Non-carcinogenic health risk assessment of nitrate and fluoride contamination in the groundwater of Noyyal basin,India

The study aims to assess the nitrate and fluoride concentration in groundwater and its adverse effects on human health.In 2019,42 groundwater samples were collected from various bore wells within the western Noyyal basin,India.Sodium and chloride are the dominant cation and anion,respectively.The nitrate concentration in groundwater samples varies from 2 to 89 mg/L,of which 33.33%are above the permissible limit of 45 mg/L for drinking water.The fluoride concentration ranges from 0.2 to 2.4 mg/L,with 28.57%of the samples exceeding the safe value of 1.5 mg/L for drinking water.Correlation plots demonstrate that the potential of hydrogen(pH),electrical conductivity(EC),total dissolved solids(TDS),Na^(+)and HCO^(-)_(3)are positively correlated with F^(-),whereas Ca^(2+)is negatively correlated.Mixed Ca-Mg-Cl is the most common water type in the investigated region.The Gibbs diagram demonstrates that the interaction between rock and water impacts the groundwater chemistry.Using the method of the United States Environmental Production Agency(USEPA),this study assesses the non-carcinogenic health risk posed by nitrate and fluoride in different age groups(infants,children,and adults).The values of total hazard index(THI)vary from 0.59 to 10.07(mean=4.76)for infants,0.36 to 6.23(mean=2.95)for children,and 0.19 to 3.32(mean=1.57)for adults.Furthermore,97.62%,92.86%,and 73.81%of the samples surpass the recommended limit(THI=1)for infants,children,and adults,respectively.Thus,the health risk assessment(HRA)indicates that infants and children are more susceptible to noncarcinogenic health hazards than adults.The THI spatial variation map shows that central and southern regions of the study area have been identified as high health risk areas(THI>3.0)for all age groups.

Dietary Intake, Carcinogenic and Non-Carcinogenic Risk Potentials of Lead, Cadmium, Mercury and Arsenic Exposure via Consumption of Dried Crayfish in Calabar, Nigeria

Intense pressure from both onshore and offshore oil exploration and exploitation activities, together with the accompanying urbanization and industrialization has resulted in massive contamination of land and water resources in Niger Delta, Nigeria. Whereas crayfish is very sensitive to contaminant in the aquatic environment and constitute an important part of human diet, its quality and safety from environmental pollutant is of serious health concern. Evaluation of dietary intake, potential carcinogenic and non-carcinogenic risk of lead, cadmium, mercury and arsenic exposure via consumption of dried crayfish purchased from major markets in Calabar, Nigeria was carried out between June and August 2021. Thirty-six composite samples of dried crayfish purchased from 180 vendors were used for the study. Heavy metals concentrations were determined using Atomic Absorption Spectrophotometer (Model AA-6800, Japan) after wet digestion. Metals concentrations (Mg/kg) were of the ranges 0.02 - 0.24, 0.14 - 0.86, 0.32 - 0.72, 0.04 - 0.19 for Pb, Cd, Hg and As respectively. The mean content of cadmium and mercury exceeded FAO/ WHO and Commission of European Communities maximum levels for crustaceans. Average Estimated Daily Intake for each of the metals was found to be above the recommended daily intake level except for arsenic. The average estimated daily intake values for Cd and Hg were also above the tolerable upper intake level. Average Target Hazard Quotient of all the metals and Hazard Index of all the markets were below 1.00. The Incremental Lifetime Cancer Risk of the metals was greater than the standard tolerable regulatory risk (10-4) for carcinogens. Consumption of crayfish purchased from major markets in Calabar could pose a range of carcinogenic and non-carcinogenic human health risks.

Health Risk Assessment on Drinking Water in Shenzhen, China

Objectives: To conduct health risk assessment on drinking water in 2012 in Shenzhen of China. Methods: The water quality monitoring data on product water and pipe water in 2012 were collected and analyzed, and the risk evaluation models recommended by the U.S. environmental protection agency (US EPA) were employed, to perform adults and children’s health risk assessments on the three kinds of genetic toxic substances such as hexavalent chromium, cadmium and arsenic and the 12 non-carcinogenic materials such as iron, manganese, lead, fluoride, volatile phenol, cyanide, mercury, ammonia nitrogen, nitrate, copper, zinc and selenium. Results: The results about water quality from the 150 factory samples and 207 peripheral water samples showed that the measured indicators in other water samples were accord with the National Health Standards (GB5749-2006) released by Ministry of Health of the People’s Republic of China, except manganese level in one factory sample and the same index in one peripheral sample, and nitrate concentration in another water sample were out of limit, respectively. Namely, the total of 3 samples was disqualification. The adults and children’s health risks (HI) on the 12 non-carcinogenic materials were 178.04 × 10-8 and 249.96 × 10-8 in the factor water samples, and 363.02 × 10-8 and 509.66 × 10-8 in the pipe samples, respectively. Lead in factory water and fluoride in peripheral water samples were the most serious harm in the all measured non-carcinogenic indicators. The adults and children’s cancer risks (R) on the 3 genetic toxic substances were 25.60 × 10-6 and 28.51 × 10-6 in the factor water samples, and 23.47 × 10-6 and 26.08 × 10-6 in the pipe samples, respectively. Hexavalent chromium was the most damage among the three detected carcinogenic indicators. Therefore, the total adults and children’s health hazard risks including the 3 carcinogenic and 12 non-carcinogenic substances were 27.38 × 10-6 and 31.00 × 10-6 in the factor water samples, and 27.10 × 10-6 and 31.17 × 10-6 in the pipe samples, respectively. Genetic toxic matters in drinking water are the main hazard and more children’s health risk than adults’ risk. Conclusions: The health risk (R) on the 15 kinds of chemicals in Shenzhen’s municipal water supply was in the range of maximum acceptable risk levels (5.0 × 10-5/a) recommended by the International Commission of Radiation Protection (ICRP). The results in this study indicate that the carcinogenic substances are greater risk comparing with the non-carcinogenic substances, and hexavalent chromium is the biggest carcinogenic risk, and lead and fluoride are the most non-carcinogenic risk, and the rather risk of children than adults.

Health Risk Assessment from Exposure to Heavy Metals in Surface and Groundwater Resources within Barkin Ladi, North Central Nigeria

Concentration of heavy metals from surface and groundwater within the communities were determined in order to assess the health risks linked to the use/consumption of same. Furthermore, the cancer risk for adults in surface water revealed medium to high cancer risk for arsenic (As);low to medium cancer risk for cadmium (Cd) and very high cancer risk for chromium (Cr). In addition, the cancer risk for adults in groundwater is as follows: high cancer risk for As;low cancer risk for Cd and very high cancer risk for Cr while that for children is very high cancer risk for As and Cr and then low cancer risk for Cd. The findings from this research confirm that the inhabitants within the study area are at direct health risk (carcinogenic and non-carcinogenic) due to the alternate use of surface and groundwater without any form of treatment.

Heavy Metals in Native Potato and Health Risk Assessment in Highland Andean Zones of Junín, Peru

Heavy metals are transferred from the abiotic environment to living organisms, accumulate in food, contaminate the food chain, and are an important route of human exposure involving a potential health risk. In this study, the concentrations of heavy metals (Cd, Fe, Pb, Zn and As) in agricultural soils and tubers of Solanum tuberosum spp. andigena (native potato) were evaluated. Also, an assessment of the health risk associated with the daily intake by the local population was performed in the four districts of the department of Junín, between altitudes of 3800 m to 4200 m. The heavy metals concentrations in soils with native potato cultivation followed the following decreasing order of Fe > Zn > Pb > As > Cd, with values below national standards. The heavy metals content in native potatoes was below the limits recommended by international standards with the exception of Pb. The bioconcentration factor (BCF) for the two native potato varieties in decreasing order was Zn > Cd > Pb > As > Fe, all less than 0.5. The estimated daily intake of metals (EDIM) in adults and children through the consumption of native potatoes was higher for Fe and Zn. The threshold carcinogenic risk values (TCR) for As exceeded the safety limits 1 × 10-4. It is concluded that the residents in the four high Andean localities would be exposed to carcinogenic adverse health effects associated with the intake of native potatoes. It is important to monitor the concentration of As and other heavy metals in the Andean soils and crops in order to implement a soil and crop management program to ensure food quality.

Health Risk Assessment of Heavy Metals in the Water of the LoutétéRiver, Mfouati District, Southeast Congo

The overall objective of this study was to assess the health risk of water in the Loutété River contaminated with heavy metals. Six surface water samples were collected during the dry season (October 2014). The physico-chemical parameters (pH, electrical conductivity, total dissolved salts) were measured using a HANNA brand device. The values of these physico-chemical parameters are below the WHO standards. The concentrations of heavy metals Cr, Cu, Fe, Pb, Zn and Mn were determined by ICP-OES. These obtained in (μg/L) are in the range: Cr (0.08 - 5.8);Cu (0.6 - 14.5);Fe (0.2 - 386.05);Pb (1.02 - 370.09);Zn (8.02 - 248.7) and Mn (37.1 - 328.08). These concentrations are below the WHO drinking water guideline value in all samples for Cr, Cu, Mn and Zn, 50, 2000, 400 and 3000 μg/L respectively. Concentrations of As, Fe and Pb exceeded the WHO guideline value for drinking water at the following stations: S1 for arsenic, S4 for iron, and for Pb at all stations except S5. The health risk assessment for adults due to ingestion exposure gave HQing. values < 1 for the following heavy metals: Cr, Cu, Fe, Mn, Zn, except for Arsenic and Lead. The hazard quotient calculated by dermal contact (HQ derm) in the waters of the river Loutété, showed that HQ derm < 1 for all heavy metals in all stations. For children, the dermal contact hazard quotient HQ derm < 1 for all heavy metals As, Fe, Cu, Zn, Mn, Cr and Pb. With the exception of station S4, we observed that HQ > 1 for lead. In the case of ingestion, HQing. < 1 for the heavy metals Cr, Cu, Zn, Mn, with the exception of the following metals Arsenic, Lead and Iron.