Valuation of external effects of air pollution due to urban transportation network - Case study: Isfahan

Most populous cities in the world are currently facing the air pollution problem, and Iran is no exception. Air pollution in many megacities of Iran has reached a dangerous level so that the PM2.5 concentration in metropolises is three times the national standard and most of this contamination originates from cars and industry. Isfahan is the third most populated city in Iran and its pollution is a leading cause of many diseases and deaths along with economic problems every year. Traffic parameter as key factor that play a very important role in PM2.5 pollutant emitted should be included as an important variable in air pollution modeling.Since one of the most important sources of air pollution is mobile sources, this paper tries to estimate the health effects and economic costs of PM2.5 concentration emitted by transportation in the urban network of Isfahan during 2018-2019. So In this study, we focus on the health endpoints assessment caused by the emission of motor vehicles pollutants in Isfahan.In this regard we estimate the concentration of pollution caused by vehicles by using the results of the Generalized Additive Model (GAM). A statistical model are used to estimate the share of traffic from PM2.5 concentrations to calculate road transport -related air pollution in Isfahan. We also calculate the spatial distribution of pollution in Isfahan using ArcGIS. Then, the health impacts of air pollution caused by motor vehicles are assessed using the AirQ+. This can estimate long-term natural mortality due to all natural causes and other mortality due to Ischemic heart disease, chronic obstructive pulmonary disease, and Lung cancer. Damages and economic costs of these health impacts are finally estimated by value of a statistical life and mortality rate approach. Value of a statistical life (VOSL) is a preferred method, calculated using the willingness to pay and means the willingness to pay of people in the community for the marginal reduction in mortality risk. In the compensation payment method (mortality rate), a fixed amount is set by the government on an annual basis to compensate for the costs of mortality.The results indicate that the mean concentrations for 2018 is 31.03 µg/m3. Using the results of Generalized Additive Model based on the shares obtained for traffic in the five areas studied in Isfahan, the concentration of PM2.5 pollution caused by urban traffic is 4.94 µg/m3.In general, 607 (95%Coeffecient Interval: 404-789) premature deaths in adults in 2018 can be attributed to PM2.5 pollution in Isfahan, among which 150 premature deaths are because of PM2.5 pollution caused by motor vehicles, i.e. about 25%. Out of a total of 150 deaths, the number of deaths caused by each factor is 51 (95%Coeffecient Interval: 30-107) cases of Ischemic heart disease (IHD), 3 (95%CI: 2-5) cases of Lung cancer (LC), 8 (95%CI: 4-12) cases of chronic obstructive pulmonary disease (COPD). Thus PM2.5 caused by traffic in 2018 accounts for 1.76% of all adult mortality.Using the value of a statistical life approach, the estimated total annual economic cost of traffic pollution in 2018 is USD 57.9 million and 304 billion IRR per year using compensation payment (mortality cost).Health effect valuation is an important part of assessing the social costs of air pollution because by implementing cost-benefit analysis, a criterion can be achieved to prioritize pollution control measures and policies can be adapted in accordance with these priorities