Air Quality Index: 11 days in 2017 recorded 'very poor'

The Air Quality Index (AQI) data of 2017 indicates that Mumbai's air quality has been worsening with each passing year. In 2017, it was worse than 2016 and 2015. Meanwhile, complaints related to pollution caused by chemical effluents in the city have increased by 67 per cent from 2015, which saw 33 complaints, to 55 in 2017.

The data, which was obtained from Central Pollution Control Board (CPCB) under Right To Information (RTI), was released by NGO Praja Foundation on Thursday. It states that the highest average monthly AQI has gone from 170 in January 2016 to 186 in January 2017.

"January continues to remain the worst month of the year for pollution in Mumbai," stated the white paper, adding that the highest AQI (worst air-quality), which is the average of 24 hours, has been constantly increasing over the years from 241 in 2015, 276 in 2016 and 500 in 2017.

In 2017, Mumbai witnessed the cleanest air (or satisfactory AQI) on 10 days in May, June, August and September, when the index ranged from 35 to 41. Eleven days recorded the worst air, of which four days were in January when it rose to 500 on January 24, three days in February, one day in March and October, and two days in December. The worst AQI's ranged from a maximum of 500 to 222.

AQI METER

• Between 0 and 100: Satisfactory
   
• Between 101 and 200: Moderate
   
• Between 201 and 300: Poor
   
• Above 301: Very poor

(Standards set by CPCB and SAFAR)