Non-cancer Risk Research Articles

Per- and polyfluoroalkyl substances in Chinese commercially available red swamp crayfish (Procambarus clarkii): Implications for human exposure and health risk assessment

The extensive utilization of per- and polyfluoroalkyl substances (PFASs) has led to their pervasive presence in the environment, resulting in contamination of aquatic products. Prolonged exposure to PFASs has been linked to direct hepatic and renal damage, along with the induction of oxidative stress, contributing to a spectrum of chronic ailments. Despite the recent surge in popularity of red swamp crayfish as a culinary delicacy in China, studies addressing PFASs' exposure and associated health risks from their consumption remain scarce. To address this gap, our study investigated the PFASs’ content in 85 paired edible tissue samples sourced from the five primary red swamp crayfish breeding provinces in China. The health risks associated with dietary exposure were also assessed. Our findings revealed widespread detection of PFASs in crayfish samples, with short-chain perfluoroalkyl carboxylic acids (PFCAs) exhibiting the highest concentrations. Notably, the total PFAS concentration in the hepatopancreas (median: 160 ng/g) significantly exceeded that in muscle tissue (5.95 ng/g), as did the concentration of every single substance. The hazard quotient of perfluorohexanesulfonic acid (PFHxS) via consuming crayfish during peak season exceeded 1. In this case, a potential total non-cancer health risk of PFASs, which is mainly from the hepatopancreas and associated with PFHxS, is also observed (hazard index>1). Thus, it is recommended to avoid consuming the hepatopancreas of red swamp crayfish. Greater attention should be paid to governance technology innovation and regulatory measure strengthening for short-chain PFASs.

Swimming benefits outweigh risks of exposure to disinfection byproducts in pools

Disinfection of swimming pool water is critical to ensure the safety of the recreational activity for swimmers. However, swimming pools have a constant loading of organic matter from input water and anthropogenic contamination, leading to elevated levels of disinfection byproducts (DBPs). Epidemiological studies have associated increased risks of adverse health effects with frequent exposure to DBPs in swimming pools. Zhang et al. (2023b) investigated the occurrence of trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and haloacetaldehydes (HALs) in eight swimming pools and the corresponding input water in a city in Eastern China. The concentrations of THMs, HAAs, HANs, and HALs in swimming pools were 1–2 orders of magnitude higher than those detected in the input water. The total lifetime cancer and non-cancer health risks of swimmers through oral, dermal, inhalation, buccal, and aural exposure pathways were assessed using the United States Environmental Protection Agency's (USEPA) standard model and Swimmer Exposure Assessment Model (SWIMODEL). The results showed that dermal and inhalation pathways were the most significant for the associated cancer and non-cancer risks. This article provides an overview and perspectives of DBPs in swimming pools, the benefits of swimming, the need to improve the monitoring of DBPs, and the importance of swimmers’ hygiene practices to keep swimming pools clean. The benefits of swimming outweigh the risks from DBP exposure for the promotion of public health.

Source Apportionment and Health Risk Assessment of Heavy Metals in Dust Around Bus Stops in Kaifeng City Based on APCS-MLR Model

In order to reveal the influence of urban transportation systems on the quality of urban ecological environment, this study selected surface dust from bus stops, which is strongly disturbed by transportation, as the research object. The contents of eight heavy metals (V, Cr, Co, Ni, Cu, Zn, Cd, and Pb) in the dust were determined through inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-ASE). The spatial distribution characteristics and pollution levels of the eight heavy metals in the dust were analyzed using the geo-accumulation index method. A combined qualitative (correlation analysis and principal component analysis) and quantitative (absolute principal component scores-multiple linear regression model (APCS-MLR)) method was used to explore the sources of heavy metals in surface dust near bus stops. The spatial distribution characteristics of heavy metals from different sources were elucidated using the Kriging interpolation method. The health risk assessment model proposed by the United States Environmental Protection Agency was used to evaluate the human health risks. The results showed that the average values of ω(V), ω(Cr), ω(Co), ω(Ni), ω(Cu), ω(Zn), ω(Cd), ω(Pb), and ω(As) in the bus stop surface dust were 68.36, 59.73, 5.81, 19.34, 40.10, 208.32, 1.01, and 49.46 mg·kg-1, respectively. The concentrations of heavy metals (Cd, Zn, Pb, Cu, and Cr) in the dust were all higher than the background values in the surrounding dust, exceeding them by 3.37, 2.70, 2.01, 1.95, and 1.28 times, respectively. The order of the geo-accumulation index for the eight heavy metals was Cd > Zn > Pb > Cu > Cr > V > Ni > Co, with Cd, Zn, Cu, and Pb in the dust indicating mild pollution levels and the others showing no pollution. The source analysis results showed that Cr, Co, and Ni were natural sources, whereas Cu, Zn, Pb, and Cd were traffic sources, and V was derived from a combination of industrial and natural sources. The APCS-MLR results indicated that the average contribution rates of the four sources were as follows:natural source (34.17 %), traffic source (29.84 %), industrial-natural mixed source (14.64 %), and unknown source (21.35 %). The spatial distribution map of the contribution rate of the traffic source was consistent with the trends of traffic volume and bus route density distribution. According to the health risk assessment, the cancer risk and non-cancer risk for children were both higher than those for adults. Cr was the main non-cancer factor, and Cd was the main cancer-causing factor. Natural and traffic sources contributed the most to non-cancer risk and cancer risk, respectively.

Different variations in PM2.5 sources and their specific health risks in different periods in a heavily polluted area of the Beijing-Tianjin-Hebei region of China

The temporal variations in source-specific health risks of airborne particles and the differences in estimated source contributions to PM2.5 mass and PM2.5 exposure in severely polluted areas with the implementation of control measures remain unclear. In this study, PM2.5 samples were collected from a city of heavy pollution in the Beijing-Tianjin-Hebei region of China in two autumn-winter seasons during 2017–2019. The dominant species of PM2.5 was SNA (sum of sulfate, nitrate, and ammonium; 34 %), organic matter (OM; 23 %), and fine soil (15 %). PM2.5 concentration decreased across the years, whereas trace elements and OM showed the largest increases. A positive matrix factorization model combined with a health risk assessment method identified six sources, and quantified their specific health risks. The major sources of PM2.5 mass were secondary source (37 %) and coal combustion (20 %). The health risks (non-cancer risk for children, and cancer risk for children and adults) exceeded the guidelines, and were dominated by industrial processes (38 % and 40 %) and coal combustion (22 % and 52 %). The interannual decline in PM2.5 concentration was mainly due to reductions in biomass burning and soil dust, but the significant increase in health risks was attributed to the enhancement of industrial processes and coal combustion. On clean days, both PM2.5 mass and health risks were significantly affected by industrial processes and soil dust. As PM2.5 pollution increased, secondary source and coal combustion contributed significantly to PM2.5 mass. Coal combustion posed high health risks during pollution and the heating periods, especially in 2018–2019. Mn, Cr, and As were the dominant elements responsible for source-specific health risks. The quantitative result highlights the different responses of PM2.5 mass and health risks to recent mitigation measures, and suggests that both source concentrations and source-specific health risks should be of concern in the future.

Distribution and health risk of chromium in wheat grains at the national scale in China

Chromium (Cr) pollution may threaten food safety in China. In this study, the concentration, pollution level, distribution, and non-cancer risk of Cr in wheat grains grown in 186 areas across 28 provinces in China were investigated. Results indicated that mean concentration of Cr was 0.28 ± 2.5 mg/kg, dry mass (dm). Of the samples, 7.5 % were found to be polluted with Cr. The mean concentrations were in the following order: Northwest > Northeast > South > East > North > Southwest > Central China. Based on deterministic models, mean hazard quotient (HQ) values for adult males, adult females, and children were 0.11 ± 3.4, 0.11 ± 3.4, and 0.13 ± 3.5, respectively with < 6 % of HQ values ≥ 1. Eleven sites in northern China were identified as hotspots, whereas Gansu Province and Northwestern China were labeled as priority provinces and regions for risk control. The mean HQ values estimated by probabilistic risk assessment were two times greater than those estimated using deterministic models. The risk probabilities for adult males, adult females, and children were 4.81 %, 3.78 %, and 6.55 %, respectively. This study provides valuable information on Cr pollution in wheat grains and its risks at a national scale in China.

Association of depressive symptoms and sleep disturbances with survival among US adult cancer survivors

BackgroundDepression and sleep disturbances are associated with increased risks of various diseases and mortality, but their impacts on mortality in cancer survivors remain unclear. The objective of this study was to characterize the independent and joint associations of depressive symptoms and sleep disturbances with mortality outcomes in cancer survivors.MethodsThis population-based prospective cohort study included cancer survivors aged ≥ 20 years (n = 2947; weighted population, 21,003,811) from the National Health and Nutrition Examination Survey (NHANES) 2007–2018 cycles. Depressive symptoms and sleep disturbances were self-reported. Depressive symptoms were assessed using the Patient Health Questionnaire 9 (PHQ-9). Death outcomes were determined by correlation with National Death Index records through December 31, 2019. Primary outcomes included all-cause, cancer-specific, and noncancer mortality.ResultsDuring the median follow-up of 69 months (interquartile range, 37–109 months), 686 deaths occurred: 240 participants died from cancer, 146 from heart disease, and 300 from other causes. Separate analyses revealed that compared with a PHQ-9 score (0–4), a PHQ-9 score (5–9) was associated with a greater risk of all-cause mortality (hazard ratio [HR], 1.28; 95% CI, 1.03–1.59), and a PHQ-9 score (≥ 10) was associated with greater risk of all-cause mortality (HR, 1.37; 95% CI, 1.04–1.80) and noncancer mortality (HR, 1.45; 95% CI, 1.01–2.10). Single sleep disturbances were not associated with mortality risk. In joint analyses, the combination of a PHQ-9 score ≥ 5 and no sleep disturbances, but not sleep disturbances, was associated with increased risks of all-cause mortality, cancer-specific mortality, and noncancer mortality. Specifically, compared with individuals with a PHQ-9 score of 0–4 and no sleep disturbances, HRs for all-cause mortality and noncancer mortality in individuals with a PHQ-9 score of 5–9 and no sleep disturbances were 1.72 (1.21–2.44) and 1.69 (1.10–2.61), respectively, and 2.61 (1.43–4.78) and 2.77 (1.27–6.07), respectively, in individuals with a PHQ-9 score ≥ 10 and no sleep disturbances; HRs for cancer-specific mortality in individuals with a PHQ-9 score ≥ 5 and no sleep disturbances were 1.95 (1.16–3.27).ConclusionsDepressive symptoms were linked to a high risk of mortality in cancer survivors. The combination of a PHQ-9 score (≥ 5) and an absence of self-perceived sleep disturbances was associated with greater all-cause mortality, cancer-specific mortality, and noncancer mortality risks, particularly in individuals with a PHQ-9 score (≥ 10).

Metal(loid) contamination in Bangladesh: a comprehensive synthesis in different landscapes with ecological and health implications.

Elevated metal(loid) concentrations in soil and foodstuffs is a significant global issue for many densely populated countries like Bangladesh, necessitating reliable estimation for sustainable management. Therefore, a comprehensive data synthesis from the published literature might help to provide a wholistic view of metal(loid) contamination in different areas in Bangladesh. This study provided a clearer view of metal(loid) contamination status and their associated ecological and health risks in different land use and ecosystems in Bangladesh. Comprehensive analyses were performed on data gathered from 143 published articles using multiple statistical techniques including meta-analysis. Considering the potential loading of metal(loid), the data were summarized under various groups, including coastal, rural, urban and industrial regions. Also, the concentrations of seven metal(loid)s, e.g., cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), zinc (Zn), and arsenic (As) in soil, sediment, cereal, vegetable, fruit, surface water and groundwater were included. Results showed that the relative concentrations of metal(loid)s in comparison to the maximum permissible limit (MPL) were mostly less than one, although they varied significantly for locations and individual metal(loid). However, the normalized cumulative relative concentrations over the MPL for all seven metal(loid)s across different environmental samples were 4.75, 2.97, 1.51 and 2.79 for coastal, industrial, rural and urban areas, respectively, which wasdue to the higher concentration of Cd, Cr and Cu. Similar to the metal(loid) concentrations, the average of cumulative median non-cancer risks for all metal(loid)s was in the order of industrial (6.46) > urban (4.05) > rural (3.83) > coastal (2.41). This research outcome will provide a foundation for future research on metal(loid)s and will help in pertinent policy-making by the relevant authorities in Bangladesh.

Spatial variations in metals of groundwater in Naini industrial area: assessing probable sources and human health risk

ABSTRACT Groundwater forms the major source of drinking water worldwide; however, its quality has been compromised due to various human activities. The contamination of groundwater with metals have increased the health risk of the consumers. In pursuit of risk assessment and source apportionment studies of groundwater of Naini Industrial Area, Prayagraj, Uttar Pradesh, India; groundwater samples (n = 60) were collected from distinct sampling locations spanning the study area. Inductively coupled plasma-mass spectrometry (ICP-MS) was employed to analyse the concentrations of Aluminium (Al), Arsenic (As), Barium (Ba), Cadmium (Cd), Chromium (Cr), Cobalt (Co), Copper (Cu), Iron (Fe), Manganese (Mn), Nickel (Ni), Lead (Pb), Selenium (Se), Strontium (Sr), Vanadium (V) and Zinc (Zn). Amongst all the metals analysed, Al and Fe surpassed drinking water standards in more than 50% of the samples. Principal component analysis (PCA) extracted four factors that collectively accounted for 76.3% of the variability in the data. As illustrated by PCA, metals in the groundwater can be attributed to geological origins combined with anthropogenic contributions. Considering the central tendency of the metals, the non-cancer risk as per United States Environmental Protection Agency (USEPA) methodology depicted by Hazard Quotient (HQ) of the metals did not exceed unity and can be inferred that they did not pose risk to the human health individually. However, the combined risk of the metals as depicted by Hazard Index (HI) suggested considerable hazard to the child residents with HI value of 1.27. Across all the sampled sites, the HI values varied from 0.48 to 4.07 for males, 0.41 to 3.51 for females, and 0.76 to 6.51 for children. Considering central tendency, carcinogenic risk associated with As and Cr was determined to be within the tolerable cancer risk value of 1 × 10−4. Nevertheless, the cancer risk for the groundwater surpassed the acceptable limit in few of the locations rendering them unsuitable for drinking without treatment.

Occupational exposure, carcinogenic and non-carcinogenic risk assessment of formaldehyde in the pathology labs of hospitals in Iran

Formaldehyde, a known carcinogenic compound, is commonly used in various medical settings. The objective of this study was to assess the carcinogenic and non-carcinogenic risks associated with occupational exposure to formaldehyde. This study was conducted in the pathology labs of four hospitals in Tehran. Cancer and non-cancer risks were evaluated using the quantitative risk assessment method proposed by the United States environmental protection agency (USEPA), along with its provided database known as the integrated risk information system (IRIS). Respiratory symptoms were assessed using the American thoracic society (ATS) questionnaire. The results indicated that 91.23% of exposure levels in occupational groups exceed the NIOSH standard of 0.016 ppm. Regarding carcinogenic risk, 41.03% of all the studied subjects were in the definite carcinogenic risk range (LCR > 10−4), 23.08% were in the possible carcinogenic risk range (10−5 < LCR < 10−4), and 35.90% were in the negligible risk range (LCR < 10−6). The highest index of occupational carcinogenesis was observed in the group of lab technicians with a risk number of 3.7 × 10−4, followed by pathologists with a risk number of 1.7 × 10−4. Furthermore, 23.08% of the studied subjects were within the permitted health risk range (HQ < 1.0), while 76.92% were within the unhealthy risk range (HQ > 1.0). Overall, the findings revealed significantly higher carcinogenic and non-carcinogenic risks among lab technicians and pathologists. Therefore, it is imperative to implement control measures across various hospital departments to mitigate occupational formaldehyde exposure levels proactively. These findings can be valuable for policymakers in the health sector, aiding in the elimination or reduction of airborne formaldehyde exposure in work environments.

Occurrence, efficiency of treatment processes, source apportionment and human health risk assessment of pharmaceuticals and xenoestrogen compounds in tap water from some Ghanaian communities

The occurrence of pharmaceuticals and xenoestrogen compounds (PXCs) in drinking water presents a dire human health risk challenge. The problem stems from the high anthropogenic pollution load on source water and the inefficiencies of the conventional water treatment plants in treating PXCs. This study assessed the PXCs levels and the consequential health risks of exposure to tap water from selected Ghanaian communities as well as that of raw water samples from the respective treatment plants. Thus the PXCs treatment efficiency of two drinking water treatment plants in the metropolises studied was also assessed. The study also conducted source apportionment of the PXCs in the tap water. Twenty six (26) tap and raw water samples from communities in the Cape Coast and Sekondi-Takoradi metropolises were extracted using SPE cartridges and analysed for PXCs using Ultra-fast-HPLC-UV instrument. Elevated levels of PXCs up to 24.79 and 22.02 μg/L were respectively recorded in raw and tap water samples from the metropolises. Consequently, elevated non-cancer health risk (HI > 1) to residential adults were found for tap water samples from Cape Coast metropolis and also for some samples from Sekondi-Takoradi metropolis. Again, elevated cumulative oral cancer risks >10−5 and dermal cancer risk up to 4 × 10−5 were recorded. The source apportionment revealed three significant sources of PXCs in tap water samples studied. The results revealed the inefficiency of the treatment plants in removing PXCs from the raw water during treatments. The situation thus requires urgent attention to ameliorate it, safeguarding public health. It is recommended that the conventional water treatment process employed be augmented with advanced treatment technologies to improve their efficacy in PXCs treatment.

Current Phthalate Exposure Risks of Rural Population in the Northwest China: Evidence from an Internal Exposure Study.

Phthalates (PAEs) are synthetic chemicals widely used in industrial and personal consumer products as adhesives or plasticizers. PAEs have been demonstrated to have toxic effects on the human body. However, biological monitoring data for the internal PAE exposure levels of Chinese rural residents are still limited. The present study investigated the exposure levels of ten phthalate metabolites (mPAEs) of rural residents in Northwest China. The results showed that mPAEs were wildly prevalent in urine and the geometric mean concentration of Σ10mPAEs was 957.02 ng mL-1 (adjusted by specific gravity). Mono-n-butyl phthalate (MBP) and metabolites of di(2-ethylhexyl)-phthalate (DEHP) were the most dominant mPAEs in urine, with specific gravity adjusted median concentrations of 174.67 and 156.30 ng mL-1, respectively. Urinary concentrations of mPAEs were significantly associated with age, body mass index and economic level (p < 0.05). By calculating the percentage and relative conversion rate of DEHP metabolites, it was found that the degree of oxidative metabolism of DEHP in children was significantly higher than that in adults (p < 0.05), indicating that the pathway and degree of DEHP oxidation were age-related. The risk assessment showed that 59.12% of rural residents may have a noncancer risk from PAE exposure. This study provides important basis for assessing the occurrence and exposure of urinary phthalate metabolites among rural residents in China.

Groundwater in the coastal areas of Ghana: Quality and associated health risks

Self-supply water sources, particularly groundwater sources, play key roles in the water supply ecosystem of developing countries. Recent studies indicate that groundwater sources in coastal communities in Ghana are under threat from improper waste management practices, seawater intrusion and atmospheric aerosol deposition. In this study, Water Quality Index (WQI) and Nemerow's Pollution Index (NPI) were employed to assess groundwater quality in four coastal communities of Ghana. The health risks associated with metal pollution of groundwater were investigated using incremental life cancer risk and hazard quotient. pH of groundwater in all the studied communities were acidic during the rainy season. Electrical conductivity ranged from 0.44 to 2.61 mS/cm in the rainy season and from 0.43 to 2.45 mS/cm in the dry season for the four studied locations. Results also showed brackish conditions and mineralization of groundwater in Winneba, Accra, and Keta. Mean nitrate concentrations in Winneba and Accra were higher than the WHO standards for both the rainy and the dry season. Arsenic was higher than the acceptable level in Accra and Keta during the dry season, while iron was higher than the acceptable levels in Accra in both the rainy and dry seasons. Principal Component Analyses showed that Pb, As, and Fe had the highest loading in the first component in Essiama, while PO43-and Pb had the highest loading in the second component in Accra. WQI showed that the quality of groundwater in all the studied communities ranged from marginal to poor indicating that groundwater in the coastal communities often or usually departs from desirable quality. NPI revealed that NO3- , As, and Fe contribute to groundwater deterioration. Health risk assessment showed that As posed a high cancer risk in Accra and potential cancer risk in Essiama, Winneba, and Keta during the dry season. As also posed potential cancer risk in Accra during the rainy season. Non-cancer health risk was observed for As in Accra and Keta. The findings of this study suggest urgent regulations and monitoring strategies to improve groundwater quality in the coastal communities of Ghana.

Heavy metals in urban soil: Contamination levels, spatial distribution and human health risk assessment (the case of Ufa city, Russia)

The article examines the concentration of 9 heavy metals (Hg, Pb, Zn, Cr, Co, Ni, Cu, Ba and V) and As in the soil cover of the urban area in one of the largest cities in Russia, Ufa (the Republic of Bashkortostan). It is compared with aggregated data of concentrations on urbanized areas in surface soils throughout the world. For elements exceeding the average background values in soils of the urban area (Cr, Ni, Cu and Co), the average concentrations in the city soils were 346, 101, 51 and 18 ppm, respectively. Using enrichment factor (EF), geoaccumulation index (Igeo), and concentration coefficients (CC), Cr and Ni were identified as elements entering the soil cover as a result of anthropogenic pollution. Although the level of their enrichment and contamination of soils in the most territory of the city corresponds to the moderate class, there are sites with critical threshold values.Spatial analysis of heavy metals distribution was carried out based on the results of pollution load index (PLI) and ecological risk factor (Er) calculations with the use of graphical presentation of results, which allowed specific and detailed description of sites calling for special attention. The use of cluster analysis allowed dividing the sample of chemical elements into groups with probably similar sources of entry into the environment.Monte Carlo modeling of risk calculation showed negligible non-cancer risks for both adult and child populations in most of the city. While children's exposure to Cr was of concern in the more residential part of the city, free of large industrial plants, As posed a threat with respect to cancer risks in the southern part of the city, with elevated concentrations and other HMs in vicinity of the oil refineries.

Pollution characteristics and risk assessment of organophosphate esters (OPEs) in typical industrial parks in Southwest China.

As alternative substances of PBDEs, organophosphate esters (OPEs), an emerging organic pollutant, were increasingly produced and used in many kinds of industries and consumer products. However, OPEs also have various adverse toxic effects. Information on the pollution levels and exposure to OPEs in related industries is still limited. This study presented data on OPE contamination in the soil, leaf, and river water samples from seven typical industrial parks in Southwest China. Total concentration of seven OPEs (Σ7OPE) including tri-n-butyl phosphate (TnBP), tris-(2-ethylhexyl) phosphate (TEHP), tris-(2-butoxyethyl) phosphate (TBEP), tris-(2-carboxyethyl) phosphine (TCEP), triphenyl phosphate (TPhP), tris-(1,3-dichloro-2-propyl) ester (TDCPP), and tris-(chlorisopropyl) phosphate (TCPP) in the soil samples (36.2 ~ 219.7 ng/g) and the surrounding river water samples (118.9 ~ 287.7 ng/L) were mostly lower than those in other studies, while the Σ7OPE level in the leaves (2053.3 ~ 8152.7 ng/g) was relatively high. There were significant differences in the concentration and distribution of OPEs in the surrounding environment of different industrial parks. TDCPP, TnBP, and TCPP could be used as the characteristic compound in soil samples from auto industrial park, river samples from shoe making industrial park, and leaf samples from logistics park, respectively. The parameter m (the content ratio of chlorinated OPEs to alkyl OPEs) was suggested to distinguish the types of industrial park preliminary. When m ≥ 1, it mainly refers to heavy industries sources such as automobiles, electronics, and machinery, etc. When m<1, it mainly for the light industrial sources such as textile industry, transportation services, and resources processing, etc. For logistics park, furniture park and Wuhou comprehensive industrial park, the volatilization of materials was the main sources of OPEs in the surrounding environment, while more effort was required to strengthen the pollution control and management of the waste water and soil in the pharmacy industrial park, shoe making industrial park and auto industrial park. Risk assessment showed that there was a negligible non-cancer and carcinogenic risk in the soil, while high attention should be paid to the non-cancer risk for children.

Variations of source-specific risks for inhalable particles-bound PAHs during long-term air pollution controls in a Chinese megacity: Impact of gas/particle partitioning

Gas/particle (G/P) partitioning is a determining factor that drives the behavior of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere. To comprehend the variations and impacts of PAHs G/P partitioning on inhalation risks from different sources, atmospheric PAHs in Chengdu were studied from January 2009 to January 2021. Chengdu's air quality demonstrated improvement, with a noticeable decline in PM10 (from 238 to 103 μg m−3), PM10-bound PAHs mass concentrations (from 0.08 to 0.01 μg m−3), as well as PAHs inhalation non-cancer (from 63.5 to 7.1) and cancer risks (from 6.2 × 10−5 to 7.7 × 10−6). Decreasing trends were also observed in the concentrations of organic carbon (OC) and the values of absorptive G/P partitioning coefficient (Kp, OM) from 2009 to 2020, indicating a slight decrease in the PM absorptive capacity. A positive matrix factorization (PMF) model utilized three distinct datasets: PMFpp (particle-phase PAHs only), PMFtot (total PAHs concentrations), and PMFpp/gas (particle-phase in parallel with gas-phase PAHs). PMFpp and PMFpp/gas provide reasonable source apportionment and source-specific risk results. However, daily variations in source contributions of PMFtot were found to be unreasonable. PMFpp/gas and PMFtot could identify a source of low molecular weight PAHs (LPAHs) related to temperature, and a significantly positive correlation between LPAHs and temperature was discovered. Gas/particle partitioning of PAHs showed a notable impact on source-specific risks associated with coal and biomass combustion (CC&BC). The findings contribute to our understanding of the variation in PAHs G/P partitioning and the PM absorptive capacity resulting from effective air pollution control in China. Additionally, they offer prerequisite information for incorporating semi-volatile organic compounds in source apportionment and source-specific risk assessment.

Insights into pollution characteristics and human health risks of plasticizer phthalate esters in shellfish species

The ubiquitous application of phthalate esters (PAEs) as plasticizers contributes to high levels of marine pollution, yet the contamination patterns of PAEs in various shellfish species remain unknown. The objective of this research is to provide the first information on the pollution characteristics of 16 PAEs in different shellfish species from the Pearl River Delta (PRD), South China, and associated health risks. Among the 16 analyzed PAEs, 13 were identified in the shellfish, with total PAE concentrations ranging from 23.07 to 3794.08 ng/g dw (mean = 514.35 ng/g dw). The PAE pollution levels in the five shellfish species were as follows: Ostreidae (mean = 1064.12 ng/g dw) > Mytilus edulis (mean = 509.88 ng/g dw) > Babylonia areolate (mean = 458.14 ng/g dw) > Mactra chinensis (mean = 378.90 ng/g dw) > Haliotis diversicolor (mean = 335.28 ng/g dw). Dimethyl phthalate (DMP, mean = 69.85 ng/g dw), diisobutyl phthalate (DIBP, mean = 41.39 ng/g dw), dibutyl phthalate (DBP, mean = 130.91 ng/g dw), and di(2-ethylhexyl) phthalate (DEHP, mean = 226.23 ng/g dw) were the most abundant congeners. Notably, DEHP constituted the most predominant fraction (43.98 %) of the 13 PAEs detected in all shellfish from the PRD. Principal component analysis indicated that industrial and domestic emissions served as main sources for the PAE pollution in shellfish from the PRD. It was estimated that the daily intake of PAEs via shellfish consumption among adults and children ranged from 0.004 to 1.27 μg/kgbw/day, without obvious non-cancer risks (< 0.034), but the cancer risks raised some alarm (2.0 × 10−9–1.4 × 10−5). These findings highlight the necessity of focusing on marine environmental pollutants and emphasize the importance of ongoing monitoring of PAE contamination in seafood.

Evaluating the human health risks of heavy metal contamination in copper and steel factory effluents in Nnewi, Anambra State, Nigeria

Heavy metal (HM) contamination above permissible limits poses a risk to human health. The study evaluated the health risk (cancer and non-cancer) of exposure to copper (Cu) and steel factory wastes on water samples near the factory based on the hazard quotient (HQ) derived from the HM concentrations. Triplicate water samples were collected by purposive sampling and their concentrations of selected HMs [Pb, Zn, Cu, Mn, Mg, Fe, Cd] were analyzed by Atomic Absorption Spectrometry. The health risks were determined from the concentrations of HMs in water samples ingested orally. The range concentrations were [Fe, 0.074–0.178], [Pb, 0.011–0.013], [Cd, 0.005–0.02], and [Mn, 0.023–0.045] which were above the reference values set by World Health Organization. The contribution of the individual metal to the chronic daily intake (CDI) in the three samples are Mg>Fe>Mn>Zn>Cd>Pb>Cu. In the three different samples, the CDI for Mg was highest in the factory borehole [0.15523]. Comparing the CDI values from the three different collection points, Cu, Pb, Zn and Fe were highest from the factory effluent. Mg contributed the highest HQ [5.46307] in all the water samples, followed by Pb [3.87618] and then Cd[2.64009], which reflect their significantly high hazard indices observed. The incremental life cancer risk [ILCR] via ingestion showed that the cancer risk resulting from Cd in the different sources demands attention. The factory effluent recorded the highest mean levels of the metals analyzed, which were higher than the permissible limits. Magnesium contributed the highest non-cancer risk, while Cd had the highest cancer risk.

Health and ecological risk assessment of heavy metals in water and sediments within a data scarce urban catchment in Tanzania – A case of Ngerengere River, Morogoro Municipality

Low-, middle- and high-income countries, exhibit indications of risks associated with water quality. The study investigated heavy metal concentrations in surface water and sediments within the Ngerengere River and its tributaries (Kikundi, Bigwa, and Morogoro) drain within in the Morogoro Municipality of Tanzania, an Urban Catchment Area (UCA) with limited available data mainly because of inadequate monitoring and reporting capabilities. Analysis of health and ecological risks associated with heavy metal pollution was also carried out using health risk assessments models, pollution indices, and multivariate analysis techniques. Between the dry and wet seasons of 2023, water and sediment samples from (13) sampling stations strategically established along the Ngerengere river and its tributaries were analyzed for six heavy metals (Pb, Cr, Ni, Cd, Cu and Zn) using the Atomic Absorption Spectrophotometer Model Perking Elmer 850 Graphite Furnace and Perking Elmer AS 800 Auto-sampler coupled with a computer interface for operational, displaying and reading the results. The calculated degree of water contamination (Cd) values in river water in both dry and wet seasons ranged from 0 to 6.803 indicating low and high degrees of contamination respectively. Heavy metal concentration in sediment decreases in the order of Zn&gt;Ni&gt;Cr&gt;Cu&gt;Cd&gt;Pb. The non-cancer risk index (HI) via ingestion and dermal pathways in dry and wet seasons for both children and adult groups was &lt;1 hence no non-cancer risk, However, cumulative dermal and ingestion exposure in both children and adults indicated potential cancer risk in dry and wet season. The analysis of ecological risks associated with heavy metal enrichment in the sediment indicated high enrichment of sediments with Cd, Ni and Zn. Conclusively, in wet months, risk indices tend to be low, while in dry months, they typically remain high.

Safety evaluation of organochlorine pesticides and polybrominated diphenyl ethers in imported canned fish in Nigeria

Organochlorine pesticide (OCP) and polybrominated diphenyl ether (PBDE) concentrations were measured in thirty popular brands of imported canned fish (mackerel, sardines, and tuna) in Nigeria to ascertain potential threats to humans arising from their consumption. The Σ20 OCP concentrations in mackerel ranged from 0.47 to 7.36 ng g−1, while those of tuna and sardines varied from 1.06 to 2.19 and 0.11 to 12.7 ng g−1, respectively. The Σ39 PBDE concentrations in mackerel varied from 0.06 to 4.21 ng g−1, while those of tuna and sardines ranged from 0.19 to 3.18 and 0.04 to 8.26 ng g−1, respectively. The estimated daily intake (EDI) of OCPs and PBDEs from ingestion of the canned fish by adults and children were in the magnitude of 0.03 to 17.6 ng kg−1 bw day−1 and 9.9 × 10−3 to 11.5 ng kg−1 bw day−1 respectively. The hazard index (HI) and total cancer risk (TCR) values for OCPs and PBDEs from ingestion of the canned fish were less than 1 and 10−6, respectively. The dietary intakes of OCPs and PBDEs from these brands of canned fish by adults and children result in no adverse non-cancer and cancer risks.

Occurrence and seasonal variation of organochlorine pesticides in selected vegetable farmlands in Lagos State, Nigeria.

Pest infestation in crop production have increased farmers' interest in pesticides use with short and long term consequences. This study investigated the occurrence and seasonal variations of organochlorine pesticide residues in vegetable farms in selected areas of Lagos State. Non carcinogenic and carcinogenic risk assessment was also evaluated. Soil samples were collected during the wet and dry seasons at soil depth of 0-30 cm. Gas chromatography coupled with an Agilent mass spectrometer was used to analyse organochlorine residues (alpha-lindane,lindane, delta.-lindane, aldrin, heptachlor epoxide, alpha.-endosulfan, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), endrin, endosulfan, m,p'-dichlorodiphenyldichloroethane (m,p'-DDD), endosulfan sulfate, o,p'-dichlorodiphenyltrichloroethane (o,p'-DDT) and endrin ketone) in soil. Heptachlor epoxide showed maximum concentration of 43.03 mg/kg in Station 19 in Western zone during the dry season while m,p'-DDD and endosulfan had minimum value of 0.004 mg/kg in Station 2 and Station 5 respectively during the wet season in the Far eastern zone. The concentrations of organochlorine residues were intermediate in the Eastern zone in both seasons. There was significant (p < 0.05) increase in dry season concentrations when compared to wet season. The risk assessment indicated Hazard Quotient (HQ) > 1 for non-cancer risk and cancer risk > 10-6. Thus a need for stringent monitoring programs for pesticides.