Prof Dr. Ahmad Kamruzzaman Majumder and Marziat Rahman :
Bangladesh is the favorite playground of nature decorated with six seasons. Researchers have started to think about new pollution as well as the new season,a kind of pollution is dust pollution. Dust pollution means the presence of particles (e.g. PM2.5 to PM10 microgram) in the air which degrades the air quality and has a harmful effect on human health. These particles vary greatly in size, composition, and origin, and may be harmful. Particulate matter may be in the form of fly ash, soot, dust, fog, fumes etc. Considering the diameter of particles, they can be classified as PM10 (coarse and fine particles), PM2.5 (fine particles). Both of them PM2.5 is more harmful then PM10.In the dry season, the amount of dust pollution increases more than the other times. Day by day the amount of dust include air pollution in the city has been increasing.
The air quality, particularly in Dhaka has undoubtedly been getting worse. According to World Bank’s Country Environmental Analysis (CEA) 2018 report, air pollution lead to deaths of 46,000 peoplein yearly in Bangladesh. The World Health Organization (WHO) and the International Cancer Agency listed PM2.5as “G -1 carcinogen”. Hence Dust pollution is not only responsible for health hazards, but also responsible for our environment and financial loss.
The Ministry of Environment, Forestryand climate changewith the assistance of the World Bank has undertaken the Clean Air and Sustainable Environment (CASE) project to address the issue of urban air pollution through demonstration intervening and providing technical assistance for capacity building and reform in key polluting sectors.
They have 11 total Continuous Air Quality monitoring stations (CAMS)which are available across the country to ensure the quality of air. Among them three stations we located in Dhaka, two in Chattagram, one for Rajshahi and Khulna, Gazipur, Narayanganj, Sylhet and Barisal respectively. Through these stations, air pollutants (PM2.5, ozone, sulfur dioxide, nitrogen oxides, carbon monoxide, etc.) are measured in these cities. Department of Environment has prepared air quality index.
According to the air quality index (AQI), if AQI less than 50, it is “green or healthy”, when it range from51 to 100, represent “medium air”, which is not harmful to humans,as well when it is between 101 to 150, then the air is called “warning air”, which is mildly harmful to humans. However, air quality index of air whenever crosses151, represents harmful to human health. If the level of AQI is 150 to 200, then it is “unhealthy”. It is “very unhealthy” in the range of 201 to 300 and the level of 301 to 500 is marked as “extremely unhealthy” or hazardous air. At present AQI level of Dhaka has 309, which is in extreme “unhealthy” position. According to the Clean Air and Sustainable Environment (CASE) project, the value of AQI is leading to a higher place from October to February of theyear. However, from March to August, average AQI is in normal stage.
At the beginning of the dry season, dust was mixed in the air due to unplanned development activities work like gas, electricity, water, drainage and roads repair and renovation. After cleaning the drain, the waste is kept on the side of the road, which is responsible for the dust-pollution.
In addition, due to the presence of the pathogen in the drain is responsible for unhealthy air. Building materials such as (bricks, sand, earth, cement, brick chips), which are usedfor Construction purposes, are transported openly from one place to another, they have a contribution to dust pollution. According to the information of the Department of Environment, 58% brick kilnsare the main sourceofair pollution in Dhaka. 4,500 bricks kilns are situated around the Dhaka.
Burning of Extra wood coal, wood pulses, furnace oils in the brick kilns is also release dust, particulate matter, carbon monoxide, sulfur oxide and nitrogen oxides which are polluting the air of Dhaka. Apart from the burning of fossil fuels (coal, oil and natural gas), various types of potential matter, ash, dust, carbon, carbon monoxide, sulfur oxide, nitrogen oxides and carbon dioxide. Moreover, Pb contaminated dust mixed with air fromproducts such as the lead battery, petrol, diesel, hair dryer, powder color, etc. Apart from color, seal and wood-industry, formaldehyde is also deterioratingair quality.
The charcoal and the tiny particles from the burning wood also mixed with the air. Harmful microbes mixed with the dust which is the resultant product of decomposition of garbage. Again, we are burning that dirtrubbish at the road side which is againleading to dust pollution.
Due to the dust pollution; temporary and chronic health problems appear. One of the most difficult problems is irritation of the eyes, coughing, sneezing, high fever, asthma, and headache. Dust mixed germs & heavy metals cause diseases such as lung cancer, asthma, bronchitis, tuberculosis, kidney damage, high blood pressure, birth defects etc. It has also effects on mental health, heart attack, liver problems, pregnant women, dermatitis and pneumonia etc. Coarse and fine particles also adversely affect the cognitive function of children by changing the brain structure.
Stamford University Bangladesh’s Department of Environmental Science and Work for Better Bangladesh jointly conducted a research on the samples collected from 12 points locations in Dhaka. The results showed that the amount of harmful dust specially PM2.5 in air of Dhaka is more than the ideal standard. This department also conducted a study on lead pollution in the Dhanmondi area and found the considerable amount of lead in the sample station. This study found the Pb contamination the dust for all samples ranges from 11.40 ppm to 1000ppm.
The Bangladesh government has made laws to prevent air pollution. According to Bangladesh EnvironmentConservation Act 1995, sub-section (1) of section 6- Restrictions vehicles emitting smoke injurious to environment-(1) A vehicle emitting smoke or gas injurious to health or environment shall not be operated nor shall such vehicles be switched on except for the purpose of test operation for stopping the emission of such smoke or gas. For the first offense of violating the provisions of Sub-section (1) of section 6; In case of the first offense, a fine not exceeding taka 5(five) thousand; in case of the second offense, a fine not exceeding taka 10 (ten) thousand.
In case of subsequent offense, an imprisonment not exceeding 1 year or a fine not exceeding taka 10 (ten) thousand or both. Law to prevent pollution of brick kiln- If a person violates the provisions of Section 4, the brick field produces brick in brick kilns without obtaining a license from the district administrator, then he is not punished with imprisonment for more than one year (one year) or more than one (one) Shall be punished with fine which may extend to one thousand taka, or with both. The government is working to create Clean Air Act to reduce air pollution.
Everyone needs to be aware to reduce air pollution. The educational campaign shall be run. It is very important to provide information, education and motivation to the public about the overall air pollution. Must have plan and act appropriately. The existing law must be applied accordingly, if necessary, new legislation shall be enacted. Modern technology and low sulfur coal should be used during brick making. Construction materials should be covered.
Roads should be kept clean, all the garbage should be removed at certain places, increasing the use of CNG gas instead of diesel and van the use of un-fitness vehicles. Everyone is interested in using public transport without using a personal car. Take effective steps to make the use of catalytic converters in brickfield and modernization of vehicles.
The threat to child health needs to be prepared, implemented, and monitored by our plans to protect against this air pollution and the health complications arising from this. Consistent action plans shall be taken at national and local levels. At the same time, the successful application of the administrative system is absolutely necessary. The media’s important role in this regard is must. With wide publicity by highlighting the negative aspects of air pollution, it has to come forward to solve this problem.
(The writers are associated with teaching and research in Department of Environmental Science at Stamford University Bangladesh).
