Out of thin air – Dhaka air pollution

Out of thin air

  • Dhaka Tribune  November 28th, 2019

Air Pollution

Photo: MEHEDI HASAN/DHAKA HASAN

Air pollution is public enemy number one

According to world health statistics, about 4.3 million people die every year due to air pollution caused by burning fuel, while 3 million people die due to outdoor pollution.

Air pollution is one of the major environmental hazards in Bangladesh, as our country is rated to be an extremely vulnerable one with an overall Environmental Vulnerable Index (EVI) of 340.

About 98% of cities in the low and middle income countries, like Bangladesh, consisting of more than 100,000 in population, violate WHO air quality guidelines. Dhaka is one of those cities. In Bangladesh, the level of air pollution is concentrated at its highest in Dhaka, followed by Chittagong and Khulna, the two other industrial cities.

In winter, smog becomes a part of the daily life of city dwellers. The Department of Environment has mentioned the sources of air pollution in urban areas: 60% of pollutants from brick kilns; 18% from road dust and soil dust; 10% from vehicle emissions; 10% from burning biomass; 10% from construction activities.

Land development leads to soil erosion, and the increased demand for bricks is the outcome of an expanding construction industry, which follows rapid urbanization. To meet this demand, the number of brickfields keeps on increasing in the outskirts of our urban areas, and these brickfields are also responsible for air pollution. They emit large amounts of smoke, fly ash, SO2, and dust.

As these are situated conveniently near the cities, they pollute both the urban and the rural environment.

Not to mention that the increase in the urban population has created tremendous pressure on the existing network of intra-urban and inter-urban roads and highways, as both the number and the volume of vehicular traffic increases within the cities or in its outskirts at specific times of the day, especially during rush hour.

Another contributing factor is the fuel being used by automobiles. The petroleum refinery in Bangladesh supplies diesel, which contains 1% sulphur per-litre, even though the international standard is 0.2%.

Air pollution is a major environmental risk to health, there is no doubt about that.

By reducing air pollution levels, countries can reduce the burden of several forms of disease. The lower the levels of air pollution, the better the cardiovascular and respiratory health of the population — both long and short term.

Additionally, indoor smoke is a serious health risk for some 3 billion people, who cook and heat their homes with biomass fuel and coal. Outdoor air pollution in both cities and rural areas has been estimated to cause 3.7 million premature deaths worldwide in 2012.

If we don’t minimize air pollution, we stand to lose a significant portion of our labour force due to its health impacts.

As fuel used by vehicles and industries contain chemicals that pollute the air — sulphur in coal and diesel, tetraethyl lead in gasoline — fuel cleaning is necessary. We have to use low pollutant fuels wherever possible. To that end, compressed natural gas should be a serious consideration.

Shishir Reza is an environmental analyst.