Trends in health burden of ambient particulate matter pollution in Iran, 1990-2010: findings from the Global Burden of Disease study 2010

Assessing the burden of diseases attributed to exposure to ambient particulate matter by air quality modeling

This study aimed to assess PM2.5 exposure levels in Ahvaz, Iran, and quantify the associated burden of disease attributable to particulate pollution. To quantify uncertainty mortality and morbidity, the exposure response function model for probabilistic risk assessment was used. The analysis of aerosol variations by the Aerosol Optical Thickness indicated a decline in PM2.5 concentrations during pandemic. During the study period, the annual mean of PM2.5 concentrations exceeded the annual limit value established by the World Health Organization. Cause-specific mortality, including trachea bronchus lung cancer, stroke, and acute lower respiratory infections, also decreased by 14-28% in 2020. Restricted activity days and work days lost decreased by 11.8% and 13.8%, respectively, correlating with lower PM2.5 concentrations. Years lived with disability dropped from 242.7 to 170.4 years per 105 capita in 2020 during the pandemic. Mitigation strategies, including green infrastructure, industrial regulation, and improved urban planning, are needed to reduce health risks in this highly polluted region.

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

Ambient particulate matter is a public health concern. We aimed (1) to estimate national and provincial long-term exposure of Iranians to ambient particulate matter (PM) < 2.5 μm (PM_2.5) from 1990 to 2016, and (2) to estimate the national and provincial burden of disease attributable to PM_2.5 in Iran. We used all available ground measurements of PM < 10 μm (PM₁₀) (used to estimate PM_2.5) from 91 monitoring stations. We estimated the annual mean exposure to PM_2.5 for all Iranian population from 1990 to 2016 through a multi-stage modeling process. By applying comparative risk assessment methodology and using life table for years of life lost (YLL), we estimated the mortality and YLL attributable to PM_2.5 for five outcomes. The predicted provincial annual mean PM_2.5 concentrations range was between 21.7 μg/m³ (UI: 19.03-24.9) and 35.4 μg/m³ (UI: 31.4-39.4) from 1990 to 2016. We estimated in 2016, about 41,000 deaths (95% uncertainty interval [UI] 35634, 47014) and about 3,000,000 YLL (95% UI: 2632101, 3389342) attributable to the long-term exposure to PM_2.5 in Iran. Ischemic heart disease was the leading cause of mortality by 31,363 deaths (95% UI: 27520, 35258), followed by stroke (7012 (5999, 8062) deaths), lower respiratory infection (1210 (912, 1519) deaths), chronic obstructive pulmonary disease (1019 (715, 1328) deaths), and lung cancer (668 (489, 848) deaths). In 2016, about 43% of all PM_2.5 related mortality in Iran was, respectively, in the following provinces: Tehran (12.6%), Isfahan (9.3%), Khorasan Razavi (8.0%), Fars (6.5%), and Khozestan (6.4%). In summary, we found that the majority of Iranians were exposed to the levels of ambient particulate matter exceeding the WHO guidelines from 1990 to 2016. Further, we found that there was an increasing trend of total mortality attributed to PM_2.5 in Iran from 1990 to 2016 where the slope was higher in western provinces.

Impaired fasting glucose prevalence surge among Iranian adolescents in a decade: The Tehran Lipid and Glucose Study

PURPOSE

Impaired fasting glucose (IFG) is associated with incident diabetes, cardiovascular risk, and markers of atherosclerosis in early adulthood. We aimed to explore the 10-year change in IFG prevalence among adolescent participants of the Tehran Lipid and Glucose Study, a population-based study from Iran.

METHODS

For our study, we used data on fasting plasma glucose (FPG), anthropometric, and demographic information of 11 to 19-year-old adolescents in study periods I (1999-2005; 1415 boys, 1583 girls) and II (2011-2014; 477 boys, 469 girls). Sex-adjusted and sex-stratified multivariable logistic regression models were used to assess the relationship of the study period (reference: study period I) with IFG.

RESULTS

The prevalence of IFG, general obesity, and central obesity increased from 7%, 13.3%, and 18.8% in study period I to 16.6%, 24%, and 37.4% in study period II; while a favorable trend was seen for blood pressure, triglycerides, and high-density lipoprotein cholesterol. In the fully adjusted model, being older (age group 15-19 vs 11-14 years) and female sex were associated with lower risk. Being overweight and obese increased the risk by risk ratios (confidence interval) of 1.57 (1.17-2.11) and 1.63 (1.15-2.30), respectively. Central adiposity did not remain as an independent risk factor. Nevertheless, study period persisted as a significant factor despite all adjustments [2.20 (1.81-2.68)]. Results in the sex-stratified models were generally the same.

CONCLUSION

Our results demonstrated that the over 2-fold rise in IFG prevalence among adolescents was not solely dependent on general and central obesity.

A study on the characteristics of pollutant release and transfer registers (PRTRs) and cancer incidence rates in Korea

This study aims to identify the past decade's trend of harmful chemical emissions, which have been disclosed on the website as open information. During the past 10 years, the number of places of business, examined for their harmful chemical emissions, increased about 1.3× and their emissions went up 1.1×. More than 50% of total emissions have occurred in the top three areas, and the largest emissions were from xylene and toluene for the past 10 years. Among the total emissions, the group 1 carcinogen decreased from 5.3 to 2.1%, and among group 1 in particular, trichloroethylene and benzene accounted for more than 80%. Although it was impossible to find out any relationship between major cancers' development and the results of carcinogen emissions, considering the features of carcinogens emitted in specific areas, more research is needed to find out relationship. And, it is necessary to come up with proactive policies to reduce harmful chemical substances which can affect human health through environmental pollution.

Association of serum complement C3 with metabolic syndrome components in normal weight obese women

BACKGROUND

Increased serum complement C3 has been related to body fat mass, metabolic syndrome and chronic diseases. The purpose of this study was to evaluate the levels of C3 in the subjects of normal weight obese (hereafter NWO) as well as their possible relationships with metabolic syndrome and inflammation.

METHODS

In this case-control study, 40 obese women with normal weight (body mass index (BMI) = 18.5-24.9 kg/m2) and body fat percentage above 30% (fat mass (FM) > 30%) and 30 non-obese women (BMI = 18.5-24.9 kg/m2) and fat percentage less than 25% (FM < 25%) were selected as the study sample. Body composition was analyzed using Bio Impedance analyzer. Blood samples were then collected and analyzed for fasting serum concentration of lipid components of metabolic syndrome, insulin, serum complement C3 and High sensitivity C reactive protein (hsCRP).

RESULTS

Mean waist and hip circumferences in NWO was higher than non-NWO (74.78 ± 4.81 versus 70.76 ± 2.91 and 99.12 ± 4.32 versus 93.16 ± 2/91, respectively, P-value < 0.001). However, the mean waist-to-hip ratio did not differ significantly (p = 0.448). The mean fasting serum concentration of complement C3, hsCRP and insulin was higher in NWO compared to that in non-NWO (P-value < 0.05). Moreover, insulin sensitivity in NWO was lower than that in non-NWO (0.357 versus 0.374, p-value = 0.043). Moreover, a significant correlation was found between body fat percentage and fasting serum complement C3 and insulin concentration (r = 0.417 and r = 0.254, p-value < 0.005, respectively).

CONCLUSION

Obese women with normal body mass index but high body fat percentage have higher serum C3 and are at a higher risk for metabolic dysregulation and metabolic syndrome than the healthy non-obese subjects.

Educational Intervention on Breast Self-Examination Behavior in Women Referred to Health Centers: Application of Health Belief Model

Introduction and aims: Screening can play a major role in reducing deaths associated with cancer. Breast selfexamination (BSE) is a cheap, non-complicated and non-invasive method for breast cancer screening. This study aimed to examine the effects of an educational intervention based on the health belief model (HBM) on BSE behavior in women referred to health centers in Fasa, Iran. Methods: This quasi-experimental study was conducted on 92 women, divided into an experimental and a control group. Data were collected using a validated questionnaire covering demographic characteristics, knowledge, HBM constructs and breast self-examination performance. An educational program was performed in five sessions through group discussion with questions and answers and training videos for participants in the experimental group. Questionnaires were filled before and three months after the intervention in the two groups. Data were analyzed with SPSS-22 software for descriptive and analytical statistics. Results: The results of this study showed that the mean scores for knowledge, HBM constructs and self-examination behavior in the experimental group were elevated compared to the control group after the intervention (P<0.001). Conclusions: Education based on the HBM is effective in promoting breast self-examination behavior. Thus development and implementation of training programs based on the model are proposed for officers involved in education and health promotion in Iran.

National and sub-national age-sex specific and cause-specific mortality and disability-adjusted life years (DALYs) attributable to household air pollution from solid cookfuel use (HAP) in Iran, 1990-2013

National and sub-national mortality, years of life lost due to premature mortality (YLLs), years lived with disability (YLDs) and disability-adjusted life years (DALYs) for household air pollution from solid cookfuel use (HAP) in Iran, 1990-2013 were estimated based on the Global Burden of Disease Study 2013 (GBD 2013). The burden of disease attributable to HAP was quantified by the comparative risk assessment method using four inputs: (1) exposure to HAP, (2) the theoretical minimum risk exposure level (TMREL), (3) exposure-response relationships of related causes (4) disease burden of related causes. All across the country, solid fuel use decreased from 5.26% in 1990 to 0.15% in 2013. The drastic reduction of solid fuel use leaded to DALYs attributable to HAP fell by 97.8% (95% uncertainty interval 97.7-98.0%) from 87,433 (51072-144303) in 1990 to 1889 (1016-3247) in 2013. Proportion of YLLs in DALYs from HAP decreased from 95.7% in 1990 to 86.6% in 2013. Contribution of causes in the attributable DALYs was variable during the study period and in 2013 was in the following order: ischemic heart disease for 43.4%, chronic obstructive pulmonary disease for 24.7%, hemorrhagic stroke for 9.7%, lower respiratory infections for 9.3%, ischemic stroke for 7.8%, lung cancer for 3.4% and cataract for 1.8%. Based on the Gini coefficient, the spatial inequality of the disease burden from HAP increased during the study period. The remained burden of disease was relatively scarce and it mainly occurred in seven southern provinces. Further reduction of the disease burden from HAP as well as compensation of the increasing spatial inequality in Iran could be attained through an especial plan for providing cleaner fuels in the southern provinces.

Attributable risk of ambient PM10 on daily mortality and years of life lost in Chengdu, China

Attributable risk is an important indicator for planning and evaluating public health interventions. However, most current measures of the attributable risk of air pollutants have not considered temporal relationships between exposure and risk. More importantly, limited information is available regarding the attributable risk due to ambient air pollutants in basin regions like the Sichuan Basin, China. To quantify the association between PM₁₀ and deaths in the Basin region, we used a measure proposed recently within the framework of the distributed lag non-linear model to estimate the attributable risk in Chengdu, China. Meanwhile, we examined the association between PM₁₀ and years of life lost (YLL). Our analysis showed that population-attributable fractions for non-accidental, respiratory, and cardiovascular mortality were 0.569% (95% CI: -3.474%, 4.374%), 0.695% (95% CI: -5.260%, 6.457%), and 0.631% (95% CI: -6.973%, 7.390%), respectively. On average, a 1μg/m³ increase in PM₁₀ was associated with cumulative increases of 0.26893, 0.30437, and 0.21924 YLL for non-accidental, respiratory, and cardiovascular mortality, respectively, referring to 20μg/m³. In addition, we found an inverse U-shaped pattern for the cumulative risk with 350μg/m³ as the reverse point. With a 1μg/m³ increase in PM₁₀, YLL changed more significantly than mortality. Moreover, PM₁₀ demonstrated remarkable effects on YLL among men and the elderly.

Associations of short-term exposure to air pollution with respiratory hospital admissions in Arak, Iran

BACKGROUND

Ambient air pollution, is one of the most frequently stated environmental problems. Many epidemiological studies have documented adverse health effects for ambient air pollution. This study aimed to investigate the association between ambient air pollution and respiratory hospital admissions.

METHODS

In this ecological time series study data about air pollutant concentrations including CO, NO₂, O₃, PM_2.5, PM₁₀ and SO₂ and, respiratory hospital admissions in the urban population of Arak, from January 1st 2010 to December 31st 2015; were inquired, from the Arak Department of Environment, and two major hospitals, respectively. Meteorological data were inquired for the same period as well. Time-series regression analysis with a distributed lag model, controlled for seasonality long-time trends, weather and day of the week, was used for data analysis.

RESULTS

Every 10 μg/m³ increase in NO₂, and PM₁₀ and every 1 mg/m³ increase in CO at lag 0 corresponded to a RR = 1.032 (95%CI, 1.003-1.06), RR = 1.01 (95%CI, 1.004-1.017) and RR = 1.09 (95%CI, 1.04-1.14), increase in respiratory disease hospitalizations, respectively. Males and the elderly were found to be more susceptible than females and other age groups to air pollutants in regard to respiratory disease admissions.

CONCLUSIONS

The results of this study showed that outdoor air pollutants significantly increase respiratory hospital admissions; especially among the men and elders in Arak.

Annual and seasonal spatial models for nitrogen oxides in Tehran, Iran

Very few land use regression (LUR) models have been developed for megacities in low- and middle-income countries, but such models are needed to facilitate epidemiologic research on air pollution. We developed annual and seasonal LUR models for ambient oxides of nitrogen (NO, NO₂, and NO_X) in the Middle Eastern city of Tehran, Iran, using 2010 data from 23 fixed monitoring stations. A novel systematic algorithm was developed for spatial modeling. The R² values for the LUR models ranged from 0.69 to 0.78 for NO, 0.64 to 0.75 for NO₂, and 0.61 to 0.79 for NOx. The most predictive variables were: distance to the traffic access control zone; distance to primary schools; green space; official areas; bridges; and slope. The annual average concentrations of all pollutants were high, approaching those reported for megacities in Asia. At 1000 randomly-selected locations the correlations between cooler and warmer season estimates were 0.64 for NO, 0.58 for NO_X, and 0.30 for NO₂. Seasonal differences in spatial patterns of pollution are likely driven by differences in source contributions and meteorology. These models provide a basis for understanding long-term exposures and chronic health effects of air pollution in Tehran, where such research has been limited.