ISLAMABAD, Oct 9: Our cities are likely to experience a higher incidence of smog in the coming winter because air pollution has crossed all safety levels.

According to a recent environmental report, the presence of pollutants suspended in the atmosphere exceed World Health Organization (WHO), guidelines by 6.4 per cent in cities. Smoke emitted from vehicles and industry with natural dust combines to create a blanket of fog over the city.

Smog becomes a leading factor in road accidents due to poor visibility and inadequate street lighting.

It also aggravates allergies and asthma, affecting people’s health.

In a study carried out by the World Bank, the annual cost to the Pakistan economy in terms of urban air pollution was estimated at $369 million. This includes expenditures on health and productivity loss due to absenteeism in schools and at the workplace.

There has been an overall increase of 400 per cent in the number of vehicles on our roads over the past two decades. In the absence of environment-friendly fuels, air pollution levels in cities have crossed permissible levels.

The majority of these vehicles are driven by high sulphur diesel and adulterated petrol. High concentrations of lead in blood levels of traffic police and pedestrians in particular prevail, despite the introduction of lead-free petrol.

Low average rainfall and low wind speed contribute to the concentration of pollutants in the air. Rains help clear the atmosphere while dry spells prolong the time it takes for these suspended particles to disperse.

The high level of pollutants in the air impacts directly on meteorological conditions in two ways: their level is likely to rise if dry weather prevails, and if suspended in the atmosphere for long, these pollutants trap sun rays and aggravate dryness. —Hajra Elahi