Spatial distribution,exposure, and potential health risk assessment from nitrate in drinking water from semi-arid region of South India

Abstract

Elevated nitrate concentration in groundwater is a worldwide problem. Continuous exposure to high levels of nitrate in groundwater may cause adverse health effects among residents who use groundwater for consumption. Therefore, this study was conducted to identify the nitrate distribution and its potential health risk assessment from semi-arid region of Peddavagu in Central Telangana (PCT), South India. Groundwater samples were collected from thirty five locations and analyzed for nitrate and other water quality parameters. Nitrate (NO₃^-) in groundwater was observed to vary from 17 to 120?mg/L, with a mean of 58.74?mg/L. About 57% of samples exceeded the maximum acceptable limit of Indian drinking water standard. About, 40% of groundwater samples drinking water quality index (DWQI) is good, while 60% of groundwater falls in poor quality for drinking purposes. Health risk maps were created based on hazard quotient to quantify the potential health risk of the residents using US Environmental Protection Agency (US EPA) health risk assessment model. Health risk assessment revealed that mean total hazard index (HI_total) for men, women, and children were found as 1.42E?+?00, 1.67E?+?00, and 1.95E?+?00, respectively. Results exhibited that children are at high health risk than men and women in the PCT. Further, the human exposure to the NO₃^- contaminated water was above the critical limit of non-carcinogenic risk.     

Non-carcinogenic risk assessment to human health due to intake of fluoride in the groundwater in rural areas of Gonabad and Bajestan,Iran: A case study

In this study, a field research regarding groundwater contamination with fluoride and its related health risks to human health was carried out in 39 rural areas of Gonabad and Bajestan, Iran, in 2017. The results indicated that fluoride levels in two rural areas exceeded the WHO guideline. A total of 55% and 4.7% of the studied rural areas in Gonabad and Bajestan, respectively, had fluoride levels below the minimum recommended value of WHO for fluoride (0.5 mg/L). In this article, chronic non-cancer risks to three different groups of people, adults, children, and infants, for exposure to the fluoride were assessed. Health risk index values for fluoride contamination for 44% and 90% of children and infants in rural areas of Gonabad and Bajestan, respectively, were more than unity (>1), which clearly reveals that these age groups at the studied areas are at the chronic health risk due to the intake of fluoride-containing water. The order of fluoride contribution to non-carcinogenic health risk among the studied age groups was infants > children > adults. Therefore, from a public health viewpoint, it would be prudent and important that risk reduction measures be implemented to diminish the total body burden of fluoride in residents.     

Assessing groundwater quality and health risks of fluoride pollution in the Shasler Vagu (SV) watershed of Nalgonda,India

Abstract

The principal objectives of this study were to evaluate groundwater quality and human health risks of fluoride contamination in Shasler Vagu (SV) watershed of Nalgonda district, India. For this purpose, 107 groundwater samples were collected and analyzed various physcio-chemical parameters including fluoride, and Gibbs diagrams, Hill–Piper trilinear diagram, and groundwater quality index (GWQI) were applied to understand the groundwater chemistry and its suitability for drinking purpose. In addition to this, non-carcinogenic health risks of high fluoride intake were also evaluated using the US Environmental Protection Agency model for adults and children in the study region. Groundwater chemistry is mainly controlled by HCO₃^?-Ca²⁺-Mg²⁺ and Na⁺-HCO₃^? type, and rock weathering. Assessment of GWQI indicates that 76% of groundwater sources in the study region have poor quality for drinking uses. Results reveal that fluoride concentration ranged from 1.4 to 5.9?mg/L in the groundwater samples, which was significantly higher than the recommended limit of 1.5?mg/L for drinking uses. Results of hazard quotient (HQ) estimates are in the ranges of 0.90–3.78 and 1.21–5.11 in adults and children populations of the study region, respectively. About 98% of adults and 100% of children population of SV watershed are at very high risks of chronic toxicity by excess fluoride intake.     

Health risk assessment of nitrates in the groundwater of Beni Amir irrigated perimeter,Tadla plain,Morocco

Abstract

Shallow groundwater contaminated with nitrates may result in human health risks. Groundwater quality in the Beni Amir irrigation perimeter in Tadla plain, Morocco, is influenced by agriculture and farming-related activities. This study was carried out to assess the nitrate contamination of groundwater for drinking purposes by comparing it to Moroccan and WHO guidelines, and by estimating the potential human health effect of nitrates using the model recommended by the USEPA. The results showed that the nitrate content of groundwater fall between 0 and 82.08?mg L^?1 (mean 24.73?mg L^?1), with 38.10% of groundwater samples exceed the Moroccan and WHO limits for drinking. Groundwater nitrates mainly originated from intensive agricultural practices. The health effects of oral exposure to nitrate are higher than those of dermal exposure. For non-carcinogenic risks, 57.14% of samples showed hazard index (HI) values >1, indicating potential risks. The non-carcinogenic risk for infant and female are higher than that for females and males. The results of this study will offer a health risk reference for local residents and can help to propose suitable management ensuring safe drinking water.     

Health risk assessment of fluoride in water distribution network of Mashhad,Iran

High and low levels of fluoride in drinking waters have been considered as a major public health issue in recent years. This cross-sectional study was conducted over five consecutive years (from 2012 to 2016) in the water distribution network of Mashhad city, Iran with the objectives of determining levels of fluoride and to perform health risk assessment among residents in the study area. Water samples were taken from 30 stations and were analyzed using UV-visible spectrophotometer. The mean annual concentrations of fluoride in all stations during five years of consecutive study were lower than the respective maximum permissible limits (1.5 mg/L) in water as regulated by the WHO. The human health risk assessment was performed by calculating the chronic daily intake and hazard quotient (HQ) of fluoride through human oral intake for adults (men and women) and children for each year during a five-year study. Health risk analysis in this study presented that the non-carcinogenic risk associated with fluoride exposure through drinking water in Mashhad was mostly acceptable because the mean HQ values of fluoride were lower than 1.     

Heavy metals contamination in shallow groundwater of a coal-mining district and a probabilistic assessment of its human health risk

To manage public health and make better use of groundwater resources, the concentration characteristics and a health risk assessment of eight heavy metals in shallow groundwater were studied. Besides this, this paper introduced triangular fuzzy numbers into the USEPA health risk assessment model to assess the health risk posed to local children and adults through different exposure pathways. The results showed that Mn levels exceeded the WHO’s guideline values of 100?µg/L with the proportion of 27.98% and Sr were over the health reference level (HRL) of 1500?µg/L with the proportion of 56.25%, while other heavy metals were below the corresponding standard. The results of the HRA showed that the non-carcinogenic risks from Sr and Mn in the district were relatively higher, while those from the remaining six heavy metals were relatively lower. All hazard index (HI) values did not exceed the safety level of 1 for either age group. The average carcinogenic risk from Cr was slightly higher than the acceptable level of 1?×?10^?6 for adults. Sensitivity analyses conducted using Monte Carlo simulation indicated that Sr and Cr concentrations were the most influential variables contributing to the non-carcinogenic and carcinogenic risk values, respectively, while body weight had a minor contribution.     

Health risk assessment of heavy metals in groundwater of coal mining area: A case study in Dingji coal mine,Huainan coalfield,China

Heavy metals enrichment in groundwater poses great ecological risks to human beings. In the present research work, a total of 59 groundwater samples from 12 sampling points in Dingji coal mine, Huainan coalfield, were collected and measured for Cu, Pb, Zn, Cd, Ni, Mn, Cr, and Fe by inductively coupled plasma mass spectrometry (ICP-MS). The human health risk caused by heavy metals through the pathway of drinking water was evaluated and analyzed using the US Environment Protection Agency (USEPA) evaluation model. It has been found that the carcinogenic risk values were between 1.05 × 10^?5 and 3.5 × 10^?4, all exceeding the maximum acceptable level recommended by the USEPA, and the carcinogenic risk of Cr accounted for 99.67% of the total carcinogenic risk. The non-carcinogenic health risk values were all lower than the negligible level given by the USEPA, and the contribution of non-carcinogenic health risk was in the order of Cr > Zn > Cu / Pb >Mn > Fe > Cd > Ni. Among them, Cr had the largest contribution, accounting for 36% of the total non-carcinogenic risk value. In this study, the carcinogenic risk constituted 99.99% of the total health risk, indicating that the total health risk essentially consisted of carcinogenic risk. The research results suggest that much more attention should be paid to the health risk caused by Cr in the groundwater.     

Hydrogeochemical evolution and risk assessment of human health in a riverbank filtration site,northeastern China

Intensive agriculture and industrial activities have resulted in contamination in rivers and groundwater quality, which threatens human health. In this study, we used comprehensive physiochemical indicators to assess the quality of groundwater used for drinking and irrigation in addition to the potential risks to local residents in a riverbank filtration site. Human health risks through drinking water intake and dermal contact were also estimated. Moreover, we analyzed the spatial distribution regularities of health risk values in a riverbank filtration site. The assessment results revealed that NH₄–N, NO₂–N, F^?, Mn, and As are main contaminants affecting groundwater quality and that 62% of the total samples is suitable for a variety of purposes. All groundwater in the study area is suitable for irrigation based on the sodium adsorption ratio (SAR), residual sodium carbonate (RSC), Na percentage (%Na), and U.S. Salinity Laboratory (USSL) and Wilcox diagrams. The health risk assessment suggests that residents in the study area are at high health risk, and women and children face higher risk than men in both non-carcinogenic and carcinogenic risks. The spatial distribution regularities of health risk values suggest that the human health risk value of each groundwater sample is different in the study area and has certain regularity. Therefore, effective measurements must be taken to address the groundwater contamination and to reduce the human health risks.     

Health risks associated with municipal waste combustion on the example of Laskowa commune (Southern Poland)

This study presents the results of an analysis of combustion waste, namely fly ashes produced from the burning of solid fuels mixed with municipal waste. Heavy metal concentrations in the fly ashes examined fell within the following ranges (mg/kg): Cd 0.39–0.79, Cr 13.48–58.51, Ni 17.01–49.37 and Pb 14.95–59.74. As this type of waste does not exceed the limit values of pollutants for organic and organic-mineral fertilisers, it is often discarded on agricultural land or dumped in illegal landfills. Fine particles of fly ashes travel considerable distances and pose a risk to human health as they stick to people's hands during field works. The mean hazard quotient (HQ) values for non-carcinogenic forms of the elements analysed were 1.06E+00 for children and 1.47E-01 for adults. A HQ>1 indicates the probability of adverse health effects. The study has shown that the dominant exposure pathway was ingestion, which accounted for approx. 91% of total health risk, while the respective percentages for other pathways were less than 9% for dermal contact and 0.05% for inhalation. The highest health risk in the ingestion exposure pathway was observed for Cr (HQ_ing = 4.50E-01 for children, HQ_ing = 5.23E-02 for adults) and Pb (HQ_ing = 4.31E-01 for children, HQ_ing = 5.01E-02 for adults). Health risk associated with the presence of Ni and Cd in the material analysed was markedly lower. For carcinogenic forms, the Risk index was established at 6.13E-08 for children and 2.13E-07 for adults. As the exposure limit (10E-5) was not exceeded, the conditions in the area studied should be considered satisfactory.     

Nitrate associated health risks from groundwater of Kadava River Basin Nashik,Maharashtra, India

Abstract

The present study was carried out to evaluate the nitrate contamination in groundwater and ascertain the associated health risks to rural populations in the agricultural area of the Kadava River basin. A total of (80) eighty representative samples from rural habitat located in agricultural fields were collected during pre- and postmonsoon seasons of 2011, which are mainly used for drinking and irrigation. The chemical results confirm that, 52.5 and 65% groundwater samples from pre- and postmonsoon season are unfit for drinking because of high nitrate contents exceeding the limit of nitrate (>45?mg L^?1) recommended by the BIS. The oral and dermal exposure pathways were calculated for different age group based on US EPA and ICMR standards. HQ₁ is much higher than the critical limit of 1 which increases the risk from 92.5 to 95% groundwater samples, while value of HQ₂ is far below to the critical value of 1; hence, all age groups free from risk. THQ values depicts that, children were at greater risk followed by infants and adults. Therefore, it is immensely important to regulate the use of nitrogen complex fertilizer and groundwater management practices should be implemented to prevent the associated risks to human health.     

Ecological and human health risk assessment of agricultural soils based on heavy metals in mining areas of Singhbhum copper belt,India

Risk characterization of agricultural soils in the mining areas of Singhbhum copper belt was done by determining the total concentrations of metals using inductively coupled plasma-mass spectrometry and assessing the potential ecological and human health risks. The concentrations were above the average shale values for most of the metals. Principal component analysis showed anthropogenic contributions of Cu, Ni, Co, Mn, Pb, and Cr in the soils. Ecological risk assessment revealed that 50% of the soil samples were at moderate to very high ecological risk. Health risks for adults and children were calculated using hazard quotients (HQs), hazard index (HI), and Cancer risks for the oral, dermal, and inhalation pathways. The HQs for all the metals except As and Co were below 1, which suggested that non-carcinogenic risks due to metal exposure through soils were within the safe limit. However, considering all the metals and pathways, the HI for adults and children was 0.71 and 5.61, respectively, suggesting appreciable risk to local residents. The carcinogenic risks due to As and Cr in the soils were within the acceptable value of 1E–04. For both carcinogenic and non-carcinogenic risks, oral ingestion appeared to be the primary pathway followed by dermal and inhalation pathways.     

Investigation and mapping of fluoride-endemic areas and associated health risk—A case study of Agra,Uttar Pradesh,India

The present study aimed at identifying the fluoride-endemic areas in five different blocks in Agra district, Uttar Pradesh, India. A total of 365 groundwater samples from 73 villages were analyzed for establishing the concentration range of fluoride in drinking water. The fluoride level in the study area varied from 0.14 to 4.88 mg/L. Out of 73, the fluoride levels in 45 villages did not meet the permissible Word Health Organization standards. The Baroli Ahir block was found the highly fluoride-endemic area followed by Saiyan, Bichpuri, Achnera and Etmadpur. Chronic daily intake of fluoride in adults was 1.25 and 1.5 times higher than those in children and infants, respectively. The probability of dental fluorosis in infants was higher (42%) while adults were more prone to bone and skeletal fluorosis (60%). The hazard quotient analysis revealed that children were found to be at maximum risk followed by infants and adults. Sensitivity analysis revealed that the fluoride concentration is the major influencing parameter responsible for different types of fluorosis in various age groups.     

Health-risk assessment related to the fluoride,nitrate, and nitrite in the drinking water in the Sanandaj,Kurdistan County,Iran

The concentration of fluoride and nitrate in groundwater is usually higher than that of surface water. The main objective of this study was to estimate the health-risk assessment associated with fluoride, nitrate, and nitrite in drinking water in Sanandaj and its villages. The number of samples in the Sanandaj and its rural was 106. The average concentration of fluoride in urban and rural drinking water was 0.22 mg/l and 0.27 mg/l, respectively. Fluoride concentration was also close to urban and rural drinking water. The concentration of nitrate in urban and rural drinking water was in the range between 0.28–27.77 mg/l and 1.28–80 mg/l, respectively. The concentration of nitrate reported in rural samples was higher than that of urban samples. The maximum concentration of nitrate reported in this study was 80 mg/l. The mean CDI for nitrate in the men, women, and children was 0.4258, 0.5110, and 1.1454, respectively. The findings of this study indicated that all three groups studied were exposed to nitrate contact hazards (HQ > 1). Therefore, the HQ in each of the three groups was higher than 1, which should be carefully monitored and necessary measures should be performed.     

Spatial distribution and seasonal variation in fluoride enrichment in groundwater and its associated human health risk assessment in Telangana State,South India

Groundwater is a vital source of drinking water in Siddipet rural and urban regions of Central Telangana, South India and it is a major cause of fluoride toxicity in humans. The intake of elevated fluoride has a significant impact on human health, especially immediate problems that are seen in children's teeth. The primary aim of the study was to identify the seasonal variation in fluoride concentration and associated health risks in the residents of the study region. To assess the fluoride contamination in groundwater, a total of 158 samples were analyzed in two seasons. The mean concentrations of fluoride 1.26 mg/L and 2.21 mg/L were 1.46 and 2.8 times higher than the acceptable limit of 1.5 mg/L, before and after monsoon respectively. To estimate the human health risks due to the ingestion of elevated fluoride through drinking water, hazard quotient fluoride (HQ_Fluoride) was calculated using the United States Environmental Protection Agency method. HQ_Fluoride values were 0.44–2.44 and 0.89–4.67 for children, 0.36–2.00 and 0.73–3.82 for females, and 0.41–2.26 and 0.82–4.31 for males in pre- and post-monsoon seasons respectively, suggesting emphatically greater risk than the acceptable limits (HQ_Fluoride > 1), which generates health risks.     

GIS based evaluation of fluoride contamination and assessment of fluoride exposure dose in groundwater of a district in Uttar Pradesh,India

Groundwater is the main source of drinking water in both rural and urban areas of the Pratapgarh district in the eastern Uttar Pradesh. Fifty-five groundwater samples were collected from 17 blocks of the Pratapgarh district and analyzed for fluoride (F^?) and other water quality parameters (pH, EC, TDS, turbidity, Cl^?, HCO₃^?, SO₄^2?, NO₃^?, Ca²⁺, Mg²⁺, Na⁺, K⁺, silica and total hardness) to assess its suitability for drinking uses. The fluoride concentration in the analyzed groundwater of the Pratapgarh district varied between 0.41 and 3.99 mg/L. Fluoride concentration in about 78% of the groundwater samples exceeded the acceptable level of 1.0 mg/L, while in 70% samples it exceeded the maximum permissible limit of 1.5 mg/L. A geographic information system (GIS) tool was used to study the spatial variation of fluoride concentrations in the groundwater of the Pratapgarh district. Fluoride is positively correlated with pH (0.36) and HCO₃^? (0.22) and negatively with Ca²⁺ (?0.23) and Mg²⁺ (?0.08), suggesting dissolution of fluoride-bearing minerals with the precipitation of Ca/Mg carbonate in the alkaline environment. The maximum exposure dose to fluoride for adults in the study area was found to be 6.8 times higher than the minimum risk level (MRL) of 0.05 mg kg^?1 day^?1 estimated by the Agency for Toxic Substances and Disease Registry (ATSDR).     

Monte Carlo Simulation-Based Health Risk Assessment of Heavy Metal Soil Pollution: A Case Study in the Qixia Mining Area,China

In recent years, heavy metal pollution accidents have occurred in many regions of China, and the public has become increasingly concerned about its health. Based on a U.S. Environmental Protection Agency model and using Monte Carlo simulation techniques, this article presents a procedure for health risk assessment of heavy metal pollution. A case study was conducted in the Qixia lead and zinc mining area. Based on the magnitude of heavy metal contamination in the mine factory, vicinal Qixia scenic site and village, the potential health risk calculated for a lifetime of exposure (through ingestion and dermal contact) was determined as the cumulative carcinogenic and non-carcinogenic risk for workers, tourists, and local residents (including children and adults), respectively. The risk assessment indicated that the carcinogenic risk is not significant. However, Pb poses a significant cumulative non-carcinogenic risk, which tends to be serious for workers. Additionally, local children are more vulnerable than adults to the risks associated with heavy metal contamination. Accordingly, risk alleviation and preventive measures should be taken, especially for children and workers.     

Health risk assessment due to exposure of arsenic contamination in drinking water of district Shiekhupura,Punjab, Pakistan

Abstract

The present study was conducted to assess the magnitude and health impacts of As in drinking water. Drinking water samples (n?=?60) were collected from twenty different sites of Shiekhupura District (Pakistan). Health risk assessment through average daily dose (ADD), hazard indices (HI), hazard quotient (HQ), carcinogenic risk (CR), and cancer indices (CI) for dermal and oral exposure were determined. Results revealed that As concentration ranged from 2 to 900?µg?L^?1 in water samples, which was significantly greater than the safe limit of As (10?µg?L^?1) in water. Health risk assessment of As showed that ADD (1.07E?02–9.85E?04), HQ (1.06E+01–9.85E+00), and CR (1.60E?02–9.85E?04) for oral exposure and ADD (1.03E?05–9.69E?06), HQ (1.19E?02–7.96E?03), and CR (1.11E?05–8.98E?05) for dermal exposure which were exceeded the toxic risk index value. Comparison of the two exposure pathways indicated that the oral exposure is much higher risk than the dermal contact. Both values of HI and CI were greater than WHO limit. It is concluded that residents of study area are at higher risk of As induced diseases and carcinogenicity.     

Chemical speciation of some heavy metals and human health risk assessment in soil around two municipal dumpsites in Sagamu,Ogun state,Nigeria

Environmental and health risk posed by heavy metals from municipal landfill cannot be over emphasized. However, the toxicity and fate of metal in the soil is dependent on its chemical form and therefore quantification of the different forms of metal is more meaningful than the estimation of its total concentration. This study investigated the chemical form and potential hazards of heavy metal pollution at two municipal landfills in Sagamu, Ogun state, Nigeria. Soil samples were collected around the landfills and chemical form of Cu, Zn, Cd, Pb, and Fe were studied, using the Tessier Five-step sequential chemical extraction procedure. The results showed that Cu and Fe were speciated into residual fractions with averages of 23.9 and 31.3% respectively, while Cd and Zn were associated with Carbonate fractions with respective averages of 20.3 and 20.6%. The order of mobility and bioavailability of these metals are: Cd > Pb > Cu > Zn > Fe. A comparison of the result of total extractible metals with standard set by USEPA reveals that Cd and Cu level in the dumpsite soils are far above the critical permissible limit of 3.0 and 250 mg kg^?1, respectively which potent a health risk. Assessment of soil pollution level using geoaccumulation index (I_geo) revealed that the landfill was extremely polluted by Cd (I_geo > 5). Pearson correlation and principal component analysis showed that there were no significant correlations (p < 0.05) among all the metals, suggesting that they are all from different anthropogenic sources. The cancer risk ranged from 1.36E?01 to 2.18E?04 and 5.82E?01 to 9.35E?04 for Children and Adult respectively. The level of cancer risk falls above the threshold values (10^?4–10^?6) which US Environmental Protection Agency considered as unacceptable risk. Based on the above findings, it was suggested that environmental management policy should be implemented to decrease the environmental risks.     

Trace Metal Levels in Rainbow Trout (Oncorhynchus mykiss) Cultured in Net Cages in a Reservoir and Evaluation of Human Health Risks from Consumption

Although fish consumption has positive health effects, metals accumulated in fish can cause human health risks. In this study, the levels of ten metals in rainbow trout (Oncorhynchus mykiss) farmed in the Keban Dam Reservoir, which has the biggest rainbow trout production capacity in Turkey, were determined and compared with the maximum permissible levels (MPLs). Also, human health risks associated with rainbow trout consumption were assessed. The metal concentrations in rainbow trout were found below the MPLs. The estimated daily intake of each metal was much lower than the respective tolerable daily intake. The target hazard quotient (THQ) for individual metal and total THQ for combined metals did not exceed 1, indicating no health risk for consumers. The cancer risk (CR) value for inorganic arsenic was within the acceptable lifetime risk range of 10⁻⁶ and 10⁻⁴. For carcinogenic and non-carcinogenic effects, the maximum allowable fish consumption rates were high enough to ensure the human health. According to these results, the consumption of rainbow trout farmed in the Keban Dam Reservoir does not pose a risk on human health.