Among India's most polluted, Hyderabad at No. 4, mainly due to auto fumes

Hyderabad, Oct 22: Among major Indian cities, Hyderabad is ranked as the fourth most polluted city after Delhi, Kolkata and Mumbai and it is the most polluted mega city in the southern part of the country.

The air pollution level in the city was categorized unhealthy with the Air Quality Index (AQI) of 159, according to the data on IQAir website on October 21.

The main pollutant was Particulate Matter (PM) 2.5 or small particles with the primary sources of this being automobiles and industries. Analysts say vehicles contribute one-third of the air pollution in the city.

PM2.5 concentration in Hyderabad was 70.4 micrograms per cubic metre of air. This was 14.1 times the World Health Organisation (WHO) annual air quality guideline value.

Experts have attributed vehicular pollution as the single biggest reason for deteriorating air quality in Hyderabad in addition to fossil fuel burning, construction, opening landfill burning and landfill fires of solid waste

Like many other cities in India and the world, Hyderabad failed to meet the WHO air quality criteria of 5 micrograms per cubic metre of air.

According to healthcare practitioners small particles pose the greatest risk to human health. While the nose can filter most coarse particles, fine and ultrafine particles are inhaled deeper into the lungs where they can be deposited or even pass into the bloodstream.

As per the World Air Quality Report 2021 by IQAir, a Swiss-based air quality technology company, during 2021 Hyderabad was found to be the fourth-worst polluted city in India with rise in PM 2.5 levels from 34.7 micrograms per cubic metre of air in 2020 to 39.4 in 2021.

The PM 2.5 level in the city had declined between 2017 and 2020 and this was attributed to green drive and strict automobile emission norms. However, the report noted that it began to rise in 2021.

The report revealed that while the average PM 2.5 during 2021 was 39.4 micrograms per cubic metre of air, it touched as high as 68.4 during December. July was relatively better with PM 2.5 hovering in the 12 micrograms per cubic metre of air range. However, even this is twice the value of 5 the permissible limit set by the WHO.

The pollution level of various Indian cities were analysed between November 20, 2020 to November 20, 2021 and the results were compared with both the prescribed air quality standards as referred by WHO and National Ambient Air Quality (NAAQS).

The report found that in terms of PM2.5, Hyderabad had an annual average of a little over 40 points, higher than NAAQS and WHO annual standards which are at 40 points and 5 points respectively. In terms of PM 10, the city had an annual average of 75 to 80 points. The NAAQS and WHO annual standards suggest this pollutant must not exceed 60 points and 15 points respectively.

Amongst the six pollution monitoring sites, the highest annual pollution levels were observed in Sanath Nagar, followed by Zoo Park and Bolarum both in terms of PM 2.5 and PM 10.

Air pollution is a significant contributor to illness and increased mortality rates and can be measured by the Air Quality Index (AQI).

The AQI quantifies five air pollutants (Ground level ozone, Carbon monoxide, Sulfur dioxide, Nitrogen dioxide, Particulate matter (PM10 and PM2.5) AQI of 0 to 50 is consistent with good air quality; AQI of 51 to 100 is consistent with moderate air quality, AQI of greater than 100 is considered unhealthy for sensitive groups, value greater than 300 signifies hazardous conditions.