Assessment Of Heavy Metal Contents Research Articles

Estimating low concentration heavy metals in water through hyperspectral analysis and genetic algorithm-partial least squares regression

Hyperspectral spectrum enables assessment of heavy metal content, but research on low concentration in water is limited. This study employed in situ hyperspectral data from Dalian Lake, Shanghai to develop a machine learning model for accurately determining heavy metal concentrations. Initially, we employed a combination of empirical analysis and algorithm-based analysis to identify the optimal features for retrieving Cu and Fe ions. Based on the correlation coefficients between heavy metals and water quality, the feature bands for TOC, Chl-a and TP were selected as empirical features. Algorithm-based feature selection was conducted by employing the random forest (RF) approach with the original spectrum (OR), first-order derivative reflectance (FDR), and second-order derivative reflectance (SDR). For the development of a prediction model, we utilized the Genetic Algorithm-Partial Least Squares Regression (GA-PLSR) approach for Cu and Fe ions inversion. Our findings demonstrated that the integration of both empirical features and algorithm-selected features resulted in superior performance compared to using algorithm-selected features alone. Importantly, the crucial wavelength data primarily located at 497, 665, 686, 831 and 935 nm showed superior results for Cu retrieval, while wavelengths of 700, 746, 801, 948, and 993 nm demonstrated better results for Fe retrieval. These results also displayed that the GA-PLSR model outperformed both the PLSR and RF models, exhibiting an R2 of 0.75, RMSE of 0.004, and MRE of 0.382 for Cu inversion. For Fe inversion, the GA-PLSR model outperformed other models with an R2 of 0.73, RMSE of 0.036, and MRE of 0.464. This research provides a scientific basis and data support for monitoring low concentrations of heavy metals in water bodies using hyperspectral remote sensing techniques.

Assessment of Heavy Metal Content and Consumption Risks At Selected Paddy Field in Malaysia: A Review

As the Malaysian population grows, there is a high demand for rice, the main staple food in this region. This has caused the overuse of agrochemicals that contain heavy metals and the utilization of contaminated groundwater to increase paddy yield, posing a risk to humans. This study reviewed the accumulated heavy metals in paddy fields of Malaysia's Selangor, Kedah and Sabah states and further calculated the consumption risks of rice grains from the selected areas. The study revealed that paddy soil in Ranau Valley (Sabah), Kota Marudu (Sabah) and Tanjung Karang (Selangor) showed presences of Cu and Cd in high concentration, respectively, creating higher potential to be uptake by paddy roots. These findings also revealed that Ranau Valley (Sabah) paddy grains contained high Cu and Cd concentrations, while Sabak Bernam (Selangor) contained high Pb concentrations. Further, a higher Cd concentration was reported from the Ranau Valley (Sabah), while the higher Pb concentrations were reported from the samples collected from Sabak Bernam (Selangor), Tanjung Karang (Selangor) and Kubang Pasu (Kedah). Based on the health risk indices calculation in this study, carcinogenic and non-carcinogenic health risks in all study areas except in Kubang Pasu (Kedah) and Langkawi (Kedah) are likely to occur due to Cu mining activities, ultrabasic soil contamination, utilization of contaminated groundwater and rock phosphate fertilizer and vehicular emission. Regular assessment of heavy metal content and consumption risks of paddy is essential to ensure the paddy field is free from contamination and will help protect the ecosystem and human health.

Assessment of heavy metal content and ecological risk in offshore surface sediments of the Northern Persian Gulf: Implications for environmental management

Offshore surface sediment samples from fifty-five stations in the northern parts of the Persian Gulf and the Strait of Hormuz were examined to evaluate the content and ecological risk of heavy metals. The physicochemical characteristics of both surface water and deep water were measured using probes and CTD. To determine the source of pollution and assess the ecological risk, various indicators were used, including contamination factor (CF), contamination degree (CD), enrichment factor (EF), pollution load index (PLI), and risk index (RI). The average concentrations of heavy metals in sediment samples were Fe: 1.4 (0.2–2.7%), Cr: 72.9 (8−127), Ni: 59.8 (14−113), V: 43.4 (7−77), Zn: 35.7 (3−58), Cu: 17.5 (2−29), Pb: 12.1 (5−48), Co: 9.4 (1−17), As: 3.9 (1.7–7.2) ppm. Ni and Cr concentrations in almost all Persian Gulf stations especially in shallower parts were higher than their threshold effect level, while Pb, As, Zn, and Cu concentrations were below the threshold values in all stations. The results revealed that EF for all investigated metals in all stations was less than 1.5, which indicates that the studied region had low enrichment and the origin of the heavy metals is natural. However, human activities have contributed to Ni enrichment in the Jask and Bandar Abbas coasts. CD values varied between 11.7 and 14.6, exhibiting the range of moderate pollution to lowest possible pollution category. The PLI for all samples was in the range of 1.2–2.2, which demonstrates advanced pollution load. RI (=∑Eij) varied between 34 and 89, indicating a low ecological risk (IR<110).

Assessment of heavy metal contents in farm produce around Ewekoro and its health implications on consumers

This study was conducted to assess the risk of exposure to thirteen (13) heavy metals from food products obtained from cassava tubers grown in the limestone mining area of Ewekoro, Ogun State in Nigeria. Four (4) samples each of soil and cassava tubers were collected at three different sites for this study. The first two sample collection sites were at 150 m and 300 m from the mining site while the third or the control samples were collected at a distance of 25 km far away from the mining activities. The collected samples were analyzed by the use of Inductively Coupled Plasma-Optical Emission Spectrometry. The concentration average of Fe, Mg, Na, Ag, As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn ranged from 2.00–1284.96 to 0.0098–646.31 mg/kg for both soil and cassava tubers, respectively at site 1, which was far higher than 0.26–622.01 and 0.90–514.35 and 0.07–688.37 and 0.07–371.74 mg/kg reported in both soil and cassava tuber samples at the other 2 locations. The transfer factor from the soil to cassava tuber for Fe, Mg, Ag, As, Cd, Cu, Co, Mn and Pb were observed to be < 1. While Na, Cr, Ni and Zn had transfer factor > 1. The estimated average daily intake at site 1 for both adults and children were 0.46 and 1.69 mg kg−1 bw−1 d−1, respectively. These values were far higher than the results noted at sites 2 and 3 for both adults and children. Similarly, the Risk Index for both adults and children at site 1 were reported to be 7.01 and 25.42, which were higher than the values noticed at the other 2 sites. Therefore, it can be concluded that although the concentrations of these heavy metals were higher than the internationally recommended standard, the EADI and RI revealed that children are at higher risk of exposure to the heavy metal contents from food products derived from cassava in the study area.

Assessment of Heavy Metal Contents in Some Common Spices Available in the Local Market of North Shewa Zone, Oromia Regional State, Ethiopia.

The objective of this study was to determine the contents of heavy metals in some common spices commercially available in the North Shewa Zone, Oromia region, Ethiopia. Korarima seed (Aframomum corrorima), ginger rhizome (Zingiber officinale), red pepper fruit (Capsicum annum), and turmeric rhizome (Curcuma longa) samples were randomly collected from the Fiche open market. These spice samples were digested using a mixture of 3mL of HNO3 (69-72%) and 1mL of HClO4 (70%), where organic components are assumed to decompose into gaseous forms while other heavy metal elements are left in the solution. The contents of heavy metals (Fe, Zn, Cu, Cr, Mn, Ni, Cd, and Pb) in the spices were determined by inductively coupled plasma‒optical emission spectrometry (ICP‒OES). The results obtained showed that the concentrations of heavy metal in the korarima, red pepper, ginger, and turmeric samples in milligrammes per kilogramme of dry weight were in the range of Fe (38.7-98.9), Mn (10.5-257), Zn (7.30-29.2), Cu (1.70-6.50), Cr (5.40-9.70), Cd (1.50-2.90), Pb (14.5-28.4), and Ni (3.90-6.70). The heavy metal contents in korarima, red pepper, ginger, and turmeric samples were compared with the maximum values given by the World Health Organization (WHO). Accordingly, the Fe, Zn, Cu, Cr, Mn, and Ni values in the spice samples were found to be lower than the maximum limit of the WHO, while the levels of Pb and Cd in four spice samples and Mn (only in ginger) were higher than the WHO permissible limit. Thisstudyshowsthatthe consumption of korarima, red pepper, ginger, and turmeric may pose a serious health threat to consumers due to the high content of lead, cadmium, and manganese (only in ginger) in spices. Therefore, it is suggested that further study be conducted on spice samples based on the origin of cultivation to determine which hotspot is responsible for high levels of contamination of lead, cadmium, and manganese to protect consumers.

Assessment of Heavy Metals Content of Hand Dug Wells in Shasha Market, South Western, Nigeria

Assessment of Heavy Metals Content of Hand Dug Wells in Shasha Market, South Western, Nigeria

Assessment of Heavy Metal Contents and Their Risks in Vegetables Collected from District Ghotki, Sindh

Vegetables are renowned for their nutritional value, as they are rich sources of dietary fiber, minerals, and vitamins offering a wide range of health benefits. They also possess antioxidative properties that contribute to overall well-being. The aim of this study was to evaluate the contamination of heavy metals like Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Iron (Fe), Manganese (Mn), Nickel (Ni), and Zinc (Zn) in the agriculture soil and most frequently consumed vegetables including; Sweet Potato (Ipomoea batatas), Turnip (Brassica rapa), Onion (Allium cepa), Carrot (Daucus Carota), Garlic (Allium sativum), Radish (Raphanus sativus), Lotus (Nelumbo nucifera), Potato (Solanum tuberosum), Beetroot (Beta vulgaris), and Ginger (Zingiber officinale) collected from various sites of District Ghotki, Sindh. The agriculture soil and vegetable samples were digested, and heavy metal levels were determined using Atomic Absorption Spectrophotometer (AAS). The Zn content was found higher in all vegetable samples. Cu, Fe, Mn, and Zn concentrations were found within the permissible levels of the Food and Agriculture Organization and World Health Organization (WHO/FAO). However, the concentrations of As, Cd, Cr, and Ni were found higher than the permissible limit suggested by WHO/FAO. Hazard index (HI), target hazard quotient (THQ), daily intake of metals (DIM), and estimated daily exposure to heavy metals (EDEM) were also measure. The hazard index (HI) values of As for all the vegetable samples were greater than 1, indicating potential health risks to those consuming these vegetables.

Assessment of Heavy Metal Content and Human Health Risk of Orogodo River, Delta State, Nigeria

The Orogodo River is a major source of water for drinking, cooking, bathing, fishing, washing and recreation for the resident community. Apparently, anthropogenic activities threaten the sustainability of this resource, hence, the need for environmental monitoring studies. This study was carried out to investigate heavy metal content and to assess human health risk of Orogodo River vis-a-vis its suitability for human consumption. Water samples were collected from four sampling stations established along the stretch of the river with the upstream station at Site 1, two midstream stations (Sites 2 and 3) and the downstream station being Site 4 and analyzed for seven heavy metals: iron (Fe), copper (Cu), manganese (Mn), chromium (Cr), nickel (Ni), zinc (Zn) and lead (Pb) concentrations using the atomic absorption spectrophotometer. The results obtained from the study showed that the mean values for Fe (2.77±0.00 mg/l) in Site 4, Ni (0.15±0.19 mg/l) in Site 2, Pb (0.05±0.02 mg/l) in Site 3, Mn (0.30±0.30 mg/l) in Site 3 and Cr (0.06±0.03) in Sites 2 and 3 exceeded the Nigerian Standard for Drinking Water Quality (NSDWQ) maximum permissible limits (Fe: 0.3 mg/l; Ni: 0.02 mg/l; Pb: 0.01 mg/l; Mn: 0.2 mg/l and Cr: 0.05 mg/l) for Nigerian freshwater and thus warranted health risk assessment. Health risk assessment for all sites indicated that with exemptions of Cr (1.33 in Sites 2 and 3 for children), other metals showed no potential health risk, but their cumulative effects as indicated by the hazard index (1.19 and 2.50 for adult and children in Site 2; 1.22 and 2.91 for adult and children in Site 3 and 1.36 for children in Site 4) could be of serious concern. This calls for caution for both adults and children exposed to the water through ingestion and the dire need for enforcement of water resource management regulations by the concerned authorities.

Risk assessment of heavy metal content in yam tubers locally produced in selected local government areas of Taraba State, Nigeria

Abstract. Olawale OF, Abah MA, Emmanuel OP, Otitoju GT, Abershi AL, Temitope DF, Andrew AE, Abdulkadir S, John A. 2023. Risk assessment of heavy metal content in yam tubers locally produced in selected local government areas of Taraba State, Nigeria. Asian J Nat Prod Biochem 21: 6-12. Yam is one of the most cultivated tubers in northern Nigeria. The increasing yam consumption and pest attack on the crop have led to increased use of fertilizers and pesticides during the cultivation process to prevent and control pest attacks. This study aims to determine the concentration of several heavy metals (Hg, Cr, Cd, Pb, and As) in locally produced yam samples harvested from Jalingo, Takum, Mutum Biyu, Wukari and Zing Local Government Area (LGA) of Taraba state as well assessing the Total Cancer Risk and Hazard Quotient associated with consuming the analyzed yam samples. The samples were collected in duplicates from five LGAs of Taraba state (Jalingo, Takum, Mutum Biyu, Wukari, and Zing). They were washed, peeled, and dried before being analyzed for heavy metal content using the method of Nitric acid-hydrochloric acid digestion (APHA 3030 f. 2018) by Atomic Absorption Spectroscopy (AAS). The data were analyzed using ANOVA (P&lt;0.05). The results showed that Hg and As values were below the permissible limit recommended by WHO, with values ranging from 0.02-0.05 mg/kg. Cadmium content was significantly high, ranging from 8.00-14.00 mg/kg. Chromium content from Zing LGA was higher than in other locations, ranging from 100.00 to 103.00 mg/kg. The risk assessment analysis revealed that chromium and arsenic had the highest and lowest hazard quotient values of 37.32 and 0.00180, respectively, for yam samples cultivated in Jalingo LGA. The highest TCR value was obtained in chromium (3.2×10-3) and the lowest in the lead (1.23×10-8). High levels of heavy metals present in yam samples could be due to excessive use of pesticides or fertilizers during cultivation, burning of plastics and rubbers, deposition from mountains, and other anthropogenic activities. The results of this study are expected to gain public awareness that consuming locally produced yam from LGAs contaminated with heavy metals is at risk of heavy metal toxicity, such as renal, neural, and respiratory disorders, among others.

Assessment of heavy metal content in groundwaters of Ikpe Community, Akwa Ibom State, Niger Delta, Nigeria

Accumulation of heavy metals in groundwater system could portend adverse health consequences to users. Heavy metal content of five randomly selected hand dug wells in Ikpe community, Akwa Ibom State, Nigeria was assessed between April and November 2022. The water was evaluated using standard methods and water quality indices to determine its suitability for human consumption. Eight heavy metals were evaluated using Heavy metal Pollution Index (HPI) and Comprehensive Pollution Index (CPI). The results were compared with the National drinking water standard. Results showed that chromium ranged from 0.001 to 0.20 mg/L, cadmium (0.001 - 0.008 mg/L), nickel (0.01- 0.08 mg/L), manganese (0.001- 0.6 mg/L), zinc (0.36 -1.90 mg/L), iron (0.1 - 0.8 mg/L), lead (0.001 - 0.02 mg/L) and arsenic (0.00 - 0.004 mg/L). HPI and CPI ranged between 44.62-126.30 and 0.18-1.33, respectively. Concentrations of these heavy metals exceeded acceptable limits, except lead and arsenic. The concentration of the metals from wells 2, 4 and 5 were generally higher and/or had values that exceeded acceptable limits. This could be attributed with geogenic and anthropogenic influences as well as the general conditions of the wells and their environment. The water quality indices (HPI and CPI) showed varying levels of heavy metal pollution in line with the heavy metal concentrations. Consequently, it can be concluded that water from wells 2, 4 and 5 is not suitable for human consumption, and it can be used for other purposes.

Quantitative analysis of minor and trace elements in blood serum of dairy cattle (Bos taurus) by WDXRF

&#x0D; &#x0D; &#x0D; &#x0D; Assessment of heavy metal content in biological fluids is essential to determine human and animal health as a result of exposure to contaminated environments, food, and water. WDXRF is a non-destructive method that involves no chemical treatments. It is possible to perform fast chemical analysis without producing hazardous waste and uses a small sample volume (± 50 mL), which is useful to veterinary usage. Therefore, the aim of this work was to implement an alternative method for minor and trace elements in blood serum samples of dairy cattle (Bos taurus) using WDXRF. It was implemented for the determination of Al, Cr, Co, Fe, Cu, As, and Hg, and the method was evaluated by comparing WDXRF and ICP-OES results of a set of 14 blood serum samples of dairy cattle using principal component analysis (PCA). Results of WDXRF and ICP-OES were statistically equivalent to all analyzed elements, except for Fe and Al, which were still comparable. WDXRF proved to be a suitable alternative methodology for heavy metal detection in animal blood serum samples due to the low sample volume. The results of this study enable a new and fast method for veterinary internal medicine, which requires a technique that quickly detects animals with a high concentration of toxic elements to assure the correct protocols to prevent the animal's death.&#x0D; &#x0D; &#x0D; &#x0D;

Assessment of Heavy Metals Content in Soil and Groundwater within the Vicinity of Automobile Mechanic Workshops in Yola and Jimeta Towns, Adamawa State, Nigeria

Although heavy metals are naturally occurring elements that are found throughout the earth’s crust, anthropogenic activities such as mechanic workshops are a source of concern for heavy metal contamination. This paper assessed the heavy metals content in soil and groundwater within the vicinity of automobile mechanic workshops in Yola and Jjimeta Towns, Adamawa State, Nigeria using standard methods. Heavy metals were determined using AAS model 210 VGP while pH was determined by electronic JENWAY glass electrode pH meter (Model 3510). Data obtained revealed that, the pH of the sample ranged from 7.52 to 5.19 (provide the average pH levels in the soil and groundwater). From the study conducted, (provide the mean of the heavy metals here) it can be seen that the level of heavy metals found in the soil is in the order of Zn&gt;Ni&gt;Fe&gt;Pb&gt;Cd. While heavy metals found in the ground water of automobile mechanic locations is in the order Ni&gt;Fe&gt;Zn&gt;Cd&gt;Pb. The levels of metals found in the present study were generally below the Department of Petroleum of Petroleum Resources target values for metals in soils.

Assessment of Heavy Metal Content in Soil and Lycopersicon esculentum (Tomato) and Their Health Implications.

In this study, the content of lead (Pb), cadmium (Cd), chromium (Cr) and manganese (Mn) was evaluated in soils and tomatoes (Lycopersicon esculentum) collected from rural areas of Dobrogea province, South-East of Romania. The risk to human health due to the heavy metal exposure via tomato consumption was also assessed.The results suggest that based on the contamination factor, the soils are moderately contaminated with Cd and Mn (Cf values of 1.266. and 1.40) and poorly contaminated with Pb and Cr. The bioconcentration factor (BAF) was below 1 and indicated that the studied species of Lycopersicon esculentum did not accumulate the monitored elements. Person's correlation analysis showed that there were significant relations between soil pH and BCF values of Cd, Pb, Cr and Mn in analysed tomatoes. The estimated daily intake of each metal was below the oral reference dose. The hazard quotient (HQ) and hazard index (HI) were below the acceptable level (< 1), and the cancer risk (CR) for Pb, Cd and Cr was found within acceptable levels (1.0 × 10-6-1.0 × 10-4). Based on health guidance values, it may be concluded that the analysed tomatoes do not present health risks to consumers in terms of content and accumulation of heavy metals. It is important to monitor the other toxic metals as well, in order to evaluate the heavy metal accumulation variation and the toxicity value of each metal in agricultural soils from both rural and industrial areas.

Assessment of heavy metal content in herbal raw materials traded in India

Presence of heavy metals in herbal raw materials exceeding the safety limit have potential security risks and has proven adverse effects and its prolonged consumption may causes serious health problems. The present study was carried out to quantify the heavy metals, content in some of the herbal raw materials traded in Indian market. A total 183 samples belongings to 74 different herbal raw materials and 69 species were sampled and analyzed for the presence of Arsenic (As), Cadmium (Cd), Mercury (Hg), and Lead (Pb). As per the permissible limit of Ayurvedic Pharmacopoeia of India (API), 5.46% samples were failed due to Cd accumulation followed by Hg (3.82%), Pb (1.09%), and As (0.55%). Higher accumulation of Cd was main reason behind higher percent of failed samples as per different safety standards such as 13.11% for World Health Organistion (WHO), 5.46% for United States Food and Drug Administration (USFDA) and 72.13% for Health Science Authority Singapore (HSA). Hg contributed higher percent of failed sample (18.03%) as per the safety standards of Pharmacopoeia of People's Republic of China (CP). The results showed that due to higher accumulation of Cd, Pb, As, and Hg, 9.58 - 12.33%, 0.00 to 10.96%, 1.37 to 2.74%, and 8.22 to 30.14% samples were failed respectively in safety standards of different pharmacopoeias. Bacopa monnieri (L.) Wettst., Caesalpinia bonduc (L.) Roxb., Cedrus deodara (Roxb. ex D. Don) G. Don, Cinnamomum zeylanicum Blume, Croton tiglium L., Curcuma longa L., Mucuna pruriens (L.) DC., Nardostachys jatamansi (D. Don) DC., Piper longum L., Pistacia chinensis Bunge, Senna alexandrina Mill., Tamarindus indica L., Teramnus labialis (L.f.) Spreng. and Valeriana wallichi DC. were among the species which failed in minimum of two or more than two pharmacopoeias due to higher concentration of one or more heavy metals. The quality of the herbal raw materials can be enhanced and the wastage of herbal raw material due to accumulation of heavy metals can be reduced by implementing WHO guidelines on Good Agricultural Practices, Good Field Collection Practice and Good Post-Harvest Processing Practices.

Assessment of natural radionuclides and heavy metals contamination to the environment: Case study of Malaysian unregulated tin-tailing processing industry

The tin tailing processing industry in Malaysia has operated with minimal regard and awareness for material management and working environment safety, impacting the environment and workers in aspects of radiation and heavy metal exposure. RIA was conducted where environmental samples were analyzed, revealing concentrations of 226Ra, 232Th and 40K between the range of 0.1–10.0, 0.0–25.7, and 0.1–5.8 Bq/g respectively, resulting in the AED exceeding UNCEAR recommended value and regulation limit enforced by AELB (1 mSv/y). Raeq calculated indicates that samples collected pose a significant threat to human health from gamma-ray exposure. Assessment of heavy metal content via pollution indices of soil and sediment showed significant contamination and enrichment from processing activities conducted. As and Fe were two of the highest metals exposed both via soil ingestion with an average of 4.6 × 10−3 mg/kg-day and 1.4 × 10−4 mg/kg-day, and dermal contact with an average of 5.6 × 10−4 mg/kg-day and 6.0 × 10−4. mg/kg-day respectively. Exposure via accidental ingestion of soil and sediment could potentially cause adverse non-carcinogenic and carcinogenic health effect towards workers in the industry. Correlation analysis indicates the presence of a relationship between the concentration of NORM and trace elements.

Heavy Metal Content Analysis and Toxicity Assessment of Oil-Based Drilling Mud using Zebrafish Embryos

Aim: Used oil-based drilling muds (OBDMs) are toxic to marine organisms due to the fluid’s complex chemical nature. The illegal dumping of used OBDMs is still rampant in many parts of the world despite of the stringent laws and regulations pertaining to its disposal. To date, study of the assessment of heavy metal content in used OBDMs from the Malaysian oil and gas industry has been limited. Furthermore, the study of the toxic effect of OBDMs using a zebrafish embryo model has never been reported before. Therefore, in this research, the used oil-based drilling muds (OBDMs) were analyzed for their heavy metal content and toxicity against Zebrafish embryos. Methods: Used OBDMs were collected from an Anchor Handling Tug Supply (AHTS) vessel mud tank from Kemaman, Terengganu. The heavy metal content in the mud was analyzed using ICP-AES. Zebrafish embryos were exposed to OBDMs of varying concentrations (i.e., 0.25 mg/ml, 0.125 mg/ml, 0.06 mg/ml, 0.03 mg/ml, 0.015 mg/ml, 0.0076 mg/ml, 0.0034 mg/ml and 0.0019 mg/ml). The toxicity and teratogenicity of the mud on zebrafish embryos were assessed every 24 hours, for 96 hours, using endpoints like embryo mortality, heart rate and hatching rate. Results: The heavy metal content of used OBDMs had the highest concentration of barium (Ba) 2360 ppm, followed by lead (Pb) 120 ppm, zinc (Zn) 104 ppm, arsenic (As) 9 ppm, and chromium (Cr) 16 ppm, with cadmium (Cd) concentration of less than 1 ppm being the lowest. The Ba (2360 mg/L) concentration in the OBDM sample exceeded the concentration of Ba in normal marine sediment reported to be around 2000 mg/L. The 96 h LC50 of the OBDM in zebrafish embryos was reported to be 0.005 mg/mL (5 ppm). Zebrafish embryos that were exposed to high concentrations of OBDMs exhibited a lower hatching rate and reduced heart rate than the control group. Conclusion: The findings of this study are indicative of the highly toxic nature of used OBDMs and its dosage-dependent teratogenicity effects on zebrafish embryo. Knowledge of the potential environmental impacts of OBDMs released into the marine environment can be the basis for prudent decision-making that will help minimize environmental damage.

Assessment of heavy metal content in tree barks: Picea abies, Pinus sylvestris, and Pinus nigra (RETRACTED)

Extracts obtained from the bark of woody plants are used for their high content in polyphenolic compounds with various biological activities. Thus, it is important to evaluate the heavy metals in various tree barks, as these pollutants may end up in the final product, affecting its properties and having potential health implications. This study assessed the heavy metal content in the barks of spruce (Picea abies) and pine (Pinus sylvestris and Pinus nigra) collected from different areas in Romania. After collecting the vegetal material from different sites, the bark samples were appropriately processed and analyzed via inductively coupled plasma optical emission spectroscopy (ICP-OES). The results showed that 6 out of 8 tested samples exceeded the normal values of selenium (Se). Arsenic (As) and cadmium (Cd) were not detected in any sample, while other metals (chromium (Cr); lead (Pb); nickel (Ni)) were detected in variable amounts. Moreover, relatively high levels of heavy metals were recorded in a spruce bark sample collected from the seemingly most unpolluted site. Although further studies are needed to determine the effects of these heavy metals on extraction yields and their transfer into the final extracts, their presence might indicate a potential problem.

Distribution and assessment of heavy metal contents in surface sediments of the western Sunda Shelf

The heavy metal contents (Cr, Cu, Zn, Cd, Pb, Hg, and As) of 88 surface sediment samples from the western Sunda Shelf were analyzed to determine their spatial distribution patterns and contamination status. The results demonstrated that high enrichment regions of heavy metals were focused in the Kelantan, Pahang, and Ambat river estuaries, and deep water regions of the study area. These high enrichment regions were mainly controlled by riverine inputs and their hydrodynamic conditions. The enrichment factor (EF), geoaccumulation index (Igeo), and potential ecological risk index (PERI) were used to assess heavy metal accumulation. The results indicated that the study area was not significantly contaminated overall at the time of the study; however, Cd, As, and Hg were at levels corresponding to moderate contamination at many stations located in the Pahang River estuary, Kelantan River estuary, and north-eastern region of the study area, primarily because of anthropogenic activities.

Potential health risk assessment of heavy metal content in Perlis soil

A determination of soil heavy metal (Cu, Mn and Ni) concentrations in Perlis state, Malaysia was performed to define the level of soil pollution. Six soil samples were collected at depth of 0 – 15 cm in industrial, residential and school areas around Perlis. The highest concentration of Mn (57.80 mg/kg) and Ni (2.83 mg/kg) were detected at limestone quarry in Bukit Air, Cu (17.43 mg/kg) in Kampung Wang Ulu. The concentration of Cu, Mn and Ni were well below their soil geochemical background values. The single pollution indices assessment revealed that the soil contamination due to heavy metals in Perlis is insignificant. On the basis of the heavy metal content, the potential health risk assessment for children and adults was calculated for a lifetime of exposure through ingestion, inhalation and dermal contact based on the USEPA model. The exposure assessment found that the exposure pathways of heavy metals to both children and adults are through ingestion. Both Hazard Quotient (HQ) and Hazard Index (HI) values are lower than 1, indicating no health risk. From the result, the HI values indicated that the soil heavy metal contamination could pose more impacts on children as compared to adults.

Assessment of Heavy Metal Contents in Three Different Land used Soils in Ohaji/Egbema Imo State, Nigeria

This assessment of some heavy metal contents in different land used soils in Ohaji/Egbema, Imo State was conducted between June, 2019 and May, 2020. Three land used soils namely; the grass land, continuously cropped and forest land were studied. Soil profile representations were established in each of the physiographic units and soil samples collected from the pedogenetic horizons for the analysis of some heavy metals like Lead (Pb), Copper (Cu), Manganese (Mn), Zinc (Zn), and Iron (Fe). The heavy metals observed in this study were Cu, Mn, Zn and Fe while Pb was not detected in this study. The results of this study showed that the grass land, continuously cropped and forest land had no Pb detected. The heavy metal contents(Cu, Mn, Zn and Fe) detected decreases with depth from 0.15cm depth to 60-90 cm depth in grass land and continuously cropped and forested land respectively. The occurrence of Fe was high in forested land which ranges from 7.8-6.3Mg/Kg with mean value of 7.0Mg/Kg than continuous cropped land and grass land with lower values. The forest land had high sodium content with mean value of 0.74 and high electrical conductivity with a mean 4.91 dsm-1. The results showed low to moderate heavy metal load in forest land and high to moderate load of heavy metals in the grass land and continuously cropped land.