SmartAir聪明空气
对不起，此内容只适用于美式英文。 For the sake of viewer convenience, the content is shown below in the alternative language. You may click the link to switch the active language.
Had trouble breathing lately? It might be because despite popular opinion, Delhi’s air pollution levels aren’t doing so great in the summer heat.
Our team regularly monitors air quality through the Air Quality Index Widget on our phone, which uses U.S. Embassy Air Quality data. The U.S. Embassy converts P.M. 2.5 (mg per cubic meter) to an Air Quality Index (AQI) to easily guide health decisions. It is fairly typical for Delhi figures to be in the orange or red zone, considered unhealthy at an AQI of 151 to 200, in the summer. Winters typically see figures in the ‘Very Unhealthy’ violet category with an AQI ranging from 201 to 300.
Though April AQIs have been, on average, showing moderate AQIs below 100, the pollution levels in the last week of April spiked.
April 28th, 29th, and 30th averaged at ‘very unhealthy’ levels of air pollution with average AQIs of 248, 246, and 300, respectively. Such high levels of pollution can cause significant aggregation for those with heart or lung problems.
The highest hourly averages on these days were above 500, with the maximum of 592 on 29th April. To put this into perspective, the U.S. Embassy Air Quality key maxes out at 500, which marks the maximum in the worst category, ‘hazardous.’ Hazardous levels of air pollution may cause serious heart and lung risks, even leading to mortality amongst those with cardiopulmonary disease. At levels above an AQI of 500, these effects may worsen.
Though there are is no evidence to help us understand the unusual spike, the high amount of air pollution may be a result of two on-going activities. One, the end of April brings an end to the wheat season. To clear the land of wheat stubbles in preparation of planting other crops, farmers often burn the wheat residue. According to Umendra Dutt of the Kheti Virasat Mission, however, only 16% of wheat reside is burned, so it is unclear how strongly the activity contributes to the PM 2.5 levels. Two, water-parched areas in Uttarakhand have resulted in an unusual number of forest fires. As of last weekend, 427 fires were simultaneously burning in the region, with reports of air pollution and poor air visibility.
Though the reasons for the poor air quality is unknown, Delhi government has yet to put precautions in place to protect public health. Contrastingly, China has frequently triggered red alerts in cities across the country when smog levels rise to unusual levels. Red alerts, which include recommendations that people should stay indoors and vehicles should be restricted, are issued when regions see an AQI of 300 or above. Delhi is seeing almost double this number during peak pollution hours, yet the government has taken limited precautions beyond odd-even. Until institutional factors are not addressed, air pollution will persist in high amounts. Such factors include industrial policies in Delhi and neighboring regions, implementation of policies restricting crop burning, and measures to reduce negative health and environmental impact of droughts.
