Target Hazard Quotient For Metals Research Articles

Monitoring and modeling of heavy metal contents in vegetables collected from markets in Imo State, Nigeria.

Vegetable consumption is one major exposure route of heavy metals to humans, but few data exist for Imo State, Nigeria. We assessed the contamination levels and associated health risk of cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) in vegetables (Telfairia occidentalis, Pterocarpus mildbraedii, Gongronenina latifolium and Vernonia amygdalina) that are consumed frequently from markets (n=16) in three zones of Imo State, Nigeria. After wet-digestion of samples, the supernatant were analyzed using atomic absorption spectrophotometry. The mean concentrations in the four vegetables ranged from 0.006±0.003 mg/kg to 0.011±0.007 mg/kg for Cd, 0.064±0.012 mg/kg to 1.225±0.226 mg/kg for Co, 10.711±1.968 mg/kg to 25.088±13.975 mg/kg for Cu, 0.062±0.013 mg/kg to 0.307±0.210 mg/kg for Ni, 0.006±0.005 mg/kg to 0.012±0.002 mg/kg for Pb and 63.55±4.055 mg/kg to 104.126±24.080 mg/kg for Zn. Except for Zn, all heavy metals in the various vegetables were below the joint standard of Food and Agriculture Organization and World Health Organization. Although, overall load of heavy metal was very low, Zn had the highest contamination factor in vegetables. Heavy metals concentrations in vegetables generally showed low to high variations and statistically different (p<0.05). Average daily intake was below the provisional tolerance limit except for Zn. The target hazard quotient of metals in vegetables for both children and adults were below 1, indicating no potential risk to the public. Overall, heavy metals hazard index were below 1, indicating acceptable level of non-carcinogenic adverse health effect. However, potential multi-element contamination from ingestion is possible as revealed by the correlation profiling of heavy metals.

Toxic metal ion in seafood: Meta-analysis of human carcinogenic and non-carcinogenic threat assessment, a geomedical study from Dhamra and Puri, Odisha

ABSTRACTThe investigation revealed the adverse health threats on human beings from toxic metals via ingestion of seafood from two contaminated sites in Odisha. Bioaccumulation through food chain was presented as tissue metal concentrations. The non-carcinogenic and carcinogenic health hazards were estimated by Target Hazard Quotient (THQ) and Target Cancer Risk (TCR) following USEPA referred safe metal intake limit. THQ of Metals like Mn, Ni, Cd, Pb in both sites showed >1, indicating a severe non carcinogenic health threat to humans from the investigated metals. THQ of Cu, Zn, Fe, Cr and Hg showed < 1, implying the least possible deleterious health effects. Cr was the most significant carcinogenic pollutant in both sites. The marine fish consumption of Dhamra site might cause extra 7 cases of cancer per 10000 populations due to higher Cr level (cancer risk 6.7 × 10−3). Carcinogenic risk of Ni and Pb were below the tolerable range of 10E-4. The presence of Cd in sea foods elevated cancer risks in both sites. The metal pollution index (MPI) indicated, the highest toxic metal bio accumulation was contributed by Arius arius species. Ilisha megaloptera and Lates calcarifer from Dhamra and Puri showed highest hazard index (HI) suggesting unaccountable non-carcinogenic health threat.

Apportionment of heavy metals in soil and vegetables and associated health risks assessment

This study assessed the concentrations of seven common heavy metals such as chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) in agricultural soils and mostly consumed vegetable species and their possible human health risk in Bogra District, northern Bangladesh. The range of mean concentrations were 20.47–59.09, 20.09–69.13, 20.50–74.99, 47.46–128.06, 5.04–23.14, 1.67–6.90 and 31.81–67.65 mg/kg for Cr, Ni, Cu, Zn, As, Cd and Pb, respectively. Accumulation factors (AFs) of heavy metals from soil to the vegetables exhibited highest values for Cu (0.56 ± 0.16), followed by Zn (0.39 ± 0.16). Multivariate principal component analysis showed significant anthropogenic contributions of Cr, Cu, As and Cd in soil and Cr, Ni, Cu and Pb in vegetables. Target hazard quotients (THQs) for individual metals (except As) were below 1, suggesting that people would not experience significant health hazards if they ingest a single metal from one species of vegetable. However, total metal THQ (1.530–5.575) signifies the potential non-carcinogenic health hazard to the highly-exposed consumers in Bangladesh. The target carcinogenic risk (TR) of As (0.275–1.108) and Pb (0.001–0.026) through consumption of vegetables were higher than the USEPA threshold level. From the health point of view, this study showed that the inhabitants who consume contaminated vegetables are exposed chronically to metal pollution with carcinogenic and non-carcinogenic risks.

Determination of Heavy Metals in Fish and Vegetables in Bangladesh and Health Implications

ABSTRACTConcentrations of six heavy metals (chromium, nickel, copper, arsenic, cadmium, and lead) in fish and vegetables were estimated to evaluate contamination levels and health risks for Bangladeshi adults. The analyzed metals varied between different species of fish and vegetables. Metals like Ni, Cd, and Pb in fish species were higher than the respective maximum allowable concentrations (MAC), whereas As, Cd, and Pb in some species of vegetables exceeded the MAC. Health risks associated with these metal intakes were evaluated in terms of dietary intake and target hazard quotients (THQs). The THQ values for individual metals were below 1 (except As for some species), suggesting that people would not experience significant health hazards if they ingest a single metal from one species of fish and/or vegetable. However, total metal THQ (TTHQ) signifies the potential non-carcinogenic health hazard to the highly exposed consumers in Bangladesh. Also, the estimation showed that the carcinogenic risk (TR) of arsenic and lead were within the acceptable range for fish but exceeded the accepted risk level for vegetables. From the health point of view, this study showed that the inhabitants who consume contaminated fish and vegetables are exposed chronically to metal pollution with carcinogenic and non-carcinogenic consequences.

Trace metals in soil and vegetables and associated health risk assessment.

The objective of this study was to assess the contamination level of trace metals in soil and vegetables and health risk to the urban population in Bangladesh. The range of Cr, Ni, Cu, As, Cd, and Pb in agricultural soils was 158-1160, 104-443, 157-519, 41-93, 3.9-13, and 84-574mg/kg, respectively. Sequential extraction tests revealed that the studied metals were predominantly associated with the residual fraction, followed by the organically bound phase. Concerning Cu, Ni, Cd, and Pb in vegetables, more than 50% samples exceeded the FAO/WHO recommended permissible limits. Considering the transfer of metals from soil to vegetables, Cu and Cd exhibited higher transfer factor (TF) values than the other metals. Target hazard quotient (THQ) for individual metal was below 1, suggesting that people would not experience significant health hazards if they ingest a single metal from vegetables. However, total metal THQ signifies the potential non-carcinogenic health hazard to the highly exposed consumers. The carcinogenic risk (TR) of As (1.9 × 10(-4)) and Pb (2.3 × 10(-5)) through consumption of vegetables were higher than the USEPA threshold level (10(-6)), indicating potential cancer risks.

Estimation of Potential Health Risks for Some Metallic Elements by Consumption of Fish

The aim of this study was to assess the bioaccumulation of heavy metals in muscle of fish in order to determine the value daily intake of heavy metals by consumption of fish and human health risk assessment. Edible muscle tissue of Rutilus rutilus (Linnaeus, 1758) from the Miankaleh international wetland was analyzed for content of Cd, Ni, Pb, Cr, Fe, As, Cu, and Zn; the levels were 0.26, 0.21, 0.67, 0.08, 28, 0.31, 1.6, and 7.2 mg kg\(^{-1}\), respectively. Provisional tolerable weekly intake (PTWI) and provisional tolerable daily intake were calculated, as well as the target hazard quotient (THQ) and target cancer risk (TR). The maximum allowable fish consumption rate (CRlim) (kg/d) was calculated to estimate health risks associated with fish consumption. Since the concentrations calculated weekly intake due to fish consumption were far below PTWI for all metals; THQ for metals were below 1 and TR for As and Ni were lower than 10\(^{-6}\), there is no human health risk of consumption of R. rutilus for consumers.

Target hazard quotient evaluation of cadmium and lead in fish from Caspian Sea

Heavy metals are being increasingly released into the natural waters from geological and anthropogenic sources. The distributions of several heavy metals such as cadmium (Cd) and lead (Pb) were investigated in muscle and liver of three different fish species seasonally collected from Caspian Sea (autumn 2011-summer 2012). The concentrations of all metals were lower in flesh than those recorded in liver due to their physiological roles. The target hazard quotient (THQ) index for fish was calculated. Estimation of THQ calculations for the contaminated fish consumption was calculated to evaluate the effect of pollution on health. Total metal THQ values of Pb and Cd for adults were 0.05 and 0.04 in Anzali and Noshahr, respectively, and for children were 0.08 and 0.05 in Anzali and Noshahr, respectively.

Health Risks Evaluation of Heavy Metals in Seafood

ABSTRACT Fish is an excellent, low-fat source of protein and provides many benefits, such as contributing to low blood cholesterol. Heavy metals are increasingly being released into natural waters from geological and anthropogenic sources. Due to the rapid development of agriculture and industry, and a historical lack of enforcement of regulations, the study areas have become contaminated by metals, especially cadmium (Cd) and lead (Pb) which has been emitted into the environment through atmospheric deposition, solid-waste emissions, sludge applications, and irrigations with wastewater. The health risks posed to the local inhabitants by exposure to Pb and Cd in two coastal regions of Iran through the consumption of contaminated fish were investigated, based on estimated target hazard quotients (THQs). The results showed that THQ values are less than 1 for both adults and children by either group consuming fish alone. The distribution of several heavy metals (Cd and Pb) was investigated in muscle and liver in six different fish species seasonally collected in the Persian Gulf (autumn 2008 - summer 2009). The concentrations of all metals were lower in flesh than those recorded in liver due to their physiological roles. The THQ index for fish was calculated. Estimation of target hazard quotients calculations for the contaminated fish consumption was calculated to evaluate the effect of pollution on human health. Total metal THQs values (Pb and Cd) for adults were 0.05 and 0.04 in Bushehr and Bandar-Genaveh, respectively, and for children was 0.08 and 0.05 in Bushehr and Bandar-Genaveh, respectively. The dietary intake of Pb estimated for the inhabitants in this area is far below the limit considered tolerable. The Cd intake through the consumption of fish is also less than the limit of daily dietary intake considered tolerable by FAO/WHO.

Health risk of Hg, Pb, Cd, Zn, and Cu to the inhabitants around Huludao Zinc Plant in China via consumption of vegetables

Huludao Zinc Plant in Huludao City, China is the largest zinc smelting plant in Asia. Heavy metals have contaminated its neighboring environment seriously. We collected 20 vegetables and the corresponding soil samples from eight sampling plots near Huludao Zinc Plant to investigate health risk of Hg, Pb, Cd, Zn, and Cu to the inhabitants around Huludao Zinc Plant in China via consumption of vegetables. Transfer factor (TF) values of Hg, Pb, Cd, Zn, and Cu from soil to vegetable and the target hazard quotients (THQs) to the possible health risks to local population through the food chain transfer were calculated accordingly. TF values of heavy metals from soil to vegetable decrease in the order of Cd>Zn>Cu>Pb>Hg. These TF values of leaves are higher than other tissues. Daily intakes of Hg, Pb, Cd, Zn, and Cu through the consumption of vegetables are 1.322, 574.3, 301.4, 5263, and 292.5 microg, respectively, for adults, and 1.029, 446.8, 234.5, 4095, and 227.6 microg, respectively, for children around Huludao Zinc Plant. This would lead to potential health risk, especially for children, since Cd or Pb individual THQ is high than 1. The total metal THQs (TTHQs) due to consumption of vegetables for adult and child are 5.79-9.90, 7.6-13.0, respectively. Comparing TTHQs in the sampling plots of different distances to Huludao Zinc Plant, it indicate that the health risks to inhabitants close to Huludao Zinc Plant (<500 m) is the highest, and at >1000 m distance is relatively higher than in 500-1000 m distance. However, the inhabitants who lived in 500-1000 m distance to Huludao Zinc Plant is also experiencing the adverse health risk due to TTHQ being higher than 1.

Health risks of heavy metals to the general public in Tianjin, China via consumption of vegetables and fish

Consumption of vegetables and fish contaminated with the heavy metals Cu, Zn, Pb, Cd, Hg, and Cr is the most likely route for human exposure in Tianjin, China. Health risks associated with these heavy metals were assessed based on the target hazard quotients (THQs), which can be derived from concentrations of heavy metals in vegetables and fish consumed in four districts (Dong Li, Xi Qing, Jin Nan, and Bei Chen) and the urban area of Tianjin, China. Individual metal THQ (<1) values indicate the relative absence of health risks associated with intake of a single heavy metal through consumption of either contaminated vegetables or fish only. However, consumption of both vegetables and fish would lead to potential health risks especially for children, since individual THQs for vegetables and fish would sum up to almost 1. If individual THQs resulting from crops consumption are considered, the health risks would be greater for children since the THQ values will always be >1. Risk contribution from Cr is minimal compared to the other elements. Hg is the major risk contributor for children in Bei Chen since the THQ contribution amounts to about 45% of the total THQ values due to vegetables and fish consumption. The health risk to adults in Ding Li is ascribed mainly to the intake of Cd by vegetables and fish consumption, which contributes a substantial fraction to the total THQ (about 51%).