As the mercury rises in the capital city, so does the amount of pollution in the air. No longer just confined to the winter months, poor air quality is now a year round problem for the citizens of Delhi.
After a big dip in the levels of PM2.5 particles at the beginning of the month, pollution has surged and air quality has tumbled.
According to India’s own NAQI, Delhi recorded its worst reading since measurements began at the start of April. The 24 hour average air quality index on 4th May was given as 476 – alarming even by the Environment Ministry’s generous health index scale.
The main cause of this pollution appears to be carbon monoxide which is produced by vehicle exhaust. However, closer inspection of the data suggests that the average figures given by the NAQI for carbon monoxide levels might not be accurate.
The chart above says that there were only two hours when carbon monoxide levels were above 400, the rest of the time the levels were well below 150. This discrepancy in data is a cause for concern because citizens and pollution authorities need to have confidence that the data they are seeing is an accurate representation of the pollutants in the air to calculate the overall air quality.
Currently the most reliable reading of air quality in Delhi comes from the US Consulate as the numbers are updated on an hourly basis. However, the numbers are only representative of the area where they were taken.
The NAQI service still has a long way to go before it becomes a reliable source of air quality in the nation but numbers alone won’t help Delhi’s air pollution crisis.