Assessing the effectiveness of improving urban air quality with solutions based on technology, nature and policy

Using smog-free towers (SFTs) for improving urban air quality poses an interesting tradeoff between cleaning the air and increasing pollution near power generating stations that supply electricity to the SFTs. This tradeoff changes significantly with variations in power-generating sources. Therefore, options of wind-powered, solar-powered, nuclear-powered, and grid-powered SFTs were evaluated for Delhi, India. The results show that only wind-powered SFTs have [health benefits (HB)] / [health cost (HC)] more than 1 (= 3.98 and 4.20 for mechanical and electrostatic SFTs) over annual operation. If SFTs are operated only in winter months, HB/HC > 1 (= 1.3 and 8.5 for mechanical SFT) is obtained for solar- and wind-powered SFTs. However, an economic analysis was done by comparing health benefits to total costs for the ecological option of vegetation and the policy-based option of odd-even vehicle rationing which do not have health costs associated. The analysis suggests that none of the approaches have higher health benefits than the total cost (TC) and the employment of vegetation to mitigate air pollution is the most cost-effective method of pollution mitigation (HB/TC = 0.08 and 0.075 for annual and cold month operation). This suggests that the maximum possible pollution should be removed at the source itself.