Temporal trends of incidence and prevalence of multiple sclerosis in Razavi Khorasan Province, Northeast Iran.

OBJECTIVES: The prevalence of multiple sclerosis (MS) in the Persian Gulf countries has been significantly increasing during the past decades. This study was conducted for investigating the prevalence and incidence of MS in Northeast Iran (Khorasan Razavi province). METHODS: This cross-sectional study was conducted during 1 January 1988 and 23 September 2018. All patients with a clinically definite diagnosis of MS according to the McDonald criteria (2005) and MRI along with the medical diagnosis, recorded in the Khorasan MS society, were considered for calculation of crude and age-standardized prevalence, and incidence rates of MS. The periodic incidence rates were calculated based on the year of onset of MS. Also, we calculated gender ratios for prevalence and incidence rates. RESULTS: The mean age-standardized prevalence and incidence rates of MS in the Khorasan Razavi were 8.69 (95% CI 8.05-9.41) per 100,000 (3.99 (95% CI 3.39-4.74) for males, 13.49 (95% CI 12.37-14.76) for females). Age-standardized prevalence was 48.87 (95% CI 48.37-49.35) per 100,000 (22.47 (95% CI 22.01-22.93) for males, 75.65 (95% CI 74.80-76.51) for females). Also, the mean incidence and prevalence for Mashhad County as capital of province were 11.38 and 59.09 per 100,000 populations, respectively. The female/male ratio was 3.33 for all age groups. CONCLUSION: Our results showed that this region is a high-risk area for MS like central region of Iran. Our results revealed that the prevalence and incidence of MS in the study area have increased during the recent decades with a sharp slope.

Socioeconomic determinants of global distribution of multiple sclerosis: an ecological investigation based on Global Burden of Disease data.

BACKGROUND: Socioeconomic factors may be involved in risk of multiple sclerosis (MS), either indirectly or as confounding factors. In this study two comprehensive indicators reflecting socioeconomic differences, including the Human Development Index (HDI) and Prosperity Index (PI), were used to assess the impact of these factors on the worldwide distribution of MS. METHODS: The data for this global ecological study were obtained from three comprehensive databases including the Global Burden of Disease (as the source of MS indices), United Nations Development Programme (source for HDI) and the Legatum Institute Database for PI. MS indices (including prevalence, incidence, mortality, and disability-adjusted life years) were all analyzed in the form of age- and sex-standardized. Correlation and regression analyses were used to investigate the relationship between HDI and PI and their subsets with MS indices. RESULTS: All MS indices were correlated with HDI and PI. It was also found that developed countries had significantly higher prevalence and incidence rates of MS than developing countries. Education and governance from the PI, and gross national income and expected years of schooling from the HDI were more associated with MS. Education was significantly related to MS indices (p < 0.01) in both developed and developing countries. CONCLUSION: In general, the difference in income and the socioeconomic development globally have created a landscape for MS that should be studied in more detail in future studies.

A systematic review and meta-analysis of human biomonitoring studies on exposure to environmental pollutants in Iran.

Population exposure to environmental contaminants can be precisely observed through human biomonitoring studies. The present study aimed to systematically review all the biomonitoring studies conducted in Iran on some selected carcinogen environmental pollutants. In this systematic review study, 11 carcinogen agents were selected including arsenic, cadmium, chromium, nickel, lindane, benzene, trichloroethylene (TCE), pentachlorophenol (PCP), radon-222, radium-224, - 226, - 228, and tobacco smoke. The Web of Science, PubMed, and Scopus databases were searched for peer-reviewed articles published in English. After several screening steps, data were extracted from the studies. Meta-analyses (a random-effect model using the DerSimonian-Laired method) were performed only for the biomarkers with more than three eligible articles, including cadmium in blood and breast milk, and arsenic in breast milk. Methodological quality of the studies was assessed using the Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies. Of the 610 articles found in the database search, 30 studies were eligible for qualitative review, and 13 were included in the meta-analysis (cadmium in blood (n = 3), cadmium in breast milk (n = 6), and arsenic in breast milk (n = 4)). The overall pooled average concentrations (95% CI) of cadmium in blood, cadmium in breast milk, and arsenic in breast milk were 0.11 (95% CI: 0.08, 0.14), 5.38 (95% CI: 3.60, 6.96), and 1.42 (95% CI: 1.02, 1.81) µg/L, respectively. These values were compared with the biomarker concentrations in other countries and health-based guideline values. This study showed that there is a need for comprehensive action plans to reduce the exposure of general population to these environmental contaminants.

Effect of long-term exposure to PM2.5 on years of life lost in a populated Middle Eastern city.

From a public health point of view, years of life lost (YLL) is a more important index than the number of deaths to evaluate the effect of risk factors. The objective of the present study was to estimate the burden of disease including years of life lost (YLL) and expected life remaining (ELR) attributed to long-term exposure to PM2.5 in Ahvaz, one of the most polluted cities of the world, during March 2014 through March 2017. AirQ + software was used for the estimation of YLL and ELR due to all natural causes of death. Hourly concentrations of PM2.5 were acquired from the Department of Environment (DoE) of Ahvaz. Several steps were performed to validate the raw air quality data. Only the monitors were included that had minimum data completeness of 75%. Two age groups were selected for this study, including 0-64 and 65 < years. The life table approach was used to estimate YLL and ELR. Annual averages of PM2.5 were 5.2-8 times higher than the air quality guideline (10 µg/m3) set by WHO for long-term exposure to PM2.5. In total, PM2.5 has caused 234,041 years of life lost due to mortality. About 84% of YLLs were attributed to people older than 65 years old. The YLLs of men were higher than those for women. The YLLs in the third year were greater than the first two years. PM2.5 has caused the average age of total population, people aged 0-64 years old, and people > 65 years old decreased by 2.5, 3, and 1.6 years, respectively. These studies indicated that people in a city that the air quality is highly affected by dust storms, industrial emissions, and urban air pollution are significantly at risk. Air pollution control strategies and actions should be designed and executed to improve the quality of ambient air.

Effects of PM2.5 and gases exposure during prenatal and early-life on autism-like phenotypes in male rat offspring.

BACKGROUND: Epidemiological studies have reported associations between elevated air pollution and autism spectrum disorders (ASD). However, we hypothesized that exposure to air pollution that mimics real world scenarios, is a potential contributor to ASD. The exact etiology and molecular mechanisms underlying ASD are not well understood. Thus, we assessed whether changes in OXTR levels may be part of the mechanism linking PM2.5/gaseous pollutant exposure and ASD. The current in-vivo study investigated the effect of exposure to fine particulate matter (PM2.5) and gaseous pollutants on ASD using behavioral and molecular experiments. Four exposure groups of Wistar rats were included in this study: 1) particulate matter and gaseous pollutants exposed (PGE), 2) gaseous pollutants only exposed (GE), 3) autism-like model (ALM) with VPA induction, and 4) clean air exposed (CAE) as the control. Pregnant dams and male pups were exposed to air pollutants from embryonic day (E0) to postnatal day (PND21). RESULTS: The average ± SD concentrations of air pollutants were: PM2.5: 43.8 ± 21.1 µg/m3, CO: 13.5 ± 2.5 ppm, NO2: 0.341 ± 0.100 ppm, SO2: 0.275 ± 0.07 ppm, and O3: 0.135 ± 0.01 ppm. The OXTR protein level, catalase activity (CAT), and GSH concentrations in the ALM, PGE, and GE rats were lower than those in control group (CAE). However, the decrements in the GE rats were smaller than other groups. Also in behavioral assessments, the ALM, PGE, and GE rats demonstrated a repetitive /restricted behavior and poor social interaction, but the GE rats had weaker responses compared to other groups of rats. The PGE and GE rats showed similar trends in these tests compared to the VPA rats. CONCLUSIONS: This study suggested that exposure to ambient air pollution contributed to ASD and that OXTR protein may serve as part of the mechanism linking them.

Carcinogenic risks and chemical composition of particulate matter recovered by two methods: wet and dry extraction.

Wet and dry extraction methods are two main methods used in toxicological in vitro and in vivo studies to recover particulate matter (PM) from filter papers. The aim of this study was to extract PM by wet and dry extraction methods and compare the elemental content and carcinogenic risks of extracts. PM10 samples were collected using fiberglass filters and a high-volume air sampler. For wet extraction, the method involved agitation in water, sonication in water bath, and agitation again. For dry extraction, the filters were sonicated and the PM was recovered using sweeping by a brush. Elemental composition of extracts was determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). Excess lifetime cancer risks (ELCR) of As, Cd, Cr, Ni, and Pb in extracts were estimated. The average recovery efficiency (%) of dry and wet extraction methods were 36.8% and 58.5%, respectively. The average elemental concentration that resulted from dry and wet methods was calculated to be 2.27 and 1.26 µg/m3, respectively. The total ELCR of all heavy metals in both methods exceeds the 1 × 10-6 limit. However, the total ELCR of heavy metals that resulted from the dry method was higher than that from the wet method. In conclusion, the dry method showed to be more effective to recover a representative extract from the filter. This can ultimately lead to a realistic and robust response in toxicological studies. However, a toxicological comparison between the extracts of these two methods is required.

Do socioeconomic factors affect the prevalence of multiple sclerosis in Iran?

BACKGROUND: A rising trend for incidence of multiple sclerosis (MS) has been observed during the recent years in Iran. Several factors have been investigated as the reason, but socioeconomic determinants have been neglected. The present study aimed to investigate the relationship between Human Development Index (HDI), income and education and MS prevalence in the provinces of Iran. METHODS: The data used in this study were obtained from three sources: (a) National Registry of MS for MS prevalence data from 2006 to 2013, (b) Statistical Centre of Iran for demographic, income, and percentage of educated people data, and (c) some previous studies for HDI data. RESULTS: The findings showed high prevalence of MS in the provinces of Iran. Most patients were residents of provinces with a higher socioeconomic level. Significant relationships were found between the prevalence of MS and HDI, income and educational level (P = .002, P = .006, and P = .001, respectively). CONCLUSION: Socioeconomic determinants in Iran are different from those in many other countries. It seems that Iranian provinces with a higher socioeconomic level have higher prevalence of MS. Further studies in smaller scale are needed to better understand the relationship between socioeconomic determinants and MS prevalence in the provinces of Iran.

Concentrations and health effects of short- and long-term exposure to PM2.5, NO2, and O3 in ambient air of Ahvaz city, Iran (2014-2017).

The primary objective of the present study was to evaluate the concentrations and short and long-term excess mortality attributed to PM2.5, NO2, and O3 observed in ambient air of Ahvaz during March 2014 to March 2017 period using the AirQ + software developed by the World Health Organization (WHO), which is updated in 2016 by WHO European Centre for Environment and Health. The hourly concentrations of PM2.5, O3, and NO2 measured at different regulatory monitoring network stations in Ahvaz city were obtained from the Department of Environment (DOE) of the city. Then, for various air quality monitoring stations, the 24-h average concentration of PM2.5, 1-h average of NO2 concentration, and maximum daily 8-h O3 concentrations were calculated using Excel 2010 software. When the maximum daily 8-h ozone means exceeding the value of 35, it was subtracted from 35 to calculate SOMO35 indicator for modeling. Validation of air quality data was performed according to the Aphekom and WHO's methodologies for health impact assessment of air pollution. Year-specific city population and baseline incidence of the health outcomes were obtained. The three-year averages of PM2.5, NO2, and O3 concentrations were 68.95 (±39.86) µg/m3, 135.90 (±47.82) µg/m3, and 38.63 (±12.83) parts-per-billion-volume (ppbv), respectively. SOMO35 values of ozone were 6596.66, 3411.78, and 470.88 ppbv in 2014-2015, 2015-2016, and 2016-2017 years, respectively. The AP and number of natural deaths due to NO2 were higher than PM2.5 except the last year (2016-2017), causing about 39.18%, 40.73%, and 14.39% of deaths within the first, the second, and the third year, respectively. However, for the last year, the natural mortality for PM2.5 was higher than NO2 (34.46% versus 14.39%). The total number of natural mortality caused by PM2.5 and NO2 in all years was 4061 and 4391, respectively. A significant number of deaths was estimated to be attributed to the given air pollutants. It can be concluded that by designing and implementing air pollution control strategies and actions, both health effects and economic losses will be prevented.

Exposure to BTEX in beauty salons: biomonitoring, urinary excretion, clinical symptoms, and health risk assessments.

Benzene, toluene, ethylbenzene, and xylene (BTEX) concentrations were measured in beauty salons (BS) and in the urine of the beauty practitioners and a control group. Indoor and outdoor concentrations of BTEX were measured in 36 randomly selected salons. Before- and after-shift urinary BTEX were measured from one female non-smoker employee in each salon, and repeated three times. Clinical symptoms in that beautician were assessed by a physician. Thirty-six unexposed women were included as the control group. Cancer and non-cancer risks of exposure were assessed using deterministic and stochastic methods. Average indoor concentrations of BTEX were higher than those in the ambient air. Urinary BTEX concentrations in the beauty practitioners were significantly higher than in the control group. Linear regression showed that 77% of urinary benzene and toluene variations can be explained by their airborne concentrations. A positive significant relationship was found between age and urinary BTEX concentrations. Although the BTEX cancer and non-cancer risks were not significant, BTEX led to irritation of the eyes, throat, lung, and nose. In addition, toluene caused menstrual disorders among beauty practitioners. These results suggest that it is essential to decrease the exposure of beauty practitioners to BTEX compounds.

Investigating the effect of several factors on concentrations of bioaerosols in a well-ventilated hospital environment.

This study characterized and quantified the bacterial and fungal bioaerosols in nine wards of the Razavi Hospital (Mashhad, Iran) that is equipped with an advanced heating, ventilating, and air conditioning (HVAC) system including HEPA filters for air cleaning. In this study, 432 samples were taken from the indoor air of multiple hospital wards during the morning and afternoon shifts during summer and autumn. The particle number concentrations with sizes of > 0.3, > 0.5, > 1, > 2, > 5, and > 10 µm were measured using a 6-channel handheld particle counter. A greater diversity of bioaerosol types were observed during the morning shifts and during summer. The microbial load was not affected significantly by the temperature, relative humidity, working shift, season, and number of visitors, indicating the effectiveness of a well-designed ventilation system to eliminate site-specific variations. For microbial number concentrations, a significant correlation was only observed between the number of particles with a diameter of > 10 µm and the airborne microbial loading. Thus, passive sampling may not properly reflect the actual concentrations of smaller bioaerosols. In conclusion, HEPA filters in the HVAC system successfully decreased the bioaerosol concentrations in the hospital environment. Additionally, we recommend that active sampling be used in cases where a well-functioning HVAC system exists.

Source Apportionment of Total Suspended Particles (TSP) by Positive Matrix Factorization (PMF) and Chemical Mass Balance (CMB) Modeling in Ahvaz, Iran.

There is a compelling need for apportionment of pollutants' sources to facilitate their reduction through proper management plans. The present study was designed to determine the contribution of each possible source of total suspended particles in Ahvaz's ambient air using positive matrix factorization (PMF), chemical mass balance (CMB), and the SPECIATE database. The sampling program undertaken followed EPA's guidelines and finally resulted in 74 samples. The concentration of 33 elemental and 10 ionic species were measured during a whole year. Three modeling approaches were applied: PMF, the integrated use of PMF and CMB, and the integrated use of the SPECIATE database and CMB. Six sources were derived by PMF: crustal dust (30.6%), industrial and mining activities (25.4%), motor vehicles (23.4%), marine aerosols (11.5%), secondary inorganic aerosols (5.7%), and road dust (3.4%). The contributions of sources from PMF-CMB approach were crustal dust (32.9%), industrial and mining activities (20.9%), motor vehicles (19.7%), marine aerosols (11.1%), secondary inorganic aerosols (9.2%), and road dust (9.36%). Seven sources were derived by SPECIATE-CMB approach: crustal dust (23.2%), industrial and mining activities (20.1%), motor vehicles (17.5%), marine aerosols (12.4%), secondary inorganic aerosols (4.8%), road dust (5.3%), and "nondetermined sources" factor (16.7%). Despite the different contributions of sources, there is a noticeable consistency between the results of these approaches. Furthermore, because of the approved performance of combined receptor models in previous studies and the presence of sufficient data on the number of species and samples, the results of the PMF-CMB approach are possibly the most realistic among those of the three applied approaches.

Elemental and carbonaceous characterization of TSP and PM10 during Middle Eastern dust (MED) storms in Ahvaz, Southwestern Iran.

Middle Eastern dust (MED) storms carry large amounts of dust particles to the Southern and Western cities of Iran. This study aimed to characterize the elemental and carbonaceous composition of total suspended particles (TSP) and PM10 in Ahvaz, Iran. TSP and PM10 samples were collected using two separate high-volume air samplers. The sampling program was performed according to EPA guidelines and resulted in 72 samples. Twenty-eight elements and two carbonaceous components in TSP and PM10 were measured. Over the entire study period, the mean concentration (SD) of TSP and PM10 was 1548.72 µg/m3 (1965.11 µg/m3) and 1152.35 µg/m3 (1510.34 µg/m3), respectively. The order of concentrations of major species were Si > Al > Ca > OC > Na > B > Zn > Mn > K > Mg and Si > Ca > Al > Na > OC > B > K > Mn > Cu > Mg for TSP and PM10, respectively. Almost all elements (except for Cd, Cr, and Cu) and carbonaceous components (except for organic carbon) had dust days/non-dust days (DD/NDD) ratios higher than 1, implying that all components are somehow affected by dust storms. Crustal elements constituted the major portion of particles for both TSP and PM10 in both DDs and NDDs. The enrichment factor of elements such as Ca, Fe, K, Mg, Na, and Ti was near unity. Species such as Al, Ca, Fe, K, Na, Si, and EC had high correlation coefficients in both TSP and PM10 (except for EC). In conclusion, Ahvaz is exposed to high concentrations of TSP and PM10 during the MED period. Immediate actions must be planned to decrease the high concentrations of particulate matter in Ahvaz's ambient air.

Association of heat and cold waves with cause-specific mortality in Iran: a systematic review and meta-analysis.

Despite the frequent occurrence of heat waves in the Middle East, there is a lack of evidence regarding the overall estimates for the effect of heat waves on mortality in this region. This study aimed to review the effect of exposure to heat and cold waves and daily cause-specific mortality. Four electronic databases were searched. The titles, abstracts, and full-texts of the articles were carefully reviewed by two researchers. Once eligible studies were identified, the required data were extracted. Separate meta-analyses were conducted based on gender, age group, and health endpoint combinations. According to the meta-analysis, heat waves had a statistically significant effect on all-cause mortality with an RR of 1.23 (CI 95%: 1.08, 1.39). Cardiovascular mortality significantly increased in heat waves with an RR of 1.08 (CI 95%: 1.05, 1.10). However, the increase in respiratory mortality was not statistically significant. Compared to young people (age < 65 years old) and women, elderly and men were more vulnerable to heat waves with RRs of 1.31 (95% CI: 1.05, 1.57) and 1.33 (95% CI: 1.08, 1.58), respectively. This study can be beneficial in developing response or adaptation plans for heat waves. Future studies should focus on other specific health endpoints like ischemic heart disease, chronic obstructive pulmonary diseases, etc., and other outcomes such as hospitalization and emergency visits.

Comparison of modeling, optimization, and prediction of important parameters in the adsorption of cefixime onto sol-gel derived carbon aerogel and modified with nickel using ANN, RSM, GA, and SOLVER methods.

Today, the main goal of many researchers is the use of high-performance, economically and industrially justified materials, as well as recyclable materials in removing organic and dangerous pollutants. For this purpose, sol-gel derived carbon aerogel modified with nickel (SGCAN) was used to remove Cefixime from aqueous solutions. The influence of important parameters in the cefixime adsorption onto SGCAN was modeled and optimized using artificial neural network (ANN), response surface methodology (RSM), genetic algorithm (GA), and SOLVER methods. R software was applied for this purpose. The design range of the runs for a time was in the range of 5 min-70 min, concentration in the range of 5 mg L-1 to 40 mg L-1, amount of adsorbent in the range of 0.05 g L-1 to 0.15 g L-1, and pH in the range of 2.0-11. The results showed that the ANN model due to lower Mean Squared Error (MSE), Sum of Squared Errors (SSE), and Root Mean Squared Error (RMSE) values and also higher R2 is a superior model than RSM. Also, due to the superiority of ANN over the RSM model, the optimum results were calculated based on GA. Based on GA, the highest Cefixime adsorption onto SGCAN was obtained in pH, 5.98; reaction time, 58.15 min; initial Cefixime concentration, 15.26 mg L-1; and adsorbent dosage, 0.11 g L-1. The maximum adsorption capacity of Cefixime onto SGCAN was determined to be 52 mg g-1. It was found the pseudo-second-order model has a better fit with the presented data.

Estimation of long-term and short-term health effects attributed to PM2.5 standard pollutants in the air of Ardabil (using Air Q + model).

Clean air is considered as a basic need for human health. However, air pollution is a significant threat to health in developed and developing countries. The aim of this study was to estimate the health effects attributed to PM2.5 pollutants in the air of Ardabil in 2018 (using Air Q + model). Raw data related to particles were collected from the Department of Environment and processed in Excel software and converted into an input file of the Air Q + model, and in the final stage, by considering appropriate epidemiological parameters and combining these data with air quality data, it was possible to estimate the health effects of air pollution. The results showed that the average annual concentrations of PM2.5 and PM10 were 15.47 and 30.94 in the study year, respectively. The total number of deaths due to ALRI, COPD, lung cancer, IHD, and stroke deaths on average during the study period were estimated to be 73, 11, 7, 15, and 14 deaths, respectively, which include 14.62, 15.78, 4.9, 12.43, and 11.6% of deaths due to ALRI, COPD, lung cancer, IHD, and stroke deaths, respectively. In conditions of concentration above 5 µg/m3, attributed proportion, total number of attributed cases and number of attributed cases per 100,000 population (with moderate relative risk and confidence interval of 95%) for cardiovascular diseases have been estimated to be 0.95% 103 people and 42.19 people. Also, the attributed proportion, the total number of attributable cases, and the number of attributable cases per 100,000 population (with moderate relative risk and confidence of 95%) for the admission of respiratory diseases have been estimated at 97.1%, 68 persons and 3 persons, respectively. Our results suggest that particle exposure even at low concentrations is associated with an increased risk of overall mortality and specific cause mortality and hospital admissions for respiratory and cardiovascular diseases.

Comparison of the Toxic Effects of Pristine and Photocatalytically Used TiO2 Nanoparticles in Mice.

TiO2 nanoparticles used in the photocatalytic degradation of pollutants in water treatment processes undergo physiochemical changes; therefore, their toxicological effects may be potentially different from those of the pristine nanoparticles. This study compared the toxic effects of exposure to pristine and photocatalytically used TiO2 nanoparticles in mice. To obtain used TiO2, the nanoparticles were used for photocatalytic degradation of a model pollutant under UV irradiation several times. Two groups of mice were exposed to pristine (PT group) and photocatalytically used TiO2 (UT group) at three different concentrations (5-20 mg/m3) using whole-body exposure chambers (2 h/day, 5 days/weeks, 4 weeks). Exposure to both pristine and used TiO2 increased the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphate (ALP), lactate dehydrogenase (LDH), C-reactive protein (CRP), and creatine kinase (CK-MB) significantly. Both exposed groups showed higher levels of WBC, lymphocytes, platelets, hematocrits, hemoglobin, and mean corpuscular volume (MCV) and lower levels of RBC and mean corpuscular hemoglobin concentration (MCHC) in a concentration-dependent manner. In all analyses, there were small non-significant differences between the PT and UT groups. More pathological changes were observed in the lung, kidney, and brain of the UT group, while the PT group showed more pathological effects in the liver and heart. The histological observations indicated that damage was mostly in the form of vascular endothelial injury. These two types of TiO2 may activate different pathways to promote adverse effects. Further studies are required to evaluate and distinguish the mechanisms through which pristine and used TiO2 induce toxicity.

Effects of ambient air pollutants on hospital admissions and deaths for cardiovascular diseases: a time series analysis in Tehran.

Short-term exposures to air pollution have been associated with various adverse health effects. In this study, we investigated the associations between ambient air pollutants with the number of hospital admissions and mortality from cardiovascular diseases (CVDs). This time series study was conducted in Tehran for the years 2014-2017 (1220 day). We collected the ambient air pollutant concentration data from the regulatory monitoring stations. The health data were obtained from the Ministry of Health and Medical Education. A distributed lag non-linear model (DLNM) was used for the analyses. Total CVDs and ischemic heart disease (IHD) admissions were associated with CO for each 1 mg/m3 increase at lags of 6 and 7 days. Also, there was a positive association between total CVDs (RR 1.01; 1.001 to 1.03), IHD (RR 1.04; 1.006 to 1.07), and cerebrovascular diseases (RR 1.03; 1.005 to 1.07) mortality with SO2 at a lag of 4 days. PM2.5 and PM10 were associated with cerebrovascular disease admissions in females aged 16-65 years and 16 years and younger for each 10 µg/m3 increase, respectively. Short-term exposure to SO2, NO2, and CO was associated with hospital admissions and mortality for CVDs, IHD, cerebrovascular diseases, and other cardiovascular diseases at different lags. Moreover, females were more affected by ambient air pollutants than males in terms of their burden of CVDs. Therefore, identifying the likely harmful effects of pollutants given their current concentrations requires the planning and implementation of strategies to reduce air pollution.

Autism-like symptoms by exposure to air pollution and valproic acid-induced in male rats.

Exposure to air pollution during prenatal or neonatal periods is associated with autism spectrum disorder (ASD) according to epidemiology studies. Furthermore, prenatal exposure to valproic acid (VPA) has also been found to be associated with an increased prevalence of ASD. To assess the association between simultaneous exposure to VPA and air pollutants, seven exposure groups of rats were included in current study (PM2.5 and gaseous pollutants exposed - high dose of VPA (PGE-high); PM2.5 and gaseous pollutants exposed - low dose of VPA (PGE-low); gaseous pollutants only exposed - high dose of VPA (GE-high); gaseous pollutants only exposed - low dose of VPA (GE-low); clean air exposed - high dose of VPA (CAE-high); clean air exposed - low dose of VPA (CAE-low) and clean air exposed (CAE)). The pollution-exposed rats were exposed to air pollutants from embryonic day (E0) to postnatal day 42 (PND42). In all the induced groups, decreased oxidative stress biomarkers, decreased oxytocin receptor (OXTR) levels, and increased the expression of interleukin 6 (IL-6), interleukin 1ß (IL-1ß), and tumor necrosis factor alpha (TNF-α) were found. The volumes of the cerebellum, hippocampus, striatum, and prefrontal decreased in all induced groups in comparison to CAE. Additionally, increased numerical density of glial cells and decreased of numerical density of neurons were found in all induced groups. Results show that simultaneous exposure to air pollution and VPA can cause ASD-related behavioral deficits and air pollution reinforced the mechanism of inducing ASD ̉s in VPA-induced rat model of autism.

The detection of SARS-CoV-2 RNA in indoor air of dental clinics during the COVID-19 pandemic.

In the indoor environment of dental clinics, dental personnel and patients are exposed to a risk of infection because of the transmission of SARS-CoV-2 via particles or droplets. This study investigated the presence of SARS-CoV-2 RNA in indoor air of dental clinics in Tehran, Iran. Air sampling was done (n = 36) collecting particulate samples on PTFE filters at flow rates of 30 to 58 L/min. The samples were analyzed with novel coronavirus nucleic acid diagnostic real-time PCR kits. Only 13 out of 36 samples were positive for SARS-CoV-2 RNA. Logistic regression showed that sampling site's volume, PM2.5 concentration, number of people, and number of active patient treatment units were significantly positively related with the presence of SARS-CoV-2 RNA. Thus, strategies to control the spread of COVID-19 should include reducing the number of infected people in dental clinics, adding filtration systems, and/or improving ventilation conditions.

A comprehensive systematic review of photocatalytic degradation of pesticides using nano TiO2.

This study has systematically reviewed all of the research articles about the photocatalytic degradation of pesticides using titanium dioxide (TiO2) nanoparticles (NPs) and ultraviolet (UV) irradiation. Online databases were searched for peer-reviewed research articles and conference proceedings published during 2009-2019, and ultimately 112 eligible articles were included in the review. Fifty-three active ingredients of pesticides and one mixture had been investigated, most of them were organophosphorus (22%), followed by triazine derivatives (11%), chloropyridines (9%), and organochlorines (9%). Sixteen types of TiO2 with an average photodegradation efficiency of 71% were determined. Based on the type of pesticide and experimental conditions such as irradiation time, the complete photodegradation had been observed. The removal of each group of pesticides has been sufficiently discussed in the article. Effect of experimental conditions on photocatalytic activity has been investigated using linear and polynomial regressions. The strategies to reduce the required energy for this process, doping TiO2 with metal and non-metal agents, innovative reactor designs, etc., were also discussed. In conclusion, TiO2 NPs have been successful for degradation of pesticides. Future direction for research incorporates developing and application of heterogeneous doped and immobilized titania having optimized characteristics such as surface area, reactive centers, recombination rate, and phase, and capable to photo-degrade low levels of pesticides residues under solar light in an efficient full-scale size.