Air pollution, especially in Dhaka, is a major Environmental risk. The pollution level is increasing day by day. According to the report conducted by Global Wind condition (WAC) 2017, Dhaka is the second most polluted city in the world in terms of its air.

Polluted air has an impact on human health, plants, animals, agricultural production and materials. Air pollution means the presence of various chemicals or compounds (called pollutants) and particles in the air which reduce the quality of air. Carbon dioxide (CO2), Carbon Monoxide (CO), Lead, Nitrogen Oxides (NOx), Volatile Organic Compounds (VOCs) Suspended Particulate (SPM), Coarse Particulate Matter (PM10), Fine Particulates (PM2.5), ozone(O3), Sulphur dioxide (SOx) ect are considered as air pollutants. We are concerned about the air pollution outside, whereas Indoor air pollution can be up to 10 times worse than outdoor air pollution.

Indoor air pollution is the degradation of indoor air quality by harmful chemicals and other materials. The beginning of this pollution was since people have learned to use fire in order to cook and keep themselves warm. Most of the indoor air pollution due to the use of coal, wood, or biomass stoves that are used in low- land or middle income countries in Southeast Asia. According to the WHO, around 3.8 million people died in those regions resulted from indoor air pollution and 4.2 million due to outdoor air pollution, among 3.8 million deaths, 27 percent are died due to pneumonia, 18 percent from stroke, 27 percent from ischemic heart disease and 20 percent from chronic obstructive pulmonary disease (COPD). The statement shows that indoor air pollution has the great impact on our health. The most affected groups are women and younger children, as they spend maximum time at home. Now it's time to make people aware about indoor air pollution.

The main source of indoor air pollution is home. Most homes have more than one source that contributes to indoor pollution. According to World Health organization (WHO), Around 300 million people still use solid fuels (such as wood, crop wastes, charcoal, coal, and dung) and kerosene for open fires and inefficient stoves for cooking purpose. More threatening indoor air pollutants are Radon, Formaldehyde, other VOCs, CO2, CO, NOX, Sox and HC Particulate matter (suspended and soluble) and PAH. They are generated by the burning of oil, gas, kerosene, wood and tobacco products or are produced by building material furnishings, wet or damp carpets, household chemical products, air conditioners etc.

The indoor air pollutants have some potential health effects. Most indoor air pollutants directly affect the respiratory and cardiovascular systems. The particulates cause respiratory infections, chronic bronchitis, COPD, and also lead to exacerbation of COPD. Coarse and fine particles also affect the cognitive function of children by changing the brain structure. Sulfur dioxide and nitrogen dioxide cause sneezing and exacerbation of asthma. In addition to this, nitrogen dioxide causes respiratory infections and deteriorates lung functions. Sulfur dioxide has an additional etiological role in the exacerbation of COPD and cardiovascular disease. The risk of poor perinatal outcomes, viz, low birth weight and perinatal death increases from exposure to carbon monoxide. Biomass smoke, especially metal ions and polycyclic aromatics, leads to the development of cataract. Polycyclic aromatic hydrocarbons lead to the development of cancers of the lungs, mouth, nasopharynx, and larynx. There are many other things that we may never have thought about, and these are harming our health and the environment. For example,

Asbestos: Asbestos is commonly used in home construction. It is usually found in color, color coating, building materials, and floor tiles. Asbestos has not been found in new homes after the use of asbestos, although the presence of asbestos remains in the old home. Still it is use in our country. If anyone has asbestos in the home, it can cause serious health problems like lung cancer, asbestosis, mesothelioma and various types of cancer in the human body.

Formaldehyde: Formaldehyde is another main cause of 'indoor air pollution'. It is not produced in the United States due to ban in the 1970s, even though it is still found in paint, seal and woodworking. This can lead to an allergic reaction with throat, eyes and nose, as well as an allergic reaction. In some cases it is responsible for the formation of cancer.

Organic pollutants: Organic pollutants include pollen grains, fungi and some bacteria from flower tubes. These cause high levels of sneezing, asthma symptoms, throat irritation, flu and other types of infectious diseases.

Smoking: Many people are smoking in the house. Tobacco emits various chemicals, which directly and indirectly harm human health. This can lead to respiratory distress, pneumonia, bronchitis, epilepsy, cardiovascular and lung cancer.

Cleaning materials: We are using various liquids to clean the floor, bathroom and furniture, which are made of many powerful chemicals. Some time we spray them out. As a result, they enter our breathing system. Due to lack of adequate ventilation, liquid cleansing takes time to dry. As a result, they are spreading in the air for a long time. As a result, there may be problems in coagulation, liver, brain and kidney in the body.

According to the World Health Organization (WHO) This year 37,000 Bangladeshis died due to air pollution. Indoor air pollution has caused by more than half the death of young children of 5 years old and who were affected by pneumonia.

Indoor air pollution is a major concern in Bangladesh as well as many other developing countries. A study of the Department of Environmental Science shows that the women who are using wood charcoal oven suffer more from health problems than gas stoves user. WHO have guidance for reducing indoor air pollution and that is "everyone has to use health-based fuels and technologies. The organization also said that only using technologies can ensure the healthy air in and around the home. Reducing the use of harmful ingredients or stop not them at all is another way to reduce indoor air pollution. Bangladesh is working with some researchers to abate the air pollution, as well as doing a number of activities to make common people aware of the problem.

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