KARACHI: Air pollution in Islamabad and Karachi was higher than usual on May 25. This fillip occurred while PTI protesters and police clashed across Pakistan. Police used tear gas to disperse the crowd and protesters burnt trees and vehicles in response. We asked experts whether one affected the other.

“Due to any disorder, if the levels of particulate matter increase and the nitrogen oxide (NOx), sulphur oxide (SOx) and carbon oxide (COx) gases released in the air, then definitely it will impact the environment, health and behaviours,” said Kamran Rajput, the Deputy Director of Sindh Environment Protection Agency.

Rafiul Haq, a consultant ecologist based in Karachi, believes that tear gas has hazardous effects on the eyes in the first place. “It affects the soft tissues and initiates itching in the throat and nose,” said Haq. “It can also cause suffocation by affecting the lungs and breathing.”

He said those targeted by the tear gas get affected severely. “But those who reside nearby where the shelling has taken place also get affected.

“Similarly, the incidents concerning setting things on fire like trees, roads and tyres also pollute the environment and decrease the ambient air quality,” said Haq.

Rajput said that if tyres are burnt somewhere in significant quantity or if any kind of gases is being released into the environment, then the area residents and passers-by can be adversely effete.

Talking about the policemen tasked with teargassing protesters, Haq pointed out that they can be seen using a wet cloth to wipe their faces even though they wear gas masks.

“This is because they also find it difficult to breathe during tear gassing,” he said. This is why water canon is considered a better alternative to tear gas

On the issue of whether a fire that rages for days can increase the temperature in the surrounding areas, Rajput said that it is temporary. “Although it does rise, for the time being, it returns to normalcy eventually.”