Don't rely on nature for pollution control

Delhi's 22 consecutive 'satisfactory' air quality days - a combination of good wind speed and rain - is a gift of nature rather than human intervention. But relying on nature for pollution control can't be an option. Beijing is a case in point. Nature contributes to the city's high pollution levels, six times higher than WHO norms, despite its impressive record of reducing particulate pollution by 60% in 10 years. A recent study attributes Beijing's persistent pollution problem to non-particulate pollutants from surrounding areas. Though the dynamics of air pollution in India and Beijing are different, the Chinese city's experience is instructive as 131 Indian cities make slow progress towards achieving the target of a 40% reduction in particulate concentrations by 2026.

GoI's 2019 National Clean Air Programme (NCAP) must shed its city-centric approach. While a city will remain the unit for administrative ease of implementation, NCAP must adopt the airshed approach to deliver results. Pollution does not recognise geographical and administrative boundaries; tackling it requires identifying geographical regions by pollutant profile and interactions. The focus needs to be on all pollutants, not just PM10. This is critical as secondary pollution is rising from increased vehicular and industrial activities.

Source-apportionment studies to identify originating points for pollutants in the local and regional/airshed is the first step for designing pollution-control measures. Mechanisms are required to allow administrative units within an airshed to coordinate policy and action. NCAP units must share findings on pollutants with departments that can take measures to eliminate, substantially reduce or mitigate pollution sources. Concerted, broad-based action is necessary to make pollution reduction long-lasting, rather than just occasional gifts from nature.