Wind conditions pose challenge to Delhi’s pollution

Even as the recent  World Health Organisation (WHO) report cites that Delhi has lost its tag of being the most polluted city in the world, the city’s geography and wind conditions pose a greater challenge of cleaning its air.  

According to Centre for Science (CSE) director Sunita Narain, the tough geographical conditions would always pose a challenge in checking the rising pollution levels in the national Capital. 

Saying that Mumbai is equally polluted, Narain asserted that the impact of pollution in the commercial capital was not as hazardous as Delhi due to the presence of sea and maritime wind. 

According to experts, the Arvind Kejriwal-led government’s odd-even scheme has had tremendous impact on the city’s air quality, but it alone cannot reduce the pollution levels due to the city’s varying wind conditions.  

Explaining the wind conditions and how it poses a challenge in cleaning the city’s air, Vivek Chattopadhyay of CSE’s air pollution control unit says, “In Delhi, there is prevalence of calm conditions, under which the wind speed is below 1 km/hour. These calm condition prevail for nearly 45 per cent time of the year. Further, the city also has dry wind conditions” 

Comparing it to the wind conditions of  Chennai and Bengaluru,Chattopadhyay added, “The wind speed in Chennai or even Bengaluru is 6-7 km/hour. Besides the higher precipitation levels, it greatly reduces the pollutants in the air in these cities.”

Polash Mukherjee of CSE said, “Delhi is a landlocked city, which poses a challenge to the air quality. In Mumbai, where the sea breeze and land breeze keeps the pollution level under control. Delhi stands a disadvantage on this front.”

Environmentalists also cite that the city’s hot weather conditions makes it vulnerable to harmful effects of ozone gas.