Assessing capabilities of conducted ambient air pollution health effects studies in 22 Eastern Mediterranean countries to adopt air quality standards: a review.

Purpose: The Eastern Mediterranean Region (EMR) countries suffer from exposure to high levels of ambient air pollutants due to dust storms and have unique climatic as well as topographic and socio-economic conditions which lead to adverse health effects on humans. The purpose of the review was to evaluate the quantity and quality of published articles on air pollution and health-based studies in 22 EMR countries to determine if they can be applied to adopting air quality standards. Methods: We designed a review based on a broad search of the literature in the Scopus, PubMed, and web of science (WOS) databases published from January 1, 2000, to January 2, 2022, using combinations of the following relevant terms: air pollution, health, and EMR countries. The generic eligibility criteria for this review were based on the population, exposure, comparator, outcome, and study design (PECOS) statement. Results: The search results showed that following the PRISMA approach, of 2947 identified articles, 353 studies were included in this review. The analysis of the types of studies showed that about 70% of the studies conducted in EMR countries were Health Burden Estimation studies (31%), Ecological and time trend ecological studies (23%), and cross-sectional studies (16%). Also, researchers from Iran participated in the most published relevant studies in the region 255 (~ 63%) and just 10 published documents met all the PECOS criteria. Conclusion: The lack of sufficient studies which can meet the PECOS appraising criteria and the lack of professionals in this field are some of the issues that make it impossible to use as potential documents in the WHO future studies and adopt air quality standards. Supplementary Information: The online version contains supplementary material available at 10.1007/s40201-023-00862-1.

Circulating Exosomes and Ambient Air Pollution Exposure in COPD.

Background: Chronic obstructive pulmonary disease (COPD) is characterized by progressive obstruction of airways due to chronic inflammation. Both genetic and environmental components are risk factors for COPD. The most common cause of COPD is smoking. However, evidence suggests that 17% to 38% of COPD patients are nonsmokers, so other factors like air pollution may also play a role. Objective: The relationship between serum exosomes and exposure to particulate matter (PM) <2.5 and 10 micrometers (µm) in the residing environment of COPD patients and healthy groups was investigated. The correlation between inflammatory cytokine levels with exosome count was also studied. Methods: Peripheral blood samples were taken from 20 COPD patients without a smoking history or a family history of COPD, along with 20 nonsmoker healthy controls. The serum exosomes were counted by flow cytometry using a CD81 marker. The exposure to PM2.5 and PM10 was measured in daily, weekly, and monthly intervals based on the longitudinal measurements of the monitoring stations, and the correlation between exosome count and air pollutants was analyzed. Results: The serum CD81+ exosome count in COPD patients was significantly elevated compared to the healthy controls and this was correlated with daily PM10 (P-value=0.02) and monthly PM2.5 (P-value=0.02) exposure. Although interferon-gamma levels of COPD patients were higher than healthy controls, there was no correlation between exosome count and cytokine level. Conclusions: Considering the significant relationship between air pollutants and the count of serum exosomes demonstrated in the present study, air pollution might be a considerable risk factor in the progression of airway inflammation.

An updated systematic review and meta-analysis on portable air cleaners and blood pressure: Recommendations for users and manufacturers.

Fine particulate matter (PM2.5) air pollution is a leading contributor to the global burden of cardiovascular disease (CVD). One important underlying mechanism is an increase in blood pressure (BP). A growing number of studies have reported a beneficial effect of portable air cleaners (PACs) on systolic and diastolic BP; SBP and DBP. We conducted an updated systematic review and meta-analysis of studies using true versus sham mode filtration reporting the effects on BP. Of 214 articles identified up to February 5, 2023, seventeen (from China, USA, Canada, South Korea and Denmark) enrolling approximately 880 participants (484 female) met the inclusion criteria for meta-analyses. Aside from studies conducted in China, research on PACs and BP has been conducted in relatively low pollution settings. Mean indoor PM2.5 concentrations during the active and sham mode purification were 15.9 and 41.2 µg/m3, respectively. The mean efficiency of PACs against indoor PM2.5 was 59.8 % (ranging from 23 % to 82 %). True mode filtration was associated with a pooled mean difference of - 2.35 mmHg (95 % confidence interval [CI]: - 4.5, - 0.2) and - 0.81 mmHg (95 % CI: - 1.86, 0.24) in SBP and DBP, respectively. After removing the studies with high risk of bias, the magnitude of the pooled benefits on SBP and DBP increased to - 3.62 mmHg (95 % CI: - 6.69, - 0.56) and - 1.35 mmHg (95 % CI: - 2.29, - 0.41), respectively. However, there are several barriers to the use of PACs, specifically in low- and middle-income countries (LMICs), such as the initial purchase cost and filter replacements. There may be several avenues to help overcome these economic burdens and improve cost effectiveness, such as implementing government or other subsidized programs to distribute PACs targeting vulnerable and higher-risk individuals. We propose that environmental health researchers and healthcare providers should be better trained to educate the public regarding the use of PACs to reduce the impacts of PM2.5 on cardiometabolic diseases globally.

Implemented indoor airborne transmission mitigation strategies during COVID-19: a systematic review.

The COVID-19 pandemic has inflicted major economic and health burdens across the world. On the other hand, the potential airborne transmission of SARS-COV-2 via air can deeply undermine the effectiveness of countermeasures against spreading the disease. Therefore, there is an intense focus to look for ways to mitigate the COVID-19 spread within various indoor settings. This work systematically reviewed articles regarding airborne transmission of SARS-COV2 in various indoor settings since the onset of the pandemic. The systematic search was performed in Scopus, Web of Science, and PubMed databases and has returned 19 original articles carefully screened with regard to inclusion and exclusion criteria. The results showed that the facilities, such as dormitories and classrooms, received the most attention followed by office buildings, healthcare facilities, residential buildings, and other potential enclosed spaces such as a metro wagon. Besides, the majority of the studies were conducted experimentally while other studies were done using computer simulations. United States (n = 5), Spain (n = 4) and China (n = 3) were the top three countries based on the number of performed research. Ventilation rate was the most influential parameter in controlling the infection spread. CO2 was the primary reference for viral spread in the buildings. The use of natural ventilation or a combination of mechanical and natural ventilations was found to be highly effective in the studies. The current work helps in furthering research on effective interventions to improve indoor air quality and control the spread of COVID-19 and other respiratory diseases. Supplementary information: The online version contains supplementary material available at 10.1007/s40201-023-00847-0.

Comparative review of ambient air PM2.5 source apportioning studies in Tehran.

Rapid urbanization and consuming lifestyles have intensified air pollution in urban areas. Air pollution in megacities has imposed severe environmental damages to human health. Proper management of the issue necessitates identification of the share of emission sources. Therefore, numerous research works have studied the apportionment of the total emissions and observed concentrations among different emissions sources. In this research, a comprehensive review is conducted to compare the source apportioning results for ambient air PM2.5 in the megacity of Tehran, the capital of Iran. One hundred seventy-seven pieces of scientific literatures, published between 2005 and 2021, were reviewed. The reviewed research are categorized according to the source apportioning methods: emission inventory (EI), source apportionment (SA), and sensitivity analysis of the concentration to the emission sources (SNA). The possible reasons for inconsistency among the results are discussed according to the scope of the studies and the implemented methods. Although 85% of the reviewed original estimates identify that mobile sources contribute to more thant 60% of Tehran air pollution, the distribution of vehicle types and modes are clearly inconsistent among the EI studies. Our review suggests that consistent results in the SA studies in different locations in central Tehran may indicate the reliability of this method for the identification of the type and share of the emission sources. In contrast, differences among the geographical and sectoral coverage of the EI studies and the disparities among the emission factors and activity data have caused significant deviations among the reviewed EI studies. Also, it is shown that the results of the SNA studies are highly dependent on the categorization type, model capabilities and EI presumptions and data input to the pollutant dispersion modelings. As a result, integrated source apportioning in which the three methods complement each other's results is necessary for consistent air pollution management in megacities. Supplementary information: The online version contains supplementary material available at 10.1007/s40201-023-00855-0.

Ambient Air Quality Standards and Policies in Eastern Mediterranean Countries: A Review.

Objectives: National ambient air quality standards (NAAQS) are critical tools for controlling air pollution and protecting public health. We designed this study to 1) gather the NAAQS for six classical air pollutants: PM2.5, PM10, O3, NO2, SO2, and CO in the Eastern Mediterranean Region (EMR) countries, 2) compare those with the updated World Health Organizations Air Quality Guidelines (WHO AQGs 2021), 3) estimate the potential health benefits of achieving annual PM2.5 NAAQS and WHO AQGs per country, and 4) gather the information on air quality policies and action plans in the EMR countries. Methods: To gather information on the NAAQS, we searched several bibliographic databases, hand-searched the relevant papers and reports, and analysed unpublished data on NAAQS in the EMR countries reported from these countries to the WHO/Regional office of the Eastern Mediterranean/Climate Change, Health and Environment Unit (WHO/EMR/CHE). To estimate the potential health benefits of reaching the NAAQS and AQG levels for PM2.5, we used the average of ambient PM2.5 exposures in the 22 EMR countries in 2019 from the Global Burden of Disease (GBD) dataset and AirQ+ software. Results: Almost all of the EMR countries have national ambient air quality standards for the critical air pollutants except Djibouti, Somalia, and Yemen. However, the current standards for PM2.5 are up to 10 times higher than the current health-based WHO AQGs. The standards for other considered pollutants exceed AQGs as well. We estimated that the reduction of annual mean PM2.5 exposure level to the AQG level (5 µg m-3) would be associated with a decrease of all natural-cause mortality in adults (age 30+) by 16.9%-42.1% in various EMR countries. All countries would even benefit from the achievement of the Interim Target-2 (25 µg m-3) for annual mean PM2.5: it would reduce all-cause mortality by 3%-37.5%. Less than half of the countries in the Region reported having policies relevant to air quality management, in particular addressing pollution related to sand and desert storms (SDS) such as enhancing the implementation of sustainable land management practices, taking measures to prevent and control the main factors of SDS, and developing early warning systems as tools to combat SDS. Few countries conduct studies on the health effects of air pollution or on a contribution of SDS to pollution levels. Information from air quality monitoring is available for 13 out of the 22 EMR countries. Conclusion: Improvement of air quality management, including international collaboration and prioritization of SDS, supported by an update (or establishment) of NAAQSs and enhanced air quality monitoring are essential elements for reduction of air pollution and its health effects in the EMR.

Estimation and predictors of direct hospitalisation expenses and in-hospital mortality for patients who had a stroke in a low-middle income country: evidence from a nationwide cross-sectional study in Iranian hospitals.

OBJECTIVE: Stroke is the second most prevalent cardiovascular disease in Iran. This study investigates the estimation and predictors of hospitalisation expenses and in-hospital mortality for patients who had a stroke in Iranian hospitals. SETTING: Patients who had a stroke in Iran between 2019 and 2020 were identified through the data collected from the Iran Health Insurance Organization and the Ministry of Health and Medical Education. This study is the first to conduct a pervasive, nationwide investigation. DESIGN: This is a cross-sectional, prevalence-based study. Generalised linear models and a multiple logistic regression model were used to determine the predictors of hospitalisation expenses and in-hospital mortality for patients who had a stroke. PARTICIPANTS: A total of 19 150 patients suffering from stroke were studied. RESULTS: Mean hospitalisation expenses per patient who had a stroke in Iran amounted to US$590.91±974.44 (mean±SD). Mean daily hospitalisation expenses per patient who had a stroke were US$55.18±37.89. The in-hospital mortality for patients who had a stroke was 18.80%. Younger people (aged ≤49 years) had significantly higher expenses than older patients. The OR of in-hospital mortality in haemorrhagic stroke was significantly higher by 1.539 times (95% CI, 1.401 to 1.691) compared with ischaemic and unspecified strokes. Compared with patients covered by the rural fund, patients covered by Iranian health insurance had significantly higher costs by 1.14 times (95% CI, 1.186 to 1.097) and 1.319 times (95% CI, 1.099 to 1.582) higher mortality. There were also significant geographical variations in patients who had a stroke's expenses and mortality rates. CONCLUSION: Applying cost-effective stroke prevention strategies among the younger population (≤49 years old) is strongly recommended. Migration to universal health insurance can effectively reduce the inequality gap among all insured patients.

Increased allergic and asthmatic risks in children residing in industrial areas by surveying the pre-inflammatory (IgE, IL-4 and IL-13) biomarkers.

Toxic metal(loid)s can lead to high damages on human. This work was conducted to investigate the levels of metal(loid)s in PM2.5 and a total of 123 male children's (aged 6-9 years) blood chosen from different areas in Ahvaz and their association with the pre-inflammatory (Immunoglobulin E and cytokines: IgE, IL-4 and IL-13) responses in serum cells. Six metal(loid)s (arsenic, cadmium, chromium, mercury, nickel and lead) in three regions including industrial (Padad), vehicle traffic (Golestan) and reference (Kianpars) areas were studied. Results showed the concentrations of As, Cr, Cd, Ni and Hg in the ambient air of industrial area (Padad) (P < 0.001), and Pb in vehicle traffic area (Golestan) were higher (p < 0.001). Moreover, the mean levels of IgE (mean = 146.44 pg/200landa, P < 0.003), IL-4 (mean = 548.23 pg/200landa, P < 0.001) and IL-13 (mean = 53.21 pg/200landa, P < 0.001) in Padad were higher than Golestan and Kianpars. Our results suggest that living in industrial areas leads to accelerated synthesis of IgE, IL-4 and IL-13 in blood. The spatial distribution of children's serum IgE, IL-4 and IL-13 concentrations showed an abnormal increase of 240 to 400 pg/200landa for IgE, 950 to 1400 pg/200landa for IL-4 and 90 to 128 pg/200landa for IL-13. Our results indicate children in the industrial area are prone to asthma, allergy, miRNA mutation, and other chronic diseases.

Meteorological dependence, source identification, and carcinogenic risk assessment of PM2.5-bound Polycyclic Aromatic Hydrocarbons (PAHs) in high-traffic roadside, urban background, and remote suburban area.

The Polycyclic Aromatic Hydrocarbons (PAHs) bound to ambient fine Particular Matter (PM2.5) are currently drawing a lot of attention due to their adverse health effects increasing lung cancer risk in humans. In this study, The PM2.5 samples were collected by high volume air samplers simultaneously from three different sites (high-traffic roadside, urban background, and remote suburban) in Tehran, Iran during warm and cold seasons (from July 2018 to March 2019), and 16 PAHs were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). Unlike previous studies, a remote suburban area was chosen so as to observe the spatial differentiation in PM2.5-bound PAH characteristics. In high-traffic roadside site, the average concentration of total PM2.5-bound PAHs (Æ©PAHs) was 3.7 times the concentration value in remote suburban area. Average (Æ©PAHs) ranged from 5.54 ng/m3 for remote suburban area to 20.67 ng/m3 for high-traffic roadside site. In all sites, seasonal trends of PAH concentrations elucidated high concentrations in the cold season and low concentrations in the warm season. Correlation analysis between Æ©PAHs and atmospheric factors (meteorology parameters and criteria air pollutants) indicated the heterogeneous processes play an important role in the level of PAHs. The results of diagnostic ratio (DR) analysis disclosed that the dominant source of PM2.5-bound PAHs was the combustion of liquid fossil fuels. Despite the fact that incremental lifetime cancer risk (ILCR) via inhaling PM2.5-bound PAHs varied significantly in high-traffic roadside site and remote suburban site, its value was beyond the acceptable risk level in both sites. Our results suggested that effective regulations are needed to monitor PAHs concentrations and reduce PAHs emissions from liquid fossil fuel combustion so as to mitigate the potential carcinogenic risk of PAHs in ambient air. Supplementary Information: The online version contains supplementary material available at 10.1007/s40201-022-00821-2.

Health and economic impacts of ambient air particulate matter (PM2.5) in Karaj city from 2012 to 2019 using BenMAP-CE.

The present study aims to estimate the effects of PM2.5 on the health and economy of Karaj city from 2012 to 2019. In this study, mortality attributed to long-term exposure to PM2.5 and its spatial distribution in Karaj over the 2012-2019 period were estimated using the Global Exposure Mortality Model (GEMM) concentration-response function and BenMAP software. PM2.5 hourly concentration data of air quality monitoring stations were used to estimate PM2.5 for the whole city of Karaj. The economic effects of this pollutant were also assessed using the value of statistical life (VSL) method. The results showed that the annual average PM2.5 concentration during the studied time increased and was higher than the air quality guideline levels recommended by the World Health Organization. Also, the annual number of deaths attributed to PM2.5 in adults (older than 25 years) was estimated to be about 1200. The highest to lowest proportions of PM2.5-related deaths were non-accidental mortality, ischemic heart attack, stroke, acute respiratory tract infection, chronic obstructive pulmonary disease (COPD), and lung cancer, in the order of their appearance. The results showed that the economic loss attributed to this pollutant was estimated at 380 to 504 million USD per year. Due to the effects of PM2.5 on health and the economy in this city, we suggest conducting special planning to control and reduce the concentration of ambient air particulate matter by improving the public transportation system and updating industrial processes.

Health burden and economic loss attributable to ambient PM2.5 in Iran based on the ground and satellite data.

We estimated mortality and economic loss attributable to PM2·5 air pollution exposure in 429 counties of Iran in 2018. Ambient PM2.5-related deaths were estimated using the Global Exposure Mortality Model (GEMM). According to the ground-monitored and satellite-based PM2.5 data, the annual mean population-weighted PM2·5 concentrations for Iran were 30.1 and 38.6 µg m-3, respectively. We estimated that long-term exposure to ambient PM2.5 contributed to 49,303 (95% confidence interval (CI) 40,914-57,379) deaths in adults ≥ 25 yr. from all-natural causes based on ground monitored data and 58,873 (95% CI 49,024-68,287) deaths using satellite-based models for PM2.5. The crude death rate and the age-standardized death rate per 100,000 population for age group ≥ 25 year due to ground-monitored PM2.5 data versus satellite-based exposure estimates was 97 (95% CI 81-113) versus 116 (95% CI 97-135) and 125 (95% CI 104-145) versus 149 (95% CI 124-173), respectively. For ground-monitored and satellite-based PM2.5 data, the economic loss attributable to ambient PM2.5-total mortality was approximately 10,713 (95% CI 8890-12,467) and 12,792.1 (95% CI 10,652.0-14,837.6) million USD, equivalent to nearly 3.7% (95% CI 3.06-4.29) and 4.3% (95% CI 3.6-4.5.0) of the total gross domestic product in Iran in 2018.

Effect of portable air purifier on indoor air quality: reduced exposure to particulate matter and health risk assessment.

We sought to investigate the impact of air purifiers in the removal of particular matter (PM)10, PM2.5, PM1, and particle number concentration (PNC) in the indoor air of dormitories located at Iran's largest medical university, Tehran University of Medical Sciences. Twelve rooms were selected and randomly assigned to two rooms: sham air purifier system deployed room (SR) and true air purifier system deployed room (TR). All study samples were drawn simultaneously from assigned rooms using portable GRIMM dust monitors for 24 h. The PM monitors of air were positioned in the middle of each room next to the air purifier at the height of the breathing zone (1.5 m in height). The mean PM10, PM2.5, PM1, and PNC removal efficiency in rooms with and without a smoker were measured to be 40.7 vs 83.8%, 31.2 vs 78.4%, 29.9 vs 72.3%, and 44.3 vs 75.6%, respectively. The results showed that smoking is an important influencing factor on the indoor air quality; smoking lowered the removal efficiency of PM10, PM2.5, PM1, and PNC by 43%, 47%, 43%, and 31%, respectively. An air purifier could decline the PM10 and PM2.5 even lower than the WHO 24-h guideline level in non-smoker rooms. This study revealed that using household air purifiers in rooms with smokers and non-smokers significantly reduces the non-carcinogenic risks of exposure to PM10 and PM2.5.

Source apportionment, identification and characterization, and emission inventory of ambient particulate matter in 22 Eastern Mediterranean Region countries: A systematic review and recommendations for good practice.

Little is known about the main sources of ambient particulate matter (PM) in the 22 Eastern Mediterranean Region (EMR) countries. We designed this study to systematically review all published and unpublished source apportionment (SA), identification and characterization studies as well as emission inventories in the EMR. Of 440 articles identified, 82 (11 emission inventory ones) met our inclusion criteria for final analyses. Of 22 EMR countries, Iran with 30 articles had the highest number of studies on source specific PM followed by Pakistan (n = 15 articles) and Saudi Arabia (n = 8 papers). By contrast, there were no studies in Afghanistan, Bahrain, Djibouti, Libya, Somalia, Sudan, Syria, Tunisia, United Arab Emirates and Yemen. Approximately 72% of studies (51) were published within a span of 2015-2021.48 studies identified the sources of PM2.5 and its constituents. Positive matrix factorization (PMF), principal component analysis (PCA) and chemical mass balance (CMB) were the most common approaches to identify the source contributions of ambient PM. Both secondary aerosols and dust, with 12-51% and 8-80% (33% and 30% for all EMR countries, on average) had the greatest contributions in ambient PM2.5. The remaining sources for ambient PM2.5, including mixed sources (traffic, industry and residential (TIR)), traffic, industries, biomass burning, and sea salt were in the range of approximately 4-69%, 4-49%, 1-53%, 7-25% and 3-29%, respectively. For PM10, the most dominant source was dust with 7-95% (49% for all EMR countries, on average). The limited number of SA studies in the EMR countries (one study per approximately 9.6 million people) in comparison to Europe and North America (1 study per 4.3 and 2.1 million people respectively) can be augmented by future studies that will provide a better understanding of emission sources in the urban environment.

Prenatal malaria exposure and risk of adverse birth outcomes: a prospective cohort study of pregnant women in the Northern Region of Ghana.

OBJECTIVE: Malaria remains endemic in most of sub-Saharan Africa and has a negative impact among pregnant women, resulting in morbidity and poor birth outcomes. The purpose of this study was to assess the relationship between malaria and adverse birth outcomes among prenatal women in the Northern Region of Ghana. DESIGN: This is a prospective cohort study of singleton pregnancies at 28 weeks of gestational age and above recruited between July 2018 and May 2019 from four public hospitals in the Northern Region of Ghana. OUTCOME MEASURES: Low birth weight (LBW), preterm birth and perinatal death. RESULTS: A total of 1323 pregnant women completed the study out of the 1626 recruited, with an average age of 27.3±5.2 years. The incidence of malaria in this population was 9.5% (95% CI 7.9 to 11.1). After adjusting for newborn admissions to the neonatal intensive care unit, parity, maternal age and glucose-6-phosphate dehydrogenase, women who were exposed to malaria during the third trimester of pregnancy had 2.02 times (95% CI 1.36 to 2.99) higher odds of premature delivery. Furthermore, they had 2.06 times (95% CI 1.09 to 3.93) higher chance of giving birth to babies with LBW, irrespective of their socioeconomic status. With an OR of 1.02 (95% CI 0.26 to 4.01), there was no difference in perinatal mortality between pregnant women with malaria and those without malaria after adjusting for caesarean section. CONCLUSION: This study confirms that prenatal malaria increases the odds of both preterm and LBW deliveries. A decisive policy to eradicate or minimise perinatal malaria is needed to contribute to the prevention of LBW and adverse pregnancy outcomes.

Air pollution exposure and mammographic breast density in Tehran, Iran: a cross-sectional study.

BACKGROUND: Air pollution is one of the major public health challenges in many parts of the world possibly has an association with breast cancer. However, the mechanism is still unclear. This study aimed to find an association between exposure to six criteria ambient air pollutants (PM2.5, PM10, SO2, NO2, O3, and CO) and mammographic breast density (MBD), as one of the strongest predictors for developing breast cancer, in women living in Tehran, Iran. METHODS: Participants were selected from women attending two university hospitals for screening mammography from 2019 to 2021. Breast density was rated by two expert radiologists. Individual exposures to 3-year ambient air pollution levels at the residence were estimated. RESULTS: The final analysis in 791 eligible women showed that low and high breast density was detected in 34.8 and 62.2 of participants, respectively. Logistic regression analysis after considering all possible confounding factors represented that an increase in each unit of NO2 (ppb) exposure was associated with an increased risk of breast density with an OR equal to 1.04 (95CI: 1.01 to 1.07). Furthermore, CO level was associated with a decreasing breast density (OR = 0.40, 95CI = 0.19 to 0.86). None of the other pollutants were associated with breast density. CONCLUSION: Higher MBD was associated with an increased level of NO2, as a marker of traffic-related air pollution. Furthermore, CO concentration was associated with a lower MBD, while other criteria air pollutants were not related to MBD. Further studies are needed to evaluate the association between ambient air pollutants with MBD.

The effect of size distribution of ambient air particulate matter on oxidative potential by acellular method Dithiothreitol; a systematic review.

Today air pollution caused by particulate matter (PM) is a global issue, especially in densely populated and high-traffic cities. The formation of reactive oxygen species (ROS) by various toxicological studies is considered as one of the important effects caused by airborne particles that can lead to adverse effects on human health. In this study, to answer the question of whether particle size affects oxidative potential (OP), we searched the main databases, including PubMed, Scopus, Embase, and Web of Science, and defined search strategy based on the MESH terms for the above-mentioned search engines. All articles published until 2021 were searched. An ANOVA was run using R software to show the correlation between the size distributions of particulate matter and oxidative potential (base on mass and volumetric units) in ambient air. As expected, the regression results showed that the relationship between particle size and OP values for the studies based on mass-logarithm has a significant difference in the different distribution size categories, which was related to the difference between the <2.5 and < 1 categories. However, ANOVA analysis did not show a significant difference in the volumetric OP logarithm in the different distribution size categories. In this study, it was found that sizes higher than 2.5 µm did not have much effect on human health, and it is recommended that future research focus on PM2.5. Supplementary Information: The online version contains supplementary material available at 10.1007/s40201-021-00768-w.

Identification and determination of the volatile organics of third-hand smoke from different cigarettes and clothing fabrics.

Third-hand smoke (THS) is a persistent mixture generated from aged second-hand smoke (SHS) that accumulates in indoor environments and reemits into the air. This work evaluates the tobacco-derived volatile organics of cigarette THS from various clothing fabrics that were exposed to side-stream smoke of several brands of cigarettes in a controlled experimental scale. The qualitative and quantitative determination of the chemicals off-gassed was performed using solid phase micro-extraction coupled with GC/MS. Sixty-six components of side-stream smoke were identified in third-hand cigarette smoke. In this study, toluene-reference concentration (TRC) was calculated for volatile compounds and estimated based on the basic response characteristics of GC/MS. Among the identified analytes, 16 compounds were quantified presenting high toxicity and/or abundance in smoke, such as: benzene, toluene, xylene, pyridine, limonene, naphthalene, furfural and nicotine. The results showed that the total quantified volatile organics released for cotton, wool, polyester and filament fabrics were 92.37, 93.09, 87.88, and 50.22 µg/l fabric, respectively. Fabric structure significantly affects chemical off-gassing. Natural fibers were more capable of holding and emitting THS than synthetic fibers. Besides, various desorption times from 15 to 45 min after exposure to cigarette smoke in the study were evaluated. With increasing desorption time, no significant decrease in the concentration of organic compounds in THS was observed. Therefore, it is necessary to pay attention to the fact that it will be difficult to clean the pollutants from the environment contaminated with cigarette smoke and it will take more hours to reduce the concentration of organic compounds.

Effects of respirators to reduce fine particulate matter exposures on blood pressure and heart rate variability: A systematic review and meta-analysis.

Particulate-filtering respirators (PFRs) have been recommended as a practical personal-level intervention to protect individuals from the health effects of particulate matter exposure. However, the cardiovascular benefits of PFRs including improvements in key surrogate endpoints remain unclear. We performed a systematic review and meta-analysis of randomized studies (wearing versus not wearing PFRs) reporting the effects on blood pressure (BP) and heart rate variability (HRV). The search was performed on January 3, 2022 to identify published papers until this date. We queried three English databases, including PubMed, Web of Science Core Collection and Scopus. Of 527 articles identified, eight trials enrolling 312 participants (mean age ± standard deviation: 36 ± 19.8; 132 female) met our inclusion criteria for analyses. Study participants wore PFRs from 2 to 48 h during intervention periods. Wearing PFRs was associated with a non-significant pooled mean difference of -0.78 mmHg (95% confidence interval [CI]: -2.06, 0.50) and -0.49 mmHg (95%CI: -1.37, 0.38) in systolic and diastolic BP (SBP and DBP). There was a marginally significant reduction of mean arterial pressure (MAP) by nearly 1.1 mmHg (95%CI: -2.13, 0.01). The use of PFRs was associated with a significant increase of 38.92 ms2 (95%CI: 1.07, 76.77) in pooled mean high frequency (power in the high frequency band (0.15-0.4 Hz)) and a reduction in the low (power in the low frequency band (0.04-0.15Hz))-to-high frequency ratio [-0.14 (95%CI: -0.27, 0.00)]. Other HRV indices were not significantly changed. Our meta-analysis demonstrates modest or non-significant improvements in BP and many HRV parameters from wearing PFRs over brief periods. However, these findings are limited by the small number of trials as well as variations in experimental designs and durations. Given the mounting global public health threat posed by air pollution, larger-scale trials are warranted to elucidate more conclusively the potential health benefits of PFRs.

Evaluation of SARS-CoV-2 in Indoor Air of Sina and Shahid Beheshti Hospitals and Patients' Houses.

Side by side air sampling was conducted using a PTFE filter membrane as dry sampler and an impinger containing a suitable culture medium as a wet sampler. Most of the samples were collected from two hospitals and few air samples were collected from private houses of non-hospitalized confirmed COVID-19 patients. The collected air samples were analyzed using RT-PCR. The results indicated that all air samples collected from the hospitals were PCR negative for SARS-CoV-2. While two of four air samples collected from the house of non-hospitalized patients were PCR positive. In this study, most of the hospitalized patients had oxygen mask and face mask, and hence this may be a reason for our negative results regarding the presence of SARS-CoV-2 in indoor air of the hospitals, while non-hospitalized patients did not wear oxygen and protective face masks in their houses. Moreover, a very high concentration of particles in the size range of droplet nuclei (< 5 µm) was identified compared to particles in the size range of respiratory droplets (> 5-10 µm) in the areas where patients were hospitalized. It can be concluded that using face mask by patients can prevent the release of viruses into the indoor air, even in hospitals with a high density of patients.

Assessment of burden of disease induced by exposure to heavy metals through drinking water at national and subnational levels in Iran, 2019.

The burden of disease attributable to exposure to heavy metals via drinking water in Iran (2019) was assessed at the national and regional levels. The non-carcinogenic risk, carcinogenic risk, and attributable burden of disease of heavy metals in drinking water were estimated in terms of hazard quotient (HQ), incremental lifetime cancer risk (ILCR), and disability-adjusted life year (DALY), respectively. The average drinking water concentrations of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and nickel (Ni) in Iran were determined to be 2.3, 0.4, 12.1, 2.5, 0.7, and 19.7 µg/L, respectively, which were much lower than the standard values. The total average HQs of heavy metals in drinking water in the entire country, rural, and urban communities were 0.48, 0.65 and 0.45, respectively. At the national level, the average ILCRs of heavy metal in the entire country were in the following order: 1.06 × 10-4 for As, 5.89 × 10-5 for Cd, 2.05 × 10-5 for Cr, and 3.76 × 10-7 for Pb. The cancer cases, deaths, death rate (per 100,000 people), DALYs, and DALY rate (per 100,000 people) attributed to exposure to heavy metals in drinking water at the national level were estimated to be 213 (95% uncertainty interval: 180 to 254), 87 (73-104), 0.11 (0.09-0.13), 4642 (3793-5489), and 5.81 (4.75-6.87), respectively. The contributions of exposure to As, Cd, Cr, and Pb in the attributable burden of disease were 14.7%, 65.7%, 19.3%, and 0.2%, respectively. The regional distribution of the total attributable DALY rate for all heavy metals was as follows: Region 5> Region 4> Region 1> Region 3> Region 2. The investigation and improvement of relatively high exceedance of As levels in drinking water from the standard value, especially in Regions 5 and 3 as well as biomonitoring of heavy metals throughout the country were recommended.