There is a good reason to worry about the air quality in Dhaka, as Bangladesh ranks 179th (out of 180 countries) at the Environmental Performance Index for air quality. According to the State of Global Air (2019), air pollution is the fifth leading risk for mortality worldwide. In 2017, the number of air quality related deaths was 108.5 per 100,000 people in Bangladesh while the lowest rate was 8.50 in Finland. 

Also, it is already proven that there is a strong link between COVID-19 and air pollution. A scientific study across 66 regions in Italy, Spain, France, and Germany concluded that 78% of the coronavirus deaths occurred in five of the most polluted regions. Sensitive groups such as people with heart or lung disease, older adults, etc. are at greater risk of air pollution.

The United States Environmental Protection Agency (U.S.EPA) introduced the Air Quality Index (AQI) which is a scorecard of six categories that describe ambient air quality relative to the relevant standards. Each category corresponds to a different level of health concern and has a specific color, such as ‘green’ means good air quality and ‘maroon’ means hazardous. 

The dominant pollutant that causes high AQI in Dhaka is fine particulate matters (PM2.5) which can penetrate deep into the human respiratory system due to their small size, causing a wide range of short and long-term health effects.

The PM2.5 concentrations are measured to be higher in the dry season due to the atmospheric conditions and anthropogenic emissions which usually runs from November to March. The major sources of pollution in Dhaka are vehicular emissions and industrial emissions. One of the major contributors to the high AQI is the brick kilns operation during the dry season in Dhaka. 

According to the data from the U.S. Embassy air quality monitor in Dhaka, there were zero days of ‘good’ category air quality in the last three dry seasons (2017-2020) where most of the days of the dry seasons shown ‘unhealthy’ and ‘very unhealthy’ AQI categories with the significant number of ‘hazardous’ days. The following table shows the percentage of total days based on the AQI category in the dry seasons in Dhaka.

Reducing exposure to the fine particle in the dry season is critical for both sensitive group and healthy people. When AQI reaches to ‘unhealthy’ category: staying indoors, avoiding activities that make breathe faster and deeper, and wearing N-95 respirators during outdoor activities can help to reduce air quality related health issues.

Biography: Iqbal Hossan is working as an Engineer in the air quality field and he is doing researches to improve the environment. 

BDST: 1532 HRS, NOV 07, 2020
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