Environmental determinants of polycyclic aromatic hydrocarbons exposure at home, at kindergartens and during a commute

Urinary Metabolites of Polycyclic Aromatic Hydrocarbons of Rural Population in Northwestern China: Oxidative Stress and Health Risk Assessment

Polycyclic aromatic hydrocarbon (PAH) exposure is suspected to be linked to oxidative damage. Herein, ten PAH human exposure biomarkers [hydroxylated PAH metabolites (OH-PAHs)] and five oxidative stress biomarkers (OSBs) were detected in urine samples collected from participants living in a rural area (n = 181) in Northwestern China. The median molar concentration of ΣOH-PAHs in urine was 47.0 pmol mL-1. The 2-hydroxynaphthalene (2-OHNap; median: 2.21 ng mL-1) was the dominant OH-PAH. The risk assessment of PAH exposure found that hazard index (HI) values were <1, indicating that the PAH exposure of rural people in Jingyuan would not generate significant cumulative risks. Smokers (median: 0.033) obtained higher HI values than nonsmokers (median: 0.015, p < 0.01), suggesting that smokers face a higher health risk from PAH exposure than nonsmokers. Pearson correlation and multivariate linear regression analysis revealed that ΣOH-PAH concentrations were significant factors in increasing the oxidative damage to deoxyribonucleic acid (DNA) (8-hydroxy-2'-deoxyguanosine, 8-OHdG), ribonucleic acid (RNA) (8-oxo-7,8-dihydroguanine, 8-oxoGua), and protein (o, o'-dityrosine, diY) (p < 0.05). Among all PAH metabolites, only 1-hydroxypyrene (1-OHPyr) could positively affect the expression of all five OSBs (p < 0.05), suggesting that urinary 1-OHPyr might be a reliable biomarker for PAH exposure and a useful indicator for assessing the impacts of PAH exposure on oxidative stress. This study is focused on the relation between PAH exposure and oxidative damage and lays a foundation for the study of the health effect mechanism of PAHs.

The underappreciated role of fugitive VOCs in ozone formation and health risk assessment emitted from seven typical industries in China

Fugitive emission from industrial sources may result in ozone formation and health risk, while the exact contribution of this source remains incompletely understood. In this study, emission characteristics, ozone formation potential (OFP) and health risk of fugitive VOCs in 7 representative industries were investigated. Chemical material industry was the dominant contributor to VOCs of fugitive emission in comparison with other industries. The OFP of VOCs from fugitive emission was in the range of 1.45 × 103-3.98 × 105 µg/m3, with a higher value than that of organized emission in seven industries except for the coking industry and the chemical material industry, suggesting that fugitive VOCs should be taken into account while developing control strategies. Acetaldehyde, m,p-xylene, n-nonane, ethylene, vinyl chloridethe and other high OFP-contributing species were the major reactive species that should be targeted. Health risk assessment investigated non-cancer and cancer risks of fugitive VOCs in 7 industries were all above safe level (HR > 1 and LCR > 1 × 10-4), posing remarkable health threats to human health. OVOCs were the main contributor to non-cancer risk, while halohydrocarbons and aromatics contributed most to cancer risks, posing remarkable health threat on human health. Our findings highlighted the contribution of fugitive VOCs on ozone formation and health risk was underestimated, indicating which should be considered in emission control strategies of industrial sources.

The association between exposure to polycyclic aromatic hydrocarbons and birth outcomes: A systematic review and meta-analysis of observational studies

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to adverse birth outcomes; however, to date, the available studies on such relations, with the exception of birth weight, has not been systematically synthesized. We conducted a systematic review and meta-analysis of the available observational studies on the association of maternal exposure to PAHs and their metabolites during pregnancy with indicators of fetal growth and gestational age at delivery. We searched Web of Science, PubMed and Scopus systematically for all relevant published papers in English until 13 January 2023. Random effects meta-analysis was applied to synthesize the association estimates. Publication bias was assessed using Egger's regression. A total of 31 articles were included in our review (n = 703,080 participants). Our quality assessment of reviewed papers showed that 19 research had excellent, nine had good, and three had fair quality. Most of the reviewed studies on exposure to PAHs and their metabolites with gestational age and preterm birth (seven studies) reported no statistically significant association. Eight studies were eligible for our meta-analysis. Results of the meta-analysis indicated that higher levels of maternal urinary 1-OHP was associated with lower birth weight, birth length and head circumference and a higher risk of low birth weight (LBW). However, these associations were not statistically significant. Similarly, the combined association between maternal urinary 1-OHP and newborn's Ponderal index (PI) and Cephalization index were not statistically significant. Overall, our systematic review and meta-analysis suggested a potential adverse impact of exposure to PAHs on LBW, HC, and CC; however, further studies are required to be able to draw concrete conclusions on such associations.

Inhalation bioaccessibility and risk assessment for PM-bound organic components: Co-effects of component physicochemical properties, PM properties, and sources

Inhalation bioaccessibility and deposition in respiratory tracts of organic components in atmospheric particulate matter (PM) are key factors for accurately estimating health risks and understanding human exposures. This study evaluated the in-vitro inhalation bioaccessibility of polycyclic aromatic hydrocarbons (PAHs) and PAH derivatives, phthalic acid esters (PAEs), polychlorinated biphenyls (PCBs), and organophosphate flame retardants (OPFRs) in size-resolved PM from a Chinese megacity. The bioaccessibility ranged from 0.2% to 77.8% in the heating period (HP), and from 0.7% to 94.2% in the non-heating period (NHP). Result suggests that less hydrophobic organics might be more bioaccessible. Bioaccessibility of medium logKow organics in sizes > 0.65 µm was significantly inhibited by high carbon fractions, indicating the co-effects. Then, this is the first study to explore effects of sources on inhalation bioaccessibility of organics. Coal and biomass combustion in HP and traffic emission in NHP negatively correlated with bioaccessibility. Secondary particles also negatively correlated with bioaccessibility of medium logKow organics. Incremental lifetime cancer risk (ILCR) and non-cancer risk (HQ) for all measured components in PM10 were estimated after considering the bioaccessibility and deposition efficiencies and the HQ and ILCR were within the acceptable range. BaP and DEHP were strong contributors to HQ and ILCR, respectively.

Level of BTEX in the Areas of Domestic Waste Incinerators in Northern Vietnam: A Comprehensive Assessment of Contamination, Composition and Human Health Risk

The trend of the treatment of solid domestic waste by the domestic waste incinerator system is an option to improve waste management and to reduce the negative impacts on the environment and human health. Benzene, toluene, ethylbenzene, and xylenes (o-, m- and p-) (BTEX) are toxic chemical environmental contaminants that are released from different sources such as the domestic waste incinerator system. To determine the concentration of BTEX in the ambient air from these incinerator areas, the research team conducted four sampling campaigns in April, June, September, and November 2021, with a total of 80 samples collected. Concentrations of benzene, toluene, (m,p)-xylenes, o- xylenes and ethylbenzene ranged from 4.53 to 36.75 µg/m³, from 16.29 µg/m³ to 125.36 µg/m³, from 2.82 µg/m³ to 31.45 µg/m³, from 1.42 µg/m³ to 25.61 µg/m³, from 1.32 µg/m³ to 10.79 µg/m³, respectively. As a result of the risk assessment, it was determined that the incinerator's exhaust gas caused secondary environmental damage, impacting the health of not only workers but also people living in nearby communities. On that basis, the article recommends applying a number of management measures to minimize the negative impacts of the operation of the solid waste incinerator on the environment and the health of the workers operating the incinerator.

Exposure assessment of children living in homes with hookah smoking parents to polycyclic aromatic hydrocarbons: urinary level, exposure predictors, and risk assessment

Children are extremely liable to indoor air pollutants as their physiology and a few metabolic pathways are different from those of adults. The present cross-sectional study aimed to assess exposure of children living with parents who use hookah tobacco smoke to polycyclic aromatic hydrocarbons (PAHs) using a biomonitoring approach. The study was conducted on 25 children (7-13 years of age) exposed to hookah smoke at home and 25 unexposed age-matched children. Urinary levels of five metabolites of PAHs were quantified via headspace gas chromatography-mass spectrometry (GC-MS). Urinary malondialdehyde (MDA) was measured, as well. Information regarding the sociodemographic and lifestyle conditions was collected through interviews using managed questionnaires. The urinary 1-OH-NaP and 9-OH-Phe concentrations were respectively 1.7- and 4.6-folds higher in the case samples compared to the control group (p < 0.05). In addition, urinary MDA levels were 1.4 times higher in the exposed children than in the unexposed group, but the difference was not statistically significant (p > 0.05). Increasing the consumption of grilled and meat food in the diet increased the participants' urinary 2-OH-Flu and 1-OH-Pyr levels, respectively. Moreover, sleeping in the living room instead of the bedroom at night was a significant predictor of high 1-OH-NaP and 2-OH-NaP concentrations in the children's urine. Overall, the findings confirmed that children living in their homes with hookah-smoking parents were significantly exposed to naphthalene and phenanthrene. Hence, implementing protective measures is critical to reduce the exposure of this group of children.

Biomonitoring of BTEX in primary school children exposed to hookah smoke

Hookah smoking is one of the major indoor sources of benzene, toluene, ethylbenzene, and xylenes (BTEX). This study aimed to investigate the potential exposure to BTEX among primary school children, particularly those exposed to hookah smoke. This cross-sectional study was conducted in Khesht, one of the southwestern cities in Iran, in mid-June 2020. Totally, 50 primary school children exposed to hookah smoke were chosen as the case group and 50 primary school children were selected as the control group. Urinary un-metabolized BTEX was measured by a headspace gas chromatography mass spectrometry (GC-MS). Additionally, a detailed questionnaire was used to gather data and information from the students' parents. The mean levels of urinary benzene, toluene, ethylbenzene, m,p-xylene, and o-xylene were 1.44, 5.87, 2.49, 6.93, and 7.17 μg/L, respectively in the exposed children. Urinary BTEX was 3.93-folds higher in the case group than in the controls (p<0.05). Household cleaning products, the floor on which the house was located, children's sleeping place, and playing outdoors were found to be important factors in predicting urinary BTEX levels. Overall, it was found necessary to avoid indoor smoking to prevent the emission of BTEX compounds via exhaled mainstream smoke and to protect vulnerable non-smokers, especially children, from exposure to second-hand and third-hand smoke.

Green space exposure during pregnancy and umbilical cord blood levels of liver enzymes

Evidence has suggested better pregnancy outcomes due to exposure to greenspace; however, the studies on such an association with the level of liver enzymes in the cord blood are still nonexistent. Hence, this study investigated the relationship between exposure to greenspace during the entire pregnancy and gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels in cord blood samples. We selected 150 pregnant women from our pregnancy cohort in Sabzevar, Iran (2018). Greenspace exposure was characterized based on (i) residential distance to green space, (ii) time spent in public/private green spaces, (iii) residential surrounding greenspace, (iv) visual access to greenspace, and (v) number of indoor natural pot plants at home. We developed linear regression models to investigate the adjusted associations of greenspace exposure with enzyme levels. Each one interquartile range (IQR) increase in the residential surrounding greenspace (100 m buffer) was related to a reduction of -12.58 (U/L) (95% CI -22.86, -2.29), -3.35 (U/L) (95% CI -5.50, -1.20), and -0.57 (U/L) (95% CI -1.12, -0.02) in the levels of GGT, AST, and ALT, respectively. Moreover, a similar association was observed for the time the participants spent in green spaces. A decrease in the residential distance to large green spaces was related with lower cord blood levels of AST, ALT, and GGT. Having a window with greenspace view at home was significantly related to lower AST level. The results for the indoor plant pots were not conclusive. Our findings suggested an inverse relationship between greenspace exposure during pregnancy and cord blood levels of liver enzymes. Further studies in other settings and populations are needed to confirm our findings.

Sources and uncertainties of health risks for PM2.5-bound heavy metals based on synchronous online and offline filter-based measurements in a Chinese megacity

Accurate measurements of PM_2.5 related heavy metals (HMs) and some components are critical to better understanding the sources and health risks of PM_2.5. HMs and other components in PM_2.5 were simultaneously measured using online and offline filter-based methods in a Chinese megacity. Online Mn, Pb, Cu, and Zn concentrations exhibited good correspondence with offline results (R² ≥ 0.7, relative biases = -3%-22%). Some differences were observed for Cr, As, Co, and V. The assessment of online and offline probabilistic health risks indicated that non-cancer and total cancer risks were higher than the acceptable limits. Different analytical methods of As may result in different uncertainties in risk analysis. The positive matrix factorization model (PMF) was used to perform online and offline source apportionment. Five sources (coal combustion, vehicle source, industrial source, secondary source, and resuspended dust) were identified. Lower online percentage contribution of resuspended dust (8%) might relate to the lack of Si and Al measurements. The different rate contributions of vehicle source were potentially linked to the different time resolutions of the online and offline data. The assessment of online and offline source-specific health risks revealed that industrial source and coal combustion were the most important sources. Online and offline source-specific risks were not significantly different (P > 0.05). This contrastive study not only helps decision makers to manage health risk more effectively, but also provides insights into the applicability of online and offline measurements for quantifying source-specific risks.

The Influence of Environmental Polycyclic Aromatic Hydrocarbons (PAHs) Exposure on DNA Damage among School Children in Urban Traffic Area, Malaysia

This study aimed to investigate the association between particulate PAHs exposure and DNA damage in Malaysian schoolchildren in heavy traffic (HT) and low traffic (LT) areas. PAH samples at eight schools were collected using a low volume sampler for 24 h and quantified using Gas Chromatography-Mass Spectrometry. Two hundred and twenty-eight buccal cells of children were assessed for DNA damage using Comet Assay. Monte-Carlo simulation was performed to determine incremental lifetime cancer risk (ILCR) and to check the uncertainty and sensitivity of the estimated risk. Total PAH concentrations in the schools in HT area were higher than LT area ranging from 4.4 to 5.76 ng m^-3 and 1.36 to 3.79 ng m^-3, respectively. The source diagnostic ratio showed that PAHs in the HT area is pyrogenic, mainly from diesel emission. The 95th percentile of the ILCR for children in HT and LT area were 2.80 × 10^-7 and 1.43 × 10^-7, respectively. The degree of DNA damage was significantly more severe in children in the HT group compared to LT group. This study shows that total indoor PAH exposure was the most significant factor that influenced the DNA damage among children. Further investigation of the relationship between PAH exposure and genomic integrity in children is required to shed additional light on potential health risks.

Exposure to polycyclic aromatic hydrocarbon-induced oxidative stress in Shiraz, Iran: urinary levels, health risk assessment and mediation effect of MDA on the risk of metabolic syndromes

PURPOSE

Polycyclic Aromatic Hydrocarbons (PAHs) have been identified as carcinogenic and endocrine disrupter compounds that cause Metabolic Syndrome (MetS). Oxidative stress can lead to carcinogenesis and MetS in exposed people. Therefore, the relationship between urinary metabolite of PAH (OH-PAHs) level and the oxidative stress biomarker (Malondialdehyde) effect as the mediator in increasing the risk of MetS due to PAH exposure and risk assessment was investigated in Shiraz, Iran.

METHODS

The first morning void urinary and blood samples were obtained from participants and analyzed. Physical examinations and anthropometric measurements were performed on the day of sampling. An automatic biochemistry analyzer was used to measure the blood cells. The participants' socio-demographic information was gathered using a questionnaire and direct interviews with participants.

RESULTS

The MetS prevalence was 26%. Malondialdehyde could act as a mediator between exposure to 1-HydroxyPyrene and increase in fast blood sugar, exposure to 2-HydroxyNaphthalene and increase in systolic blood pressure and exposure to 2-HydroxyFluorene and increase in SBP. Hazard quotients varied from 0.009 to 14.92 in women, and from 0.005 to 8.43 for Fluorene and Naphthalene in men, respectively. The Hazard Indexes were greater than one meaning that the non-cancer health risk related to the PAH exposure could be identified in the participants.

CONCLUSION

Although oxidative stress has been suggested to lead to MetS and the high HI levels obtained in the current study, future researches are essential to achieve more reliable findings and monitoring the environmental influencing factors in PAH exposure.

Probabilistic risk assessment of soil contamination related to agricultural and industrial activities

Soil contamination related to industrial and agricultural activities were associated with many adverse health effects and climate change could exacerbate this effect. However, the evidence on this topic in low and middle-income countries (LMICs) is still scarce. We, therefore, aimed to investigate the heavy metals (HMs) concentrations in topsoil around Lake Urmia (which dried about 50 % of it in recent years). Accordingly, 96 surface soil samples were collected from an area of about 4000 km² in 2019. An inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used to measure the HMs concentrations, including cadmium (Cd), arsenic (As), chromium (Cr), cobalt (Co), nickel (Ni), copper (Cu), lead (Pb) and zinc (Zn). Health risk assessment of exposure to HMs was performed using Monte Carlo simulations technique. The mean concentrations of Zn, Cu, Ni, Co, Pb, Cr, As and Cd were 68.66, 35, 31.66, 15, 14.4, 11.2, 7.04, and 0.26 mg/kg, respectively, which was in the allowable range of USEPA guideline. The mean enrichment factor (EF) values for Zn, Cd, Cu, Cr, Ni, Pb, Co and As were1.3, 1.9, 1, 1.2, 1.7, 2.8, 1.8 and 2, respectively. Carcinogenic risks of exposure to HMs for inhalation, dermal and ingestion exposure pathways were at safe level. Similarly, the hazard index (HI) was at safe level (HI < 1). The sensitivity analysis indicated that the exposure duration (ED) for As, exposure frequency (EF) for Cd and Ni, concentration (C_soi) for Cr and Pb had the highest impact on ELCR values. Our finding confirmed that HMs concentrations around Lake Urmia had no health risk for inhabitants.

Assessing BTEX concentrations emitted by hookah smoke in indoor air of residential buildings: health risk assessment for children

Hookah smoke is one of the major indoor sources of Volatile Organic Compounds (VOCs), including Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX). The present study aimed to investigate potential exposure to BTEX compounds among primary school children whose parents smoked hookah at home. BTEX concentrations in indoor air were measured in 60 residential buildings of Khesht, southwestern Iran (case = 30 and control = 30). Target compounds were sampled by charcoal tubes, and the samples were then analyzed by GC-FID. Monte Carlo simulation was used to assess the carcinogenic and non-carcinogenic risks of BTX exposure for the children aged 7-13 years. The concentrations of benzene (7.19 ± 3.09 vs. 0.82 ± 0.5 μg/m³), toluene (1.62 ± 0.69 vs. 0.3 ± 0.22 μg/m³), and xylenes (2.9 ± 1.66 vs. 0.31 ± 0.22 μg/m³) were considerably higher in the indoor air of the case houses compared with the control houses (p < 0.05). The Incremental Lifetime Cancer Risk (ILCR) of benzene for non-smoking and smoking houses were estimated 1.8 × 10^-6 and 15 × 10^-6, respectively, exceeding the recommendations of the World Health Organization (WHO) and the Environmental Protection Agency (EPA) (1 × 10^-6). Moreover, Hazard Quotients (HQs) of all BTX compounds were < 1. The indoor benzene concentration was significantly influenced by the floor at which families lived and type of the kitchen. In order to prevent children's exposure to BTX emitted by hookah, banning indoor smoking is the only way to eliminate these compounds in the indoor air.

Occurrence and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in dust of an emerging industrial city in Iran: implications for human health

Polycyclic aromatic hydrocarbons (PAHs) bounded to street dust are a severe environmental and human health danger. This study provides preliminary information on the abundance of PAHs in street dust from Rafsanjan city, Iran, where industrial emissions are high and data are lacking. Seventy street dust samples were collected from streets with different traffic loads. The United States Environmental Protection Agency (USEPA) Standard Methods 8270D and 3550C were used for the measurement of PAHs using GC mass spectroscopy. The total concentration of PAHs was 1443 ng g-1, with a range of 1380-1550 ng g-1. Additionally, the concentration of carcinogenic PAHs (∑carcPAHs) ranged from 729.5 to 889.4 ng g-1, with a mean value of 798.1 ng g-1. Pyrene was the most abundant PAH, with an average concentration of 257 ng g-1. Source identification analyses showed that vehicle emissions along with incomplete combustion and petroleum were the main sources of PAHs. The ecological risk status of the studied area was moderate. Spatial distribution mapping revealed that the streets around the city center and oil company had higher PAH levels than the other sectors of Rafsanjan. The results indicated that dermal contact and ingestion of contaminated particles were the most important pathways compared to inhalation. The mean incremental lifetime cancer risk (ILCR) was 1.4 × 10-3 and 1.3 × 10-3 for children and adults, respectively. This implies potentially adverse health effects in exposed individuals. The mutagenic risk for both subpopulations was approximately 18 times greater than the one recommended by USEPA. Our findings suggest that children are subjected to a higher carcinogenic and mutagenic risk of PAHs, especially dibenzo[a,h]anthracene (DahA), bounded to street dust of Rafsanjan. Our study highlights the need for the development of emission monitoring and control scenarios.

Urinary benzophenones and synthetic progestin in Chinese adults and children: concentration, source and exposure

The endocrine-disrupting activities of UV filters and synthetic progestin have raised concerns about their adverse risks. In this study, 208 urine samples were collected from Shanghai residents for the determination of seven benzophenones (BPs) and six synthetic progestins. The highest median concentration (6.21ng g^-1 Cr) was observed in young adults (21-50 years), followed by a concentration of 3.86 ng g^-1 Cr in elderly adults (over 50 years old), and the lowest median concentration (1.32 ng g^-1 Cr) was found in children (8-11 years old). The detection rates of BP-3 and EE2 in adults were 97% and 82%, and in children were 31% and 24%, respectively. Synthetic progestin levels in Shanghai, China, were relatively low compared to other countries. And the urinary BPs level showed an increasing trend in Chinese in the past 5 years. The principal component analysis suggested that adults' exposure to BP-1 and BP-3 was related, which occurs through food or dermal absorption of these chemicals present in cosmetic products and coatings. And diet was an important exposure pathway for children exposed to BPs. Despite relatively high levels of synthetic progestin for female and obese, the total estimated daily intake (EDI) was still lower than acceptable daily intake adopted by America. In the Monte-Carlo analysis, the 95th percentile of hazard quotients (HQs) was 0.83, which indicated that potential health risks were appreciated in the studied population.

Spatial distribution and health risk of exposure to BTEX in urban area: a comparison study of different land-use types and traffic volumes

Many previous studies have investigated BTEX concentrations in urban areas; however, the available evidence on the association of different land-use types and BTEX concentrations is still scarce. In this study, the BTEX concentrations were measured and compared in different land-use types and traffic volumes of Mashhad metropolis, Iran. Sampling was conducted in summer and winter of 2018 based on NIOSH 1501 method in six land-use types, including Residential, Commercial/official, Industrial, Greenspace, Transportation, and Tourism. The spatial autocorrelation model was used to investigate the emission pattern. The Monte Carlo simulation technique and sensitivity analysis were used to assess the health risk of exposure to BTEX compounds. The median [interquartile range (IQR)] of benzene, toluene, ethylbenzene m-xylene, o-xylene and total BTEX concentrations based on overall mean were 4 (2.23), 8.37 (4.48), 1.2 (1.46), 0.89 (2.59), 0.8 (1.73) and 17.7 (8.19) µg/m³, respectively. Benzene and toluene had clustered emission patterns (z-score > 1.96). Exposure to benzene in the study area had a carcinogenic risk for inhabitants. The concentration of BTEX compounds was significantly different based on land-use type. The maximum and minimum concentrations of BTEX were observed in Transportation and Greenspace land uses, respectively. The BTEX concentrations in summer were significantly higher than in winter, and traffic had a significant effect on BTEX concentrations. Overall, our results supported a significant relationship between land-use type and BTEX concentrations in the urban area. Moreover, ambient benzene concentration had a carcinogenic risk potential for inhabitants of study area.

Children's exposure to polycyclic aromatic hydrocarbons in the Valencian Region (Spain): Urinary levels, predictors of exposure and risk assessment

Polycyclic aromatic hydrocarbons (PAHs) are pollutants that are released into the environment during incomplete combustion of organic matter and which can have a negative effect on human health. PAHs enter the human body mostly through ingestion of food or inhalation of tobacco smoke. The purpose of the present study is to evaluate the internal levels of PAHs that children living in the Valencian Region (Spain) are exposed to. In total, we measured eleven biomarkers of exposure to naphthalene, fluorene, phenanthrene, pyrene, and benzo(a)pyrene in the urine of 566 children aged 5-12. The analytical method was based on a liquid-liquid extraction of the PAH metabolites from the urine samples, followed by their determination by liquid chromatography coupled to tandem mass spectrometry. In addition, we used a questionnaire to collect the socio-demographic characteristics and 72 h dietary recall information of the participants in our study. Overall, we detected PAH metabolites in more than 78% of the children, with the exception of 3-hydroxyfluorene and 3-hydroxybenzo(a)pyrene, which were found in less than 37% of the analyzed samples. The most abundant biomarker found was 2-hydroxynaphthalene, with a geometric mean of 10 ng·ml^-1. Reference values (RV₉₅) ranging from 0.11 (4-hydroxyphenanthrene) to 53 ng·ml^-1 (2-hydroxynaphthalene) in urine of Spanish children were derived from the present study. According to the statistical analysis, the factors that were significantly associated with the internal exposure to PAHs were province of residence, body mass index (BMI), children's age, consumption of plastic-wrapped food, and dietary habits. The estimated daily intakes in geometric mean terms ranged from 5 (fluorene) to 204 ng·kg-bw^-1·day^-1 (naphthalene). Risk assessment calculations showed higher hazard quotients and hazard indexes for children aged 5-8 than those aged 9-12, but all were below 1. In conclusion, no potential non-cancer health risk due to PAH exposure was observed in children living in Spain.

Spatial-temporal characteristics, source-specific variation and uncertainty analysis of health risks associated with heavy metals in road dust in Beijing, China

Based on the concentrations of ten heavy metals (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn, Fe) in 144 road dust samples collected from 36 sites across 4 seasons from 2016 to 2017 in Beijing, this study systematically analyzed the levels and main sources of health risks in terms of their temporal and spatial variations. A combination of receptor models (positive matrix factorization and multilinear engine-2), human health risk assessment models, and Monte Carlo simulations were used to apportion the seasonal variation of the health risks associated with these heavy metals. While non-carcinogenic risks were generally acceptable, Cr and Ni induced cautionary carcinogenic risks (CR) to children (confidence levels was approximately 80% and 95%, respectively).. Additionally, fuel combustion posed cautionary CR to children in all seasons, while the level of CR from other sources varied, depending on the seasons. Heavy metal concentrations were the most influential variables for uncertainties, followed by ingestion rate and skin adherence factor. The values and spatial patterns of health risks were influenced by the spatial pattern of risks from each source.

In utero exposure to phenanthrene induced islet cell dysfunction in adult mice: Sex differences in the effects and potential causes

Epidemiological studies show that the burden of polycyclic aromatic hydrocarbons in human body is associated with the occurrence of insulin resistance and diabetes. In the present study, pregnant mice were exposed to phenanthrene (Phe) at doses of 0, 60 and 600 μg/kg body weight of by gavage once every 3 days. The female F1 mice at 120 days of age showed no change in their fasting glucose levels (FGLs) but exhibited significantly decreased homeostasis model assessment (HOMA) β-cell (49% and 43%) and significantly downregulated pancreatic proinsulin gene (ins2) transcription. The downregulation of transcription factors, such as PDX1, PAX4 and FGF21, indicated impaired development and function of β-cells. The significantly reduced α-cell mass in 60 and 600 μg/kg groups, and the significantly downregulated expression of proglucagon gene gcg and ARX in the 600 μg/kg group suggested that the development and function of α-cells had been impacted. The males exhibited significantly increased FGLs (1.14- and 1.15-fold) in Phe exposed treatments and significantly elevated HOMA β-cell (3.15-fold) in the 600 μg/kg group. Upregulated ins2 transcription and FGF21 protein in male mice prenatally exposed to 600 μg/kg Phe suggested that these animals appeared compensatory enhancement in β-cell function. The reduced serum estradiol levels and downregulated pancreatic estrogen receptor α and β were responsible for the dysfunction of β-cells in the females. In the males, the significantly elevated androgen levels in the 600 μg/kg group might be related to the upregulated ins2 transcription, and the increased expression of pancreatic FGF21 further demonstrated the enhancement of β-cell potential. The results will be helpful for assessing the risk of developing diabetes in adulthood after prenatal exposure to phenanthrene.

Maternal exposure to phenanthrene during gestation disturbs glucose homeostasis in adult mouse offspring

Epidemiological studies have indicated that polycyclic aromatic hydrocarbons were related to diabetes and insulin resistance. However, studies in mammals on the development of diabetes caused by polycyclic aromatic hydrocarbons are lacking. Pregnant mice were orally exposed to phenanthrene (0, 60 and 600 μg kg^-1 body weight) once every 3 days during gestation. In adult mouse offspring, in-utero phenanthrene exposure caused glucose intolerance and decreased insulin levels in females, while caused elevated fasting blood glucose and insulin levels in males. Serum resistin and interleukin-6 levels were elevated in offspring of both sexes. Serum adiponectin levels were decreased in females but increased in males. The insulin receptor signals were upregulated in the liver and downregulated in the skeletal muscle of F1 females, while they were inhibited in both tissues of F1 males. The visceral fat weight and body weight of the treated mice were not increased, suggesting that phenanthrene is not an obesogen, which is supported by the nonsignificant alteration in pparγ transcription in visceral adipose tissue. The transcription of retn in visceral adipose tissue was upregulated in both sexes, and that of adipoq was downregulated in females but upregulated in males, which were matched with the promoter methylation levels of these genes. The results indicated that phenanthrene exposure during gestation could disturb adipocytokine levels via epigenetic modification in adult offspring, and further influence glucose metabolism. These results might be helpful for understanding nonobesogenic pollutant-induced insulin resistance and preventing against diabetes without obesity.

Polycyclic aromatic hydrocarbons exposures and telomere length: A cross-sectional study on preschool children

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with shorter telomere length (TL), a marker of ageing at cellular level. However, the available evidence on this association among children is still scarce. We therefore aimed to assess, the relationship between urinary 1-hydroxipayrene (1-OHP), a marker of exposure to PAHs, and relative leukocyte TL (LTL) in children at preschool age. Our study was based on 200 children enrolled from 27 randomly-selected kindergartens in the city of Sabzevar, Iran (2017). 1-OHP levels in the participants' urine samples were measured using solid phase extraction (SPE) method and high-performance liquid chromatography (HPLC). Moreover, real-time PCR was used to measure the LTL in the participants' blood samples. Linear mixed effects models, controlled for relevant covariates, were applied to investigate the association of 1-OHP concentration and LTL. The median (interquartile range (IQR)) of relative LTL and urinary 1-OHP were 0.83 (0.7) and 257 (375.5) ng/L, respectively. In the fully adjusted model, an IQR increase in urinary 1-OHP was related to -0.05 (95% confidence interval (CI): 0.09, -0.01, P-value = 0.02) decrease in relative LTL. This association was similar among boys and girls; however, we observed indications for a stronger association for those children whose parents had university education. Our study suggested an inverse relationship between urinary 1-OHP and LTL in children at preschool age. However, further longitudinal research with repeated measures of PAHs and LTL are needed to confirm these findings.

The association of fractional cover, foliage projective cover and biodiversity with birthweight

INTRODUCTION

Environmental exposures can contribute both benefits and risks to human health. Maternal exposure to green space has been associated with improvements in birthweight, among other birth outcomes. Newer measures of green space have been developed, which allows for an exploration of the effect of different ground covers (green, dry and bare earth), as well as measures of biodiversity. This study explores the association of these novel green space measures with birthweight in a large birth cohort in Queensland, Australia.

METHODS

Birthweight was acquired from the routine health records. Records were allocated green space values for fractional cover, biodiversity and foliage projective cover. Directed acyclic graphs were developed to guide variable selection. Mixed-effects linear regression and generalised linear mixed-effects models were developed, with random intercepts for maternal residential locality and year of birth. Results are presented as standardised beta coefficients or odds ratios, with 95% confidence intervals.

RESULTS

An IQR increase of green cover (29.6 g, 95% CI 13.8-45.5) and foliage projective cover (26.0 g, 95% CI 10.8-41.3) are associated with birthweight in urban areas. An IQR increase in dry cover -34.4 g, 95% CI -60.4 to -8.4) and bare earth (-17.7 g, 95% CI -32.8 to -2.6) are associated with lower birthweight. Mothers living in rural areas had similar results, with an IQR increase in green cover (17.8 g, 95% CI 2.9-32.7) associated with higher birthweight, and bare earth (-27.7 g, 95% CI -45.7 to -9.7) was associated with lower birthweight. The biodiversity measure used in this study was not associated with any birthweight outcomes.

CONCLUSION

This study finds that the types of ground cover within the maternal residential locality are associated with small, but significant, changes in estimated birthweight, and these effects are not limited to urban areas.

Spatial distribution and correlations among elements in smaller than 75 μm street dust: ecological and probabilistic health risk assessment

This study aimed to investigate spatial distribution, correlations among elements and ecological and probabilistic health risk assessment in smaller than 75 μm street dust in Kerman city, Iran. Street dust samples were collected from 35 different points. Elements were detected by ICP-AES. Pollution degree was characterized through Enrichment Factor (EF), Contamination Factor (CF), Geo-accumulation Index (Igeo) and Potential Ecological Risk (PER). The health risk was assessed using the Monte Carlo simulation method. The mean values of elements were in the order of Al > Mn > Zn > Cu > V > Pb > Cr > Ni > Li > As > Co > Mo > Sb > Cd > Ag. The results of Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) showed that Al, As, Co, Li, Mn and V were possibly derived from natural sources (local soil), while traffic and mining activities were proposed as the main source of Cd, Cr, Cu, Mo, Ni, Pb, Sb and Zn. The order of EF and CF mean values decreased as follows: Mn > Ag > Cu > Zn > Pb > Sb > Mo > Li > Co > V > Cd > As > Cr > Ni. In addition, 73% of Cu and 35% of Zn, Ag and Mn had significant enrichment in the street dust samples. Also, Ag and Mn were categorized in the significant and very significant pollution category. In terms of the PER index, all samples could be classified at low-risk category. Ingestion of street dust was the significant route for exposure of residents of Kerman to the elements studied. No significant ecological hazards and health risks were observed from street dust in the study area in the period of the study. The improvement in the fuels quality and development of green spaces can be suggested to control natural and anthropogenic street dust pollution sources in the Kerman city.

Biomonitoring of polycyclic aromatic hydrocarbons in the urine of lactating mothers: Urinary levels, association with lifestyle factors, and risk assessment

Polycyclic aromatic hydrocarbons (PAHs) are pollutants produced during incomplete combustion of organic matter and several industrial processes. Humans can be exposed to PAHs through ingestion of food, inhalation of tobacco smoke or polluted air, and dermal contact, causing immunologic, developmental, and reproductive problems. In the present research, eleven metabolites of PAHs were analyzed in the urine of 110 lactating women living in Spain (2015). PAH metabolites were extracted from the urine samples by liquid-liquid extraction and their determination was performed by liquid chromatography coupled to tandem mass spectrometry. In addition, information on lifestyle and dietary habits of the participants was collected using a questionnaire. All the PAH metabolites were detected in more than 70% of the samples, except for 3-hydroxybenzo(a)pyrene which was detected in less than 1% of the samples. The highest urinary levels were found for naphthalene metabolites, with geometric means of 0.8 (1-hydroxynaphthalene) and 7.1 ng ml^-1 (2-hydroxynaphthalene). The statistical analysis showed that smoking status, as well as the ingestion of certain food groups (vegetables, cereals, oils and fats, smoked fish and coffee), were the main influencing factors of exposure to PAHs. The estimated daily intake (EDI) was calculated for naphthalene, fluorene, phenanthrene, and pyrene, ranging from 6 to 1522 ng kg^-1·day^-1. The non-cancer risk associated to PAH exposure was estimated, showing hazard quotients (HQs) and hazard indexes (HIs) below 1. Therefore, it did not reveal a significant health risk for Spanish women due to PAH exposure.

Probabilistic health risk assessment of occupational exposure to isoflurane and sevoflurane in the operating room

Risk assessment is an important tool in predicting the possible risk to health. It heightens awareness by estimating the probability of adverse health effects in humans who are exposed to chemicals in the course of their work. Therefore, the present work aims to determine the occupational exposure of operating room staff to the volatile anesthetic gases, isoflurane and sevoflurane, and estimates non-cancer risk using the United States Environmental Protection Agency method. Air samples from the breathing zone of staff members were collected using the Occupational Safety and Health Administration Method 103 and analyzed using gas chromatography-mass spectroscopy. The results indicate that the measured concentrations of isoflurane and sevoflurane are below the National Institute of Occupational Safety and Health standard (2 ppm) for technicians and nurses, but not for anesthesiologists and surgeons. Moreover, the estimated non-cancer risk due to isoflurane is above the acceptable value for anesthesiologists (but acceptable for other occupational categories). A sensitivity analysis indicates that exposure time has the most effect on calculated risk (53.4%). Occupational exposure to anesthetic gases may endanger the health of operating room personnel. Therefore, control measures, such as daily testing of anesthetic devices, ensuring the effectiveness of ventilation systems, advanced scavenging methods, and regular training of staff are highly recommended.

Has air pollution emission level in the Beijing-Tianjin-Hebei region peaked? A panel data analysis

The Beijing-Tianjin-Hebei (BTH) region is one of the important economic centers of China, but it suffers from severe air pollution. Based on the panel pollution-related data of 2013-2017, this research adopted a Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) equation to fit the relationship between pollution emission level and its related socio-economic indicators. The pollution emission level of the BTH region was fitted and projected by using the entropy evaluation method to measure the emission levels, the partial least squares algorithm to estimate the STIRPAT equation parameters, and the hybrid trend extrapolation model to forecast the future development of the above socioeconomic indicators. Empirical analysis showed that the fitting curve to air pollution emission level reached the peak in 2015 and then decreased with a fluctuating and slow process. The air pollution emissions in 2025 will decrease to the level of 2007. With regard to the impacts on the change of the air emission pollution level, industrial waste gas emissions play a decisive role. The influence of soot (dust) emissions is considerably smaller but still larger than that of SO₂ emissions. Besides, the slowing down of the economic development in the future will contribute to air quality improvement. However, the rapid growth of population in Hebei and Tianjin would hinder such improvement. Empirical analysis also implied that governments in this region should specially monitor the operation of building material industries to ensure the steady improvement of air quality.

Polycyclic aromatic hydrocarbons in railway stations dust of the mega traffic hub city, central China: Human health risk and relationship with black carbon

Twenty dust samples collected from Wuchang and Wuhan Railway Stations, the biggest transport stations in the mega traffic hub city in Central China, were analyzed for polycyclic aromatic hydrocarbons (PAHs) to investigate the concentration, sources apportionment, and relationship with black carbon (BC) and assess the health risk. The results suggested that the concentrations of PAHs, BC and TOC in Wuhan Railway Station (WHRS) (PAHs = 5940 ± 1920 ng g^-1, BC = 53.2 ± 23.1 mg g^-1 and TOC = 80.7 ± 44.4) were twice higher than those in Wuchang Railway Station (WCRS) (PAHs = 2580 ± 1630 ng g^-1, BC = 20.4 ± 14.3 mg g^-1 and TOC = 33.9 ± 20.1 mg g^-1). Moreover, the 3 - and 4 - rings PAHs were major PAHs in railway station dust. The composition pattern of PAHs in these railway station dusts had a common characteristic with HMW-PAHs contribution. The results of source identification revealed that different local development features and energy consumption of trains would influence the sources of PAHs and BC. PAHs and BC were most likely related to industrial activities in WHRS. Coal and biomass combustion may influence the PAHs components and BC distribution in WCRS. Moreover, BC had played an important role in retaining PAHs in urban railway stations. Especially in WHRS, BC would more likely to absorb the high molecular weight PAHs, such as 4 -ring (p<0.05), 5 -ring (p<0.05) and 6 -ring (p<0.05) PAHs; while BC just played limited roles in the binding of volatile and semi-volatile organic pollutants, such as 2 -ring and 3 -ring PAHs. With the coexistence of BC and PAHs, passengers would face significant potential health risks by exposure to toxic dust in railway stations, especially for children. The cancer risk in WHRS was almost twice higher than that in WCRS, and it would tend to be stable by a semi-confined structure in the platform area.

Comparing BTEX concentration related to surgical smoke in different operating rooms

The available evidence on the indoor air quality of operating rooms (ORs) in the Low- and Middle-income Countries (LMICs) is very scarce. Moreover, there is no study on the comparing the concentration of indoor air pollutants in different ORs. Therefore, this study aimed to measure and compare the benzene, toluene, ethylbenzene and xylene (BTEX) concentrations in the air of different ORs in hospitals of Sabzevar, Iran. Moreover, carcinogenic and non-carcinogenic risk of exposure to these pollutants were assessed using Monte Carlo simulations technique. This cross-sectional study was based on volatile organic compounds (VOCs) passive sampling of eight ORs including General surgery, Curettage, Eye surgery, Neurosurgery, Orthopedic, Laparoscopic, Cesarean and Ear, nose, throat (ENT) in two monthly campaigns from November 2019 to February 2020. One-way ANOVA and Post-hoc analyses were used to compare the concentration of BTEX compounds in different ORs. The overall mean (standard deviation (SD)) of benzene, toluene, ethylbenzene, xylene and total BTEX concentrations were 10.0 (1.8), 7.2 (1.9), 1.8 (0.6), 0.4 (0.2) and 19.4 (4.1) μg/m³. The Curettage OR had the highest (12.93 μg/m³) and ENT OR had the lowest (7.42 μg/m³) benzene concentrations. The highest concentrations of toluene, ethylbenzene and total BTEX were observed in General surgery OR. The cancer risks of exposure to benzene in all ORs were higher than the acceptable range recommended by Unite State Environmental Protection Agency (USEPA, 1 × 10⁶). However, the hazard quotient (HQ) values for all ORs were at safe level (HQ < 1). Overall, our study suggested that the concentrations of BTEX compounds were significantly difference in different ORs and benzene had a carcinogenic risk for personnel and surgical staff in different ORs.

Exposure to greenspace and birth weight in a middle-income country

An emerging body of evidence has associated exposure to greenspace during pregnancy with improved fetal growth; however, all available studies have been conducted in high-income countries and the available evidence evaluating such an association for visual access to greenspace, use of green spaces and indoor plants is non-existent. We aimed to evaluate the association between a comprehensive array of indicators of exposure to greenspace during pregnancy, including the aforementioned indicators, and birth weight, in a middle-income country and evaluating air pollution and visual access as possible mechanisms underlying the association. This study was based on 301 pregnant women residing in Su et al. (2019). For each pregnant woman, we characterized exposure to residential surrounding greenspace, visual access to greenspace, residential proximity to green space, use of green spaces, and the number of plant pots at home. We used linear regression models adjusted for relevant covariates including measures of socioeconomic status. We found positive associations of maternal exposure to residential surrounding greenspace across a 100 m buffer, frequent viewing of greenspace through the window, percentage of window area covered by greenspace, residential proximity to any green space regardless of its area, time spent in public green spaces and total time spent in public and private green spaces with birth weight. We also observed positive associations of maternal exposure to residential surrounding greenspace across 300 m and 500 m buffers, residential proximity to a green space with an area ≥5000 m², and indoor plant pots with birth weight, but none of these associations were statistically significant. The magnitude of the associations tended to be higher among parents with lower socioeconomic status. Mediation through air pollution or visual access was not established. Findings from this study suggested a positive role of different aspects of exposure to greenspace during pregnancy on birth weight in a middle-income country.

Assessing schoolchildren's exposure to air pollution during the daily commute - A systematic review

Air pollution is mostly caused by emissions from human activities, and exposure to air pollution is linked with numerous adverse human health outcomes. Recent studies have identified that although people only spend a small proportion of time on their daily commutes, the commuter microenvironment is a significant contributor to their total daily air pollution exposure. Schoolchildren are a particularly vulnerable cohort of the population, and their exposure to air pollution at home or school has been documented in a number of case studies. A few studies have identified that schoolchildren's exposure during commutes is linked with adverse cognitive outcomes and severe wheeze in asthmatic children. However, the determinants of total exposure, such as route choice and commute mode, and their subsequent health impacts on schoolchildren are still not well-understood. The aim of this paper is to review and synthesize recent studies on assessing schoolchildren's exposure to various air pollutants during the daily commute. Through reviewing 31 relevant studies published between 2004 and 2020, we tried to identify consistent patterns, trends, and underlying causal factors in the results. These studies were carried out across 10 commute modes and 12 different air pollutants. Air pollution in cities is highly heterogeneous in time and space, and commuting schoolchildren move through the urban area in complex ways. Measurements from fixed monitoring stations (FMSs), personal monitoring, and air quality modeling are the three most common approaches to determining exposure to ambient air pollutant concentrations. The time-activity diary (TAD), GPS tracker, online route collection app, and GIS-based route simulation are four widely used methods to determine schoolchildren's daily commuting routes. We found that route choices exerted a determining impact on schoolchildren's exposure. It is challenging to rank commute modes in order of exposure, as each scenario has numerous uncontrollable determinants, and there are notable research gaps. We suggest that future studies should concentrate on examining exposure patterns of schoolchildren in developing countries, exposure in the subway and trains, investigating the reliability of current simulation methods, exploring the environmental justice issue, and identifying the health impacts during commuting. It is recommended that three promising tools of smartphones, data fusion, and GIS should be widely used to overcome the challenges encountered in scaling up commuter exposure studies to population scales.

Elevated expression of AhR and NLRP3 link polycyclic aromatic hydrocarbon exposure to cytokine storm in preschool children

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs), as a group of persistent organic pollutants, are linked to impaired immune function and low-grade inflammation in adults and children. However, the potential of PAHs to lead to a cytokine storm associated with AhR (aryl hydrocarbon receptor) and NLRP3 (NLR family pyrin domain containing 3) in humans has been poorly studied.

OBJECTIVES

We aimed to investigate the associations between PAH exposure, AhR and NLRP3 expression, and cytokines associated with a cytokine storm in healthy preschoolers.

METHODS

Basic demographic surveys and physical examinations were conducted on 248 preschoolers from an electronic waste (e-waste) recycling area (Guiyu, n = 121) and a reference area (Haojiang, n = 127). Ten urinary PAH metabolite (OH-PAH) concentrations were measured. We also measured the expression levels of AhR and NLRP3 and seventeen serum cytokine levels.

RESULTS

The concentrations of multiple OH-PAHs were significantly higher in the exposed group than those in the reference group, especially 1-hydroxynaphthalene (1-OH-Nap) and 2-hydroxynaphthalene (2-OH-Nap). PAH exposure was closely related to a child's living environment and hygiene habits. Expression levels of AhR and NLRP3 were significantly higher in the exposed group than in the reference group. Similarly, serum IL-1β, IL-4, IL-5, IL-10, IL-12p70, IL-13, IL-17A, IL-18, IL-22, IL-23, and IFN-γ levels were notably higher in the e-waste-exposed children than in the reference children. After adjusting for age, gender, BMI, family income, parental education level, and second-hand smoke exposure, we found that increased PAH exposure was associated with higher AhR and NLRP3 expression and elevated IL-4, IL-10, IL-12p70, IL-18, IL-22, IL-23, TNF-α, and IFN-γ levels. The associations between PAH exposure and IL-1β, IL-18, IFN-γ, and TNF-β were mediated by NLRP3 expression, and the relationships between PAH exposure and IL-4, IL-10, IL-12p70, IL-22, IL-23, and TNF-α were mediated by AhR expression.

CONCLUSIONS

Our findings suggest that the association between PAH exposure and a cytokine storm may be mediated by AhR and NLRP3 expression among preschoolers.

Association of exposure to air pollution and green space with ovarian reserve hormones levels

Exposure to air pollution has been associated with adverse health effects while exposure to greenspace has been associated with public health benefits. However, the available evidence on the association of exposure to air pollution with ovarian reserve markers is still scarce, with no study on such an association with greenspace exposure. Therefore, this study aimed to investigate the association of exposure to particulate matter with diameter of less than 1, 2.5 and 10 μm (PM₁, PM_2.5, PM₁₀), traffic indicators (distance from women's residence to major roads and total street length in different buffers around women's residential address) and greenspace indicators (residential surrounding greenspace and distance to green spaces) with serum levels of anti-müllerian hormone (AMH) and follicle stimulating hormone (FSH) as markers of ovarian reserve. This cross-sectional study was based on 67 women residing in Sabzevar, Iran (2018). Basal serum levels of FSH and AMH were measured by the enzyme-linked immunosorbent assays (ELISA). Land use regression models were used to estimate PMs concentrations at residential addresses and the average of normalized difference vegetation index (NDVI) in different buffers was used to characterize residential surrounding greenspace. Multiple linear regression models were developed to estimate the association of AMH and FSH with exposure to air pollution, traffic, and greenspace (one at a time) controlled for relevant covariates. In fully adjusted models, there was an inverse association between exposure to PM₁, PM_2.5 as well as total street length in 100 m buffer around women's residence and AMH level (β = -0.89, 95% confidence interval (CI): -1.43, -0.35, P-value ≤ 0.01, β = -1.11, 95% CI: -1.67, -0.55, P-value ≤ 0.01 and β = -0.76, 95% CI: -1.48, -0.50, P-value = 0.03, respectively). Moreover, increase in distance from home to nearest major road as well as residential surrounding greenspace (100 m buffer) and decrease in residential distance to a green space larger than 5000 m² were associated with increase in serum level of AMH. However, we did not observe any significant association between exposure to air pollution, traffic, and greenspace with FSH level. Overall, our findings supported a beneficial association of exposure to greenspace and detrimental association of exposure to air pollution with ovarian reserve.

Personal black carbon exposure and its determinants among elderly adults in urban China

Personal exposure to air pollution is affected by its concentration in the microenvironment and individual time-activity patterns. To investigate personal black carbon (BC) exposure levels and identify their potential determinants, we conducted a panel study among 67 elderly residents aged 60-69 years in Jinan, China. Personal BC exposure was measured using portable real-time monitors, while corresponding ambient BC concentrations and meteorological conditions were also collected from the local central site. Time-activity and household characteristics were recorded. A linear mixed-effects model was used to identify potential determinants of personal BC exposure. The daily average personal BC exposure concentration was 4.1 ± 2.0 μg/m³ (±standard deviation, SD), which was significantly lower than the ambient concentration (4.6 ± 2.5 μg/m³) (p < 0.001). Strong correlation (Spearman's r = 0.63, p < 0.001) was found between personal and ambient BC concentrations. The fixed-site monitoring ambient concentration cannot fully reflect the actual personal exposure concentration. Ambient BC concentration, ambient temperature, relative humidity, education level and air purifier use were significant determinants of personal BC exposure. Our findings highlight the need for detailed assessment of personal exposure on health risk assessment of BC and also help develop strategies for targeted risk reduction.

Spatial analysis and risk assessment of urban BTEX compounds in Urmia, Iran

Land Use Regression models (LUR) are the most common tools to estimate intra-urban air pollutant exposure in epidemiological studies. However, number of available and published models in developing and middle up income countries is still scarce. Here, we developed seasonal and overall LUR models for the spatial distribution of benzene, toluene, ethylbenzene and xylene (BTEX) based on 20 monitoring stations and 166 potentially predictive variables (PPVs) in Urmia, Iran. Carcinogenic and non-carcinogenic risks of exposure to BTEX and its sensitivity analysis were assessed using a probabilistic approach. The mean and standard deviation (in brackets) of overall benzene, toluene, ethylbenzene and xylene were 12.83 (16.19), 27.03 (32.00), 4.72 (4.15) and 27.35 (29.36) μg/m³, respectively. In all models the R² value of LUR models of benzene, toluene, ethylbenzene, xylene and total BTEX ranged from 0.66 to 0.85, 0.61, 0.88, 0.72 to 0.94, 0.75 to 0.84 and 0.67 to 0.93. The root mean square error (RMSE) for leave-one-out cross-validations (LOOCV) for benzene, toluene, ethylbenzene and xylene ranged from 7.48 to 10.31, 23.0 to 30.0, 3.40 to 6.90, 16.27 to 24.49, 36.10-50.0 μg/m³, respectively. The estimated lifetime carcinogenic risk (LTCR) indicated that ambient concentration of benzene is at a risk level for Urmia inhabitants (LTCR >10^-6). Sensitivity analysis for LTCR model indicated that concentration of benzene (C) was the most effective variable in increasing the carcinogenic risk (correlation coefficient ranged from 0.97 to 0.98 for all models).

Maternal exposure to ambient particulate matter and green spaces and fetal renal function

Exposure to air pollution has been associated with different harmful effects and exposure to greenspace has been related to improved human health. However, the available evidence on the impact of these exposures on renal function is still scarce. The aim of this study was to determine the relationship between exposure to ambient levels of PM₁, PM_2.5, PM₁₀ and indicators of exposure to traffic as well as greenspace during pregnancy and fetal renal function based on the umbilical cord blood. This study was based on 150 pregnant women residing in Sabzevar, Iran (2018). Multiple linear regression models were developed to estimate the association of glomerular filtration rate (GFR), creatinine (Cr) and blood urea nitrogen (BUN) with exposure to air pollution, traffic, and greenspace (one at a time) controlled for relevant covariates. There was an inverse significant association between exposure to PM₁, PM_2.5, PM₁₀ and total street length in a 100 m buffer around the home and eGFR. Increase in distance to major road and residential surrounding greenness (100 m buffer) was associated with increase in eGFR. We observed a significant direct association between exposure to PMs as well as street length in 100 m buffer and serum level of Cr. There was also an inverse association between distance to major road and NDVI in 100 m buffer and Cr. The associations for blood urea nitrogen (BUN) were not statistically significant. Our results suggest that exposure to air pollution during pregnancy could have negative impact and exposure to greenspace could have positive impact on renal function of fetal.

Ecological and health risk assessment of exposure to atmospheric heavy metals

In the present study, we assessed the concentration of airborne HMs (Zn, Cu, Pb, and Cd) and their probable sources using the bark of Pinus eldarica as a bio-indicator. Hence, 47 tree bark samples were harvested according to the land uses and biomonitoring techniques in the city of Yazd, Iran. The potential health risks in 13 age groups, ecological risk, as well as the possible relationship between HM concentrations and traffic indicators, were evaluated. The order of average HM concentrations in the P. eldarica bark samples was as Zn > Pb > Cu > Cd. The mean values of non-carcinogenic risks of all HMs in entire age groups were within secure range (HQ < 1); however, the carcinogenic risk of Cd was higher than the allowed level (TCR > 1 × 10^-6). About Pb, it was in the safe level. The main element causing potential ecological risks was Cd, indicating moderate to very high ecological risk in most of the study areas. There was an inverse significant association between distance from major roads and Pb concentration (β = -0.011 95% confidence interval (CI): 0.022, -0.0001). All HMs in bark samples render the negative Moran's index, representing a random spatial distribution pattern. Besides, according to principal component analysis (PCA), the first component accounted for 36.55% of the total variance, dominated by Cd, Pb, Cu, and Zn, respectively, and characterized by vehicle and industrial emissions. Our results infer that industrial activities and traffic are the main sources of HMs pollution in urban environments that should be considered by decision-makers.

Probabilistic risk assessment of occupational exposure to volatile organic compounds in the rendering plant of a poultry slaughterhouse

In this study, occupational exposure to volatile organic compounds (VOCs) in the rendering plant of poultry slaughterhouse was determined and subsequently, carcinogen and non-carcinogenic risks were assessed using the US Environmental Protection Agency (USEPA). National Institute for Occupational Safety and Health (NIOSH) methods of 1501 and 1600 were used to measure VOCs in the breathing zone of the workers. Samples were analyzed by GC/MS. Carcinogenic and non-carcinogenic risks and sensitivity analysis were carried out using Monte Carlo simulations technique. The concentration of benzene and CS₂ was higher than the occupational exposure limits (OEL). The hazard quotient (HQ) values for all measured compounds was more than 1, which indicating the high potential for non-carcinogenic risks. Furthermore, the calculated Lifetime Cancer Risks (LCR) for carcinogenic compounds revealed that cancer risk due to benzene is higher than the maximum acceptable level provided by USEPA (10^-6). Based on the sensitivity analysis, the concentration and exposure frequency are the most important variable influencing both carcinogen and non-carcinogenic risks. Therefore, the concentration levels of the VOCs and exposure frequency should be controlled using engineering control measures.

Prenatal polycyclic aromatic hydrocarbons metabolites, cord blood telomere length, and neonatal neurobehavioral development

BACKGROUND

Prenatal exposure to polycyclic aromatic hydrocarbon (PAH) is a potential risk factor for child neurobehavioral development. Telomere length (TL) has important implications for health over the life course.

OBJECTIVE

In this study, we aimed to investigate whether prenatal urinary PAH metabolites were associated with adverse neonatal neurobehavioral development and altered cord blood TL and to explore whether the change of TL was a predictor of neonatal neurobehavioral development.

METHOD

We enrolled 283 nonsmoking pregnant women in Taiyuan city. Eleven PAH metabolites were measured in maternal urine samples. TL in cord blood was measured by real time quantitative polymerase chain reaction. Neonatal behavioral neurological assessment (NBNA) tests were conducted when the infants were three days old. Multiple linear regression models were used to analyze the associations of maternal urinary PAH metabolites with NBNA scores and cord blood TL, and restricted cubic spline models were further used to examine the shapes of dose-response relationships. A mediation analysis was also conducted.

RESULT

We observed dose-response associations of maternal urinary 2-hydroxyfluorene (2-OHFlu) and 2-hydroxyphenanthrene (2-OH Phe) with decreased active tone scores, sum of NBNA scores, and cord blood TL (P for trend<0.05). Each 1 unit increase in urinary levels of Ln (2-OH Flu) or Ln (2-OH Phe) was associated with a 0.092 or 0.135 decrease in the active tone scores and a 0.174 or 0.199 decrease in the sum of NBNA scores. Mediation analysis showed TL could explained 21.74% of the effect of sum of NBNA scores change related to prenatal exposure to 2-OH Phe (P for mediator = 0.047).

CONCLUSION

Our data indicates maternal urinary specific PAH metabolites are inversely associated with neonatal neurobehavioral development and cord blood TL. TL mediates the associations of 2-OH Phe with neonatal neurobehavioral development and partly explains the effect of 2-OH Phe on neonatal neurobehavioral development.

Estimate annual and seasonal PM1, PM2.5 and PM10 concentrations using land use regression model

Exposure to ambient particulate matter (PM) can increase mortality and morbidity in urban area. In this study, annual and seasonal spatial pattern of PM₁, PM_2.5 and PM₁₀ pollutants were assessed using land use regression (LUR) models in Sabzevar, Iran. The studied pollutants were measured at 26 monitoring stations of different microenvironments in the study area. Sampling was conducted during four campaigns from April 2017 to February 2018. LUR models were developed based on 104 potentially predictive variables (PPVs) subdivided in six categories and 22 sub-categories. The annual mean (standard deviation) of PM₁, PM_2.5 and PM₁₀ were 36.46 (8.56), 39.62 (10.55) and 51.99 (16.25) μg/m³, respectively. The R² values and root mean square error for leave-one-out cross validations (RMSE for LOOCV) of PM₁ models ranged from 0.23 to 0.79 and 3.43-22.5, respectively. Further, R² and RMSE for LOOCV of PM_2.5 models ranged from 0.56 to 0.93 and 3.66-28.3, respectively. For PM₁₀ models the R² ranged from 0.31 to 0.82 and the RMSE for LOOCV ranged from 9.16 to 33.9. The generated models can be useful for population based epidemiologic studies and to estimate these pollutants in different parts of the study area for scientific decision making.

Urinary levels of 1-hydroxypyrene and health risk assessment in children living in Mexican communities with a high risk of contamination by polycyclic aromatic hydrocarbons (PAHs)

Health complications have been associated with polycyclic aromatic hydrocarbons (PAHs) exposure, a widespread environmental pollutants family. Therefore, the objective of this investigation was to develop a probabilistic health risk evaluation (using Monte-Carlo simulation) in an infantile population living in areas with a high risk of pollution by PAHs (indoor wood combustion, brick kiln industry, municipal landfill, and low and high vehicular traffic) in Mexico. Urine samples were obtained from Mexican children (n = 135) and urinary 1-OHP concentrations (used as a PAHs biomarker) were quantified. Highest urinary 1-OHP concentrations were detected in children living in areas that use wood combustion as the principal indoor fuel (3.50 ± 0.95 µg/L). Nevertheless, estimated hazard quotients (HQ) lower than 1 were found in all assessed sites after Monte-Carlo analysis. Although HQ <1.0 (a toxic effect is not expected), more data are necessary to determine the real impact of PAHs exposure on children health status.

Children environmental exposure to particulate matter and polycyclic aromatic hydrocarbons and biomonitoring in school environments: A review on indoor and outdoor exposure levels, major sources and health impacts

Children, an important vulnerable group, spend most of their time at schools (up to 10 h per day, mostly indoors) and the respective air quality may significantly impact on children health. Thus, this work reviews the published studies on children biomonitoring and environmental exposure to particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) at school microenvironments (indoors and outdoors), major sources and potential health risks. A total of 28, 35, and 31% of the studies reported levels that exceeded the international outdoor ambient air guidelines for PM₁₀, PM_2.5, and benzo(a)pyrene, respectively. Indoor and outdoor concentrations of PM₁₀ at European schools, the most characterized continent, ranged between 7.5 and 229 μg/m³ and 21-166 μg/m³, respectively; levels of PM_2.5 varied between 4 and 100 μg/m³ indoors and 6.1-115 μg/m³ outdoors. Despite scarce information in some geographical regions (America, Oceania and Africa), the collected data clearly show that Asian children are exposed to the highest concentrations of PM and PAHs at school environments, which were associated with increased carcinogenic risks and with the highest values of urinary total monohydroxyl PAH metabolites (PAH biomarkers of exposure). Additionally, children attending schools in polluted urban and industrial areas are exposed to higher levels of PM and PAHs with increased concentrations of urinary PAH metabolites in comparison with children from rural areas. Strong evidences demonstrated associations between environmental exposure to PM and PAHs with several health outcomes, including increased risk of asthma, pulmonary infections, skin diseases, and allergies. Nevertheless, there is a scientific gap on studies that include the characterization of PM fine fraction and the levels of PAHs in the total air (particulate and gas phases) of indoor and outdoor air of school environments and the associated risks for the health of children. There is a clear need to improve indoor air quality in schools and to establish international guidelines for exposure limits in these environments.

Six sources mainly contributing to the haze episodes and health risk assessment of PM2.5 at Beijing suburb in winter 2016

Aiming to a better understanding sources contributions and regional sources of fine particles, a total of 273 filter samples (159 of PM_2.5 and 114 of PM_1.0) were collected per 8 h during the winter 2016 at a southwest suburb of Beijing. Chemical compositions, including water soluble ions, organic carbon (OC), and elemental carbon (EC), as well as secondary organic carbon (SOC), were systematically analyzed and estimated. The total ions concentrations (TIC), OC, and SOC of PM_2.5 were with the following order: 16:00-24:00 > 08:00-16:00 > 00:00-08:00. Since primary OC and EC were mainly attributed to the residential combustion in the night time, their valley values were observed in the daytime (08:00-16:00). However, the highest ratio value of SOC/OC was observed in the daytime. It is because that SOC is easily formed under sunshine and relatively high temperature in the daytime. Positive matrix factorization (PMF), clustering, and potential source contribution function (PSCF) were employed for apportioning sources contributions and speculating potential sources spatial distributions. The average concentrations of each species and the source contributions to each species were calculated based on the data of species concentrations with an 8 h period simulated by PMF model. Six likely sources, including secondary inorganic aerosols, coal combustion, industrial and traffic emissions, road dust, soil and construction dust, and biomass burning, were contributed to PM_2.5 accounting for 29%, 21%, 17%, 16%, 9%, 8%, respectively. The results of cluster analysis indicated that most of air masses were transported from West and Northwest directions to the sampling location during the observation campaign. Several seriously polluted areas that might affect the air quality of Beijing by long-range transport were identified. Most of air masses were transported from Western and Northwestern China. According to the results of PSCF analysis, Western Shandong, Southern Hebei, Northern Henan, Western Inner Mongolia, Northern Shaanxi, and the whole Shanxi provinces should be the key areas of air pollution control in China. The exposure-response function was used to estimate the health impact associated with PM_2.5 pollution. The population affected by PM_2.5 during haze episodes reached 0.31 million, the premature death cases associated with PM_2.5 reached 2032. These results provided important implication for making environmental policies to improve air quality in China.