Health Hazard Quotient Research Articles

Integrated assessment of groundwater quality dynamics and Land use/land cover changes in rapidly urbanizing semi-arid region

Rapid urbanization worldwide, poses numerous environmental challenges between escalating land use land cover (LULC) changes and groundwater quality dynamics. The main objective of this study was to investigate the dynamics of groundwater quality and LULC changes in Sargodha district, Punjab, Pakistan. Groundwater hydrochemistry reveals acceptable pH levels (<8) but total dissolved solids (TDS), electrical conductivity (EC) and HCO3− showed dynamic fluctuations by exceeding WHO limits. Piper diagrams, indicated dominance by magnesium and bicarbonate types, underscoring the influence of natural processes and anthropogenic activities. Major ion relationships in 2010, 2015, and 2021 showed a high correlation (R2 > 0.85) between Na+ and Cl−, suggesting salinization. whereas, the poor correlation (<0.17) between Ca2+ and HCO3− does not support calcite dissolution as the primary process affecting groundwater composition. The examination of nitrate contamination in groundwater across the years 2010, 2015, and 2021 was found to be high in the municipal sewage zone, suggesting a prevailing issue of nitrate contamination attributed to urban activities. The Nitrate Pollution Index (NPI) reveals a concerning trend, with a higher proportion of samples classified under moderate to high pollution categories in 2015 and 2021 compared to 2010. The qualitative assessment of nitrate concentration on spatiotemporal scale showed lower values in 2010 while a consistent rise from 2015 to 2021 in north-east and western parts of district. Likewise, NPI was high in the north-eastern and south-western regions in 2010, then reduced in subsequent years, which may be attributed to effective waste management practices and alterations in agricultural practices. The health risk assessment of 2010 indicated Total Health Hazard Quotient (THQ) within the standard limit, while in 2015 and 2021, elevated health risk was observed. This study emphasizes the need to use multiple approaches to groundwater management for sustainable land use planning and regulations that prioritize groundwater quality conservation.

Human Health Risk Assessment through Depiction of Major Ion Chemistry of Groundwater from Part of Balaghat District (MP), Central India

The key interpretations on the study concerning the human health risk appraisal and hydrogeochemical environment of major ions (cations and anions) of the groundwater samples from the part of Balaghat District (MP) latitude 21°31’42”: 2143’11” N and longitude 79°50’ 30”: 80°11’30”E., Central India are presented here. The pH and EC values were found to grade between 7.3 to 8.6 and 50 to 5080 µS/cm, unraveling the alkaline nature of groundwater and numerous phases of processes in groundwater characterization. The ion exchange along with the solubilization processes during the rock-water interaction undoubtedly represents the geogenic as well as non-geogenic sources for the salinity in the groundwater of the study area. The Ca2+ is predominant over the other cations, wherein the abundance succession of cations is Ca2+ &gt; Na+ &gt; Mg2+ &gt; K+ . The HCO3 - predominates over the other anions with the abundance succession as - HCO3 - &gt; Cl- &gt; NO3 - &gt; SO4 2- &gt; F- . The concentrations of the cations and the anions have been subjected to Aquachem4 software to get the Piper trillinear diagram for the groundwater samples of the study area and it has been found that the alkaline earths (Ca + Mg) exceed the alkalis (Na + K). The three major facies evaluated after the analysis from the study area are Mg-HCO3 (75%), Na-HCO3 (16%) and Ca-HCO3 (9%). The total health hazard quotient (THI) values due to NO3 - content range from 0.026 to 6972 mg/kg/day for the adult and from 0.034 to 1002.7 mg/kg/day for children. Similarly, the health hazard quotient (THI) values due to Fconcentration ranges from 0.01 to 0.19 mg/kg/day and from 0.02 to 0.52 mg/kg/day for adult and children respectively. Thus, the study points out that the children are more susceptible to the non-carcinogenic risk than to adults and may pose undesirable health effects.

Characterization of toxic air pollutants in Hong Kong, China: Two-decadal trends and health risk assessments

Exposure to toxic air pollutants (TAPs) is linked to the development of cancer and various chronic health issues. While studies on the ambient characteristics of criteria air pollutants such as particulate matter, nitrogen oxides, and ozone have been extensively conducted, research on TAPs in China remains limited. In particular, there has been a lack of long-term observation studies on the potential health risks associated with ambient TAP concentrations. To address this gap, we characterize the long-term trends (2000–2020) of a wide range of TAPs in Hong Kong using ambient monitoring data derived from a TAP monitoring program that has been in operation since the late 1990s. We analyzed TAPs such as diesel particulate matter (DPM), volatile organic compounds, carbonyl compounds, polycyclic aromatic hydrocarbons, hexavalent chromium, and others. We found that most of the TAPs decreased notably over the last two decades, translating to a reduction in economic loss of over HK$2 billion per year in 2016–2020. However, the current state of TAPs still poses significant health risks. The total TAP concentrations in 2016–2020 exceeded the chronic reference guideline value for noncancer health hazard quotient of 1.0 (1.53). The aggregated inhalation cancer risks in the corresponding period were 562.8 in a million population. We found that the top ten TAPs disproportionately accounted for more than 80% of both health estimators. In contrast to earlier years where DPM dominated the cancer risks, the measured VOCs have grown in importance, and they pose cancer risks as significant as DPM in recent years. Our work identifies several areas in enhancing TAP monitoring, which have implications for expanding the monitoring across the Greater Bay Area for improving air quality management from a health-oriented perspective.

Statistical Evaluation and Hydrogeochemistry of Groundwater from Western Part of Chandrapur District, Maharashtra with Special Emphasis on Human Health Risk Assessment

The groundwater samples were collected from the phreatic aquifers of PG2 watershed of western part Chandrapur district, Maharashtra. The geogenic processes like dissolution of calcium rich minerals are responsible for increase of Ca2+ content in groundwater. In the groundwater samples, HCO - and SO 2- are the prevailing dominant anions. The TDS, TH, Ca2+, Mg2+, Na+, HCO - as well as Cl- ions present in basement rocks have been attributed to the geogenic factor through the factor analysis. K+, SO 2- as well as NO - correspond to fertilizers and soil amendments used by people to enhance crop production, which is regarded as anthropogenic input. The silicate weathering at water-rock interface is the main process of generation of various solutes in groundwater. The multiple regression analysis expresses the TDS as a linear function of the ions and Ca2+, Mg2+, Na+, HCO -, Cl-, SO 2- and NO - contribute significantly to the bulk chemical composition of the groundwater from the study area. The health hazard quotient (HQ) for children (4.94%) and adults (7.95%) denotes the intensity of different health risk vulnerable zones at a specific site. Keywords: Rock-Water Interaction, Silicate Weathering, Statistical Evaluation, Health Risk Assessment, Chandrapur District, Maharashtra

Statistical Evaluation and Hydrogeochemistry of Groundwater from Western Part of Chandrapur District, Maharashtra with Special Emphasis on Human Health Risk Assessment

The groundwater samples were collected from the phreatic aquifers of PG2 watershed of western part Chandrapur district, Maharashtra. The geogenic processes like dissolution of calcium rich minerals are responsible for increase of Ca2+ content in groundwater. In the groundwater samples, HCO - and SO 2- are the prevailing dominant anions. The TDS, TH, Ca2+, Mg2+, Na+, HCO - as well as Cl- ions present in basement rocks have been attributed to the geogenic factor through the factor analysis. K+, SO 2- as well as NO - correspond to fertilizers and soil amendments used by people to enhance crop production, which is regarded as anthropogenic input. The silicate weathering at water-rock interface is the main process of generation of various solutes in groundwater. The multiple regression analysis expresses the TDS as a linear function of the ions and Ca2+, Mg2+, Na+, HCO -, Cl-, SO 2- and NO - contribute significantly to the bulk chemical composition of the groundwater from the study area. The health hazard quotient (HQ) for children (4.94%) and adults (7.95%) denotes the intensity of different health risk vulnerable zones at a specific site. Keywords: Rock-Water Interaction, Silicate Weathering, Statistical Evaluation, Health Risk Assessment, Chandrapur District, Maharashtra

Concentrations and Community Structures of Culturable Bacteria in Aerosols of Household Garbage Stations in Shanghai

The airborne microorganism has attracted increasing attention, and household garbage carries various pathogenic bacteria that affect the surrounding environment and public health. In this study, the culturable bacteria in the air were collected by using a six-level Anderson sampler, and the temperature, relative humidity, PM2.5, and PM10 in the garbage stations and their surrounding environment were recorded. The relationships between environmental factors and culturable bacterial pollution in the air were also analyzed. The results showed that the culturable bacterial concentrations in five sampling sites (the garbage station of a villa and the area downwind, the garbage station of a campus, the roof of an office building, and the garbage station of a residential area) were (1254±92), (280±123), (172±47), (84±18), and (175±174) CFU·m-3, respectively. The concentrations of the culturable bacteria in the garbage station of the villa were significantly higher than those of other sampling sites, mainly because there were biochemical treatment facilities for the on-site treatment of wet garbage in the garbage house. The sizes of the culturable bacteria in the garbage station of the villa mainly ranged from 1.1-4.7 μm, and the bacterial sizes at the other four sampling sites were primarily larger than 7 μm, with a few bacteria ranging from 1.1-2.1 μm. In this study, Proteobacteria and Firmicutes were the dominant phyla, and Corynebacterium and Bacillus were the dominant genera. More importantly, some opportunistic pathogens such as Corynebacterium, Staphylococcus, and Acinetobacter were also detected. The concentrations of the culturable bacteria in the garbage station of the villa were highly correlated with temperature, relative humidity, PM2.5, and PM10. Exiguobacterium in the air was highly correlated with PM10, temperature, and relative humidity. The health hazard quotient (HQ) values of the five sampling sites were all less than 1; however, the results of microbial quantitative risk assessment showed that the health risks of the male and female staff in the three garbage houses were all higher than the corresponding reference values. This study revealed the influence of garbage stations on the bioaerosol in the surrounding environment and provided references for the evaluation of air quality in and around garbage stations.

Are we at risk because of road dust? An ecological and health risk assessment of heavy metals in a rapid growing city in South India

Here, we focus on the concentration of six heavy metals (Cd, Cr, Cu, Fe, Pb, and Zn) in the road dust collected from Tiruchirappalli city, one of the cleanest Tier II cities in South India. Five metals were detected in the road dust, except for Cd that was below measurable limit in all 22 dust samples (15 from the urban city and 7 from the sub-urban city). The mean metal concentration in the road dust collected in Tiruchirappalli city was in the order: Fe (506.39 μg/g) > Zn (47.08 μg/g) > Cu (11.84 μg/g) > Cr (11.47 μg/g) > Pb (0.24 μg/g). The metal levels were higher in outer city compared with inner city due to the increased industrial activities on the outskirts of the city and the reduced cleaning routine. Using principal component analysis (PCA) and hierarchical cluster analysis (HCA), the metal sources were found to be a mix of both natural and anthropogenic activities. Various pollution valuation indices viz., geoaccumulation index, pollution load index, contamination degree, potential ecological risk, health hazard quotient, and carcinogenic risk (2.5 x 10-7), revealed that Tiruchirappalli city falls in the unpolluted category. Also, an increasing trend in the metal pollution is observed in the industrial zones due to the heavy traffic and metal processing activities in the region. For now, the status of metal pollution in Tiruchirappalli is safe, but continuous monitoring is crucial to sustain the unpolluted status.

Health risk assessment of nitrate in drinking water in Shiraz using probabilistic and deterministic approaches and impact of water supply

Increased nitrate concentration in water resources due to human activities and lack of wastewater management can affect consumers' health adversely. The objective of this study is health risk assessment of nitrate in distribution drinking water in Shiraz using probabilistic and deterministic approaches. Nitrate concentration was determined in 31 sampling sites of distribution system. N-carcinogenic human health risk as a consequence of the drinking contaminated water to nitrate was assessed in four age groups (less than 2, 2 to 6, 6 to 16, and more than 16 years). Also, health Hazard Quotient (HQ) and sensitivity analysis were investigated using the Monte Carlo simulation technique with a probabilistic approach. The lowest and highest two-year mean concentration were 2.1, 58.35 and the total two-year mean of nitrate concentration was 22.6 mg/l. Nitrate concentration was higher than standard level in grab sampling at some points. While the total mean of HQ was less than the adopted threshold in all age groups, the results showed that HQ at some sites is higher than adopted threshold level. The minimum and maximum of the HQ belonged to adults (0.22) and infants (0.8). The mean and the 90th percentile estimated HQ using probabilistic approach for infants, children, teenagers, and adults were (0.78, 1.66), (0.45, 0.0.95), (0.41, 0.86), and (0.23, 0.48), respectively. Sensitivity analysis indicated that concentration is the most effective parameter in HQ. Considering that the highest estimated HQ was related to infants and also increased nitrate concentration can have adverse health effects for this age group, it is suggested to apply management and control measures to reduce the nitrate concentration in groundwater resources with a high concentration of nitrate.

Biochar amendment reduced the risk associated with metal uptake and improved metabolite content in medicinal herbs.

Contaminations of heavy metals such as lead (Pb) and cadmium (Cd) in medicinal plants (MPs) not only restrict their safe consumption due to health hazards but also lower their productivity. Biochar amendments in the soil are supposed to immobilize the toxic metals, improve the soil quality and agricultural productivity. However, the impact of biochar on growth attributes, metal accumulation, pharmacologically active compounds of MPs, and health risk is less explored. An experiment was performed on three medicinal plants (Bacopa monnieri (L.), Andrographis paniculata (Burmf.) Nees, and Withaniasomnifera (L.)) grown in a greenhouse in soil co-contaminated with Pb and Cd (at two concentrations) without and with biochar amendments (2 and 4% application rates). The fractionation of Pb and Cd, plant growth parameters, stress enzymes, photosynthetic capacity, pharmacologically active compounds, nutrient content, uptake and translocation of metals, antioxidant activities, and metabolite content were examined in the three MPs. The accumulation of Pb and Cd varied from 3.25-228 mg kg1 and 1.29-20.2 mg kg-1 , respectively, in the three MPs, while it was reduced to 0.08-18 mg kg-1 and 0.03-6.05 mg kg-1 upon biochar treatments. Plants grown in Pb and Cd co-contaminated soil had reduced plant biomass (5-50% depending on the species) compared to control and a deleterious effect on photosynthetic attributes and protein content. However, biochar amendments significantly improved plant biomass (21-175%), as well as photosynthesis attributes, chlorophyll, and protein contents. Biochar amendments in Pb and Cd co-contaminated soil significantly reduced the health hazard quotient (HQ) estimated for the consumption of these medicinal herbs grown on metal-rich soil. An enhancement in secondary metabolite content and antioxidant properties was also observed upon biochar treatments. These multiple beneficial effects of biochar supplementation in Pb and Cd co-contaminated soil suggested that a biochar amendment is a sustainable approach for the safe cultivation of MPs. This article is protected by copyright. All rights reserved.

Inhibition of arsenic transport from soil to rice grain with a sustained field-scale aerobic rice cultural practice

A field-scale investigation has been carried out to assess the uptake of Arsenic (As) in rice under aerobic practice. Two consecutive field experiments have been designed considering the rice cultivation system's variation in the comparison between aerobic and flooded practices during monsoon and post-monsoon seasons using the cultivars of Swarna masuri and Satabdi, respectively. Notwithstanding the impact of the rice cultivation systems, the implications of amendments like iron, silicon, and organic matter were also taken into account on As uptake by rice. We hypothesized that the application of amendments in combination with sustained aerobic practice would reduce the subsequent accumulation of As in rice as compared to flooded practice (control). However, regardless of the cultivation systems, the grain productivity of rice delivered a non-significant impact. Results revealed that the plant available As content in soil under aerobic practice was averaged 22% and 26% lower than flooded, during monsoon and post-monsoon seasons, respectively. Aerobic treatment significantly reduced accumulation of As in root and straw as compared to flooded (p < 0.05), which in accordance corresponded to lower translocation efficiency of As from root to straw. For Swarna masuri, the bioaccumulation of As in polished rice, husk and bran was reduced by 33%, 48% and 47%, respectively, under aerobic practice. On the contrary, Satabdi exhibited a reduction in As accumulation with 54% in polished rice, followed by 31% and 38% in husk and bran, respectively. The inhibition of As uptake in rice was notably impacted by iron, silicon, and organic matter. Following the treatments of rice cultivation system and amendment, the bioaccumulation of As in rice plant parts was arranged in the order of root > straw > grain > husk > bran > polished rice in both the cultivars. The health risk assessment was also considered to estimate the potential human health risk measuring the estimated dietary intake and the health hazard quotient. The results highlighted that the consumption of rice grown in aerobic practice was ensured to provide non-carcinogenic health risk as compared to rice grown in flooded practice. In the overall attempt, the present investigation corroborates the insinuation of specific management practices in quantifying the reduction of As bioavailability in rice with subject to the concern of reducing human health risk.

Levels, Potential Sources and Risk Assessment of Organochlorine Pesticides in Atmospheric Particulate Matter at Regional Background Site

ABSTRACT Forty-eight PM2.5 samples were collected from June to August 2015 at the summit of Mount Tai. The samples were analyzed to determine the concentrations, potential sources and health risk of organochlorine pesticides (OCPs). Total OCPs concentration in PM2.5 ranged from 20.5 to 331 pg m–3. Hexachlorocyclohexane (HCHs) were the most abundant compounds. The sources of OCPs used potential source contribution function (PSCF), back trajectory analysis and principal component analysis suggested that the southwest agricultural areas and southeast regions of Mount Tai were the significant contributions regions of OCPs. Both old residual and new input were considered to the contribution of OCPs contamination. Human health risk assessment was carried out by non-carcinogenic health hazard quotient (HQ). The HQ values through inhalation and dermal contact ranged from 9.28 × 10–12 to 6.56 × 10–3, indicating a negligible risk of the study area.

Risk assessment of mercury and lead in fish species from Iranian international wetlands

The aim of this study is determination of mercury concentration in the muscle, intestine, gonad and kidney of Rutilus rutilus, Hemiculter Leucisculus (Anzali wetland), and Alosa Caspia Caspia (Caspian Sea), and mercury and lead concentrations in the muscle of Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Schizocypris altidorsalis, and Schizothorax zardunyi (Hamun wetlands). The results of this study were compared with global standards. As well as in this multispecies monitoring, health risk assessment of consumers by EPA/WHO instructions has been done. The concentrations of mercury were below the limits for fish proposed by United Nations Food and Agriculture Organization (FAO), World Health Organization (WHO), US Food and Drug Administration (FDA) and US Environmental Protection Agency (EPA), and European Union (EU). Lead concentrations in Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix was under the scope proposed by FAO, WHO, FDA, Turkish Acceptable Limits (TAL), United Kingdom Ministry of Agriculture Fisheries and Food (UK MAFF) and National Health and Medical Research Council (NHMRS), but lead concentration in Schizocypris altidorsalis, and Schizothorax zardunyi were higher than WHO and TAL. Health risk assessment of consumers from the intake of metal contaminated (mercury and lead) was evaluated by using Hazard Quotient (HQ) calculations. The human health hazard Quotient (index) showed that the cumulative risk greatly increases with increasing fish consumption rate, thus yielding an alarming concern for the consumer’s health.•The results of the present study aimed to provide data from Caspian Sea, Anzali wetland, and Hamoon wetland as indicators of natural and anthropogenic impacts on aquatic ecosystem as well as to evaluate the human hazard index associated with fish consumption.•The results show that for mercury, the Maximum Allowable Fish Consumption Rate (Meals/Month) is related to Hemiculter Leucisculus.•The results for lead concentration indicate that there is no HQ value?>?1, indicating that humans would not experience any significant health risk if they only consume metals from these species of fish from the hamun wetland.

Health Risks Assessment Diagnosis of Toxic Chemicals (Heavy Metals) via Food Crops Consumption Irrigated with Wastewater

The present study investigated the concentration of metals in commonly grown vegetables (Luffa acutangula L., Zea mays L., Solanum melongena L.) irrigated with waste water in District Bannu, Khyber Pakhtunkhwa, Pakistan. The pH (5.80) and electrical conductivity (13 dS/m) of waste water indicated the acidic nature that is not suitable for irrigation purposes. Soil and vegetables samples were analyzed for metals concentration through flame atomic absorption spectrometry (Varian FAAS-240). The findings showed that waste water irrigated soil was highly contaminated with Cd (4.62 mg/kg) which was above permissible limits set by European Union Standard (EU 2006, 2002). The concentrations of heavy metals such as Cr and Cd in vegetables were higher than the permissible limits set by World Health Organization/Food and Agriculture Organization U.S.A guidelines 2001. The health hazard quotient (HQ) of waste water irrigated vegetables was observed higher for Ni (0.699-0.1029 mg/kg), (0.0456-0.1040 mg/kg), (0.731-0.0994 mg/kg) in Luffa acutangula, Solanum melongena and Zea mays, respectively. The study concluded that the consumption of commonly grown vegetables in waste water zone of the study area may pose potential health threats in local population.

The estimation of consumer health risk associated with organochlorine xenobiotics in hard smoked cheese in Poland

The aim of this study was to estimate the health risks associated with consumption of smoked cheeses, which are popular in Poland. The analysis covered polychlorinated biphenyl (PCB) indicator congeners (ndl-PCBs: PCB 28, PCB 52, PCB 101, PCB 138, PCB 153, PCB 180), dioxin-like PCBs (dl-PCBs): non-ortho (PCB 77, PCB 81, PCB 126, PCB 169) and mono-ortho (PCB 105, PCB 114, PCB 118, PCB 156, PCB 157), as well as organochlorine pesticides (OCPs: αHCH, βHCH, γHCH, heptachlor, aldrin, heptachlor epoxid isomer B, dieldrin, pp'DDE op′DDD, pp′DDT, pp′DDD, op′DDT, endrin). The pesticide residues detected in the examined cheese were below the maximum residues levels. The estimated daily intake [lifetime average daily dose (LADD)] referring to the sum of the compounds varied within 4.21·10−7–3.92·10−6 mg·kg−1·day−1 and was significantly lower than the tolerable daily intake/acceptable daily intake (TDI/ADI) for individual compounds. The health hazard quotient, being the exact measure of the magnitude of exposure potential or a quantifiable potential for developing non-carcinogenic health effects after an averaged exposure period, was also very low, ranging from 2.87·10−6 to 5.32·10−5. The obtained results confirmed that the intake of rennet cheese does not pose any consumer health risk in Poland.

Assessment of health risk from organochlorine pesticides residues in high-fat spreadable foods produced in Poland

Currently, butter and margarine are food products attracting wide customer interest. Every day, consumers around the world buy these products for human consumption. Butter is obtained from milk fat, while margarine is derived from vegetable oils. The content of organochlorine pesticide (OCP) residues was examined in both types of these high fatty products. A gas chromatograph with MSD (HP 5973) detector was used for the determination of pesticides such as α-HCH, β-HCH, γ-HCH, DDT, DDD, DDE, aldrin, dieldrin, endrin, heptachlor and heptachlor epoxide. The examined products had diverse concentrations of the analyzed compounds. Visible was the division based on the origin of the product, which might be composed of animal or vegetable fats. The research has revealed the presence of OCP residues in all examined spreads. Quantities of organochlorine compounds did not pose an immediate danger to the consumers’ health. Human and environmental health risk assessment was carried out by the estimation of lifetime average daily dose (LADD) and non-carcinogenic health hazard quotient (HQ). Total estimated LADD ranged between 1.3 × 10−5 and 3.1 × 10−5 mg kg−1 d−1 for butter, and 1.9 × 10−6 and 4.6 × 10−6 mg kg−1 d−1 for margarine and mix spread. The HQ ranged between 1.1 × 10−4 and 3.7 × 10−4 for butter, and 1.4 × 10−5 and 9.0 × 10−6 for margarine and mix spread for adults. These estimated HQs were within the safe acceptable limits, indicating a negligible risk to the residents of the study area.

DDT and HCH (Organochlorine Pesticides) in Residential Soils and Health Assessment for Human Populations in Korba, India

ABSTRACTDichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), and their isomers’ levels in residential soils were determined for the assessment of health risk in Korba, India. Observed concentrations of total HCH and total DDT in soils were more or less comparable with other parts of India and the world. ΣHCH and ΣDDT concentrations ranged between 0.9–20 μg kg−1 and 2–315 μg kg−1, respectively, which were lower than recommended soil quality guidelines indicating low ecotoxicological risk. Carcinogenic and non-carcinogenic impacts of HCH and DDT on human populations through soil ingestion were evaluated and presented. The incremental lifetime cancer risk (ILCR) for adults and children ranged between 7.8 × 10−10–1.6 × 10−7 and 4.1 × 10−9–8.2 × 10−7, respectively. Non-cancer health hazard quotient (HQ) ranged between 5.9 × 10−7–1.8 × 10−3 and 3.1 × 10−6–9.4 × 10−3, respectively, for adults and children. The estimated ILCR and HQ were within the safe acceptable limits of 10−6–10−4 and ≤1.0, respectively, indicating low risk to human populations from exposure to organochlorine pesticides (HCH and DDT) in the study area.

Geochemistry of sediments and water with a health risk assessment of heavy metal contaminated vegetables grown in Dhapa, a waste disposal site in Kolkata, India

Dhapa, is a well known municipal solid waste (MSW) disposal site in the eastern part of the city of Kolkata. Geochemical study reported here shows that in its sediments, the concentration of Zn, Cu and Pb greatly exceed the average worldwide shale concentration. The water samples collected from tubewells, dugwells, pond and canals have elevated concentrations of Zn, Mn, Cr, Cu, Ni and Pb. The pollution load index values for the twenty sampling sites ranged from 1.03–6.44. High enrichment factors for Pb, Zn, Cr, Mn and Cu, imply high accumulation of metal toxins in leaves and edible portions of locally grown vegetables. The transfer factors for the different metals were in the order of TFNi > TFCr > TFCu > TFPb > TFMn. However, compared with the health hazard quotient of < 1 for heavy metals, except for Pb, the consumption of Dhapa vegetables showed a low health risk.

Distribution of dichlorodiphenyltrichloroethane and hexachlorocyclohexane in urban soils and risk assessment

This study deals with the distribution of dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) in urban soils, their possible sources and probabilistic human and environmental health risk. The average concentrations of total HCHs and total DDTs in the soils were in the range of 0.56-8.52 mg kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; and 0.54-37.42 mg kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;, respectively, which were lower than guideline limits. The compositional analysis of HCH isomers reflects contaminations from recent usage. However, isomeric ratios between DDT, DDE and DDD, indicate anaerobic degradation of DDT and contaminations from aged DDT. Human and environmental health risk assessment was carried out by the estimation of lifetime average daily dose (LADD), incremental life time cancer risk (ILCR) and non carcinogenic health hazard quotient (HQ). LADD of total pesticides (HCH and DDT) for human adults and children was ranged between 3.3x10&lt;sup&gt;&amp;ndash;9&lt;/sup&gt;-6.6x10&lt;sup&gt;&amp;ndash;8&lt;/sup&gt; mg kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; and 1.7x10&lt;sup&gt;&amp;ndash;8&lt;/sup&gt;-3.4x10&lt;sup&gt;&amp;ndash;7&lt;/sup&gt; mg kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;, respectively. The cumulative ILCR for adults and children was ranged from 5.1x10&lt;sup&gt;&amp;ndash;9&lt;/sup&gt; to 4.6x10&lt;sup&gt;&amp;ndash;8&lt;/sup&gt; and 2.6x10&lt;sup&gt;&amp;ndash;8&lt;/sup&gt; to 2.4x10&lt;sup&gt;&amp;ndash;7&lt;/sup&gt;, respectively. The HQ was ranged between 1.8x10&lt;sup&gt;&amp;ndash;6&lt;/sup&gt;- 1.4x10&lt;sup&gt;&amp;ndash;4&lt;/sup&gt; and 9.5x10&lt;sup&gt;&amp;ndash;6&lt;/sup&gt;-7.2x10&lt;sup&gt;&amp;ndash;4&lt;/sup&gt;, respectively for adults and children. These estimated ILCR and HQ were within the safe acceptable limits, indicating negligible risk to the residents of the study area.

Congener specific distribution and health risk assessment of polychlorinated biphenyls in urban soils

Polychlorinated biphenyls (PCBs) were primarily used in transformers and capacitors, lubricants, flame retardants, plasticizers, paint, carbonless papers, etc. These are capable of long-range atmospheric transport and have been designated as persistent organic pollutants by the Stockholm Convention. Due to their characteristic properties, PCBs are found worldwide in all environmental matrices (including human) and biota. Soils are usually considered to be the source as well as sink for environmental pollutants, with cumulative effects of long-range atmospheric transport and local sources. Around the world, comparatively higher concentrations of PCBs have been reported in urban soils than suburban or rural soils. Higher amount of PCBs in urban soils may cause toxicological health risks to urban residents through ingestion, inhalation and skin contact. This paper presents the PCB distribution in soils from Delhi, India, and exposure risk estimates for human health through soil ingestion. The concentration of &amp;Sigma;PCBs ranged between 1.08-100.67 ng g&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; (mean 21.16 ng g&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;&amp;plusmn;5.24 ng g&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;), which was much lower than the Canadian soil quality guideline value of 1.3 mg/kg or 1300 ng g&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;. Human health risk estimates through the soil ingestion pathway were made in terms of lifetime average daily dose (LADD), incremental lifetime cancer risks and non-carcinogenic hazard quotient (HQ). The LADD for Delhi adults and children was 3.02x10&lt;sup&gt;&amp;ndash;8&lt;/sup&gt; mg kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; and 1.57x10&lt;sup&gt;&amp;ndash;7&lt;/sup&gt; mg kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;, respectively, which corresponds to toxic equivalent quotients (TEQ) intake of 0.105 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; (0.735 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; week&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;) and 0.543 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; (3.801 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; week&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;), respectively. The estimated LADD for Delhi residents was lower than the acceptable intake values recommended by the World Health Organization (1 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;), the European Commission (14 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;;1 week&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;) and by the Japanese government (4 pg TEQ kg&lt;sup&gt;&amp;ndash;1&lt;/sup&gt; d&lt;sup&gt;&amp;ndash;1&lt;/sup&gt;). The probability of cancer risk ranges from 6.04x10&lt;sup&gt;&amp;ndash;8&lt;/sup&gt; (&amp;Sigma;PCBs) to 1.57x10&lt;sup&gt;&amp;ndash;5&lt;/sup&gt; (&amp;Sigma;TEQ) and 3.13x10&amp;ndash;7 (&amp;Sigma;PCBs) to 8.15x10&amp;ndash;5 (&amp;Sigma;TEQ) for adults and children, respectively, and was within acceptable ranges of 10&lt;sup&gt;&amp;ndash;6&lt;/sup&gt; to 10&lt;sup&gt;&amp;ndash;4&lt;/sup&gt;. The non-carcinogenic risk in terms of health HQ was 0.105 and 0.330 for adults and children, respectively, which was lower than the acceptable limit of 1. The study found lower concentrations of PCBs than guideline values and low health risk estimates through the soil ingestion pathway within acceptable levels, indicating a minimum risk for Delhi residents.

Health risks for human intake of aquacultural fish: Arsenic bioaccumulation and contamination

Aquacultural tilapia (Oreochromis mossambicus L.) and shrimp (Penaeus monodon L.) from groundwater-cultured ponds in southwestern Taiwan were analyzed to estimate arsenic (As) bioaccumulation and the potential health risk to human intake. Most of aquacultural ponds exhibited higher arsenic than maximum allowed concentrations (50 μg L−1) in pond water of Taiwan. Arsenic levels in tilapia in Budai, Yichu and Beimen were 0.92 ± 0.52 μg g−1, 0.93 ± 0.19 μg g−1 and 0.76 ± 0.03 μg g−1, respectively and in shrimp was 0.36 ± 0.01 μg g−1 in Beimen. Total arsenic in tilapia is highly correlated (R2 = 0.80) with total arsenic concentration of pond water. Total arsenic in fish showed high correlation with that in bone (R2 = 0.98), head (R2 = 0.97) and tissue (R2 = 0.96). Organic arsenic species (DMA) was found higher relative to inorganic species of As(III) and As(V). The average percent contribution of inorganic arsenic to total arsenic in fish samples was 12.5% and ranged between 11.7 to 14.2%. Bioaccumulation factors (BAFs) for total arsenic in fish ranged from 10.3 to 22.1, whereas BAF for inorganic arsenic ranged from 1.33 to 2.82. The mean human health cancer risk associated with the ingestion of inorganic arsenic in the fish was estimated at 2.36 × 10−4 ± 0.99 × 10−4, which is over 200 times greater than a de Minimus cancer risk of 1 × 10−6. The mean human health hazard quotient associated with ingesting inorganic arsenic in the fish was 1.22 ± 0.52, indicating that expected human exposure exceeds the reference dose for non-cancer health effects by 22%. These results suggest that the inhabitants in this region are being subjected to moderately elevated arsenic exposure through the consumption of tilapia and shrimp raised in aquaculture ponds.