National and sub-national exposure to ambient fine particulate matter (PM2.5) and its attributable burden of disease in Iran from 1990 to 2016

Risk of cardiovascular and respiratory diseases attributed to satellite-based PM2.5 over 2017-2022 in Sanandaj, an area of Iran

The risk of cardiovascular and respiratory diseases attributed to satellite-based PM2.5 has been less investigated. In this study, the attributable risk was estimated in an area of Iran. The predicted air PM2.5 using satellite data and a two-stage regression model was used as the predictor of the diseases. The dose-response linkage between the bias-corrected predictor employing a strong statistical approach and the outcomes was evaluated using the distributed lag nonlinear model. We considered two distinct scenarios of PM2.5 for the risk estimation. Alongside the risk, the attributable risk and number were estimated for different levels of PM2.5 by age and gender categories. The cumulative influence of PM2.5 particles on respiratory illnesses was statistically significant at 13-16 µg/m3 relative to the reference value (median), mostly apparent in the middle delays. The cumulative relative risk of 90th and 95th percentiles were 2.03 (CI 95%: 1.28, 3.19) and 2.25 (CI 95%: 1.28, 3.96), respectively. Nearly 600 cases of the diseases were attributable to the non-optimum values of the pollutant during 2017-2022, of which more than 400 cases were attributed to high values range. The predictor's influence on cardiovascular illnesses was along with uncertainty, indicating that additional research into their relationship is needed. The bias-corrected PM2.5 played an essential role in the prediction of respiratory illnesses, and it may likely be employed as a trigger for a preventative strategy.

Associations between long-term exposure to air pollution, diabetes, and hypertension in metropolitan Iran: an ecologic study

Epidemiological studies on air pollution, diabetes, and hypertension conflict. This study examined air pollution, diabetes, and hypertension in adults in 11 metropolitan areas of Iran (2012-2016). Local environment departments and the Tehran Air Quality Control Company provided air quality data. The VIZIT website and Stepwise Approach to Chronic Disease Risk Factor Surveillance study delivered chronic disease data. Multiple logistic regression and generalized estimating equations evaluated air pollution-related diabetes and hypertension. In Isfahan, Ahvaz, and Tehran, PM2.5 was linked to diabetes. In all cities except Urmia, Yasuj, and Yazd, PM2.5 was statistically related to hypertension. O3 was connected to hypertension in Ahvaz, Tehran, and Shiraz, whereas NO2 was not. BMI and gender predict hypertension and diabetes. Diabetes, SBP, and total cholesterol were correlated. Iran's largest cities' poor air quality may promote diabetes and hypertension. PM2.5 impacts many cities' outcomes. Therefore, politicians and specialists have to control air pollution.

Impacts of socioeconomic and environmental factors on neoplasms incidence rates using machine learning and GIS: a cross-sectional study in Iran

Neoplasm is an umbrella term used to describe either benign or malignant conditions. The correlations between socioeconomic and environmental factors and the occurrence of new-onset of neoplasms have already been demonstrated in a body of research. Nevertheless, few studies have specifically dealt with the nature of relationship, significance of risk factors, and geographic variation of them, particularly in low- and middle-income communities. This study, thus, set out to (1) analyze spatiotemporal variations of the age-adjusted incidence rate (AAIR) of neoplasms in Iran throughout five time periods, (2) investigate relationships between a collection of environmental and socioeconomic indicators and the AAIR of neoplasms all over the country, and (3) evaluate geographical alterations in their relative importance. Our cross-sectional study design was based on county-level data from 2010 to 2020. AAIR of neoplasms data was acquired from the Institute for Health Metrics and Evaluation (IHME). HotSpot analyses and Anselin Local Moran's I indices were deployed to precisely identify AAIR of neoplasms high- and low-risk clusters. Multi-scale geographically weight regression (MGWR) analysis was worked out to evaluate the association between each explanatory variable and the AAIR of neoplasms. Utilizing random forests (RF), we also examined the relationships between environmental (e.g., UV index and PM2.5 concentration) and socioeconomic (e.g., Gini coefficient and literacy rate) factors and AAIR of neoplasms. AAIR of neoplasms displayed a significant increasing trend over the study period. According to the MGWR, the only factor that significantly varied spatially and was associated with the AAIR of neoplasms in Iran was the UV index. A good accuracy RF model was confirmed for both training and testing data with correlation coefficients R2 greater than 0.91 and 0.92, respectively. UV index and Gini coefficient ranked the highest variables in the prediction of AAIR of neoplasms, based on the relative influence of each variable. More research using machine learning approaches taking the advantages of considering all possible determinants is required to assess health strategies outcomes and properly formulate policy planning.

Burden of cardiovascular disease attributed to air pollution: a systematic review

BACKGROUND

Cardiovascular diseases (CVDs) are estimated to be the leading cause of global death. Air pollution is the biggest environmental threat to public health worldwide. It is considered a potentially modifiable environmental risk factor for CVDs because it can be prevented by adopting the right national and international policies. The present study was conducted to synthesize the results of existing studies on the burden of CVDs attributed to air pollution, namely prevalence, hospitalization, disability, mortality, and cost characteristics.

METHODS

A systematic search was performed in the Scopus, PubMed, and Web of Science databases to identify studies, without time limitations, up to June 13, 2023. Exclusion criteria included prenatal exposure, exposure to indoor air pollution, review studies, conferences, books, letters to editors, and animal and laboratory studies. The quality of the articles was evaluated based on the Agency for Healthcare Research and Quality Assessment Form, the Newcastle-Ottawa Scale, and Drummond Criteria using a self-established scale. The articles that achieved categories A and B were included in the study.

RESULTS

Of the 566 studies obtained, based on the inclusion/exclusion criteria, 92 studies were defined as eligible in the present systematic review. The results of these investigations supported that chronic exposure to various concentrations of air pollutants, increased the prevalence, hospitalization, disability, mortality, and costs of CVDs attributed to air pollution, even at relatively low levels. According to the results, the main pollutant investigated closely associated with hypertension was PM2.5. Furthermore, the global DALY related to stroke during 2016-2019 has increased by 1.8 times and hospitalization related to CVDs in 2023 has increased by 8.5 times compared to 2014.

CONCLUSION

Ambient air pollution is an underestimated but significant and modifiable contributor to CVDs burden and public health costs. This should not only be considered an environmental problem but also as an important risk factor for a significant increase in CVD cases and mortality. The findings of the systematic review highlighted the opportunity to apply more preventive measures in the public health sector to reduce the footprint of CVDs in human society.

Evaluating the mortality and health rate caused by the PM2.5 pollutant in the air of several important Iranian cities and evaluating the effect of variables with a linear time series model

All over the world, the level of special air pollutants that have the potential to cause diseases is increasing. Although the relationship between exposure to air pollutants and mortality has been proven, the health risk assessment and prediction of these pollutants have a therapeutic role in protecting public health, and need more research. The purpose of this research is to evaluate the ill-health caused by PM2.5 pollution using AirQ + software and to evaluate the different effects on PM2.5 with time series linear modeling by R software version 4.1.3 in the cities of Arak, Esfahan, Ahvaz, Tabriz, Shiraz, Karaj and Mashhad during 2019-2020. The pollutant hours, meteorology, population and mortality information were calculated by the Environmental Protection Organization, Meteorological Organization, Statistics Organization and Statistics and Information Technology Center of the Ministry of Health, Treatment and Medical Education for 24 h of PM2.5 pollution with Excel software. In addition, having 24 h of PM2.5 pollutants and meteorology is used to the effect of variables on PM2.5 concentration. The results showed that the highest and lowest number of deaths due to natural deaths, ischemic heart disease (IHD), lung cancer (LC), chronic obstructive pulmonary disease (COPD), acute lower respiratory infection (ALRI) and stroke in The effect of disease with PM2.5 pollutant in Ahvaz and Arak cities was 7.39-12.32%, 14.6-17.29%, 16.48-8.39%, 10.43-18.91%, 12.21-22.79% and 14.6-18.54 % respectively. Another result of this research was the high mortality of the disease compared to the mortality of the nose. The analysis of the results showed that by reducing the pollutants in the cities of Karaj and Shiraz, there is a significant reduction in mortality and linear modeling provides a suitable method for air management planning.

Associations between short-term exposure to fine particulate matter and acute myocardial infarction: A case-crossover study

BACKGROUND

Previous studies evaluated the impact of particle matters (PM) on the risk of acute myocardial infarction (AMI) based on local registries.

HYPOTHESIS

This study aimed to evaluate possible short term effect of air pollutants on occurrence of AMI based on a specific case report sheet that was designed for this purpose.

METHODS

AMI was documented among 982 patients who referred to the emergency departments in Tehran, Iran, between July 2017 to March 2019. For each patient, case period was defined as 24 hour period preceding the time of emergency admission and referent periods were defined as the corresponding time in 1, 2, and 3 weeks before the admission. The associations of particulate matter with an aerodynamic diameter ≤2.5 μm (PM2 .5 ) and particulate matter with an aerodynamic diameter ≤10 μm (PM10 ) with AMI were analyzed using conditional logistic regression in a case-crossover design.

RESULT

Increase in PM2.5 and PM10 was significantly associated with the occurrence of AMI with and without adjustment for the temperature and humidity. In the adjusted model each 10 μg/m3 increase of PM10 and PM2.5 in case periods was significantly associated with increase myocardial infarction events (95% CI = 1.041-1.099, OR = 1.069 and 95% CI = 1.073-1.196, and OR = 1.133, respectively). Subgroup analysis showed that increase in PM10 did not increase AMI events in diabetic subgroup, but in all other subgroups PM10 and PM2 .5 concentration showed positive associations with increased AMI events.

CONCLUSION

Acute exposure to ambient air pollution was associated with increased risk of AMI irrespective of temperature and humidity.

Air pollution in Iran: The current status and potential solutions

Air pollution has been integrated into global challenges over the last few years due to its negative impact on the health of human beings, increasing socio-economic risks, and its contribution to climate change. This study attempts to evaluate the current status of Iran's air pollution with regard to the sources of emissions, control policies, and the health and climate consequences that have resulted through available data from monitoring stations reported in the literature, official documents, and previously published papers. Many large cities in Iran surpass the permissible concentration of air pollutants, particularly particulate matter, sulfur dioxide, black carbon, and ozone. Although regulations and policies are in place and enormous efforts are being made to address air pollution issues in the country, implementation and enforcement are not as effective as they could be. The significant challenges may be regarded as the inefficiency of regulation and supervision systems, the lack of air quality monitoring systems and technology, particularly in industrial cities rather than Tehran, and the lack of continual feedback and investigations on the efficiency of regulation. Providing such an up-to-date report can bring opportunities for international collaboration, which is essential in addressing air pollution worldwide. We suggest that a way forward could be more focused on conducting systematic reviews using scientometric methods to show an accurate picture and trend in air pollution and its association in Iran, implementing an integrated approach for both climate change and air pollution issues, collaborating with international counterparts to share knowledge, tools, and techniques.

Effects of sulfur dioxide and particulate matter pollution on hospital admissions for hypertensive cardiovascular disease: A time series analysis

Background and aims: Air pollution is a major environmental risk factor and the leading cause of disease burden with detrimental effects on cardiovascular systems. Cardiovascular diseases are predisposed by various risk factors, including hypertension, as the most important modifiable risk factor. However, there is a lack of sufficient data concerning the impact of air pollution on hypertension. We sought to study the associations of short-term exposure to Sulfur dioxide (SO₂) and particulate matter (PM₁₀) with the number of daily hospital admissions of hypertensive cardiovascular diseases (HCD). Methods: All hospitalized patients between March 2010 to March 2012 were recruited with the final diagnosis of HCD based on the International Classification of Diseases 10 (codes: I10-I15) from 15 hospitals in Isfahan, one of the most polluted cities in Iran. The 24-hour average concentrations of pollutants were obtained from 4 monitoring stations. In addition to single- and two-pollutant models, we used Negative Binomial and Poisson models with covariates of holidays, dew point, temperature, wind speed, and extracted latent factors of other pollutants controlling for multi-collinearity to examine the risk for hospital admissions for HCD affected by SO₂ and PM₁₀ exposures in the multi-pollutant model. Results: A total of 3132 hospitalized patients (63% female) with a mean (standard deviation) age of 64.96 (13.81) were incorporated in the study. The mean concentrations of SO2 and PM10 were 37.64 μg/m3 and 139.08 μg/m3, respectively. Our findings showed that a significantly increased risk of HCD-induced hospital admission was detected for a 10 μg/m3 increase in the 6-day and 3-day moving average of SO2 and PM₁₀ concentrations in the multi-pollutant model with a percent change of 2.11% (95% confidence interval: 0.61 to 3.63%) and 1.19% (0.33 to 2.05%), respectively. This finding was robust in all models and did not vary by gender (for SO₂ and PM₁₀) and season (for SO₂). However, people aged 35-64 and 18-34 years were vulnerable to SO2 and PM10 exposure-triggered HCD risk, respectively. Conclusions: This study supports the hypothesis of the association between short-term exposure to ambient SO₂ and PM₁₀ and the number of hospital admissions due to HCD.

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: PM_2.5, 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 PM_2.5 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 PM_2.5, we used the average of ambient PM_2.5 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 PM_2.5 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 PM_2.5 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 PM_2.5: 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.

Gas-phase and PM2.5-bound phthalates in nail salons: characteristics, exposure via inhalation, and influencing factors

This study aimed to investigate the characteristics of, exposure to, and factors influencing gas-phase and PM_2.5-bound phthalates (PAEs) in nail salons. Data on both indoor and outdoor gas-phase and PM_2.5-bound PAEs, carbon dioxide (CO₂), temperature, and relative humidity were collected in nail salons. We also used questionnaires to survey building characteristics and occupants' behaviors. The average total gas-phase and PM_2.5-bound PAE concentrations indoors were higher than those outdoors by 6 and 3 times, respectively. Diethyl phthalate, diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and di-(2-ethylhexyl) phthalate (DEHP) were the predominant compounds among both the gas-phase and PM_2.5-bound PAEs in indoor air. The volume of the salon's space or the difference of indoor and outdoor CO₂ concentrations (dCO₂) was significantly associated with indoor PAE concentrations. The ratios of PM_2.5-bound to gas-phase PAEs, especially high-molecular-weight PAEs, were positively associated with the dCO₂ concentrations. Higher ratios of indoor to outdoor PM_2.5-bound DiBP, DnBP, and DEHP concentrations were discovered when more clients visited each day. Building characteristics, ventilation conditions, and occupants' activities have influences on the gas-phase and particle-phase PAEs. The study identifies the characteristics of gas-phase and PM_2.5-bound PAEs in nail salons and their influencing factors.

National and subnational survey on diabetes burden and quality of care index in Iran: a systematic analysis of the global burden of disease study 1990-2019

Purpose

Diabetes care is one of the major healthcare problems . This study aimed to introduce a recently-developed Quality of Care Index (QCI) for type 2 diabetes and utilized it to compare different genders, age groups, and Iranian provinces.

Methods

From the Global Burden of Disease 1990-2019 database, we obtained primary epidemiologic measures and combined them to build four secondary indices, all indicating the quality of care provided to patients. We utilized the principal component analysis (PCA) method to calculate the substantial component named QCI (with a scale of 0-100). Gender inequality was shown by the gender disparity ratio (GDR), defining female to male QCI.

Results

National QCI ranged from 43.0 in 1990 to 38.6 in 2019. By excluding the more frequent outlier province; Tehran as the Capital of Iran, the QCI score reached 50.27 in 2019. The GDR decreased from 1.04 to 0.95. QCI indicated rather more favorable conditions in Iranian provinces with a higher socio-demographic index (SDI). Conversely, provinces with a lower SDI had worse QCI. In 2019, Tehran, the capital of Iran, with the highest (58.5), and South Khorasan with the lowest QCIs (0.4) were the two Iranian provinces' extremes. Moreover, the elderly QCI improved in 2019.

Conclusion

During 1990-2019, there are remarkable disparities between Iran's provinces, genders and age groups. The equitable and widespread provision of facilities should be considered along with the decentralization of healthcare resources.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01108-x.

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 PM_2.5 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 PM_2.5. The remaining sources for ambient PM_2.5, 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.

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 PM_2·5 air pollution exposure in 429 counties of Iran in 2018. Ambient PM_2.5-related deaths were estimated using the Global Exposure Mortality Model (GEMM). According to the ground-monitored and satellite-based PM_2.5 data, the annual mean population-weighted PM_2·5 concentrations for Iran were 30.1 and 38.6 μg m^-3, respectively. We estimated that long-term exposure to ambient PM_2.5 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 PM_2.5. The crude death rate and the age-standardized death rate per 100,000 population for age group ≥ 25 year due to ground-monitored PM_2.5 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 PM_2.5 data, the economic loss attributable to ambient PM_2.5-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.

Estimates of incidence, prevalence, mortality, and disability-adjusted life years of lung cancer in Iran, 1990-2019: A systematic analysis from the global burden of disease study 2019

BACKGROUND

Lung cancer is one of the leading cancers, with a high burden worldwide. As a developing country, Iran is facing with population growth, widespread tobacco use, demographic and epidemiologic changes, and environmental exposures, which lead to cancers becoming a severe concern of public health in Iran. We aimed to examine the burden of lung cancer and its risk factors in Iran.

METHODS

We utilized the Global Burden of Disease 2019 data and analyzed the total burden of the lung cancer and seven related risk factors by sex, age at national and sub-national levels from 1990 to 2019.

RESULTS

The lung cancer age-standardized death rate increased from 11.8 (95% Uncertainty Interval: 9.7-14.4) to 12.9 (11.9-13.9) per 100,000 between 1990 and 2019. This increase was among women from 5 (4.2-7.1) to 8 (7.2-8.8) per 100,000; in contrast, there was a decline among men from 18.5 (14.8-22.6) to 17.8 (16.2-19.4) per 100,000. The burden of lung cancer is concentrated in the advanced age groups. Smoking with 53.5% of total attributable deaths (51.0%-55.9%) was the leading risk factor. At the provincial level, there was a wide range between the lowest and highest, from 8.3 (7.0-10.0) to 19.1 (16.4-22.0) per 100,000 population in the incidence rate and from 8.7 (7.3-10.3) to 20.6 (17.7-24.0) per 100,000 population in mortality rate, respectively in Tehran and West Azerbaijan provinces in 2019.

CONCLUSION

The increasing trend of lung cancer burden among the entire Iranian population, the inter-provincial disparities, and the significant rise in burden of this cancer in women necessitate the urgent implementation and development of policies to prevent and manage lung cancer burden and strategies to reduce exposure to risk factors.

Urban grey spaces are associated with increased allergy in the general population

BACKGROUND

the built environment in urban areas may have side effects on children's respiratory health, whilst less is known for adulthood.

AIM

to assess the association between increasing exposure to grey spaces and allergic status in an adult general population sample.

METHODS

2070 subjects (age range 15-84 yrs), living in Pisa/Cascina, Italy, were investigated in 1991-93 through a questionnaire on health status and risk factors, skin prick test (SPT), serum Immunoglobulins E (IgE), and serum antibodies to benzo(a)pyrene diol epoxide (BPDE)-DNA adducts. Land-cover exposure within a 1000 m buffer from each subject's home address was assessed through the CORINE Land Cover program (CLC 1990) within the FP7/HEALS project (2013-2018). Participants' residential addresses were geocoded and the proportion of surrounding grey spaces was calculated. Through logistic regression models, adjusting for potential confounding factors, the effect of a 10% increase in grey spaces exposure on allergic biomarkers/conditions was assessed; the relationship with serum antibodies to BPDE-DNA adducts positivity was also analyzed.

RESULTS

A 10% increase in grey spaces coverage was associated with a higher probability of having SPT positivity (OR 1.07, 95% CI 1.02-1.13), seasonal SPT positivity (OR 1.12, 1.05-1.19), polysensitization (OR 1.11, 1.04-1.19), allergic rhinitis (OR 1.10, 1.04-1.17), co-presence of SPT positivity and asthma/allergic rhinitis (OR 1.16, 1.08-1.25), asthma/allergic rhinitis (OR 1.06, 1.00-1.12), presence of serum antibodies to BPDE-DNA adducts positivity (OR 1.07, 1.01-1.14).

CONCLUSIONS

grey spaces have adverse effects on allergic status and are related to a biomarker of polycyclic aromatic hydrocarbons exposure in adulthood. Thus, they may be used as a proxy of urban environmental exposure.

Does air pollution increase child mortality? Evidence from 58 developing countries

This study aims to investigate the effects of air quality on child mortality in developing countries. We consider annual data covering the period from 2010 to 2016 of 58 countries and estimate the empirical models using recently developed panel quantile regression with the method of moments (MM-QR). It is found that outdoor air quality (measured by the concentration of PM_2.5 in the air) has a positive and significant effect on total child mortality, post-neonatal mortality, and under-five child mortality. However, its effect on neonatal mortality is not statistically significant at lower quantiles. Furthermore, Household air pollution (HAP) also has a positive and significant effect on total child mortality, neonatal mortality, and under-five child mortality. The effect of HAP on post-neonatal mortality is not significant in most cases. Overall, the adverse effect of HAP is larger than the PM_2.5. For instance, a 1% increase of PM_2.5 concentration in the outdoor causes 0.231% total child mortality due to respiratory diseases at [Formula: see text], while a 1% increase of HAP causes 0.532% total child mortality at the same quantile. In many cases, the coefficients of PM_2.5 and HAP increase at the higher quantiles, supporting asymmetric effects of pollutants on child mortality. However, per capita income, access to basic drinking water and sanitation facilities, and domestic and external health expenditures significantly reduce child mortality. On the contrary, open defecation increases mortality. Consequently, policymakers should take adequate measures to improve indoor and outdoor air quality to combat child mortality due to respiratory diseases in developing countries. They should also take initiatives to enhance per capita income, basic drinking water, and sanitation facilities, domestic and external health expenditures, and public awareness against open defecation.

Temporal variations, regional contribution, and cluster analyses of ozone and NOx in a middle eastern megacity during summertime over 2017-2019

Particulate matter is usually regarded as the dominant pollutant in Tehran megacity in Iran. However, the number of ozone exceedance days significantly increased in recent years. This study analyzes simultaneous measurements of O3 and NOx (NO+NO2) concentrations to improve our understanding of ozone evolution during the summers of 2017 to 2019. The k-means clustering technique was used to select five representative air quality monitoring sites in Tehran to capture O3 and NOx concentrations' variability. The findings show that all of the investigated sites failed to meet the ozone non-attainment criterion. The ozone weekend effect is seen in the study of weekday/weekend differences in 2017 and 2018, but not in 2019, which can be due to the shift in the ozone production regime. The summer mean variation analysis can also be used to deduce this regime change. In 2017, the O3 and NO2 summer mean variations suggest a holdback in the NO2 upward trend and a reversal in the O3 downward trend that had been in place since 2012. Air mass back trajectory clustering reveals that east and north-east air mass clusters have the most significant impact on Tehran's O3 pollution and the highest regional contribution to OX. The study of OX against NOx shows that the regional contribution to OX increased from 2017 to 2018 and then decreased in 2019; however, the local contribution is the opposite. The diurnal analysis of the regional and local contributions to OX indicated that OX in Tehran might be primarily affected by pollutants from a short distance. The findings reveal critical changes in the behavior of O3 in recent years, indicating that decision-makers in Tehran should reconsider air pollution control measures.

Effect of omega-3 fatty acids on TH1/TH2 polarization in individuals with high exposure to particulate matter ≤ 2.5 μm (PM2.5): a randomized, double-blind, placebo-controlled clinical study

Background

Long-term exposure to high concentrations of PM2.5 may cause immune system dysfunction and damage to the respiratory and cardiovascular systems. PM2.5 may cause CD4 + T helper cells to polarize toward TH1 or TH2 cell types, which may be associated with the onset and progression of many human diseases. Recent studies have shown that omega-3 fatty acids can regulate human immune function and reduce physiological damage caused by air pollution; however, only limited research has examined the therapeutic effects of omega-3 fatty acids on subjects with high exposure to PM2.5 in mass transit systems such as subways.

Methods

This study was designed as a prospective, randomized, double-blinded (to participants and researchers), placebo-controlled clinical trial. The research plan is to randomly select 120 eligible adults based on the difference in PM2.5 exposure in the Chengdu subway station. They should be aged 20–65 years old and work in the subway station more than or equal to 3 times a week, each time greater than or equal to 8 h, and had worked continuously in the subway station for more than 2 years. All participants will receive omega-3 fatty acids or placebo for 8 weeks. The primary outcomes will be changes in the TH1/TH2 cell polarization index and changes in serum cytokine concentrations. Secondary outcomes will be changes in early indicators of atherosclerosis, pulmonary function, COOP/WONCA charts, and scores on the Short-Form 36 Health Survey for quality of life. Results will be analyzed to evaluate differences in clinical efficacy between the two groups. A 6-month follow-up period will be used to assess the long-term value of omega-3 fatty acids for respiratory and cardiovascular disease endpoints.

Discussion

We will explore the characteristics of the TH1/TH2 cell polarization index in a population with high exposure to PM2.5. Omega-3 fatty acids and placebo will be compared in many ways to test the effect on people exposed to PM2.5 subway stations. This study is expected to provide reliable evidence to support the promotion of omega-3 fatty acids in clinical practice to protect individuals who are highly exposed to PM2.5.

Trial registration

Chinese Clinical Trial Registry ChiCTR2000038065. Registered on September 9, 2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06091-5.

Burden of disease induced by public overexposure to solar ultraviolet radiation (SUVR) at the national and subnational levels in Iran, 2005-2019

Estimating the burden of diseases induced by overexposure to solar ultraviolet radiation (SUVR) can help to prioritize environmental health interventions. The age-sex specific and cause-specific mortality and disability-adjusted life years (DALYs) attributable to overexposure to SUVR at the national and subnational levels in Iran, 2005-2019 were estimated. The burden of disease induced by overexposure to SUVR was quantified in four steps as follows: (1) estimating exposure to SUVR, (2) estimating total incidences and deaths of target causes, (3) assessing population attributable fractions of the target causes for the SUVR, and (4) calculating the attributable burden of disease. The attributable DALYs, deaths, age-standardized DALY rate, and age-standardized death rate at the national level were determined to be respectively 21896, 252, 42.59, and 0.56 in 2005 and were respectively changed to 28665, 377, 38.76, and 0.53 in 2019. The contributions of causes in the attributable DALYs at the national level were different by year and sex and for both sexes in 2019 were as follows: 46.15% for cataract, 20.36% for malignant skin melanoma, 16.07% for sunburn, 12.41% for squamous-cell carcinoma, and 5.01% for the other five causes. The contributions of population growth, population ageing, risk exposure, and risk-deleted DALY rate in the temporal variations of the attributable burden of disease in the country were +20.73%, +20.68%, +2.01%, and -12.51%. The highest and lowest provincial attributable age-standardized DALY rates in 2019 were observed in Fars (46.8) and Ardebil (32.7), respectively. The burden of disease induced by exposure to SUVR caused relatively low geographical inequality in health status in Iran. Due to increasing trends of the SUVR as well as the attributable burden of disease, the preventive interventions against the SUVR overexposure should be considered in the public health action plan all across the country.

Association between ambient particulate matter exposure and metabolic syndrome risk: A systematic review and meta-analysis

Although the association between ambient particulate matter and metabolic syndrome (MetS) has been investigated, the effect of particulate matter (PM) on MetS is inconclusive. We conducted a systematic review and meta-analysis to study the association between long-term ambient PM exposure and MetS risk. The data from five databases were extracted to analyze the association between ambient PM exposure and MetS risk. A random-effects model was performed to estimate the overall risk effect. The present systematic review and meta-analysis illustrated that an increase of 5 μg/m³ in annual PM_2.5 or PM₁₀ concentration was associated with 14% or 9% increases of MetS risk, respectively (PM_2.5, RR = 1.14, 95%CI [1.03, 1.25]; PM₁₀, RR = 1.09, 95%CI [1.00, 1.19]). The population-attributable risk (PAR) was 12.28% for PM_2.5 exposure or 8.26% for PM₁₀ exposure, respectively. There was statistical association between PM_2.5 exposure and risk of MetS in male proportion ≥50%, Asia, related disease or medication non-adjustment subgroup as well as cohort study subgroups, respectively. The significant association between PM₁₀ exposure and risk of MetS was observed in male proportion ≥50% and calories intake adjustment subgroups, respectively. Sensitivity analyses showed the robustness of our results. No publication bias was detected. In conclusion, there was positive association between long-term PM exposure and MetS risk. 12.28% of MetS risk could be attributable to PM_2.5 exposure.

National and Subnational Cancer Incidence for 22 Cancer Groups, 2000 to 2016: A Study Based on Cancer Registration Data of Iran

BACKGROUND

Cancer is an increasing public health concern, and detailed knowledge of the cancer incidence is required for developing effective cancer control plans. The objective of this study is to present the cancer incidence of 22 cancer groups in Iran and all 31 provinces of the country from 2000 to 2016, for both sexes across different age groups.

METHOD

To study the national and provincial cancer incidence in Iran, we extracted data from the Cancer Project, which collects the Iranian cancer registry data and visualizes it in the VIZIT data visualization system. The methodology and statistical analysis that is used in this study follow the cancer project study protocol. Joinpoint analysis was performed to calculate the average annual percent change of the crude rates and age-standardized rates from 2000 to 2016.

RESULTS

Cancer incidence was 126,982 patients in 2016, and the crude rate (CR) of cancer in both sexes and all ages was 155 per 100,000 people. Cancer incidence approximately doubled between 2000 and 2016; however, the age-standardized rate (ASR) had a less drastic increase. The most incident cancers in 2016 were breast, skin, and colorectal cancers; however, the ranking of cancer groups by incidence was different in different age and sex groups and provinces. Some cancers exhibited a unique distribution pattern in the country with high-incidence local areas. Discussion. The study showed that cancer incidence, crude rate, and age-standardized rate (ASR) in Iran had increased in 2000-2016 with vast heterogeneity by cancer type, province, and sex. Moreover, it was shown that the crude rate of cancer in Iran was much less than the global cancer crude rate. Providing such data helps to allocate resources and develop effective national cancer control plans appropriately.

Airborne particulate matter upregulates expression of early and late adhesion molecules and their receptors in a lung adenocarcinoma cell line

BACKGROUND

Epidemiological evidence associates chronic exposure to particulate matter (PM) with respiratory damage and lung cancer. Inhaled PM may induce systemic effects including inflammation and metastasis. This study evaluated whether PM induces expression of adhesion molecules in lung cancer cells promoting interaction with monocytes.

METHODS

The expression of early and late adhesion molecules and their receptors was evaluated in A549 (human lung adenocarcinoma) cells using a wide range of concentrations of PM_2.5 and PM₁₀. Then we evaluated cellular adhesion between A549 cells and U937 (human monocytes) cells after PM exposure.

RESULTS

We found higher expression of both early and late adhesion molecules and their ligands in lung adenocarcinoma cells exposed to PM_2.5 and PM₁₀ particles present in the air pollution at Mexico City from 0.03 μg/cm² with a statistically significant difference (p ≤ 0.05). PM₁₀ had stronger effect than PM_2.5. Both PM also stimulated cellular adhesion between tumor cells and monocytes.

CONCLUSIONS

This study reveals a comprehensive expression profile of adhesion molecules and their ligands upregulated by PM_2.5 and PM₁₀ in A549 cells. Additionally these particles induced cellular adhesion of lung cancer cells to monocytes. This highlights possible implications of PM in two cancer hallmarks i.e. inflammation and metastasis, underlying the high cancer mortality associated with air pollution.

The Influence of Air Pollutants and Meteorological Conditions on the Hospitalization for Respiratory Diseases in Shenzhen City, China

Air pollutants have significant direct and indirect adverse effects on public health. To explore the relationship between air pollutants and meteorological conditions on the hospitalization for respiratory diseases, we collected a whole year of daily major air pollutants’ concentrations from Shenzhen city in 2013, including Particulate Matter (PM₁₀, PM_2.5), Nitrogen dioxide (NO₂), Ozone (O₃), Sulphur dioxide (SO₂), and Carbon monoxide (CO). Meanwhile, we also gained meteorological data. This study collected 109,927 patients cases with diseases of the respiratory system from 98 hospitals. We investigated the influence of meteorological factors on air pollution by Spearman correlation analysis. Then, we tested the short-term correlation between significant air pollutants and respiratory diseases’ hospitalization by Distributed Lag Non-linear Model (DLNM). There was a significant negative correlation between the north wind and NO₂ and a significant negative correlation between the south wind and six pollutants. Except for CO, other air pollutants were significantly correlated with the number of hospitalized patients during the lag period. Most of the pollutants reached maximum Relative Risk (RR) with a lag of five days. When the time lag was five days, the annual average of PM₁₀, PM_2.5, SO₂, NO₂, and O₃ increased by 10%, and the risk of hospitalization for the respiratory system increased by 0.29%, 0.23%, 0.22%, 0.25%, and 0.22%, respectively. All the pollutants except CO impact the respiratory system’s hospitalization in a short period, and PM10 has the most significant impact. The results are helpful for pollution control from a public health perspective.

Effect of PM2.5 exposure on circulating fibrinogen and IL-6 levels: A systematic review and meta-analysis

BACKGROUND

Ambient fine particulate matter (PM_2.5) pollution poses a great threat on global health. Previous studies have reported that PM_2.5 regulates circulating fibrinogen and IL-6 levels in the development of cardiovascular and respiratory disease. However, the correlation between PM_2.5 exposure and both biomarkers remains inconsistent.

METHODS

We searched related articles through PubMed, Web of Science and ScienceDirect. Random effects model was used to obtain a pooled estimate effect of both biomarkers as PM_2.5 concentration increased by every 10 μg/m³. Meta-regression analysis, sensitivity analysis and publication bias test were conducted to evaluate the heterogeneity, stability and reliability of this meta-analysis.

RESULTS

A total of 22 articles were included. Each 10 μg/m³ increase in PM_2.5 concentration was significantly correlated with a 1.76% increase in circulating fibrinogen level (95% CI: 0.38%-3.14%, P = 0.013) and a 4.66% increase in IL-6 level (95% CI: 1.14%-8.18%, P = 0.010). Subgroup analysis revealed that high-level PM_2.5 exposure had a more significant association with circulating IL-6 level (11.67%, 95% CI: 0.66%-22.69%, P = 0.038) than low-level exposure, but this association was not observed in fibrinogen (2.50%, 95% CI: -0.78%-5.77%, P = 0.135). Sensitivity analysis and publication bias test confirmed the stability of the results.

CONCLUSION

Circulating fibrinogen and IL-6 significantly increased with exposure to PM_2.5, may serve as promising biomarkers for PM_2.5-related adverse effects.

Short and long term exposure to air pollution increases the risk of ischemic heart disease

Previous studies have suggested an increased risk of ischemic heart disease related to air pollution. This study aimed to explore both the short-term and long-term effects of air pollutants on the risk of ischemic heart disease after adjusting for meteorological factors. The Korean National Health Insurance Service-Health Screening Cohort from 2002 to 2013 was used. Overall, 2155 participants with ischemic heart disease and 8620 control participants were analyzed. The meteorological data and air pollution data, including SO₂ (ppm), NO₂ (ppm), O₃ (ppm), CO (ppm), and particulate matter (PM)₁₀ (μg/m³), were analyzed using conditional logistic regression. Subgroup analyses were performed according to age, sex, income, and region of residence. One-month exposure to SO₂ was related to 1.36-fold higher odds for ischemic heart disease (95% confidence interval [95% CI] 1.06–1.75). One-year exposure to SO₂, O₃, and PM₁₀ was associated with 1.58- (95% CI 1.01–2.47), 1.53- (95% CI 1.27–1.84), and 1.14 (95% CI 1.02–1.26)-fold higher odds for ischemic heart disease. In subgroup analyses, the ≥ 60-year-old group, men, individuals with low income, and urban groups demonstrated higher odds associated with 1-month exposure to SO₂. Short-term exposure to SO₂ and long-term exposure to SO_2, O₃, and PM₁₀ were related to ischemic heart disease.

Air pollution aggravating COVID-19 lethality? Exploration in Asian cities using statistical models

The present work estimates the increased risk of coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 by establishing the linkage between the mortality rate in the infected cases and the air pollution, specifically Particulate Matters (PM) with aerodynamic diameters ≤ 10 µm and ≤ 2.5 µm. Data related to nine Asian cities are analyzed using statistical approaches, including the analysis of variance and regression model. The present work suggests that there exists a positive correlation between the level of air pollution of a region and the lethality related to COVID-19, indicating air pollution to be an elemental and concealed factor in aggravating the global burden of deaths related to COVID-19. Past exposures to high level of PM_2.5 over a long period, is found to significantly correlate with present COVID-19 mortality per unit reported cases (p < 0.05) compared to PM₁₀, with non-significant correlation (p = 0.118). The finding of the study can help government agencies, health ministries and policymakers globally to take proactive steps by promoting immunity-boosting supplements and appropriate masks to reduce the risks associated with COVID-19 in highly polluted areas.

Temporal fluctuations of PM2.5 and PM10, population exposure, and their health impacts in Dezful city, Iran

Morbidity and mortality impacts of particulate matter (PM) are globally important health critical parameters. In this ecological-descriptive study, the health impact of PM10 and PM2.5 associated with there temporal variations in Dezful city were assessed from 2013 to 2015. AirQ+ software handles the PM air pollutants by addressing impact evaluation and life table evaluation. We used a new method to analysis fine particles feature by using regular daily observations of PM10. In this method, relationship between PM2.5 and PM10 mass concentrations were analyzed and calculated. The annual average concentrations of PM10 were 147.1, 114.3 and 158.8 μg/m3, and the annual average concentration of PM2.5 were 57.8, 50.7 and 58.2 μg/m3 in 2013, 2014 and 2015, respectively. PM10 also had obvious diurnal variations with highest hourly concentrations in 13:00 and 22:00 but the lowest concentrations often occurred in 05:00 and 16:00. Unexpectedly, in weekends the concentration of PM pollutants appeared to have increased from 18:00 to midnight. The daily based analysis showed that there are 147 dusty days in the study period during which the most severe dusty day occurred in 2014. Over the study period, mean levels of PM10 and PM2.5 in both conditions were higher in 2015 compare to 2013 and 2014, which probably is due to higher frequency of dust storms in 2015. Hence, during 2015 and 2013 they're were higher morbidity and mortality compare to 2014 due to exposure to higher polluted air with PMs in all cases except lung cancer (LC).

PM2.5-associated bacteria in ambient air: Is PM2.5 exposure associated with the acquisition of community-acquired staphylococcal infections?

Particulate matter (PM), a major component of air pollution, is an important carrier medium of various chemical and microbial compounds. Air pollution due to PM could increase the level of bacteria and associated adverse health effects. Staphylococci as important opportunistic pathogens that cause hospital- and community-acquired infections may transmit through air. This study aimed to obtain knowledge about the concentration of airborne bacteria as well as staphylococci associated with particulate matter with a diameter of less than 2.5 micrometers (PM_2.5) in ambient air. The impact of meteorological factors including ultraviolet (UV) index, wind speed, temperature, and moisture on microbial concentrations was also investigated. Quartz filters were used to collect PM_2.5 and associated bacteria in ambient air of a semiarid area. Airborne bacteria were quantified by culture method and Staphylococcus species identified by molecular methods. The mean (SD) concentration of PM_2.5 and airborne bacteria was 64.83 (24.87) µg/m³ and 38 (36) colony forming unit (CFU)/m³, respectively. The results showed no significant correlation between the levels of PM_2.5 and concentrations of bacteria (p < 0.05). Staphylococcus species were detected in 8 of 37 (22%) samples in a concentration from 3 to 213 CFU/m³. S. epidermidis was detected with the highest frequency followed by S. gallinarum and S. hominis, but S. aureus and methicillin-resistant Staphylococcus aureus (MRSA) were not detected. No significant correlation between the concentrations of bacteria with meteorological parameters was observed (p < 0.05). Our finding showed that, although the study area is sometimes subject to air pollution from PM_2.5, the concentration of PM_2.5- associated bacteria is relatively low. According to the results, PM_2.5 may not be a source of community-associated staphylococcal infections.

Long-term exposure to air pollution and stroke incidence: A Danish Nurse cohort study

Ambient air pollution has been linked to stroke, but few studies have examined in detail stroke subtypes and confounding by road traffic noise, which was recently associated with stroke. Here we examined the association between long-term exposure to air pollution and incidence of stroke (overall, ischemic, hemorrhagic), adjusting for road traffic noise. In a nationwide Danish Nurse Cohort consisting of 23,423 nurses, recruited in 1993 or 1999, we identified 1,078 incident cases of stroke (944 ischemic and 134 hemorrhagic) up to December 31, 2014, defined as first-ever hospital contact. The full residential address histories since 1970 were obtained for each participant and the annual means of air pollutants (particulate matter with diameter < 2.5 µm and < 10 µm (PM_2.5 and PM₁₀), nitrogen dioxide (NO₂), nitrogen oxides (NOx)) and road traffic noise were determined using validated models. Time-varying Cox regression models were used to estimate hazard ratios (HR) (95% confidence intervals (CI)) for the associations of one-, three, and 23-year running mean of air pollutants with stroke adjusting for potential confounders and noise. In fully adjusted models, the HRs (95% CI) per interquartile range increase in one-year running mean of PM_2.5 and overall, ischemic, and hemorrhagic stroke were 1.12 (1.01-1.25), 1.13 (1.01-1.26), and 1.07 (0.80-1.44), respectively, and remained unchanged after adjustment for noise. Long-term exposure to ambient PM_2.5 was associated with the risk of stroke independent of road traffic noise.

Can respirator face masks in a developing country reduce exposure to ambient particulate matter?

Respirator face masks (RFMs) as a personal-level intervention is increasingly being utilized to reduce ambient particulate matter (PM) exposure, globally. We tested the effectiveness of 50 commercially available ones in reducing the exposure of ambient particle number concentrations (PNC), PM₁₀, PM_2.5, and PM₁ (PM ≤ 10, 2.5, and 1 μm in diameter, respectively) in a traffic-affected urban site in Tehran. To examine the efficiency of RFMs, we applied a specific experimental setup including vacuum pumps, dummy heads, connecting tubes, glass chambers, and GRIMM Aerosol Spectrometer to measure all metrics after dummy heads. The average effectiveness of RFMs was in the range of 0.7-83.5%, 3.5-68.1%, 0.8-46.1%, and 0.4-32.2% in reducing ambient PNC, PM₁₀, PM_2.5, and PM₁, respectively. Considering all metrics, the highest effectiveness was observed always for Biomask, followed by 3 M 9332, due to their well-designed physical characteristics (e.g., adjustable nose clip for any face/nose shape, and size, soft inner material in the nose panel to provide a secure seal against leakage, adjustable or elasticated straps/ear loops to better adjust on any face). Biomask reduced ambient PM₁₀ with a mean value of 94.6 μg m^-3 (minimum-maximum: 51.7-100.3 μg m^-3), whereas it filtered on average just 29.0 μg m^-3 (25.7-43.5 μg m^-3) of ambient PM_2.5 and 18.2 μg m^-3 (14.7-21.8 μg m^-3) of PM₁. A fuzzy analytical hierarchy process to find the most important design-related factors of RFMs affecting their effectiveness, which showed the exhalation valve and its diaphragm (20.4%), nose clip (19.7%), and cheek flaps (18.6%) are ranked as the main design-related variables. The fuzzy technique for order preference by similarity to ideal solution indicated that Biomask and 3M 9332 had scores of 1 and 0.97, the highest scores compared with other RFMs. This study provides crucial evidence-based results to elucidate the effectiveness and design-related factors of RFMs in real-environmental circumstances.

The burden of cardiovascular and respiratory diseases attributed to ambient sulfur dioxide over 26 years

INTRODUCTION

Developing countries, particularly those with a rapid development, are experiencing increasing pollution by sulfur dioxide (SO₂). Despite the considerable SO₂ exposure effect on health, there is little evidence regarding this fact in Iran, as one of the largest oil and gas producing countries in the world. The present study, therefore, was designed to investigate the burden of cardiovascular and respiratory diseases attributed to the SO₂ exposure in Iran, over a 26-year period.

MATERIALS AND METHODS

All measured SO₂ levels were collected from 92 air quality monitoring stations (AQMSs) in 29 cities, during 1996-2013. Since the study years were from 1990 to 2015, and also due to missing data at existing stations, the spatiotemporal model was used to estimate the exposure to this gas during this period. To calculate the burden of cardiovascular and respiratory diseases, the population attributable fraction (PAF) value was calculated, and the SO₂-attributed mortality and years of life lost (YLL) were determined per province, and in the whole country.

RESULTS

The results of this study showed that the SO₂ concentration was increased from 22.00 ppb (7.69-67.28) in 1990 to 27.81 ppb (9.88-82.27), in 2015. The lowest annual value of 11.53 ppb (4.68-32.06) and the highest value of 45.11 ppb (16.58-1226) were estimated at 2004 and 1997, respectively. There was a sinusoidal trend in the gas concentration changes. The highest occurrence of SO₂-attributed deaths due to cardiovascular and respiratory diseases were 0.080 (0.024-0.168) and 0.076 (0.026-0.165), and the lowest levels were 0.017 (0.004-0.044) and 0.047 (0.017-0.124), respectively.

CONCLUSIONS

According to the results in our country, the SO₂ trend was sinusoidal during 26 years, with a recurrent rise occurring after each declining period. It is recommended to design the sustainable national method policies and programs with the continuous evaluation and modification for the reduction of fossil fuel consumption and further implementation in the use of clean energy.

Study of in vitro and in vivo genotoxic effects of air pollution fine (PM2.5-0.18) and quasi-ultrafine (PM0.18) particles on lung models

Air pollution and particulate matter (PM) are classified as carcinogenic to humans. Pollutants evidence for public health concern include coarse (PM₁₀) and fine (PM_2.5) particles. However, ultrafine particles (PM_0.1) are assumed to be more toxic than larger particles, but data are still needed to better understand their mechanism of action. In this context, the aim of our work was to investigate the in vitro and in vivo genotoxic potential of fine (PM_2.5-018) and quasi ultra-fine (PM_0.18) particles from an urban-industrial area (Dunkirk, France) by using comet, micronucleus and/or gene mutation assays. In vitro assessment was performed with 2 lung immortalized cell lines (BEAS-2B and NCI-H292) and primary normal human bronchial epithelial cells (NHBE) grown at the air-liquid interface or in submerged conditions (5 µg PM/cm²). For in vivo assessment, tests were performed after acute (24 h, 100 µg PM/animal), subacute (1 month, 10 µg PM/animal) and subchronic (3 months, 10 µg PM/animal) intranasal exposure of BALB/c mice. In vitro, our results show that PM_2.5-018 and PM_0.18 induced primary DNA damage but no chromosomal aberrations in immortalized cells. Negative results were noted in primary cells for both endpoints. In vivo assays revealed that PM_2.5-018 and PM_0.18 induced no significant increases in DNA primary damage, chromosomal aberrations or gene mutations, whatever the duration of exposure. This investigation provides initial answers regarding the in vitro and in vivo genotoxic mode of action of PM_2.5-018 and PM_0.18 at moderate doses and highlights the need to develop standardized specific methodologies for assessing the genotoxicity of PM. Moreover, other mechanisms possibly implicated in pulmonary carcinogenesis, e.g. epigenetics, should be investigated.

Temporal variations of ambient air pollutants and meteorological influences on their concentrations in Tehran during 2012-2017

We investigated temporal variations of ambient air pollutants and the influences of meteorological parameters on their concentrations using a robust method; convergent cross mapping; in Tehran (2012–2017). Tehran citizens were consistently exposed to annual PM_2.5, PM₁₀ and NO₂ approximately 3.0–4.5, 3.5–4.5 and 1.5–2.5 times higher than the World Health Organization air quality guideline levels during the period. Except for O₃, all air pollutants demonstrated the lowest and highest concentrations in summertime and wintertime, respectively. The highest O₃ concentrations were found on weekend (weekend effect), whereas other ambient air pollutants had statistically significant (P < 0.05) daily variations in which higher concentrations were observed on weekdays compared to weekend (holiday effect). Hourly O₃ concentration reached its peak at 3.00 p.m., though other air pollutants displayed two peaks; morning and late night. Approximately 45% to 65% of AQI values were in the subcategory of unhealthy for sensitive groups and PM_2.5 was the responsible air pollutant in Tehran. Amongst meteorological factors, temperature was the key influencing factor for PM_2.5 and PM₁₀ concentrations, while nebulosity and solar radiation exerted major influences on ambient SO₂ and O₃ concentrations. Additionally, there is a moderate coupling between wind speed and NO₂ and CO concentrations.