WHO report - pollution highest in North Indian cities, lowest down South

#airpollution #WHO #mostpollutedcities According a report of WHO, the cities facing maximum pollution in India are located in the northern regions and cities in the states of Uttar Pradesh, Punjab and Rajasthan dominate the list. These states lie in the fog belt and air pollution is worsening the problem. Incidentally, it had been already reported that the average fog hours in the month of January in Delhi had increased by as much as eight hours since 1989 — this is a trend that can be attributed to rising pollution.
Delhi has earned the dubious tag of the most polluted city in the world. The breakup of polluted cities statewise is nine in UP, five in Punjab, four in Rajasthan. There were three cities each in the states of Madhya Pradesh and Maharashtra and one city each in J&K, Bihar and Uttarakhand.
At the other end of the spectrum are five cities with the cleanest air – all of these are located in south India. Two of these were in Kerala - Kollam and Pathanamthitta, one in Karnataka - Hassan, one in Tamil Nadu - Madurai, and Pondicherry.
A total of 124 Indian data stations - mostly in cities – have been featured in the report of WHO.
A comparison between the cleanest and most polluted cities will reveal the extent of variation - Pathanamthitta, the cleanest city on the list, recorded a concentration of 10 parts per million of particles under 2.5 microns while in Delhi it was a concentration of 153 parts per million of such particles. This is more than fifteen times that of Pathanamthitta.
WHO relied on the concentration of particles in the air under 2.5 microns to determine how bad air pollution is because such tiny particles cause the most damage to health - when inhaled, they can go deep into the lungs, whereas larger particles are usually filtered out before they reach that far.