Risk Index Of Heavy Metals Research Articles

Ecological Risk and Human Health Implications of Heavy Metals Contamination of Surface Soil in E-Waste Recycling Sites in Douala, Cameroun.

Background.Recycling of electronic waste (e-waste) in developing nations poses a risk to the environment and human health through the release of heavy metals.Objectives.The aim of the present study was to evaluate the levels of heavy metals in Douala, Cameroun, the site of e-waste recycling activities.Methods.Soil samples were collected from Makea, Ngodi and New Bell e-waste recycling sites, as well as from a control site. Samples were digested and levels of heavy metals were determined.Results.The concentrations of the heavy metals in Makea occurred in the order of lead (Pb) (290±40) > zinc (Zn) (160±30) > chromium (Cr) (130±40) > copper (Cu) (130±20) > nickel (Ni) (56±5.7) > cadmium (Cd) (20±3.0); Pb (310±30) >Zn (150±20) >Cu (80±30) >Cr (70±40) >Ni (50±1.0) >Cd (30±5.0) in Ngodi; and Pb (280±40) >Zn (155±35) >Cu (80±50) >Cr (70±40) >Ni (53±2.0) >Cd (20±10) in New Bell. The levels of metals in all of the samples were higher compared to the control site, which was composed of vegetation and far from the e-waste sites, and in some cases, higher than permissible limits or guidelines. The ecological risk index of heavy metals for soil samples in all the e-waste sites indicated a very high risk.Conclusions.Heavy metals concentrations in soil around e-waste recycling sites present serious health risks and further investigations are needed.Competing Interests.The authors declare no competing financial interests.

Spatial Variation of Soil Heavy Metals in Lin'an City and Its Potential Risk Evaluation

Urban soil is an important part of the urban ecosystem, which is strongly correlated with human health and life quality. In this study, Lin'an city was chosen as a typical small city to study the spatial variation and distribution of heavy metals in urban soils and their pollution characteristics using multivariate analysis, geostatistics, and GIS techniques. A total of 62 soil samples were collected from the study areas. The results indicated that the average concentrations of soil Mn, Cu, Zn, Pb, Cr, and Cd were 439.42, 42.23, 196.80, 62.55, 63.65, and 0.22 mg·kg-1, respectively. Compared with the background values and the environmental quality standards, these heavy metals were accumulated in urban soils to some extent. Almost 80% of the study area was polluted by heavy metals. The single potential ecological risk index of heavy metals indicated that Pb had the highest ecological risk. The pH and most of the heavy metals had strong correlations, and there were strong correlations among the heavy metals. The principle component analysis (PCA) showed that Pb, Zn, and Cu had the same pollution source, which was related to vehicle exhausts; Mn and Cr were mainly from the parent material; and Cd was from the emissions of manufacturing plants. The spatial structure and distribution of heavy metals and their corresponding available fractions had strong spatial autocorrelation with all of the C0/(C0+C)<50%. Their spatial patterns were influenced by human activities.

Hydrogeochemical assessment of mine-impacted water and sediment of iron ore mining

This study was carried out to evaluate the hydrogeochemical behaviour of mine-impacted water and sediment of a former iron ore mining area. Sampling of mine water and sediment were carried out at selected locations within the mine including the former mining ponds, mine tailings and the nearby stream. The water samples were analysed for their hydrochemical facies, major and trace elements including heavy metals. The water in the mining ponds and the mine tailings was characterised as highly acidic (pH 2.54-3.07), but has near-neutral pH in the nearby stream. Results indicated that Fe and Mn in water have exceeded the recommended guidelines values and was also supported by the results of geochemical modelling. The results also indicated that sediments in the mining area were contaminated with Cd and As as shown by the potential ecological risk index values. The total risk index of heavy metals in the sediment were ranked in the order of Cd>As>Pb>Cu>Zn>Cr. Overall, the extent of potential ecological risks of the mining area were categorised as having low to moderate ecological risk.

Proximate Compositions and Health Risk Evaluation of Heavy Metal Uptake by Vegetables Grown at a Waste –Water Irrigated Site in Fct, Abuja, Nigeria

The purpose of the study was to evaluate some proximate compositions and health risk of heavy metal uptake by vegetables grown at a waste-water irrigated sites in FCT, Abuja. The study was carried in dry seasons between 2015 and 2017. Two different types of vegetable samples (Lagos Spinach- Celosia argentea and African Egg-plant- Solanum macrocarpon) were collected simultaneously from three irrigated farm sites. Heavy metal levels were quantified using Atomic Absorption Spectrophotometer (AAS). Other parameters were determined using standard methods. The levels of heavy metals in vegetables varied according to sites. Proximate composition in both vegetable leaves recorded higher mean values for total ash (8.65-8.97), crude fibre (10.83-11.25), protein (4.96-5.08), Fat (3.05-3.29) and dry matter (65.58-68.85) indicating that they were rich in nutrients that promote healthy living. The mean levels of Zn (3.36±0.50) and Ni (0.03±0.01) in Lagos Spinach ; and Zn (2.80±0.36) and Ni (0.04±0.02) in African Egg-plant were generally lower than the FAO/WHO permissible limits except for Fe (14.96±0.86),(15.81±0.89) and Pb (1.12±0.11), (1.31±0.11) in both vegetables that were significantly higher (P<0.05) . Lagos Spinach recorded lower Metal Pollution Index (10.35) while African Egg-plant had the highest value (12.18) suggesting that these vegetables may present more health risk to the consumers of these vegetable. Daily Intake values of Fe (0.089), Zn (0.020), Ni (0.001) and Pb (0.006) in Lagos Spinach and Fe (0.094), Zn (0.017), Ni (0.001) and Pb (0.008) in African Egg-plant were below the WHO/FAO and USEPA permissible limits. However, Health risk index of heavy metals in vegetable samples were less than 1 indicating no significant health risk associated with the consumption of vegetables by the consumers.

Comparison of the Ecological Risk Index of Heavy Metals in the North of Persian Gulf: Hormozgan and Bushehr Provinces

هدف از مقاله حاضر، بررسی مقایسه­ای شاخص ریسک اکولوژیک فلزات سنگین در شمال خلیج فارس (استان­های هرمزگان و بوشهر) است. به همین منظور در سال 1391 نمونه­گیری از رسوبات سطحی 58 ایستگاه در حوزه خلیج فارس به صورت ترانسکت خطی از ساحل به سمت منطقه فرا ساحل انجام گردید. کلیه نمونه­ها با رعایت اصول نمونه­برداری برای آنالیز فلزات سنگین به آزمایشگاه انتقال یافتند و غلظت کل فلزات Cu As, Cr, Cd, Pb, Zn, Hg, با استفاده از هضم اسیدی و توسط دستگاه پلاسمای جفت شده القایی- اسپکترومتری جرمی (ICP-MS [1] ) آنالیز شدند. همچنین دانه­بندی ذرات و میزان محتوای کربنات رسوب اندازه گیری شد. نتایج نشان داد که بافت عمومی رسوبات سیلت- لومی و میزان کربنات­ها از 5/8 تا 72/53 متغیر است. با توجه به شاخص ریسک انفرادی اکولوژیک (ER [2] ) عناصر کادمیوم، جیوه وآرسنیک ریسک متوسط ایجاد می­نمایند. میانگین شاخص ریسک اکولوژیک ( [3] (RI 335 بدست آمد که نشان­دهنده وجود ریسک بالا در کل حوزه مورد مطالعه است. علی­رغم بالاتر بودن این شاخص در استان هرمزگان هر دو استان بوشهر و هرمزگان در رده خطر بسیار بالا از نظر ریسک اکولوژیک قرار گرفتند. پهنه­بندی انجام شده برای ریسک اکولوژیک در محیط GIS نشان دهنده کاهش تدریجی شاخص RI از ساحل به سمت فراساحل است که این موضوع اهمیت تخلیه آلاینده­های زیست محیطی از منابع زمینی به حوزه دریایی را خاطر نشان می­سازد. 1 Inductively coupled plasma-mass spectrometry [2] Individual ecological risk index [3] Ecological risk index

Heavy metals in soil at a waste electrical and electronic equipment processing area in China.

For the objective of evaluating the contamination degree of heavy metals and analysing its variation trend in soil at a waste electrical and electronic equipment processing area in Shanghai, China, evaluation methods, which include single factor index method, geo-accumulation index method, comprehensive pollution index method, and potential ecological risk index method, were adopted in this study. The results revealed that the soil at a waste electrical and electronic equipment processing area was polluted by arsenic, cadmium, copper, lead, zinc, and chromium. It also demonstrated that the concentrations of heavy metals were increased over time. Exceptionally, the average value of the metalloid (arsenic) was 73.31 mg kg-1 in 2014, while it was 58.31 mg kg-1 in the first half of 2015, and it was 2.93 times and 2.33 times higher than that of the Chinese Environmental Quality Standard for Soil in 2014 and the first half of 2015, respectively. The sequences of the contamination degree of heavy metals in 2014 and the first half of 2015 were cadmium > lead > copper > chromium > zinc and cadmium > lead > chromium > zinc > copper. From the analysis of the potential ecological risk index method, arsenic and cadmium had higher ecological risk than other heavy metals. The integrated ecological risk index of heavy metals (cadmium, copper, lead, zinc, and chromium) and metalloid (arsenic) was 394.10 in 2014, while it was 656.16 in the first half of 2015, thus documenting a strong ecological risk.

Release Activity and Potential Ecological Risk Assessment of Heavy Metals in Coal Gangue of Hancheng, China

Focused on release activity of different weather degree gangue of Han Cheng, evaluate heavy metals potential release risks by Hakanson instrument. The results showed that the content of heavy metals were more than their background in unweathered gangue. The Sang shuping gangue were Cd，Cr and As, so did Cd, Pb, Cr, Cu, Ni and As in Xia yukou. Residue fraction were the main fraction of heavy metals in gangue. The release potential and activity of heavy metals decreased with the weather degree increasing. The release activity of unweathered and weathered one year of Sang shuping gangue from high to low were Cu, Pb, Ni, Cd, Cr, As and Cd, Pb, Cu, Ni, Cr, As respectively. The release activity of unweathered and weathered one year of Xia yukou gangue from high to low were Cu, Ni, Cr, Pb, Cd, As. The potential ecological risk of heavy metals were in slight degree, and the potential risk index of heavy metals decreased gradually with the increasing of weather degree. The potential risk index of heavy metals from high to low were Cd, Pb, Cu, Ni, As, Cr and Cd, Cu, Pb, Ni, Cr, As respectively.

Determination of trace elements in gluten-free food for celiac people by ICP-MS

This paper is the first analytical approach to the study of twenty heavy metals in the gluten-free foods for celiac people. Only the ICP-MS technique was used. One of the advantages about the use of ICP-MS for this characterization is the high sensitivity that improved the limits of quantification levels for some elements that are present at low quantities in some samples.The concentration values of As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, V and Zn in seventeen gluten-free food samples are reported.The highest arsenic and molybdenum levels were measured in Rice noodle from China (0.088 and 0.47mgkg−1, respectively). The highest concentrations of some metals (Cu, Ba, Cd, Pb, Hg, Sr and V) were found in bread and breadstick samples produced in different bakeries located at Palermo.To examine the overall heavy metal concentrations in all gluten-free samples analyzed, metal pollution index (MPI) was calculated.Gluten-free foods analyzed contain levels of trace elements under the limits tolerated by the law.Considering the average concentrations of some trace elements found in the present study, it can be concluded that they are inadequate if compared with the recommended daily intake by international organisms, providing from 1.1 to 53% of the RDI for the essential metals. These conclusions are in good agreement to some authors affirming that commercial gluten-free cereal foods, made of refined flours or starches, are of lower nutritional value compared to their wheat counterparts.The metal pollution index and health risk index of heavy metals also suggest that Cd, Pb and Ni contamination in most of the test gluten-free food had potential for human health risk due to consumption of food at contaminated not industrial laboratory. Considering our data, health risk index was lower than 1 for all the samples except nickel in a sample of pasta.