Nowadays air pollution is a great concern. According to the global State of Air 2018, indoor and outdoor air pollution led to 123,000 deaths in Bangladesh in 2017. The report says that the life of South Asian children will be shortened by 30 months on average if they grow up with the current high levels of air pollution.

The report considered air pollution as the fifth risk factor for mortality worldwide. It also shows that less developed countries suffer PM2.5 exposures that are four to five times greater than developed countries. This report estimated that air pollution contributes to almost 5 million deaths globally, that is nearly 1 in every 10 deaths in 2017. Air pollution (ambient PM2.5, household, and ozone) is also estimated to have contributed to 147 million years of healthy life lost in 2017. This report further mentioned that more than 90% of the world's population lives in areas exceeding the annual air Quality guideline set by the World Health Organization (WHO).

Other findings, PM2.5 pollution contributed to nearly 3 million early deaths in 2017. Scientific evidence supports a relationship between exposure to ambient PM2.5 to ischemic heart disease, cerebrovascular disease, lung cancer, chronic obstructive pulmonary disease (COPD) and lower respiratory infections. Air pollution contributes to both non-communicable and communicable diseases. WHO reported that 21% deaths due to pneumonia, 20% from stroke, 34% from ischemic heart disease, and 19% from (COPD) 7% from lung cancer. In 2017, exposure to PM2.5 was the third leading risk factor for Type 2 diabetes and disability-adjusted life year (DALYs). Household air pollution remains a leading cause of death and disability worldwide, with a particularly heavy toll in less-developed countries and the study found that 3.6 billion people were to household air pollution from the use of solid fuels for cooking in 2017.

This report represents life expectancy at birth. Air pollution collectively reduces life expectancy by 1 year and 8 months on average worldwide, and 1 year and 7 months in South Asia. High exposures to ambient PM2.5 are a major contributor to loss of life expectancy around the world.

On the other side, WHO reported that due to indoor and outdoor air pollution every year 570,000 children under 5 years die from respiratory infections, such as pneumonia. According to the WHO Global Ambient Air Quality Database-2018, 97% of cities are in low- and middle- income countries where the place people live in exceeds WHO air quality limit.

Reference to Cancer Fact and Figures-2018, published by the American Cancer Society, the number of patients suffering from respiratory cancer is approximately 25.33 lacks and people died for respiratory cancers are approximately 15,877. According to the National Institute of Cancer Research and Hospital, in 2018 about 269 people have died from cancer disease in our country, among these 54 people died from lung cancer. According to the UNICEF study, 30 million children live in the presence of polluted air in the world, of which 22 million live in South Asia. International private environmental organization Green Peace estimates that due to air pollution, 70 million people worldwide are likely to die next year.

Some sources are continuously emitting PM2.5. Brick kilns are a major source of PM2.5 in Bangladesh. Various development activities, burning of fossil fuel (coal, oil and natural gas), unplanned gas, electricity, water, drainage, and roads activities are released PM2.5.

In 2018, The Department of Environmental Sciences of Stamford University Bangladesh conducted a study to detect outdoor airborne mycoflora. Four air samples for microbial pollution were collected from the different area of Dhaka University. There are total of 2,681 fungal colonies found in the sample. In this study, 8 fungal genera have been recorded viz- Alternaria, Aspergillus, Curvularia, Fusarium, Penicillium, Rhizopus and Trichoderma. Aspergillus was found in the highest frequency in the present investigation, among the identified fungal genera. Those mycoflora have a great impact on human health and plant.

The Bangladesh government has made laws to prevent air pollution. According to the Bangladesh Environment Conservation 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, imprisonment not exceeding 1 year or a fine not exceeding taka 10 (ten) thousand or both. Law to prevent pollution of the 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 then one (one) Shall be punished with fine which may extend to one thousand taka, or with both. The government is working to formulate the Clean Air Act to reduce air pollution.

Our effective role will be to prevent air pollution. First to identify the sources of contamination and reduce pollution. It is necessary to apply conventional law appropriately. If necessary, new legislation should be implemented. Children, old and pregnant women are more vulnerable to air pollution. Awareness is key to preventing air pollution. Air pollution great threatens child health. To protect children from this, we need to formulate, implement and monitor our plans. Action should be taken at the national and local level against air pollution. An educational campaign should be run in print and electronic media.

Professor Dr. Ahmad Kamruzzaman Majumder, Chairman, Department of Environmental Science, Stamford University Bangladesh.