Dr. Muhammad Mahtab Hossain Mazed

Bangladesh has become the country with the most polluted air in the world. Due to breathing in this polluted air, the average life expectancy of Bangladeshis is decreasing by about 6.8 years. This situation is even worse in different areasAnd air is one of the few important elements for healthy and beautiful living. We need pollution free environment and clean air to live healthy. But unfortunately it is true, the pure air is disappearing day by day in our country. Bangladesh is one of the countries in the world that suffer from severe air pollution. According to a new study, 54 out of 64 districts in Bangladesh have poor air quality. Only 10 districts have air quality within ideal levels. The worst effect of this excess air pollution is on human fertility. Air pollution seriously harms health. Air pollution primarily affects the respiratory system. Most of the non-communicable diseases that kill people worldwide are caused by air pollution. Polluted air particles are so small that they easily enter through the eyes, nose and mouth of people and mix with blood and affect the lungs, heart, kidneys, liver etc. Air pollution can lead to lung cancer. But the most horrendously affected is reproductive health. Air pollution has a major impact on miscarriages, birth defects, and the development of the baby's nervous system. As a result of this pollution, according to the World Health Organization, about 7 million people die worldwide every year.

> Harmful effects of air pollution

Air pollution is caused by the mixing of harmful substances in the air. Air pollution causes damage to health, environment and resources. As a result, the ozone layer in the atmosphere becomes thinner. This affects the climate and causes global climate change. Industries, vehicles, population growth and urbanization are some of the major causes of air pollution. Air pollution is caused by many factors, many of which are beyond human control. Dust storms and forest or grass fires in desert regions cause chemical and dust pollution in the air.

Air pollution is the contamination of the atmosphere by harmful and toxic substances, either naturally or as a result of human activities. The harmful effects of pollution can be easily identified as the amount of harmful substances released into the air is higher in any area of air pollution than in other places. The main sources of air pollution are vehicular smoke, smoke from power and heat generators, factories and solid waste burning. Another cause of air pollution is the increasing depletion of the ozone layer in the atmosphere above the continent of Antarctica. Air pollution also has negative effects on humans, flora, fauna and aquatic ecosystems through acid rain.

Recently, air pollution has become more prominent among environmental issues in Asia as elsewhere in the world. The problem is evident in Bangladesh's capital, Dhaka, and other centers of commercial activity. The health impact of air pollution in urban areas of Chittagong, Khulna, Bogra and Rajshahi regions is less than that of Dhaka. In the urban areas of different countries of the world, houses are often built on rocks and soils whose foundations emit radioactive gases.

Long-term inhalation of this gas can cause lung cancer. Air pollution has not yet been identified as a major problem in rural areas of Bangladesh. Because the number of motorized vehicles in these areas is less, so the number of industries is also less. However, substantial air pollution is occurring in urban and rural areas from brick kilns and cooking stoves. Wood, coal and different types of biomass are used as fuel in rural areas. As a result, the main air pollutants in rural areas are particulate matter and volatile organic compounds.

Air pollution in Bangladesh mainly comes from two sources – industrial smoke and vehicular smoke. Brick kilns, fertilizer factories, sugar mills, paper mills, jute mills, textile factories, spinning mills, tanneries, garment factories, bread and biscuit factories, chemical and pharmaceutical industries, cement factories, metal workshops, saw mills etc. are major sources of air pollution. . Air pollution is also caused by dust from cultivated land and salt particles from sea waves near coastal islands and coastal land areas. These sources of air pollution produce large amounts of smoke, vapors, gases and dust particles which create fog and smoky environment.

Some types of industries in Bangladesh such as tanneries are constantly emitting hydrogen sulphide, ammonia, chlorine and other odorless chemicals which are on the one hand toxic and on the other hand causing annoyance and suffering to the local people. These pollutants are causing headaches and other health problems. Due to high rate of urbanization, the number of vehicles in cities is increasing, resulting in higher rates of air pollution. Children suffer the most damage due to air pollution. The presence of excess lead in the air impairs the mental development of children. About 50 tons of lead is being released into the air of Dhaka city every year.

> Ways to prevent air pollution

The first step in air pollution control is to control the emissions of air pollutant sources before they are released into the atmosphere. In this case, application of modern technology, fuel purification, public awareness in motor vehicle driving etc. can be applied-

(1) Vehicle smoke control: Air pollutants emitted from vehicles such as carbon monoxide, nitrogen oxide, sulfur dioxide are the main ones. This pollution is less in CNG powered vehicles.

(2) Factory smoke control: Filters or other technology should be used to separate particulate matter from smoke exhaust pipes and chimneys.

(3) Absorption of polluting substances: In this method polluting substances are absorbed.

(4) Use of alternative fuels: By reducing the amount of fossil fuels, the use of solar energy, biogas etc. can be increased.
(5) Abandoned waste management: Abandoned waste can be buried underground without burning.

(6) Control of pesticide use: Crop diseases should be controlled by alternative means by reducing the use of pesticides.

(7) Quick removal of perishable goods: There should be quick removal of perishable goods from the bazaars, homesteads. Dustbins should be sent to treatment plants quickly.

(8) Zoning: Urban settlements, industries should be planned.

(9) Plantation: Plants maintain the balance of nature. Plants maintain balance by giving off oxygen and taking in carbon dioxide.

Finally, air pollution is mainly caused by natural and human activities.
One of the most talked about issues of the present time is the air pollution which is increasing at a great rate in different parts of the country including the capital Dhaka. Despite the grinding situation of the country, there is no necessary action. And the awareness of people of all classes and professions has increased in the world about the current issue of air pollution. Everyone has learned that air pollution is a serious threat. Yet the level of public awareness has not reached the desired target. It is expected that it will be possible to bring benefits if the government, related authorities, other organizations and people take joint initiatives to prevent air pollution. We all should come forward and be aware to protect the environment nationally. Above all, the Department of Environment should take effective measures to ensure proper enforcement and implementation of the Environmental Protection Act to prevent environmental pollution.

The writer is a, organizer, columnist and researcher Founder and Chairman, Jatiya Rogi Kallyan Society.