Health Risk Assessment Study Research Articles

Health Impacts from PM2.5 Exposure Using Environmental Epidemiology and Health Risk Assessment: A Review

Exposure to PM2.5 has been known to cause a variety of serious health consequences. Quantifying and investigating the health effects of PM2.5 pollution are imperative to understand and collect scientific evidence for supporting policies and associated actions. In this paper, we reviewed published environ-mental epidemiological studies and health risk assessments evaluating the health impacts of PM2.5 exposure in the PubMed database to identify the attributes of each method and aggregate the health impact results to perform analyses and summaries. Forty-two studies were identified after applying our search strategy, inclusion, and exclusion criteria. The epidemiological studies found an increased risk of several diseases from short- and long-term exposure, such as cardiovascular and respiratory diseases, lung cancer, stroke, pneumonia, depression, and diabetes. However, several conditions remain to be explored as the associations remain unclear, such as asthma, bronchitis, breast cancer, Parkinson’s disease for long-term exposure, chronic obstructive pulmonary disease, stillbirth, and hypertension for short-term exposure. Health risk assessment (HRA) studies at a global scale found more than 4 million deaths from diseases associated with PM2.5 exposure. These studies also emphasized the importance and benefits of health guidelines that demonstrated to help avoid the number of fatalities significantly, especially guidelines from the World Health Organization (WHO) that showed the highest benefit. HRA studies in Thailand also showed that the country's air quality needs to be improved to avoid deaths and hospital admission cases. We also found that cohort studies for the Thai population are required to improve the quality of data and limit overestimation from using global estimates. Finally, the benefits and limitations of each study approach were collated to assist future studies in determining the most suited instruments for their purposes.

Computational fluid-particle dynamics modeling of ultrafine to coarse particles deposition in the human respiratory system, down to the terminal bronchiole

Background and objectivesSuspended respirable airborne particles are associated with human health risks and especially particles within the range of ultrafine (< 0.1 μm) or fine (< 2.5 μm) have a high possibility of penetrating the lung region, which is concerned to be closely related to the bronchial or alveoli tissue dosimetry. Nature complex structure of the respiratory system requires much effort to explore and comprehend the flow and the inhaled particle dynamics for precise health risk assessment. Therefore, this study applied the computational fluid-particle dynamics (CFPD) method to elucidate the deposition characteristics of ultrafine-to-coarse particles in the human respiratory tract from nostrils to the 16th generation of terminal bronchi. MethodsThe realistic bronchi up to the 8th generation are precisely and perfectly generated from computed tomography (CT) images, and an artificial model compensates for the 9th-16th bronchioles. Herein, the steady airflow is simulated at constant breathing flow rates of 7.5, 15, and 30 L/min, reproducing human resting-intense activity. Then, trajectories of the particle size ranging from 0.002 – 10 μm are tracked using a discrete phase model. ResultsHere, we report reliable results of airflow patterns and particle deposition efficiency in the human respiratory system validated against experimental data. The individual-related focal point of ultrafine and fine particles deposition rates was actualized at the 8th generation; whilst the hot-spot of the deposited coarse particles was found in the 6th generation. Lobar deposition characterizes the dominance of coarse particles deposited in the right lower lobe, whereas the left upper-lower and right lower lobes simultaneously occupy high deposition rates for ultrafine particles. Finally, the results indicate a higher deposition in the right lung compared to its counterpart. ConclusionsFrom the results, the developed realistic human respiratory system down to the terminal bronchiole in this study, in coupling with the CFPD method, delivers the accurate prediction of a wide range of particles in terms of particle dosimetry and visualization of site-specific in the consecutive respiratory system. In addition, the series of CFPD analyses and their results are to offer in-depth information on particle behavior in human bronchioles, which may benefit health risk assessment or drug delivery studies

Fluoride and Metals in the Agricultural Soils of Mica Mining Areas of Jharkhand, India: Assessing the Ecological and Human Health Risk

ABSTRACT The concentration of metals and fluoride in the agricultural soils of the mica mining areas of Jharkhand was estimated for human health risk assessment and source apportionment studies. The elemental concentrations of As, Co, Cu, Fe, Ni, Pb and Zn in the study area exceeded the world average values. The sources of the metals and fluoride in soil were suggested to be from both natural and human-induced activities as per principal component analysis (PCA) and cluster analysis (CA). The sources of Al, Fe, Mn and F in the soil were ascribed to the mica mining–related activities as indicated by PCA and CA. Potential ecological risk assessment suggested moderate risk with respect to Cd, Cu and Pb at few locations. Considering metals and fluoride content of the soils, non-cancer risk assessment suggested considerable risk to the child population which was largely due to Al and Fe. Taking into account all the pathways and elements, the HIs for the study area were calculated to be 0.586 and 3.58 for the adult and child residents, respectively. The carcinogenic risk assessment evaluated the cancer risk to be within the target risk of 1 × 10−4, suggesting insignificant cancer risk to the residents.

A novel regional-scale human health risk assessment model for soil heavy metal(loid) pollution based on empirical Bayesian kriging

Soil heavy metal(loid)s contamination caused by rapid urbanization and industrialization seriously affects human health and hinders the global sustainable development goals (SDGs). Currently, there is a lack of comprehensive human health risk assessment (HHRA) studies for multiple land use types at the regional scale. We propose a practical risk assessment framework that integrates empirical Bayesian kriging (EBK), pollution level analyses, and modified HHRA modeling. The concentrations of copper industry-related metals (Cu, Ni, Cd, As, and Hg) in 332 topsoil samples from the south bank of the Yangtze River in Tongling were investigated. Obvious enrichment of Cu, Cd, As, and Hg was detected, and the average concentration of Cu was 5.24 times higher than the background values. The distribution of heavy metal(loid) pollution was typically high in the south and east, and low in the north and west. The mean errors of interpolation for Cu, Ni, and Hg were 0.84, 1.29, and 0, respectively, and the root mean square errors of interpolation for Cd and As were 1.29 and 0.86, respectively. Non-carcinogenic risks of soil heavy metal(loid)s were assessed as acceptable throughout the studied area. The hazard index decreased in the order As (0.448) > Ni (0.0729) > Cd (0.0136) > Hg (9.04 ×10−4) > Cu (6.41 ×10−4). Nevertheless, the carcinogenic risks of Ni, Cd, and As in 70–80% of the administrative units (AUs) were between 10−6 to 10−4, considered an unacceptable level. Exposure through the oral ingestion route accounted for 88.0–99.2% of the total three exposure routes. It is worth noting that four AUs were considered to be the priority control units, and Ni and As were identified as the priority control soil heavy metal(loid)s. This case demonstrates the feasibility and scientific validity of the new EBK-HHRA framework, which confirms that EBK can effectively predict the spatial distribution patterns of soil heavy metal(loid)s and that modified HHRA models are conducive to risk integration at the regional scale. The EBK-HHRA approach is generic and provides substantial support for risk source identification and risk management of soil heavy metal(loid)s contamination at the regional scale.

Health risk assessment of PM2.5 and PM2.5-bound trace elements in Pretoria, South Africa

Exposure to outdoor air pollutants poses a risk for both non-carcinogenic and carcinogenic respiratory disease outcomes. A standardized health risk assessment (US EPA) utilizes air quality data, body mass and breathing rates to determine potential risk. This health risk assessment study assesses the hazard quotient (HQ) for total PM2.5 and trace elemental constituents (Br, Cl, K, Ni, S, Si, Ti and U) exposure in Pretoria, South Africa. The World Health Organization (WHO) air quality guideline (5 µg m−3) and the yearly South African National Ambient Air Quality Standard (NAAQS) (20 µg m−3) were the references dosages for total PM2.5. A total of 350 days was sampled in Pretoria, South Africa. The mean total PM2.5 concentration during the 34-month study period was 23.2 µg m−3 (0.7–139 µg m−3). The HQ for total PM2.5 was 1.17, 3.47 and 3.78 for adults, children and infants. Non-carcinogenic risks for trace elements K, Cl, S and Si were above 1 for adults. Seasonally, Si was the highest during autumn for adults (1.9) and during spring for S (5.5). The HQ values for K and Cl were highest during winter. The exposure to Ni posed a risk for cancer throughout the year and for As during winters.

Strengthening Urban Informal Trading and Improving the Health of Vendors: An Integrated Management Model.

Within the urban areas, especially the central business districts, informal trading is growing in large numbers, and the informal vendor's health is also at risk. Despite various frameworks developed for this industry, there are few guidance and implementation strategies on how to accomplish better-managed informal trading, mostly one that entails better occupational settings. The goal of the proposed model is to improve the working conditions for informal vendors in South Africa by redesigning the current informal trading management approach, thus ensuring a healthy workplace. An evidence-based approach was used to inform the development of this model. This paper outlines the current challenges of informal vendors in urban areas as per the quantitative health risk assessment study that was conducted in 16 markets amongst 617 informal food vendors in the inner city of Johannesburg, South Africa. The study investigated the respiratory health caused by air pollution and associated risk factors. Findings revealed a lack of infrastructure and higher exposure to air pollution, resulting in respiratory ill-health amongst outdoor vendors as compared to indoor vendors. The vendors were more exposed to particulate matter pollution in the spring and winter seasons as compared to the autumn and summer seasons. Furthermore, the upper respiratory symptoms were statistically significant to the type of work location (indoor/outdoor), type of cooking fuel, duration of work, frequency of hand hygiene, and wearing of protective equipment. An informal vendors' integrated management model that encompasses a specific informal food vendor's directorate was developed with five main components: the reviewing of informal vendors' legislation, the restructuring of designated vending or trading sites, space allocation and occupancy, vendors' training and skills development, and the sustainability of vending sites and vendors' health. The status revealed the legislation fragmentation of the informal vendors' activities. The goal of this informal vendors' "healthy workplace management model" is to inform government responses to the current challenges of the informal vendors' sector, as well as to guide policies and actions to reduce ill-health in the industry and to avoid disruptions to informal food supply chains, which are critical in the food sector. This model is explained well and documented for easier implementation in local governments. This paper contributes to the extant literature on street vendors and future management strategies of this trade.

Geochemical characterization, its controlling factors, and comparison between the upstream and downstream segments of the Himalayan Satluj River basin, India

Satluj River Basin (SRB) has special economic significance, representing the country's most incredible hydro-structure with fresh water, a primary source of irrigation and hydroelectric power in Northern India. Therefore, SRB's geochemical characterization is vital for hydropower and agricultural sustainability. This study provides a preliminary characterization of the hydrogeochemical processes controlling the natural water evolution in SRB by observing the spatial variation and qualitative assessment of solute chemistry (major ions and trace/heavy elements) in the Satluj river, associated tributaries, and groundwater. Hydrochemical characteristics displayed the predominance of geogenic weathering processes with carbonates dissolution and silicate weathering as end members that could explain all the geochemical variability within the SRB. The results reveal that the chemical signature of the upstream segment is possibly influenced more by carbonate weathering than silicate weathering, and the trends reverse in the downstream section with the increasing influence of silicate weathering. Dissolved heavy metals (HMs) such as Mn, Cr, Fe, Co, Ni, Cu, Zn, As, Cd, and Pb showed large fluctuations among upstream and downstream sampling sites, indicating diverse environmental conditions. Human health risk assessment (HHRA) studies revealed less or no potential noncarcinogenic via HMs, except for the downstream stretch of tributaries inferring increased non-cancerous risk. Moreover, the HHRA with HMs (Cr, As, Cd, and Pb) manifested high carcinogenic risks for adults and children across the SRB. The finding of this study could be the baseline dataset for assessing the future status, effective management, and better utilization of water resources of the SRB.

Methodology for Mobile Toxics Deterministic Human Health Risk Assessment and Case Study

Air toxic emissions from on-road mobile sources are significant contributors to the degradation of air quality in urban and dense population centers. Research led by the United States Environmental Protection Agency (EPA) identified more than 1162 hazardous air pollutants (HAPs) in the exhaust and evaporative emissions from on-road mobile sources. However, less than 70 hazardous air pollutants are monitored by regulatory agencies. HAPs emitted from Mobile Sources are known as Mobile Source Air Toxics (MSATs). The EPA estimates that approximately half of the cancer risk and 74% of noncancer health impacts from air toxics is attributed to mobile sources. The quantification of the risk associated with MSATs exposure remains limited to date, and only a few MSATs have ambient air quality standards to protect human health and welfare. This work presents a novel and validated methodology to quantify the myriad health risks associated with exposure to on-road mobile emissions. This methodology is introduced in the form of a pipelined analysis process, which may be employed in existing and new transportation projects. The proposed new methodology integrates results from three different types of models: on-road vehicle emissions inventory models such as MOVES and IVE, air dispersion models such as AERMOD and SCIPUFF, and risk estimate models for human and ecological receptors such as the 2005 Final U.S. EPA Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities. The result of this research work is a new methodology that provides regulators and risk analysts with a more detailed awareness of the health impacts of MSATs. A case study of Saint Paul, Minnesota, validated the air dispersion modeled results against monitored data, and the agreement was acceptable (i.e., the estimates were within a factor of two of the observations). Three high-population locations in the Saint Paul area were evaluated for human health risk, with the observation that at two of these locations, the Saint Paul—Ramsey Health Center and Anderson Office Building, the calculated cancer risk is in excess of the target risk level of 1.0E-05 for benzo(a)pyrene. The methodology presented in this paper allows regulators, risk analysts, and air quality engineers to better estimate multi-pathway cancer and noncancer risk associated with acute and chronic exposure to MSATs. Moreover, this work provides a science-based aid to policy decision makers when considering factors that most significantly affect population health and ecology.

Personal PM2.5 Exposure Monitoring of Informal Cooking Vendors at Indoor and Outdoor Markets in Johannesburg, South Africa.

Air pollutants of concern include particulate matter (PM) in fine size fractions. Thus far, a few studies have been conducted to study the adverse health effects of environmental and occupational air pollutants among informal vendors in big cities in South Africa. Informal vendors in these cities may experience higher exposure to road dust, cooking fumes, and air pollution. This exposure assessment was part of a health risk assessment study of vendors. The objective of this exposure assessment was to determine the differences between outdoor and indoor informal vendors' personal PM2.5 exposures during trading hours. A walkthrough survey was conducted to map the homogeneous exposure groups (HEGs) at vendor markets for sampling purposes, and one market was selected from each of the three identified HEGs. Twenty-five informal cooked food vendors from both indoor (inside buildings) and outdoor (street or roadside vendors) markets in the inner city of Johannesburg, South Africa, participated in the study. HEG-1 were vendors from indoor stalls who used electricity and gas for cooking (10 vendors), HEG-2 was composed of informal outdoor vendors at a fenced site market who used open fire for cooking (10 vendors), and HEG-3 (5 vendors) were roadside vendors who used gas for cooking. Cooking vendors from outdoor markets recorded higher TWA concentrations than indoor market vendors. The vendors' PM2.5 concentrations ranged from <0.01 mg/m3 to 0.77 mg/m3. The mean concentrations of PM2.5 were found to be 0.12 mg/m3, and 0.18 mg/m3 for HEG-2, and HEG-3, respectively. HEG-2 recorded the highest PM2.5 TWA concentrations, followed by HEG-3 and HEG-1. All concentrations were below the South African occupational exposure limit. The findings point to the need for further research into the health risks associated with outdoor cooking vendors, particularly those who utilize open fires.

Simultaneous Analysis of Mycotoxins, Potentially Toxic Elements, and Pesticides in Rice: A Health Risk Assessment Study.

Rice is a widely consumed food worldwide; however, it can be a source of pollutants, such as potentially toxic elements (PTEs), mycotoxins, and pesticides. Sixty rice samples imported from Pakistan (PAK), India (IND), and Thailand (THAI), as well as domestic Iranian (IRN) rice, were collected from Bushehr, Iran, and investigated for the contamination of PTEs, including arsenic (As), lead (Pb), cadmium (Cd), and nickel (Ni); pesticides, including chlorpyrifos, trichlorfon, diazinon, fenitrothion, and chlorothalonil; mycotoxins, such as aflatoxin B1 (AFB1), zearalenone (ZEN), ochratoxin A (OTA), and deoxynivalenol (DON); and molds. Estimated daily intake (EDI) and hazard quotient (HQ) of pollutants and hazard index (HI) and incremental lifetime cancer risk (ILCR) of rice types for the Iranian adult population were calculated. The content of PTEs in Iranian rice was not higher than Iran's national standard limits. In contrast, other types of rice (imported) had at least one PTE above the permissible level. OTA content was below the detection limit, and all other mycotoxins were within the allowable range in all rice types. Thai rice was the only group without pesticides. The HI order of rice types was as follows: HIPAK = 2.1 > HIIND = 1.86 > HIIRN = 1.01 > HITHAI = 0.98. As was the biggest contributor to the HI of Iranian and Thai rice, and diazinon in the HI of Pakistani and Indian rice. The calculation of ILCR confirmed that the concentrations of Ni and Pb in Pakistani and Ni and As in Indian, Thai, and Iranian rice were not acceptable in terms of lifetime carcinogenic health risks.

LC-MS/MS ve GC-MS ile Türkiye menşeli patateslerde insektisit kalıntılarının araştırılması ve sağlık risk değerlendirmesi

Insecticide, acaricide, nematicide and metabolite residues were assayed in 104 potato samples collected from local markets in Tokat, Türkiye in 2022 and the potential health risk for consumers assessed. Analytical method verification was performed for 135 pesticide active substances in potato matrices by liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry. Matrix-matched calibration curves were constructed and good linearity was obtained with a coefficient of determination between 0.990 and 0.999. Average recoveries varied from 73.2 to 119.6%. Repeatability and intra-laboratory reproducibility conditions of the method expressed as %RSD were less than 20%. These figures were within the SANTE/11312/2021 recovery limits (70-120%) and the values specified for the repeatability (RSD ≤ 20%). The limits of quantification were lower than the maximum residue limits set by the European Union for the potato. No pesticide residues were found at detectable limits in 93 samples. Two samples contained residues below the maximum residue limit (MRL), while nine samples contained residues above the MRLs. Clothianidin and thiamethoxam residues detected in one sample, while acetamiprid were detected in nine samples. The health risk assessment study indicated that potato consumption was safe for consumers.

Determination of metal(oids) in different traditional flat breads distributed in Isfahan city, Iran: Health risk assessment study by latin hypercube sampling.

This survey was conducted to assess the metal(oids) content in 93 samples of bread, including barbari, lavash, and tafton, using inductive couple plasma/optical emission spectroscopy (ICP-OES) method and atomic absorption spectroscopy (AAS). The amounts of measured element were compared with the permissible limit set for bread by FAO/WHO and Iranian National Standardization Organization (INSO). The limit of detection (LOD) was ranged from 6.6 × 10-5 to 2.1 × 10-2 mg l-1 with recoveries ranged from 92% to 102%. The average concentrations of aluminum (Al), arsenic (As), boron (B), cadmium (Cd), iron (Fe), mercury (Hg), magnesium (Mg), sodium (Na), lead (Pb), and zinc (Zn) in bread were 29.88 ± 8, 0.03 ± 0.004, 12.77 ± 3.70, 0.01 ± 0.006, 34.16 ± 8.95, 0.01 ± 0.008, 346.07 ± 36.08, 3314.81 ± 317.19, 0.24 ± 0.11, and 19.65 ± 4.66 mg Kg-1, respectively. Amounts of As, Cd, Hg, Mg, Pb, and Zn were lower, and those of Al, Fe, and Na were higher than the permissible limits defined by FAO/WHO. The Latin Hyper Cube (LHC) sampling results revealed that children were exposed to higher non-carcinogenic risk and adults were more threatened by carcinogenic risk. It is recommended to control the entrance of metals in bread in the farm-to-fork chain in order to prevent probable future health challenges.

The concentration of cadmium, lead, and nitrate in tomato and onion from Fars province, Iran: a health risk assessment study

ABSTRACT As the most abundant element in the atmosphere, nitrogen is a vital nutrient for plant growth. Nitrate is the main form of nitrogen uptake by plants. Although nitrates are relatively low in toxicity, if they accumulate in vegetables can be converted to nitrite and nitrous acids in the human body. This study collected 83 tomato and 40 onion samples cultivated in Fars province; then nitrate concentration was determined by an HPLC, also cadmium (Cd) and lead (Pb) concentration by an atomic absorption instrument. The Cd and Pb in samples were below the detection limits (LOD) of the techniques used. However, the nitrate concentration in tomato and onion samples from Fars province varied from 0 to 154.40 mg/kg and 0 to 317.20 mg/kg, respectively. The mean chronic daily intake (CDI) for tomatoes in children, women and men was 0.1188, 0.0375, and 0.0366, and for onions, 0.1899, 0.0605, and 0.0447, respectively. On the other hand, the 95th percentile hazard index in the probabilistic method for nitrate for children, women, and men were 0.81, 0.26, and 0.21, respectively. Also, nitrate concentration in onion for children and tomatoes in both men and women was identified as the most considerable parameter in assessing the non-carcinogenic risk of nitrate. This study showed that the amount of nitrate in some samples of tomatoes and onions was not within the acceptable international standard limits. Therefore, monitoring the nitrate concentration in these high-consumption vegetables is crucial.

Potential Association of Isolated γ-Glutamyltransferase Elevation with Incident Ischemic Heart Disease in Lean Koreans.

Isolated elevation of γ-glutamyltransferase (GGT), a microsomal membrane-bound protein, is commonly observed in non-obese Koreans without diabetes, and its clinical implications are not well-known. Therefore, we aimed to investigate the longitudinal effect of isolated GGT on the incidence of ischemic heart disease (IHD) risk in a large cohort of lean non-diabetic Koreans. Data were obtained from the Health Risk Assessment Study (HERAS) and Korea Health Insurance Review and Assessment (HIRA) datasets. The participants were divided into four groups according to the GGT quartile after the exclusion of those participants with diabetes, a body mass index (BMI) ≥ 25 kg/m2, alanine aminotransferase (ALT) ≥ 40 IU/L, and aspartate aminotransferase (AST)/ALT &gt; 1.5, as well as those positive for hepatitis B surface antigen or hepatitis C antibody. We prospectively assessed the hazard ratios (HRs) with 95% confidence intervals (CIs) for IHD using multivariate Cox proportional hazard regression models over a 50-month period. During the follow-up period, 183 individuals (1.85%) developed IHD. After setting the lowest GGT quartile as a reference group, the HRs of IHD for GGT quartiles 2-4 were 1.66 (95% CI 0.95-2.89), 1.82 (95% CI 1.05-3.16), and 1.98 (95% CI 1.12-3.50), respectively, after adjusting for age, sex, body mass index, smoking status, alcohol consumption, physical activity, mean arterial blood pressure, fasting plasma glucose, and dyslipidemia. An isolated high GGT may be an additional measure for assessing and managing future IHD risks among lean Koreans without diabetes.

A sensitive and robust method for the simultaneous determination of thirty-three legacy and emerging per- and polyfluoroalkyl substances in human plasma and serum.

Legacy and emerging per- and polyfluoroalkyl substances (PFAS) have attracted growing attention due to their potential adverse effects on humans. We developed a method to simultaneously determine thirty-three PFAS (legacy PFAS, precursors, and alternatives) in human plasma and serum using solid phase extraction coupled to ultra-performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS). The method yielded good linearity (>0.995) and excellent limits of detection (LODs) (0.0005~0.012ngmL-1 in plasma and 0.002~0.016ngmL-1 in serum). The relative recoveries ranged from 80.1 to 116%, with intra- and inter-day precision less than 14.3%. The robustness of this method has been tested continuously for 10months (coefficients of variation <14.9%). Our method was successfully applied to the PFAS analysis of 42 real human plasma and serum samples collected from women. The proposed method is attractive for the biomonitoring of multi-class PFAS in human health risk assessment and epidemiological studies.

Health risk assessment of hazardous VOCs and its associations with exposure duration and protection measures for coking industry workers

Coke making is extremely problematic from the environment and health perspectives, as the massive hazardous volatile organic compounds (HVOCs) being driven off during the coking process. Here, we conducted a health risk assessment study on coking workers, through on-situ HVOCs measurements and questionnaire investigation on activity time parameters and protection measures. The ambient HVOCs at major working stations were 58.4–376.5 μg/m3 with relative deviation of 59.4% for the certain station. The total working hours during career would reach 43283–51695 h, and protection efficiency (PE) to resist HVOCs inhalation ranged from 16% to 87%. According to the exposure evaluation model recommended by the U.S. EPA, there was little non-cancer risk for the workers at most positions with hazard quotient (HQ) value of less than 1; however, the cancer risk widely existed with lifetime cancer risk (LCR) value of 3.6–15.0 × 10−6, in which benzene, 1,2-dichloropropane, 1,2-dichloroethane, and 1,3-butadiene were dominant inducers. The cancer risk regarding the large plants was about 28.6% lower compared to the small and medium plants, due to the greater PE. In terms of the response of the health risk to exposure duration (ED, working years) and PE, non-cancer risk effectively responded only for the byproduct recovery stations, while cancer risk more sensitively responded for all stations. Health risk management therefore is essential, and the potential health hazards can be avoided by limiting ED and strengthening PE. For workers in coking, byproduct recovery and office areas, the PE should be higher than 93.8%, 97.7% and 77.3% under the ED of 20 years, the ED in three areas should be lower than 12.5 years, 4.5 years and 30 years under PE of 90%, respectively.

Hydrogeochemistry and quality evaluation of groundwater and its impact on human health in North Tripura, India.

Groundwater contamination becomes an alarming threat to the provision of ecosystem services and natural resources. A very high level of groundwater contamination has been observed in the northeastern states particularly in North Tripura district. Therefore, the present study considered the region as a case study to evaluate the hydrogeochemical facies, heavy metal pollution and irrigation indices, and their impact on human health. For the investigation, we have collected a total of 35 groundwater samples from North Tripura district. Hydrogeochemical facies through Piper plot reflect Ca2+-Mg2+-HCO3- and Na+-HCO3- as dominant water types. Gibbs plot identifies the dominance of rock-water interaction process in groundwater hydrochemistry. Geochemical plots indicate the dominance of silicate weathering, ion exchange and carbonate dissolution processes in groundwater mineralisation. The order of trace metal contaminations follows Fe > As > Zn > Mn > Cu > Pb. Results of heavy metal indices suggest above 80% samples are at high risk due to high Fe contamination. The risk of the heavy metal indices is associated with rising elevation in southern part of North Tripura. Findings of health risk assessment study imply that children face much carcinogenic and non-carcinogenic risks than adults because of unsafe levels of Fe and As. Multivariate statistical tools are applied to unravel interrelationships among all ions and trace metals as well as probable hydrogeochemical processes in groundwater. Results of Wilcox and USSL plots suggest 77% samples meet irrigation suitability criteria. Besides, the analysis suggests a better insight to identify hydrogeochemical processes controlling groundwater chemistry and the suitability of groundwater for irrigation and drinking purposes. The study also suggests treatment and sustainable management of groundwater resources is compulsory to reduce trace metal contaminations before public use.

Profiling and occupational health risk assessment study on coal ashes in terms of polycyclic aromatic hydrocarbons (PAHs)

Profiling and cancer risk assessment on the polycyclic aromatic hydrocarbons (PAHs) content of coal ashes produced by the major coal combustion plants from the eastern coalfield region in India was conducted. Thirteen PAHs were detected on coal ashes collected from ash deposition sites of major thermal power plants and the profiling of the PAHs was done. Benzo[a]pyrene equivalents (BaPeq) for individual PAHs were calculated and applied to the probabilistic assessment model from US EPA (1989). Monte Carlo simulations were conducted to assess the risk of inhabitants exposed to PAHs through the dust of the coal ash deposition site. In fly ash, the range of total amount of carcinogenic PAHs was from 3.50 to 6.72 µg g−1 and for the bottom ash, the range was 8.49 to 14.91 µg g−1. Bottom ashes were loaded with ample amounts of 5- and 6-ring carcinogenic PAHs, whereas fly ashes were dominated by medium molecular weight PAHs. The simulated mean cancer risks from fly ashes were 2.187 E–06 for children and 3.749 E–06 for adults. For the case of bottom ash, the mean risks were 1.248 E–05 and 2.173 E–05 respectively for children and adults. Among all the three exposure routes, dermal contact was the major and caused 81% of the total cancer risk. The most sensitive parameters were exposure duration and relative skin adherence factor for soil, which contributed the most to total variation. The 90% risks calculated from the bottom ashes (2.617 E–05 for children and 4.803 E–05 for adults) are marginally above the acceptable limit (>1.000 E–06) according to US EPA. In this study, a comprehensive risk assessment on carcinogenic PAHs present in coal ashes was done for the first time that may be helpful to develop potential strategies against occupational cancer risk.

Potential health risk assessment, spatio-temporal hydrochemistry and groundwater quality of Yamuna river basin, Northern India

Groundwater which is an essential source of freshwater for various domestic, agricultural, industrial applications is facing a severe deterioration in quality due to demographic pressure and intense industrial activities. Present study appraises the influence of human induced activities on groundwater quality of Agra-Firozabad industrial belts of Western Uttar Pradesh, Yamuna basin, India. The maximum concentrations of metals and anions found during pre and post monsoon are as follows: Lead 0.302; 0.086, calcium 672; 1260, magnesium 215; 16.8, cadmium 0.0; 0.066, chromium 0.016; 0.005, manganese 0.340; 0.076, nickel 0.044; 0.028, sulfate 514; 286, nitrate 66.7; 3.56 and fluoride 1.17; 2.02 mg/L respectively. Based on results of Water Quality Index, groundwater samples were classified under ‘Poor water’ category in 34.2% and 52.63% during pre and post-monsoon period, respectively. Accordingly, higher concentrations of bicarbonate and sulfate might have attributed to excess hardness, instrumental in making it unsuitable for industrial usage. However, values of Percent Sodium, Sodium Adsorption Ratio, Magnesium Hazard and Permeability Index signified that groundwater from majority of locations was fit for agricultural use. Health risk assessment studies revealed that children consuming polluted water were affected more as compared to adults. Timely action and strict compliance of regulation is recommended towards groundwater management for defined usage to avert severe health effects and to meet sustainable development goals.

The human health risk assessment and countermeasures study of groundwater quality.

Due to various geological, hydrogeological conditions and human activities, groundwater of different regions has distinct hydrochemical characteristics. The harmful chemical components of groundwater affect human health, and thus, the groundwater quality health risk assessment (GQHR) is important to local residents. It is vital to select GQHR factors combined with hydrochemical features, and to explore their formation, concentration characteristics and the prominent controlling role of influencing risk distribution from natural and human reasons. The factors of NO3-, NO2-, NH4+ and F- were extracted as assessment factors to evaluate the GQHR. The factors NO3-, NO2- and NH4+ are derived by human activities and F- stems from irrigation of geogenic high-fluoride groundwater and fertilizer use. The results of GQHR showed the risk order as children > adult females > adult males. The low- and medium-risk regions correspond to high groundwater levels, which are mainly controlled by natural factors. The high-risk regions located in eastern part of the study area, which were affected by both natural and human reasons. The targeted measures to prevent the increase of groundwater health risk caused by different dominant controlling effects were put forward. The research provides a scientific basis for the safety of groundwater supply and environmental exposure in this area. The research ideas and methods can be a reference for similar studies.