 in 2019. An inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used to measure the HMs concentrations, including cadmium (Cd), arsenic (As), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), lead (Pb) and zinc (Zn). Health risk assessment of exposure to HMs was performed using Monte Carlo simulations technique. The mean concentrations of Zn, Cu, Ni, Co, Pb, Cr, As and Cd were 68.66, 35, 31.66, 15, 14.4, 11.2, 7.04, and 0.26 mg/kg, respectively, which was in the allowable range of USEPA guideline. The mean enrichment factor (EF) values for Zn, Cd, Cu, Cr, Ni, Pb, Co and As were1.3, 1.9, 1, 1.2, 1.7, 2.8, 1.8 and 2, respectively. Carcinogenic risks of exposure to HMs for inhalation, dermal and ingestion exposure pathways were at safe level. Similarly, the hazard index (HI) was at safe level (HI < 1). The sensitivity analysis indicated that the exposure duration (ED) for As, exposure frequency (EF) for Cd and Ni, concentration (Csoi) for Cr and Pb had the highest impact on ELCR values. Our finding confirmed that HMs concentrations around Lake Urmia had no health risk for inhabitants.

Evaluation of Contamination and Accumulation of Heavy Metals in the Dhaleswari River Sediments, Bangladesh

The Dhaleswari river is considered as one of the most important rivers of Bangladesh due to its geographical location and ecological services. The present study attempts to evaluate the degree of heavy metal pollution, contamination, and accumulative behavior in the sediment of the Dhaleswari river. The sediment samples were collected from fifteen different locations of the Dhaleswari river. Heavy metals were analyzed using the Flame Atomic Spectrophotometer (FAAS). The mean concentrations of Zn, Cu, Cr, Pb and Cd were 131.9, 48.89, 43.16, 33.23 and 0.37 mgkg-1, respectively. According to the United States Environmental Protection Agency (USEPA) Sediment Quality Guideline, the sediment of most of the locations were not polluted for Pb and Cd. But S-11 location for Cd (0.8 mg kg-1) was highly polluted. For Cr, Cu and Zn, maximum locations were moderately polluted. Although the geo-accumulation index (Igeo) values of Dhaleswari river sediments showed almost no severe contamination for most of the sampling locations, the pollution load index (PLI) values showed that most of the sampling sites were contaminated for all heavy metals tested. Moreover, for all measured heavy metals, the mean Contamination Factor (CF) values indicated moderate pollution, except for Cr, which suggested low pollution. The Pearson’s correlation coefficient matrix among the selected heavy metals of Dhaleswari river sediment showed no significant correlation among each other. Therefore, regular monitoring of the heavy metal concentration of the Dhaleshwari river sediment from different location is necessary to identify the sources of pollution so that proper initiative could be taken to prevent heavy metal pollution.

Assessing risk to human health for heavy metal contamination from public point utility through ground dust: a case study in Nantong, China.

Heavy metal contamination in ground dust presents potential environmental and human health threats. However, the heavy metal contamination status of ground dust in the vicinity of public point utilities remains poorly explored. Therefore, this study has been designed to analyze the heavy metal contaminations in the ground dust collected monthly near a public bronze sculpture in an urban campus of Nantong, China, using geo-accumulation indexes (Igeo), enrichment factors (EF), potential ecological risk indexes (RI), and health risks (noncarcinogenic risks (HI) and carcinogenic risks (CR)). This study revealed that the maximum Cr, Cu, Mn, Ni, Pb, and Zn concentrations in ground dust samples were 156.2, 708.8, 869.8, 140.8, 180.5, and 1089.7 mg kg-1, respectively, in which the mean Cu and Zn concentrations were 9 and 7 times higher than the background level in the soil. Temporally speaking, for the majority of heavy metals (with the exception of Ni), the high-concentration seasons tend to be mainly summer and autumn. It was observed that Cu and Zn exhibited significant enrichment (EF = 11.7 and 8.4, respectively), moderate-to-strong pollution (Igeo = 2.4 and 2.0, respectively), and moderate- and low-potential ecological risks ([Formula: see text] = 45.6 and 6.6, respectively). The noncarcinogenic risks which adults exposed to the heavy metal concentrations suffered were found to be insignificant. However, the carcinogenic risks related to Ni (1.3E-04) had exceeded the acceptable level. Based on principal component analysis (PCA) and correlation analysis, the heavy metal concentrations in the ground dust of urban campuses could be related to public point utilities, traffic-related exhaust sources, and industrial activities. This study's findings demonstrated that urban public utilities require more attention due to their significant enrichment, ecological risk factors, and the significant carcinogenic risks to the population.

Bioaccumulation of zinc, lead, cadmium in water hyacinth, hippo grass and papyrus reed as water quality indicator in River Kisat in Kisumu County, Kenya

River Kisat in Kenya is increasingly being polluted serving as a sink for waste receiving effluent from sewerage, industrial waste and agricultural pesticide residues leading to heavy metal contamination. This has led to the contamination of the aquatic ecosystem and water used by communities for consumption and farming. Little information is available on the bio-indicative aspects of water quality using bioaccumulation factor by macrophytes. This study aimed at determining concentrations of Zn, Pb and Cd in water, (Eichhornia crassipes (water hyacinth), Vossia cuspidata (hippo grass), Cyperus papyrus (papyrus reed) and bioaccumulation factors (BAF) in River Kisat, Kisumu County. This was determined following laboratory standard procedures using Atomic Absorption Spectrophotometer (AAS). Results showed mean concentrations (mg/L) of Cd (Below detectable limit), Zn (0.2 -0.15) and Pb (0.03-0.03) in water. Mean values were within allowable WHO drinking water limits except for Pb which was above acceptable limits. Zn recorded highest accumulated levels in E. crassipes (72.43mg/L), C. papyrus (70.13mg/L) and V. cuspidate (71.03mg/L). E. crassipes was observed to bioaccumulate the highest concentration of the heavy metals with C. papyrus bioaccumulating the lowest (E. crassipes &gt; V. cuspidata&gt; C. papyrus). Pearson matrix correlation analysis showed positive significant correlations (r = 0.621; p = 0.027) between Zn and Pb in water and the macrophytes which reflected a common source of pollution and indication of accumulation. BAF recorded for all macrophytes ranged from 2.45 to 6.85, above value of 1, indicating significant bioaccumulation for Zn and Pb. The findings from this study showed higher concentrations of Zn and Pb in the macrophytes in comparison to the water in River Kisat with BAF values &gt;1 indicating bioaccumulation which represented poor water quality. The study recommends local authorities employ monitoring processes with incorporation of BAF as a water quality indicator where low metal concentrations in water are recorded, introduce penalties for polluters and sensitize local inhabitants on detrimental health effects of heavy metal and avoid use of River Kisat water for agricultural activities.

Zinc stable isotope analysis reveals Zn dyshomeostasis in benign tumours, breast cancer, and adjacent histologically normal tissue.

The disruption of Zn homeostasis has been linked with breast cancer development and progression. To enhance our understanding of changes in Zn homeostasis both inside and around the tumour microenvironment, Zn concentrations and isotopic compositions (δ66Zn) were determined in benign (BT) and malignant (MT) tumours, healthy tissue from reduction mammoplasty (HT), and histologically normal tissue adjacent to benign (NAT(BT)) and malignant tumours (NAT(MT)). Mean Zn concentrations in NAT(BT) are 5.5 µg g-1 greater than in NAT(MT) (p=0.00056) and 5.1 µg g-1 greater than in HT (p=0.0026). Zinc concentrations in MT are 12.9 µg g-1 greater than in HT (p=0.00012) and 13.3 µg g-1 greater than in NAT(MT) (p <0.0001), whereas δ66Zn is 0.17‰ lower in MT than HT (p=0.017). Benign tumour Zn concentrations are also elevated compared to HT (p=0.00013), but are not significantly elevated compared to NAT(BT) (p=0.32). The δ66Zn of BT is 0.15‰ lower than in NAT(BT) (p=0.045). The similar light δ66Zn of BT and MT compared to HT and NAT may be related to the isotopic compensation of increased metallothionein (64Zn-rich) expression by activated matrix metalloproteinase (66Zn-rich) in MT, and indicates a resultant 66Zn-rich reservoir may exist in patients with breast tumours. Zinc isotopic compositions thus show promise as a potential diagnostic tool for the detection of breast tumours. The revealed differences of Zn accumulation in healthy and tumour-adjacent tissues require additional investigation.

Heavy Metals in Indoor Dust Across China: Occurrence, Sources and Health Risk Assessment.

In this study, the occurrence of heavy metals including cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) was investigated in indoor dust samples collected from 33 urban and rural areas in 11 provinces, China. The concentrations of the selected heavy metals were determined by an inductively coupled plasma mass spectrometry. The mean concentrations of Zn (166mgkg-1), Pb (40.7mgkg-1), Cr (19.8mgkg-1), Cu (16.9mgkg-1), and Cd (2.29mgkg-1) in indoor dust are in low or moderate levels compared with other countries or regions. Cd was significantly enriched with the highest enrichment factor of 23.7, followed by Zn, Pb, Cu, and Cr, which were all lower than 3. The concentrations of Pb from Northern China (61.4mgkg-1) were significantly higher than those from Southern China (8.88mgkg-1). The concentrations of heavy metals in indoor dusts from rural areas were higher than those from urban areas except for Cu. The multivariate analysis of variance revealed that wall cover, fuel types, and air conditioning were dominant factors influencing the levels of heavy metals in indoor dust. Principal component analysis showed that outdoor dust and wall paint were main factors for the high concentrations of Cd, Pb, and Cr, accounting for 40.6% of the total contribution; traffic sources contributed to the high levels of Cu and Zn explained 20.6% of the total variance. The hazard indexes of selected heavy metals were less than 1 and carcinogenic risk value of Cr were between 1.01 × 10-6 and 1 × 10-4, indicating minor noncarcinogenic and carcinogenic risks from heavy metals in indoor dust for residents in China. Pb contributed 72.0% and 86.9% to the sum of noncarcinogenic risk values of selected heavy metals for adults and children, respectively. The carcinogenic risk value of Cr was approximately 13-fold higher than that of Cd for both adults and children. Children endured higher risks from heavy metals in indoor dust compared with adults.

Heavy metals in vegetables grown in the vicinity of Hawassa industrial zone, Ethiopia: Estimation of possible human health risks

Concentration of heavy metals (Cr, Ni, Cu, Zn, As, Cd, Pb and Hg) in cabbages and potatoes were determined and the potential human health risks due to the consumption of the vegetables have been estimated. Mean concentrations of Zn (134.0 + 5.62 mg/kg), As (0.12 + 0.01 mg/kg) and Cd (0.32 + 0.01 mg/kg) in cabbages from Biological Lagoon area as well as Zn (103.0 + 8.34 mg/kg), As (0.14 + 0.01 mg/kg) and Cd (0.31 + 0.01 mg/kg) in cabbages from Boicha stream area were above the safety limits of FAO/WHO. Likewise, mean concentrations of As (0.24 + 0.03 mg/kg) in potatoes from Biological Lagoon area as well as As (0.35 + 0.07 mg/kg) and Pb (0.50 + 0.04 mg/kg) from Boicha stream area were also above safety limits. Assessment of Target Hazard Quotients (THQ) indicated no human health concern from consumption of both cabbages and potatoes grown in the areas except as through consumption of potatoes from Biological Lagoon and Boicha stream areas. However, effects of all the metals put together may affect human health as revealed by the high Hazard Index (HI > 1). Assessment of Target Cancer Risk (TCR) revealed human health concern from consumption of these vegetables for As and Cd. Overall, vegetables consumption from industrial zone is more risky than consuming vegetables from the Reference site indicating effluents from industries to be a potential sources of the heavy metals.

Heavy Metals Content in Great Shearwater (Ardenna Gravis): Accumulation, Distribution and Biomarkers of Effect in Different Tissues.

The purpose of this study was to explore the usefulness of Great Shearwater (Ardenna gravis) as a bioindicator for biomonitoring programs for metal pollution. Three different metals were analysed in liver, kidney, and feathers, including cadmium, lead, and zinc. Glutathione-S-transferase, malondialdehyde, reduced glutathione, and catalase were assessed as oxidative stress biomarkers. Sex-related trends in metal accumulation also were evaluated. In liver and kidney, the mean concentrations of Zn (146.1 ± 5.14 and 108 ± 2.70mg/kg, respectively) and Pb (0.19 ± 0.01 and 0.13 ± 0.01mg/kg, respectively) in A. gravis were generally comparable to values reported in other studies. However, animals presented slightly higher concentrations of Cd (9.67 ± 0.65 in liver and 17.41 ± 0.84mg/kg in kidney) than those reported in the same species sampled in Southern Atlantic waters. The slightly higher levels of Cd found in this study compared with other studies are probably affected by the location in Northern Atlantic waters (with different diet intake). In feathers, levels of Zn (70.70 ± 1.76mg/kg) were lower than in other Ardenna shearwaters, whereas higher levels were found for Cd (0.16 ± 0.01mg/kg) and Pb (0.84 ± 0.06mg/kg). The lack of differences found between males and females could be influenced by the migration status, because both sexes stay in similar physiological conditions, with no laying eggs. Levels found in the feathers of the present study were related to concentrations in internal tissues below those which cause adverse effects in birds. Thus, feathers would appear as a potential noninvasive tool for metals biomonitoring in seabirds, because it is possible to quantify them. Baseline data of oxidative stress levels have been reported, both in liver and kidney, presenting no correlations with the levels of metals in these tissues. The low internal metal levels and the lack of correlations between oxidative stress metrics suggest a low risk of the environmental concentrations for seabirds.

Lead smelting alters wheat flour heavy metal concentrations and health risks.

Wheat (Triticum aestivum L.) flour consumption may be a major source of human metal intake, especially when wheat is cultivated in metal-contaminated soils. This work investigated Cd, Cu, Pb, and Zn distribution in whole wheat flour, wheat flour, and wheat bran when grown in an area polluted by Pb smelting. Wheat product heavy metal concentrations were analyzed, and the (non)carcinogenic risks were assessed. Mean Cd, Cu, Pb, and Zn concentrations in whole wheat flour were 0.38, 3.83, 0.48, and 29.3mg kg-1 , respectively; those in flour were only slightly reduced. The ratios between noncarcinogenic average daily dose of whole wheat flour and wheat flour consumption ranged from 1.06 to 3.76, with Pb having the greatest values compared with other metals. For children, the average hazard quotients (HQs) of whole wheat flour consumption of Cd, Cu, Pb, and Zn were 4.19, 1.06, 1.53, and 1.07; those for wheat flour consumption were 3.81, 0.68, 0.70, and 0.98, respectively. The HQs of adults were less than those of children. Overall results indicated that consumption of wheat products may lead to health concerns in the heavy metal contaminated area, yet when wheat flour rather than whole wheat flour is consumed, only the human health risk from Pb ingestion is reduced. Altering or removing human edible crops in the most contaminated areas should be considered.

Variation in Micronutrient and Macronutrient Concentrations in Grain of Four Wheat Genotypes Grown in Albaha Region, Saudi Arabia

Major dependence on wheat-based foods with low bioavailability of nutrients led to high malnutrition rates, especially in developing counties. Four wheat genotypes (Albelad (BE), Aldwasair (AD), Australia (AU) and Najran (NJ)) grown in Albaha region were analyzed for the first time for the variation in micronutrient (Se, Mo, Cu, Zn, Mn, Fe, B and Na) and macronutrient concentrations (P, Ca, Mg and K) in the whole wheat grain using Inductively coupled plasma mass spectrometry (ICP-MS) in order to select genotype of high nutritional value of the wheat for human consumption for further breeding by farmers. Substantial micronutrient variation existed among the four genotypes according to their mean Se, Mo, Zn, and Na concentrations, while macronutrient variation existed in their P and Ca concentrations. The NJ genotype appeared to contain higher concentrations of Se, Na, and Ca than the other genotypes while AU contained higher concentrations of Zn and P than AD, BE, or NJ. The results of this study can provide information about micro- and macro-nutrient enriched wheat genotypes for agricultural strategies aimed at improving the nutritional value of wheat plants.

Pollution, human health risk assessment and spatial distribution of toxic metals in urban soil of Yazd City, Iran

Heavy metal pollution significantly reduces the quality of the environment and threatens human health, especially in industrial cities. This study investigated toxic metals concentrations, pollution levels and human health risks assessment of urban soils in Yazd City, as an industrial city in center of Iran. Soil surface samples (0-10cm) were collected from 30 points in the area for geochemical analysis. The concentrations of heavy metals were determined using an inductively coupled plasma mass spectrometry (ICP-MS). The values of the mean concentrations of toxic metals (mg kg-1) in the urban soils decrease in the order of Zn (83.9) > Pb (34.5) > Cr (32.6) > Cu (23.5) > Ni (23.4) > As (5.86) > Co (4.86) > Cd (0.27). The mean concentration of Zn, Pb, As and Cd elements was higher than the background and the crust values. A pollution assessment by Geo-accumulation Index (Igeo), Pollution Index (PI), Contamination Degree (CD), the Integrated Pollution Index (IPI), the Pollution Load Index (PLI) and Integrated Nemerow Pollution Index (INPI) showed that As, Cd and Pb were moderately enriched and the study area polluted considerably by these toxic metals. Based on PI results, 88.9% of the urban soil samples highly polluted by As. Overall, the quality of the urban soil in Yazd City is clearly affected by toxic metals. Due to the prevailing wind direction, the route of the north-south highway of Iran and the population density and traffic of the northwestern and southern areas of the study area were found the highest level of pollution indicators (IPI > 1.8; LPI > 1.3; CD > 15 and INPI > 4.3). The results of Pearson correlation analysis indicated that all pollution evaluation indicators were influenced by As and Cu, and showed high significant correlation with these two elements, while neither of them had a significant relationship with Pb and was found also a weak link statistically with Cd. Health risk assessment of toxic metals has been performed in both carcinogenic and non-carcinogenic sectors. The results indicate that oral intake is the main pathway that toxic metals can harm human health for both the child and adults. The carcinogenic risks (RI) of adults and child by toxic metals were as follows: Ni > Pb > Cr > As > Cd. Hazard quotients (HQ) and hazard index (HI) values for child also were higher than these for adults. Generally, the results demonstrated that the potential carcinogenic health risks for adults of toxic metals were in an acceptable range in study area, whereas for Cr, Ni and Pb with RI > 10-4, the risk of cancer in child probably increases.

Tree species as a biomonitor of metal pollution in arid Mediterranean environments: case for arid southern Tunisia.

We investigated the accumulation of Zn, Cu, Pb, and Cd in the soil and the leaves and bark of five common tree species (Eucalyptus occidentalis Endl., Acacia salicina Lindl., Cupressus sempervirens L., Casuarina equisetifolia L., and Tamarix aphylla (L.) Karst.) in the city of Gabès Tunisia to elucidate their bioaccumulation potential and determine their usefulness as biomonitors of metallic pollution in arid urban areas. Our results indicated that the bark had higher mean concentrations of Pb and Cd than leaves. In contrast, the leaves had higher mean concentrations of Zn and Cu than bark. No hyperaccumulation was detected for any of the analyzed metals in any of the studied species. E. occidentalis and T. aphylla had the highest mean concentrations of the investigated metals in leaves and bark. Based on the calculated metal accumulation index (MAI) values, these two species accumulated more metals than other studied tree species. Likewise, the concentrations of Zn, Cu, Pb, and Cd in soil had significant positive correlations with that in leaves and bark. Accordingly, E. occidentalis could be used for biomonitoring in arid areas subjected to industrial and traffic pollution. T. aphylla would be a good alternative when native species are a priority.

Impact of Irrigation with Polluted River Water on the Accumulation of Toxic Metals in Soil and Crops in the Region of Dhaka, Bangladesh and Potential Effects on Health

The present study was designed to investigate the detrimental effects of toxic metals on agricultural practices carried out with polluted river water from one of the most polluted rivers, the Turag in Dhaka city, Bangladesh. Toxic metal concentrations in irrigation water, soil and rice grains (Oryza sativa) were measured from three different sites near the river. Bioaccumulation factors (BAF) were calculated to recognize the transfer of toxic metals from the soil to rice grains. The estimated daily intake (EDI), target hazard quotient (THQ), total target hazard quotient (TTHQ) and the target carcinogenic risk (TR) were calculated to evaluate the health risks. All values from these three sites were compared to the values obtained from a nearby site where irrigation was carried out with bore-well water. The mean concentrations of Zn, As, Cu, Ni, Pb and Cr in rice grains were 1.71 ± 0.52, 2.20 ± 0.84, 1.47 ± 0.17, 1.27 ± 0.10, 1.98 ± 0.21 and 0.21 ± 0.09 ppm, respectively, indicating that the concentrations of As and Pb were much higher. For all sites, THQ values for As and Pb were higher than 1.0 indicating that consumption of such rice will have a long-term, harmful effect on consumers. Furthermore, the TR values for As and Pb were higher than the threshold level (10−6), implying that the lifetime cancer risk is increased for residents eating this rice. Toxic metals intrude into the river water as well as the bore-well water. Rice cultivated at all sites is thus burdened with toxic metals that make it unsafe for human consumption.

Trace metal bioaccumulation in oysters (Crassostrea gigas) from Liaodong Bay (Bohai Sea, China)

Cd, Cr, Cu, Pb, and Zn concentrations were measured in oysters (C. gigas), plankton, and seawater during spring, summer, and autumn in Liaodong Bay (Bohai Sea, China) to elucidate the effects of season, region, and oyster size on metal bioaccumulation in oysters. Metal concentrations were quantified via atomic absorption spectrophotometry. Our study determined that metal concentrations in oysters, plankton, and seawater were the highest in summer, whereas the lowest levels occurred in autumn. Regarding oyster sizes, the highest Pb levels occurred in C3-sized oysters (> 5-cm length), whereas the highest Cd, Cr, Cu, and Zn levels occurred in C2 (3–5-cm length) oysters. In contrast, the lowest Cu and Pb levels occurred in C1 (< 3-cm length) oysters, whereas the lowest mean Cd, Cr, and Zn concentrations were observed in C3 oysters. Significant differences in trace metal concentrations in the three sample types were observed in all sampling sites.