A comprehensive study on the spatial and temporal variation of BTEX and asbestos in the northwest of Iran: Human risk assessment.

Substances like asbestos and other air pollutants, such as BTEX (benzene, toluene, ethylbenzene, and xylene), are hazardous compounds due to their adverse effects on human health. This study aims to investigate the levels, seasonal variations, spatial distribution, potential sources, and associated health risks associated with BTEX compounds and asbestos fibers in the ambient air of Tabriz. Air samples were taken at 16 different locations during the 2020-2021 period. Glass containers with charcoal were used for sample collection, and the BTEX content was determined using the GC-FID method. Phase-contrast microscopy (PCM) analysis was conducted with a low-volume peripheral pump for asbestos fiber sampling. The results showed that the average concentration of ∑BTEX was 37.94 and 27.98 µg/m3 in autumn and spring, respectively. The same parameter was 2.26 and 1.68 f/L for asbestos in the autumn and winter, respectively. The contribution of BTEX to ozone formation potential (OFP) in the research area showed that xylene and toluene were the major contributors to ozone production in different seasons. The risk of exposure to benzene compounds was 24 × 10-4 in children and 55.9 × 10-4 in adults, while the risk of exposure to ethylbenzene was 3.78 × 10-4 in children and 3.25 × 10-4 in adults. The estimated lifetime cancer risk was found to be the highest for benzene, followed by ethylbenzene. The estimated cancer risk for benzene and ethylbenzene exceeded the threshold values set by EPA, which signals a significant carcinogenic risk due to exposure to these substances in the ambient air of Tabriz. According to the EPA guidelines, the low carcinogenicity risk levels are between 10-4 and 10-6. According to the findings for the exposure to asbestos fibers, the maximum values of excess cancer risk (ECR) and estimated lifetime cancer risk (ELCR) were observed in the 16-30 age range across all locations, suggesting increased exposure to asbestos fibers compared to other age groups.

Exposure to outdoor particulate matter and risk of respiratory diseases: a systematic review and meta-analysis.

According to epidemiological studies, particulate matter (PM) is an important air pollutant that poses a significant threat to human health. The relationship between particulate matter and respiratory diseases has been the subject of numerous studies, but these studies have produced inconsistent findings. The purpose of this systematic review was to examine the connection between outdoor particulate matter (PM2.5 and PM10) exposure and respiratory disorders (COPD, lung cancer, LRIs, and COVID-19). For this purpose, we conducted a literature search between 2012 and 2022 in PubMed, Web of Science, and Scopus. Out of the 58 studies that were part of the systematic review, meta-analyses were conducted on 53 of them. A random effect model was applied separately for each category of study design to assess the pooled association between exposure to PM2.5 and PM10 and respiratory diseases. Based on time-series and cohort studies, which are the priorities of the strength of evidence, a significant relationship between the risk of respiratory diseases (COPD, lung cancer, and COVID-19) was observed (COPD: pooled HR = 1.032, 95% CI: 1.004-1.061; lung cancer: pooled HR = 1.017, 95% CI: 1.015-1.020; and COVID-19: pooled RR = 1.004, 95% CI: 1.002-1.006 per 1 µg/m3 increase in PM2.5). Also, a significant relationship was observed between PM10 and respiratory diseases (COPD, LRIs, and COVID-19) based on time-series and cohort studies. Although the number of studies in this field is limited, which requires more investigations, it can be concluded that outdoor particulate matter can increase the risk of respiratory diseases.

PAHs pollution in the outdoor air of areas with various land uses in the industrial city of Iran: distribution, source apportionment, and risk assessment.

Shahryar city regions with various land uses had their outdoor air concentrations of PM2.5-bound PAHs determined. Totally, 32 samples were taken - eight samples from the industrial region air (IS), eight samples from the high-traffic urban regions air (HTS), eight samples from the air of commercial regions (CS), and eight samples from residential areas (RS), which were analyzed by GC-MS. According to the study's findings, in the outdoor air of IS, HTS, CS, and RS, there were mean Æ©PAHs concentrations of 23.25 ± 20.22, 38.88 ± 26.53, 6.97 ± 4.26, and 4.48 ± 3.13 ng/m3, respectively. As comparison to CS and RS, mean concentration of Æ©PAHs in samples from HTS and IS was substantially greater (p < 0.05). Using the Unmix.6 receptor model, sources of PAHs in the air of Shahryar were allocated. The model's results show that 42% of PAHs come from diesel vehicles and industrial activities, 36% from traffic and other transportation sources, and 22% from heating sources and coal burning. The carcinogenicity suffering resulting from exposure to PAHs was as follows: This value for children of the ingestion, inhalation pathways and dermal contact is (1.90 × 10-6-1.38 × 10-4), (5.5 × 10-11-2.67 × 10-9) and (2.36 × 10-6-1.72 × 10-4), respectively. Also, for adults were (1.47 × 10-6 - 1.07 × 10-4), (1.14 × 10-10 - 5.27 × 10-9) and (3.68 × 10-6- 2.87 × 10-4), respectively. In general, the analyzed region's carcinogenicity risk estimates fell within the range of acceptable limit.

Subnational exposure to secondhand smoke in Iran from 1990 to 2013: a systematic review.

Every year, almost eight million people die from tobacco-related diseases, among which around 1.2 million die from secondhand smoke (SHS) exposure. Generally, it is estimated that SHS constituents generated in the interval between puffs are approximately 3 times more toxic than those produced at the moment of puffing. There is no risk-free level of SHS exposure, and even brief exposure can be harmful to health. The aim of this study was to assess SHS exposure and its trend in the different provinces of Iran from 1990 to 2013. To collect available data on SHS exposure, a systematic review was performed. We searched international and national databases using a combination of Medical Subject Headings (MeSH) and relevant text words in the titles, abstracts, and/or keywords. Also, the data in national surveys were gathered. The frequency of exposure in different provinces as well as age, sex, and rural/urban areas were extracted. Afterwards, modeling was done to estimate SHS exposure from the smoking data. According to our findings, SHS exposure was more prevalent among young people. Moreover, this exposure was greater in rural areas as compared to urban areas. A national study on 13-15-year-old individuals showed the highest exposure occurred outdoors. In addition, a declining trend was observed on SHS exposure over time. It seems that attention to the importance of SHS exposure in researches in Iran dates back to 2001, and gradually, especially in recent years, further studies have been conducted on SHS exposure.

Maternal exposure to air pollutants and birth weight in Tehran, Iran.

BACKGROUND: Air pollution can cause various health outcomes, especially in susceptible groups including pregnant women. Low birth weight (LBW) is among the adverse birth outcomes and is one of the main causes of infant mortality. The aim of this study was to assess the association between air pollutants and LBW in Tehran, Iran. METHODS: In this case-control study, 2144 babies born in three hospitals of Tehran (Iran) during 2011 to 2012 whose mothers were the residents of this city in last 5 years were considered. Of these, 468 infants with birth weight < 2500 g and 1676 with birth weight ≥ 2500 g were regarded as case and control groups, respectively. Gestational age was also considered for definition of cases (small for gestational age (SGA)) and controls (appropriate for gestational age). Land use regression models were used to assess exposure to particulate matter ≤10 µm in aerodynamic diameter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2) and volatile organic compounds (benzene, toluene, ethylbenzene, o-xylene, m-xylene, p-xylene (BTEX), and total BTEX) during pregnancy. Logistic regression model was applied to assess the association between air pollutants and LBW. RESULTS: The concentrations of air pollutants were very high but similar in cases and controls. After adjustment for potential confounding variables, no statistically significant association was observed between air pollutants and LBW. The adjusted odds ratios (95% confidence interval) for PM10, SO2, and benzene were 0.999 (0.994-1.005), 0.998 (0.993-1.003), and 0.980 (0.901-1.067), respectively. CONCLUSIONS: No association was found between LBW and air pollutants. Further studies with more rigorous designs and access to more comprehensive information are suggested to assess the effect of other air pollutants, such as CO, O3, PM2.5, ultrafine particles, and oxidative potential of particles on birth outcomes.

Air pollution and exacerbation of skin itching and sleep disturbance in Iranian atopic dermatitis patients.

BACKGROUND: For about three decades now, the number of people suffering from atopy including atopic dermatitis (AD) has been increasing in developed countries. Genetic background and environmental factors including air pollution play an effective role in its incidence. This study examined the association between air pollutants and exacerbation of AD symptoms including sleep disturbance and itching in AD patients of Tehran. METHODS: In this panel study, 31 patients with AD who admitted to Razi Hospital, dermatology hospital in Tehran, entered the research. Daily information including questions on disease symptoms (sleep disturbance, itching) and duration of outdoor stay (in hours) were collected using a questionnaire. The mean 24-h concentrations of PM2.5 and PM10 pollutants were obtained from the Air Quality Control Company. The relationship between the concentrations of the pollutants and exacerbation of the disease symptoms was investigated using the GEE (Generalized Estimating Equations) model. RESULTS: There was a significant relationship between the concentrations of air pollutants and exacerbation of sleep disturbance and itching on the same day, before, and after adjusting the effects of the confounding variables, so that the estimated odds ratios (95% confidence interval) between PM10 and PM2.5 and exacerbation of itching were 1.06 (1.02-1.10) and 1.17 (1.07-1.28), respectively. CONCLUSIONS: There was a significant statistical relationship between the concentration of particulate matter (PM2.5 and PM10) and exacerbation of sleep disturbance and itching. PM2.5 showed a stronger relationship with the exacerbation of symptoms compared to PM10.