The database, titled ‘WHO Global Urban Ambient Air Pollution Database (update 2016)’, finds that both the cities exceeded the WHO limit of 10 microgram per cubic metre for PM2.5 levels during the assessment.

PM2.5 refers to the concentration of small particles of less than 2.5 micrometres in diameter, which is believed to pose the greatest health risk owing to its deeper penetration into the lungs.

It is found that Kochi has the most polluted air in the state with PM2.5 level recording an annual average of 38 microgram per cubic metre. The PM10 level which causes diseases like asthma and other respiratory disorders stands at 70 microgram per cubic metre in the city. In state capital Thiruvananthapuram, the annual PM2.5 level recorded was 29 microgram per cubic metre.

In the previous such report released by WHO in 2014, the PM2.5 level in Kochi and

Thiruvananthapuram was 28 and 23 microgram per cubic metre respectively.

The analysis of the database further reveals that the Kozhikode, Kottayam, Alappuzha and Kollam also

exceeded the WHO safe limit.

“Growing air pollution is the result of not adhering to the existing rules and regulations. Pollution can only be controlled by strictly adhering to the rules but unfortunately the state pollution control board is not implementing the law in a way it is expected to do. There is no question on development but at the same time polluting industries should not be allowed at any cost. We should develop a policy for achieving zero pollution,” said, V S Vijayan, environmentalist and former chairman, Kerala State Biodiversity Board.

The WHO report released on September 27 notes that more than 80 per cent of people living in urban areas that monitor air pollution are exposed to air quality levels that exceed the WHO. WHO collected air quality data from 3,000 locations across the globe and looked for concentrations of fine particulate matter, including sulfates, nitrates, mineral dust, and black carbon, which are less than 2.5 micrometers in diameter.