Hazard Quotient Values Research Articles

Chemometric assessment of bioaccumulation and contamination pathways for toxic metals in diet and environment: implications for chronic kidney disease of unknown etiology (CKDu) in Sri Lankan agricultural regions.

Prolonged consumption of foods containing toxic metals can elevate the risk of noncommunicable diseases, including chronic kidney disease of uncertain etiology (CKDu). Despite the increasing number of CKDu cases in Maradankulama and Mahakanadrawa Grama Niladhari Divisions (GN) in Sri Lanka, no prior studies have examined the accumulation of heavy metal(loid)s and their potential association with CKDu prevalence. Furthermore, there is an absence of comprehensive analyses using chemometric techniques such as PCA and hierarchical studies regarding CKDu and heavy metal contamination in Sri Lanka. This study aims to provide initial insights into the accumulation and potential pathways of toxic metals in staple foods within local diets and their subsequent presence in the agricultural environment of examined GNs. Cr, Cd, As, and Ni concentrations in analyzed foods were within permissible limits (MPLs), whereas Pb levels exceeded MPLs in rice (Oryza sativa), gotukola (Centella asiatica), lime (Citrus crenatifolia), and inland fish (Etroplus suratensis). High target hazard quotient (THQt) values in polished rice suggest possible health risks with prolonged intake. Hierarchical analysis suggested a common source of Pb accumulation. PCA and hierarchical clustering revealed the intricate connection between As and Cd, with their concurrent clustering in samples suggesting a potential common origin. This indicates that while individual concentrations comply with acceptable standards, the potential synergistic effects of Cd and As accumulation might pose elevated health risks. Further, the gut tissues of inland fish exhibited pronounced metal concentrations and significant (p < 0.05) positive correlations with toxic metals in the tank sediments suggesting a diet-based bioaccumulation pathway through sediments.

Human Health Risk Assessment and Water Quality Index of piped water supply system in Gulshan-e-Iqbal Town, Karachi (A Preliminary Town level study).

In the present study, piped water samples from Gulshan-e-Iqbal Town, Karachi, were evaluated for their Health Risk Assessment (HRA) and Water Quality Index (WQI). For this, different physicochemical and microbiological parameters were analyzed, and the results were evaluated according to the guidelines established by the WHO (2011) and the National Standards for Drinking Water Quality (NSDWQ) (2008). With the exception of sulphate, all physicochemical parameters were well within the guideline values. The mean concentrations of the metals in the samples were in the following order: Ca2+ > Mg2+ > Zn > Fe > Pb > Ni > Cr > As. More than 70% of the samples tested for Total Coliform Count (TCC), Total Faecal Coliform Count (TFC), Total Feacal Streptococci (TFS), and Total Aerobic Count (TAC) were feacal contaminated. E. coli was also isolated in almost 84.61% of the tested piped water samples. Results from the WQI revealed that 95.6% of samples had good physico-chemical characteristics, and 26% of the piped water samples had good microbiological quality. The WQI readings of all the samples for metals showed that they were unfit for human consumption. The mean Chronic Daily Intake (CDI) and Hazard Quotient (HQ) values, respectively, were in the following order: Zn > Fe > Pb > Ni > Cr > As, and Pb > As > Ni > Cr > Zn > Fe. All HQ values for As and Pb were greater than 1, and 50% of piped water samples had an HQ value for Ni that was greater than 1, indicating that people may suffer serious health issues as a result. All of the piped water samples except the area of block 13 D (S-5), had HQ values of less than 1 in relation to iron, but Zn HQ values of less than 1 indicated only mild health problems. Discharge of untreated sewage and cross-contamination are all potential sources of contamination that could result in diseases that are harmful to the public's health. Water monitoring and management projects should be implemented in order to improve pipeline infrastructure and reduce sewage leakages.

Pollution assessment, ecological risk and source identification of heavy metals in paddy soils and rice grains from Salem, South India

The present study investigated concentrations of metals (Cu, Zn, Fe, Mn, Ni, Pb, and Cd) in paddy soils and rice tissues of nine different widely used indica rice varieties in Salem district, India. The order of DTPA soil available metal contents (mg kg-1) were Fe (33.50) > Mn (8.86) > Cu (2.58) > Pb (1.99) > Zn (1.67) > Ni (1.48) > Cd (0.13). Pollution load index (PLI) levels for Cd (1.28) were ‘moderately polluted’, contamination factor (CF) and enrichment factor (EF) values for all metals showed ‘medium contamination’ and ‘less enrichment’ except for Cu and Pb. Ecological risk factor (ERF) and potential ecological risk index (PRI) values of Cd (31.94 and 287.50) showed ‘moderate risk’ and ‘strong ecological risk’. Bio-accumulation factor (BAF) levels of Cd (48.12) and Pb (27.89) are classified as ‘high concentrators’. Translocation factor (TF) values of Pb (2.9), Cd (2.5) and Ni (1.7) were greater than one for roots to plants. Children had higher target hazard quotient (THQ) and hazard index (HI) values for Cd, Pb and Ni than adults. Principal component analysis (PCA) revealed with all parameters that they fell within the two primary factors 1 and 2, with an eigenvalue of 4.69 (33.52% variation) and 3.73 (26.66% variation), respectively. However, cluster analysis (CA) revealed three distinct groups between the metals studied. Although the soil metal contents were within the permissible levels, the grain Cd (6.07 mg kg-1), Pb (56.20 mg kg-1), and Fe (116.11 mg kg-1) contents in all the rice varieties exceeded the prescribed limits of 0.4, 0.2, and 15 mg kg-1, respectively. Our findings will provide important data for metal enrichment in soils to implement more effective measures to reduce the contamination of metals in paddy fields.

Mineral pollutants and coliform contamination in groundwater pose health risks to consumers: a spatiotemporal study in a mining-impacted area

The presence of mineral pollutants, combined with bacterial contamination, has significantly impacted groundwater quality and led to various health-related issues in mining-impacted areas. Therefore, we measured the concentration of fluoride (F-), phosphate (PO43-), sulphate (SO42-), ammonium (NH4+), nitrate (NO3-), the total coliforms (TCs), and physiochemical characteristics in groundwater samples of South Khorasan, Eastern Iran. For this, we collected water samples from 100 wells in spring and autumn across this mining-impacted area. We then measured the concentrations of mineral pollutants and assessed their associated health risks to children and adults using the Environmental Protection Agency (EPA) models and spatiotemporal zoning maps in ArcGIS. The concentrations of PO43-, NH4+, SO42-, NO3-, and F- were 0.70 ± 0.34, 0.82 ± 0.9, 175.45 ± 123, 15.26 ± 9.41, and 0.53 ± 0.68 mg/L in spring, and 0.71 ± 3.18, 4.68 ± 31, 306.72 ± 615.80, 19.30 ± 15.61, and 0.72 ± 0.65 mg/L in autumn, respectively. PO43-, NH4+, and SO42- exceeded both the World Health Organization (WHO) and EPA, but NO3- exceeded only EPA standards. TCs in both seasons exceeded the standards set by the EPA and WHO. The hazard quotient (HQ) values indicated non-carcinogenic risks for F⁻ and NO3⁻, while posing no risks NH4⁺ and PO43⁻ in both adults and children during autumn and spring.Hazard index (HI) was greater than 1 for all minerals in both children and adults in autumn and spring. No correlation was observed between mineral compounds and TCs in the study area, yet the water samples were highly contaminated by coliform with a significant risk to adults and children. In essence, both mineral pollutants and TCs potentially pose serious risks to human, and more efforts are required to improve the quality of water in this area.

Health Risk Assessment of Ambient Air Benzene Among Primary School Children in Urban and Rural Areas in Johor, Malaysia

Introduction: It is a fact that children are vulnerable, and are at risk from benzene, a volatile, carcinogenic organic compound. The aim of our study is to determine the levels of ambient air benzene and examine the non-carcinogenic and carcinogenic risks involved Methods: A cross-sectional study was conducted in two urban and two rural primary schools in Johor, Malaysia. Benzene concentrations were measured using BUCK Libra L-4 pumps and analyzed in the gas chromatography-mass spectrometry (GC-MS). Data were collected from 334 10-12 year old children, to calculate the exposure levels based on their body weights and heights. The hazard quotient (HQ) served to evaluate the non-carcinogenic risks, whereas the lifetime cancer risk (LCR) was determined with the aid of the United States Environmental Protection Agency (USEPA). Results and Discussion: Benzene concentrations were higher in rural than urban areas, surpassing the European Union (EU) standard of 5 μg/m³. It was also established that the highest average levels recorded were 6.89 ± 6.68 μg/m³. The HQ values, nonetheless, had indicated no immediate non-carcinogenic risk, while LCR estimates were found to be within a tolerable range across all sites. Findings showed that although the immediate risk from benzene exposure is low, long-term exposure still poses a significant cancer risk to children; even low levels of chronic exposure can heighten the likelihood of children to develop cancers. Conclusion: This study has produced a revelation that there are elevated benzene levels in rural areas in Johor. Despite the low, immediate non-carcinogenic risks, further investigation on the potential for long-term cancer risks is warranted. These risks can be addressed by conducting stricter air quality monitoring, enhancing vehicle emission standards, and introducing educational programs that can raise awareness about benzene exposure.

Monitoring and Assessment of Toxicological Risks of Poultry Meat Contaminated with Heavy Metals.

This study aimed to investigate the heavy metal contamination in poultry meat of Kotli Sattian, Rawalpindi. The meat samples from ten sites were analyzed for lead, cadmium, chromium, copper, arsenic, nickel, zinc, iron, sodium, and calcium. The possible health risks of these metals were also observed. Mean lead, cadmium, chromium, arsenic, and nickel concentrations were higher than the permissible limits of the World Health Organization (WHO). Metals in meat samples showed the trend of Fe > Na > Zn > Ni > Ca > As > Cr > Pb > Cu > Cd. All the studied metals except lead were statistically significant (P ≤ 0.05). The hazard quotient (HQ) values of all the metals were below one, except iron. Iron showed chronic health risks in both adults (1.63) and children (3.64). Moreover, the cumulative hazard index (HI) of the metals indicated that meat consumption can pose a significant chronic toxic risk in both adults and children as the HI value was 2.06 for adults and 4.61 for children, which is greater than one. The carcinogenic risk (CR) of arsenic in meat for adults and children exceeded the acceptable range, making it a metal of concern. This means that the consumption of small concentrations of metal through meat may be the source of severe toxicological consequences. It can be concluded that meat is contaminated with metals; therefore, appropriate precautions should be taken to minimize this contamination.

Assessment of radioactive nuclides and heavy metals in soil and drink water in Lahij city, Yemen

This study was conducted in Lahij city, Yemen, to evaluate the concentrations and potential health risks of natural radioactive nuclides and heavy metals in soil and drinking water. A total of 21 soil samples and 17 water samples were collected from various locations. A high-purity germanium gamma detector HPGe was used to measure the concentrations of 40K, 232Th, and 226Ra in all samples, along with the concentrations of heavy metals. In soil samples, the average concentrations of 40K, 232Th, and 226Ra were 731.5, 30.7, and 28.16 Bq kg−1, respectively. While some samples showed higher than permissible levels for 226Ra and 232Th, the overall average remained within acceptable limits. However, 40K levels were almost twice the recommended global limits. In water samples, the average concentrations of these nuclides were 5.38, 0.73, and 0.66 Bq L−1, all within the global safety limits. Radiological risk assessments for soil indicated an average radium equivalent activity (Raeq) of 124.4 Bq kg−1, absorbed dose rate in air of 59.9 nGy h−1, annual effective dose rate of 0.07 mSv y−1, outdoor excess lifetime cancer risk (ELCR) of 0.26 × 10−3, and annual gonad equivalent dose (AGED) of 336.6 mSv y−1. Risk indices, including the activity concentration index (Iγ), external hazard index (Hex), and internal hazard index (Hin), averaged 0.48, 0.34, and 0.41, respectively, all below global limits except for AGED, which slightly exceeded the recommended level. For drinking water, the total ingestion dose was calculated for different age groups. The average doses for infants, children, and adults were 0.15, 0.27, and 0.19 mSv y−1, respectively. The doses for children and adults exceeded the permissible limits, while those for infants were within safe levels. Heavy metal concentrations were measured in all samples, and the Hazard Quotient (HQ) was calculated. In soil samples, HQ values for all metals >1, indicating potential health risks. In water samples, HQ values were also >1 for all metals except vanadium (V) and iron (Fe). To reduce the dangers associated with radioactive nuclides and heavy metals, regular monitoring and cleanup are crucial, and further research is needed to understand contamination sources and long-term health impacts.

Determination of heavy metals and health risk assessment in drinking water in Bukayriyah City, Saudi Arabia

Abstract Heavy metal levels, including arsenic, lead, cadmium, mercury, chromium, and nickel, were analyzed in 124 samples of tap and filtered water obtained from Bukayriyah city, Saudi Arabia, using inductively coupled plasma mass spectrometry. Additionally, measurements of total dissolved solids, conductivity, and pH were also performed. The study also evaluated the potential non-cancer and cancer risks (CRs) associated with the ingestion of these heavy metals for both children and adults. The results indicated that the average concentrations of heavy metals in both tap and filtered water were found to be below the recommended limits set by the World Health Organization and the Gulf Standard Organization. To assess the non-carcinogenic risks, the chronic daily intake (CDI), hazard quotient (HQ), and hazard index were calculated for analyzed metals present in both tap and filtered water. In both the children and adult populations, the CDI indices for heavy metals in tap and filtered water followed the order of Cr &gt; Hg &gt; Ni &gt; Pb &gt; As &gt; Cd. However, it is worth noting that the CDI values for tap water were higher than those for filtered water for both children and adults. The descending order of HQ values is as follows: Hg &gt; Cr &gt; As &gt; Cd &gt; Pb &gt; Ni. This indicates that the HQ values for all metals are below the acceptable limit of 1. These findings confirm that the exposure to the examined metals from both tap and filtered water in Bukayriyah City is within safe limits and poses no non-carcinogenic risks. To assess the carcinogenic risks, the incremental lifetime cancer risk (ILCR) and total carcinogenic risk (TCR) were calculated. The order of ILCR values for both children and adults in tap and filtered water is as follows: Ni &gt; Cr &gt; Cd &gt; As &gt; Pb. All ILCR values were below the acceptable limit of 10−6 to 10−4. However, TCR values exceeded this threshold range only for children exposed to tap water, with a value of 1.43 × 10−4. Thus, children exposed to tap water have a potential risk of developing carcinogenic diseases.

Long-term analysis of BTEX concentrations and health risks in semi-arid urban regions

Rajasthan, experiencing rapid industrialization and urbanization, faces critical air quality challenges, particularly concerning toxic volatile organic compounds (VOCs) such as BTEX (Benzene, Toluene, Ethylbenzene, Xylene). This study presents a long-term analysis of BTEX concentrations across various cities in Rajasthan, India, using data from the Central Pollution Control Board (CPCB) from 2017 to 2022. The findings revealed that the average ∑BTEX concentrations increased from 4.15 µg/m3 in 2017 to 12.29 µg/m3 in 2022, with a temporary decline in 2020. The Hazard Quotient (HQ) values for BTEX exposure ranged from 0.052 to 0.15 for males, 0.056 to 0.17 for females, and 0.09 to 0.29 for children over the study period, indicating higher health risks for children. Similarly, the Lifetime Cancer Risk (LCR) values varied from 6.04 × 10⁻⁶ to 1.92 × 10⁻5 for males, 1.09 × 10⁻⁶ to 2.24 × 10⁻5 for females, and 1.17 × 10⁻5 to 3.73 × 10⁻5 for children. The results demonstrate that children are at a greater cancer risk from BTEX exposure compared to adults. This study emphasizes the urgent need for effective air pollution control measures and continuous monitoring to protect public health, particularly vulnerable populations like children.

Spatial distribution, ecological and human health risks of potentially toxic elements (PTEs) in river Ravi, Pakistan: A comprehensive study

Significant quantities of potentially toxic elements have been and are still being discharged into Pakistan's rivers through natural sources and anthropogenic activities. The present study provides a comprehensive study of potentially toxic element contamination in the water and sediment of the Ravi River, Pakistan. The research aims to examine the extent of pollution, its ecological risks, and the potential human health impacts through detailed geospatial analysis and statistical correlation. Water and sediment representative samples were taken and analyzed for potentially toxic elements, including Cobalt (Co), Cadmium (Cd), Zinc (Zn), Nickel (Ni), Arsenic (As), Chromium (Cr), Lead (Pb), Copper (Cu), and Manganese (Mn). Various pollution indices, such as the “Geo-accumulation Index (Igeo), Modified degree of Contamination (mCd), Nemerow comprehensive pollution index (Pt), Contamination factor (CF), Enrichment factor (EF), Pollution Load Index (PLI), and Potential Ecological Risk Index (PERI),” were calculated to determine the contamination levels and ecological risks. The results indicated significant spatial variability in metal concentrations, with higher levels observed in industrial and urban areas (near Lahore). Cd and As were identified as the most critical pollutants, exhibiting high Igeo, CF, EF, and PERI values. The PLI revealed that several regions along the river are heavily polluted. Pt shows high comprehensive pollution near Lahore and moderate to high pollution in surrounding areas. According to mCd, most of the study area, especially sampling points near Lahore, ranges between 8 and 16, indicating a high degree of pollution. The Human Health Risk (HHR) assessment, considering ingestion, inhalation, and dermal contact pathways, highlighted that children are particularly vulnerable, showing higher Hazard Quotient (HQ) and Hazard Index (HI) values for several metals. Correlation analysis revealed significant relationships between certain metals, suggesting common sources of contamination, likely from industrial discharges and urban runoff. The comprehensive mapping and statistical analysis underscore the urgent need for implementing effective pollution control measures to mitigate the risks posed by potentially toxic element contamination in the Ravi River. This study provides critical insights for policymakers and environmental managers to prioritize areas for remediation and to develop strategies to protect both ecological and human health in the region.

Spatial distribution and risk assessment of perchlorate in raw cow milk from China

Perchlorate is a ubiquitous environmental contaminant worldwide, recognized as an emerging thyroid toxicant. This study focused on the pollution status, spatial distribution, possible sources of perchlorate in raw cow milk collected from 155 dairy farms in China, as well as the health risk of exposure to perchlorate through dairy products. The results showed that the detection rate of perchlorate in raw milk was 100% with the mean of 15.9 μg/kg, indicating the ubiquitous contamination of perchlorate in raw milk from China. The simulation of spatial distributions indicated that the levels of perchlorate in raw milk were spatially correlated, and relatively high levels of perchlorate exist in certain parts of Beijing-Tianjin-Hebei, Shanxi, Henan, and Zhejiang, suggesting potential environmental perchlorate contamination in these regions. A positive correlation was found between the perchlorate level in milk and the perchlorate level in feed, indicating the transfer process of perchlorate from feed to milk. The hazard quotient (HQ) values of exposure to perchlorate by dairy products ranged between 0 and 2.14, with the mean of 0.0188 and P95 of 0.101, indicating relatively low health risk to perchlorate through dairy products. To our knowledge, this is the first nationwide study on the spatial distribution and risk assessment of perchlorate in raw cow milk from China.

Classroom indoor air quality and noise level assessment of different educational institutions in a university area in Bangladesh

Introduction: The classroom environment is crucial for fostering effective learning and safeguarding teacher-student health. This study assessed the Indoor Air Quality (IAQ) and noise levels in classrooms across three institutions: a university, a secondary and higher secondary school (called a school and college), and a primary school. Materials and methods: Various IAQ parameters such as Particulate Matters (PM2.5 and PM10), Carbon monoxide (CO), Carbon dioxide (CO2), Total Volatile Organic Compound (TVOC), and temperature, Relative Humidity (RH), light, and noise levels were measured using calibrated instruments from February to March 2024. Results: The air pollutants and noise levels varied among the institutions. The mean values of PM 2.5 (76.6 µg/m3) and PM (116.7 µg/m3) were highest The mean values of PM 2.5 (76.6 µg/m3) and PM (116.7 µg/m3) were highest in the primary school, while CO (0.82 ppm), light (92.9 lux), temperature (27.6 °C), and noise levels (77.6 dB) peaked in the school and college. University classrooms showed the maximum concentrations of CO2 (804.9 ppm), TVOC (32.9 ppb), and RH (58.6%). In all institutions, PM2.5, PM10, and noise levels exceeded WHO-recommended limits, whereas CO, CO2, RH, and temperature remained within their respective standards. Light levels were below Occupational Safety and Health Administration (OSHA) guidelines. Correlation analysis showed significant positive correlations between PM2.5 PM10, and CO. Hazard Quotient (HQ) values for PM 2.5 and PM10 exceeded 1.0, indicating potential health risks. Variations in pollutants and noise levels among institutions may be due to classroom facilities, student density, ventilation systems, and student activities. Conclusion: Long-term exposure to IAQ pollutants and noise levels could impair cognitive function, respiratory health, and overall well-being of the students and educators. Implementing proper ventilation (e.g., HEPA filters) systems, soundproofing acoustic panels, and continuous IAQ monitoring is recommended for a safer classroom environment.

Health risk assessment of lead and cadmium exposure from food and snuff in Pakistani population

BackgroundSmokeless tobacco (SLT) is a tobacco-based product consumed without burning or smoking. Snuff, commonly known as naswar, is a widely used SLT product in Pakistan. This study is designed to investigate the concentrations of lead (Pb) and cadmium (Cd) in snuff and their associated health risks to consumers. MethodsBlood samples from snuff consumers and non-consumers were analyzed for Pb and Cd concentrations. Additionally, samples of drinking water and wheat flour were also analyzed for Pb and Cd. Health risk assessments were calculated using hazard quotient (HQ) and incremental lifetime cancer risk (ILCR) for Pb and Cd. ResultsSnuff consumers had significantly higher blood-Pb and blood-Cd levels compared to non-consumers. Approximately 38.5 % of snuff consumers were found to exceed blood-Pb levels from the safe limits (10 µg dL⁻¹) of the World Health Organization (WHO), while 48.9 % of snuff consumers were found to exceed blood-Cd levels from the WHO safe range of 0.03–0.12 µg dL⁻¹. Snuff samples contained Pb and Cd concentrations ranging from 5.3 to 22.4 µg g⁻¹ and 0.5–2.2 µg g⁻¹, respectively. Drinking water and wheat flour samples were found within the safe limits for Pb and Cd concentration, suggesting snuff as the primary source of exposure. Health risk assessments indicated elevated HQ values, for Pb (38.9 %) and Cd (14.3 %) detected in snuff, surpassing the safe HQ threshold of 1. Concerning ILCR from snuff, values for Pb were within the acceptable range, but alarmingly 100 % of samples for Cd exceeded the safe limits of USEPA (1.0×10⁻⁴), indicating a significant cancer risk in snuff users. ConclusionThis study highlights the exceeded Pb and Cd concentrations in snuff as well as also reporting significant carcinogenic and non-carcinogenic health risks to consumers. These findings emphasized the urgent need for regulatory bodies to ensure the safety of snuff before selling in the market. Public Health Professionals should also initiate educational campaigns to raise awareness among consumers and manufacturers about various health risks associated with the snuff.

Phthalate Esters in Water and Surface Sediments of Anambra River in Dry Season: Distribution and Human Health Risks Assessment

This study investigated phthalate ester (PAE) contamination in water and sediment samples due to their persistence and potential health risks as endocrine disruptors. Sediment analysis revealed pH ranged from 5.35 to 6.72, with total organic carbon (TOC) levels varying between 0.74% and 2.56%. Water pH values were within WHO guidelines (5.5–8.5), and turbidity levels ranged from 0.60 to 1.40 NTU. Phthalate concentrations in sediment revealed Monobutyl phthalate (MBP), Diethyl phthalate (DEP), Dipentyl phthalate (DPP), Butyl benzyl phthalate (BBP), Dibutyl phthalate (DBP), and Di(2-ethylhexyl) phthalate (DEHP). Sample SA exhibited the highest levels of MBP (0.40 mg/kg) and DEP (0.93 mg/kg). In water samples, MBP peaked at 0.01 mg/kg, while DEP reached 0.03 mg/kg, with DBP (0.07 mg/kg) and DEHP (0.08 mg/kg) also detected. Phthalate contamination in water remained below harmful thresholds. A health risk assessment calculated Chronic Daily Intake (CDI) and Hazard Quotients (HQ) for both children and adults. CDI results indicated higher risks for children, with DBP (2.20E-06 mg/kg/day) and DEHP (2.46E-06 mg/kg/day) showing the greatest concern. The HQ for children was highest for DBP (0.22), though still below the risk threshold. Adults exhibited lower CDI and HQ values, with minimal non-carcinogenic risk. These findings highlight the need for continued monitoring of phthalate pollution, especially given children’s heightened vulnerability.

Risk assessment of dietary perchlorate exposure in typical areas of fireworks manufacturing in China using a perchlorate intake model

Perchlorate can disrupt the production of thyroid hormones, impact metabolism, and even affect the cognitive development of infants and toddlers. Typical areas of fireworks manufacturing might face severe perchlorate pollution due to perchlorate is an important raw material. But related study has not been reported. We assess the risk caused by perchlorate and identify the critical exposure pathways for different age/gender groups in typical area of fireworks manufacturing. Liuyang city, a major fireworks manufacturing center in China, was selected as study region. Perchlorate concentrations were measured in 230 local food samples from Liuyang using LC/MS/MS. Risks for different age/gender groups were estimated using a perchlorate intake model. The detection rate of perchlorate in samples from all eight food groups, including vegetables, fruits, meat, seafood, egg, cereal, beans, and drinking water was 100%, and the perchlorate concentrations were higher than those reported in the United States, Canada, South Korea, Kuwait, and other regions of China. Liuyang residents are currently facing an extremely high perchlorate dietary exposure risk, with the mean Estimated Daily Intakes (EDIs) approximately 6–49 times higher than US EPA's recommended reference dose (RfD, 0.7 μg/kg bw/day), and 14–115 times higher than the tolerable daily intake (TDI, 0.3 μg/kg bw/day) established by EFSA. Breast milk and drinking water are identified as the primary exposure pathways for infants and toddlers under the age of two, contributing 44–86% and 13–41% to their total exposure, respectively. For individuals > two years, vegetable consumption (constituting 54–66% of exposures) and ingestion of drinking water (constituting 23–32% of exposures) represent the chief exposure routes. The Hazard Quotient (HQ) values for Liuyang City residents all exceed 2, indicating an extremely high non-carcinogenic risk associated with perchlorate. Scientific and systematic perchlorate pollution control measures should be taken by local government.

Heavy metal contamination in Lebanese lettuce: Quantification and health risk assessment

Heavy metals (HM) contamination in food products is a major risk to public health. Lebanon is constantly suffering from unresolved environmental pollution issues, which have led to an increase in atmospheric deposition of contaminants in water and soil. This study aims to investigates the levels of HM in Lettuce products collected from different market regions in Lebanon. We also estimated the potential human exposure to HM through ingestion of lettuce. We used the Atomic Absorption Spectrophotometry to determine HM levels in the collected samples. Furthermore, we calculated the Metal Pollution Index (MPI) and the Hazard Quotient (HQ) to determine the expectance of adverse health effects in comparison to other countries. The results showed that Lead (Pb), Arsenic (As) and Chromium [Cr (III)] levels in the capital city exceeded the maximum allowable values set by FAO/WHO, whereas Palladium (Pd) was above the safety limit in all collected samples. The MPIs fluctuated over all investigated regions but remained below the critical value (of 1). However, the maximum As HQ exceeded the permissible limit by 186 % and the maximum Pb HQ value was higher than that of industrialized countries including China, Brazil, and Egypt. These findings prove that regular testing and monitoring are highly required to investigate the importance of human exposure to HM in Lebanon and any associated health impacts.

Health Risk Assessment of Nitrate, Nitrite, and Fluoride Ions in Water Reservoirs of Mehriz, Iran in 2023

Introduction: High concentrations of nitrate, nitrite, and fluoride in drinking water can cause adverse health effects. This study aims to investigate concentration and health risks assessment of nitrate, nitrite, and fluoride ions in water reservoirs of Mehriz city and Bahadoran district. Materials and Methods: Monthly sampling was done from water reservoirs of Mehriz city and Bahadoran district for 6 months. Nitrate, nitrite, and fluoride concentrations were measured in the samples using a spectrophotometer. Then, health risk assessment and sensitivity analysis were performed on the obtained data using Crystal Ball software and Monte Carlo simulation method. Results: Nitrate, nitrite, and fluoride concentrations were lower than the standard limitation in all of the studied areas. Risk assessment findings indicated that hazard quotient (HQ) values of nitrite in Miankoh-Movahedin, Bidok and Bahadoran water reservoirs were less than 1 for all age groups. HQ values of nitrate were also below 1 for all age groups except children. HQ values of fluoride in Bahadoran water reservoir were below 1 for all age groups except children. Conclusion: Health risk of consuming water containing nitrates and fluorides is high for children. Based on sensitivity analysis, the concentration of nitrate and fluoride in drinking water is the key factor in raising health risks. Reducing nitrate and fluoride concentrations in drinking water can reduce health risks in the population.

The Bioaccumulations of Metal(loid)s in the Tissues of Invasive Carassius gibelio (Bloch, 1782) Fish from the Kızılırmak River (Türkiye) and Health Risk Assessment.

The present research was an examination of the concentration levels of 10 metal(loid)s that had accumulated in the muscle, gills, and liver tissues of Carassius gibelio (Prussian carp) fish. The fish species, used as samples in the study, were obtained from the part of the river in Gülşehir (Türkiye). Besides, possible health risks to consumers were specified based on the daily estimated intake (EDI) of metal(loid)s in adults. Additionally, considering the inhabitants' frequency of fish consumption in the area, target hazard quotient (THQ), hazard index (HI), carcinogenic risk (CR), and maximum safe consumption quantity (MSCQ) values were assessed. All of the examined metal(loid)s in the research were determined in all of the tissues of the fish. Also, Fe and Zn had the highest levels in the tissues, and Pb had the lowest level. There were statistically significant differences of Fe, Co, Cu, Zn, As, Cd, and Pb among the tissues (p < 0.05). It was determined that the gender of the fish did not affect the accumulation of the metal(loid)s in the tissues. According to the research results, no significant statistical difference was found between the accumulation of the metal(loid)s (except Ni) and the size of the fish (length and weight) (p > 0.05). The estimated daily intake levels of the metal(loid)s accumulating in the eatable muscle of the samples were calculated to be lower than the reference dose limit. Besides, the THQ and the HI values lower than 1 were found. Carcinogenic risk values related to inorganic As were below 10-6. This result specifies that consumption of the fish poses no carcinogenic risks to consumers' health. It was concluded that less than 70g of C. gibelio daily consumption would not harm consumers' health.

Assessing water quality and human health risk near coal mines and industrial area of Singrauli, India: special emphasis on toxic elements.

Water contamination is a major environmental issue, especially in rapidly growing industrialized areas like Singrauli. This study addresses research gaps regarding the hydrochemical characterization, health risk assessment, and source identification of contaminants. Hydrochemistry shows the concentrations of Na+, Ca2+, F-, Mn, As, Mo, Sr, and Ni were above the permissible limit for drinking usage. Water quality index (WQI), heavy metal pollution (HMPI), and evaluation indices (HMEI) revealed As, Mn, Cd, Mo, Co, and Ni were the key heavy elements contributing towards aqueous media pollution in the Singrauli area. Additionally, F was also considered one of the major contaminants. In health risk assessment, the higher values of hazard quotient (HQ) for non-carcinogens were associated with Mn, As, Mo, and F; and hazard index (HI) values > 1 were found in 70% and 55% of samples for children and adults, respectively. Carcinogenic risk (CR) for human health was associated with As. CR values in 56.7% (for adults) and 61.7% (for children) of the total samples exceeded 1 × 10-4. Monte Carlo simulation was applied and highlighted the significant risk factors responsible for both carcinogenic and non-carcinogenic health impacts. 19.2%, 7.3%, and 6.9% of the simulated HQ values for adults and 30.1%, 16.9%, and 10.6% for children were above the safe limit for F, As, and Mn, respectively. Additionally, only 43.8% and 24.8% of the simulated HI for adults and children were within the safe limit. Irrespective of age groups, all the simulated values of As in CR were above 1 × 10-6; and 60% (for adults) and 77.1% (for children) of the values were above 1 × 10-4. This outcome emphasizes the urgency of pollution control measures, especially for As, F, and Mn, to safeguard public health. Moreover, a multivariate statistical approach revealed that both geogenic and anthropogenic sources were responsible for contamination. Therefore, regular monitoring, filtration, and purification are mandatory to ensure safe drinking water for human consumption.

First exploratory study of gaseous pollutants (NO2, SO2, O3, VOCs and carbonyls) in the Luanda metropolitan area by passive monitoring

An air quality monitoring campaign for gaseous pollutants using passive sampling techniques was carried out, for the first time, at 25 locations in the metropolitan area of Luanda, Angola, in June 2023. Concentrations of benzene, toluene, ethylbenzene, xylenes, trimethylbenzenes, SO2 and NO2 were generally higher in locations more impacted by traffic. Benzene, SO2 and NO2 levels did not exceed the World Health Organisation guidelines. Ozone concentrations surpassed those documented for other African regions. Higher O3 formation potential values were recorded at heavy-trafficked roads. The top 5 species with potential for ozone formation were m,p-xylene, toluene, formaldehyde, propionaldehyde and butyraldehyde. The Mulenvos landfill presented a distinctive behaviour with a very low toluene/benzene ratio (0.47), while values close to 5 were obtained at traffic sites. The maximum levels of α-pinene, D-limonene, formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, butyraldehyde, benzaldehyde, valeraldehyde, hexaldehyde and crotonaldehyde were recorded at the landfill. The formaldehyde/acetaldehyde ratio ranged from 0.40 at the Mulenvos landfill to 3.0, averaging 1.8, which is a typical value for urban atmospheres. Acetaldehyde/propionaldehyde ratios around 0.4–0.6 were found in locations heavily impacted by traffic, whereas values between 0.7 and 1.2 were observed in green residential areas and in places with more rural characteristics. All hazard quotient (HQ) values were in the range from 1 to 10, indicating moderate risk of developing non-cancer diseases. The exception was the Mulenvos landfill for which a HQ of 11 was obtained (high risk). The cancer risks exceeded the tolerable level of 1 × 10−4, with special concern for the landfill and sites most impacted by traffic. A mean lifetime cancer risk of 9 × 10−4 was obtained. The cancer risk was mainly due to naphthalene, which accounted, on average, for 94.6% of the total.