Soil, water and air are considered as important elements of the environment. These three components are constantly being polluted due to human activities. The rate of pollution is increasing day by day, In the future; people will not be living in the environment rather than in the pollution. The image of pollution is so terrible that millions of people are injured or killed every year because of it. According to the World Bank's Country Environmental Analysis 2018 report, in 2015 about 2 lakh 34 thousand people died in Bangladesh due to pollution. Among them, 80,000 thousand died in the city. This pollution is destroying lots of lives. Air pollution, noise pollution, plastic pollution, water pollution, soil pollution, river pollution and waste management problem are the most recent issues. People are mostly affected by that pollution. Hence, pollution not only responsible for health hazard but also responsible for our financial loss.

Air pollution

At present, among all the pollution, the severity of air pollution is most. According to the Global Air Condition-2017 report, Dhaka is the second most air-polluted city in the world. According to the World Bank's Country Environmental Analysis 2018 report, in 2015 there are about 46,000 died due to air pollution in Bangladesh. According to Department of Environment, 4,500 brick kilns are the source of 58% air pollution which is situated around the Dhaka. According to this report, vehicle smog is the source of 10%, dust is the source of 8% and burning fossil fuels and firewood is the source of 7% of the air pollution. Apart from the burning fossil fuels (coal, oil and natural gas), various types of particulate matter (PM2.5 and PM10), ash, dust, lead, carbon, particulate carbon monoxide, sulfur oxide, nitrogen oxides and Carbon dioxide is constantly polluting the indoor and ambient air. Building materials such as (bricks, sand, earth, cement, brick chips), which are used for Construction purposes, are transported openly from one place to another, they have a contribution to air pollution. Due to air pollution; temporary and chronic health problems appear. Most common problems are irritation of the eyes, coughing, sneezing, high fever, asthma and headache etc. Dust mixed germs and heavy metals cause diseases such as lung cancer, asthma, bronchitis, tuberculosis, kidney damage, high blood pressure, birth defects etc. Stamford University Bangladesh's Department of Environmental Science and Work for Better Bangladesh jointly conducted a research on air pollution. The samples were collected from 12 different location points in Dhaka. The results showed that the amount of harmful dust especially PM2.5, in the air of Dhaka, is more than the ideal standard. To prevent air pollution; there have some rules and regulation. Environmental Conservation Act 1995, Vehicle Act 1965, Motor vehicles ordinance 1983, Brick kilns Act 2013 are some effective act to preventing air pollution.

Sound pollution

Hydraulic horns from vehicle, rail and boat horn, VIP/ Emergency horns, faulty vehicles/mechanical sounds of machine, political gathering, and open concert, building construction, generator and factory is responsible for high noise pollution. According to European Union Transport and Environment Research - in 2008, 5 million people suffered from severe heart attack due to noise pollution from rail and road transport, and 200,000 became victims of cardiovascular disease. Sound Pollution (Regulation) Rules - 2002 are enacted with the power of Bangladesh Environment convention Act, 1995. In this act, the standard of sound is identifying for silent, residential, mixed, commercial and industrial areas. In violation of this law for the first time there is a provision for a month's imprisonment or an amount of 5 thousand BDT as fine or both punishments. And subsequent offenses are punishable with imprisonment for six months or more than 10 thousand BDT as fine or both. Awareness, proper planning and law enforcement can be used to reduce noise pollution.

Plastic pollution

At present plastic pollution is a common pollution but have a great effect on our health. At once only polythene bags, bottles, etc. were considered as plastic pollution, but in reality micro plastic is the most harmful among all. Micro plastic is also known as micro beads which are a tiny plastic particle, of fewer than five millimeters, derived from the breakdown of larger plastic debris, both at sea and on land. There are plenty of micro beads available in face wash, detergents, soap, body wash, toothpaste etc. Plastic and micro beads cause thyroid, hypertension, kidney damage, dermatitis etc. Besides this, marine animals (whales, birds) die due to plastic presence and plastic intrusion in the food cycle, Rivers lose their navigability, polluting groundwater and depleting soil fertility. According to Bangladesh Environment Conservation Act, 1995 (amended by law no 9 of 2002) "transportation and production, import, marketing, sale, and distribution of all kinds of plastic shopping bags are prohibited." in Section 4 use of jute packaging is compulsory. In 2010 (Act No. 53), rules were made that, no person shall be permitted to sell, distribute or supply the goods. Stamford University Bangladesh's, Department of Environmental Science have done research on micro beads in personal care. They collected 104 types of cosmetics; among them 51 cosmetics contain micro beads. This study found 49% of all products contain micro beads whereas 29% of face wash, 17% of detergent, 66% of body wash, 52% of scrub, 26% of soap, 20% of toothpaste and 50% of cream have presence of micro beads within them. According to the study, the presence of micro beads in face wash and scrub is comparatively higher than soap, detergent and toothpaste. To reduce plastic pollution, people should be encouraged using jute, paper, and cloth bags (golden bags) instead of plastic products and we also should implement polythene prohibition law 2002 and also banned micro beads containing products.

River pollution

The main reason for river pollution is that 70-80 percent of industries have been established beside rivers. Apart from this, the industries only maintain ETP during the daytime; otherwise the municipal authority is releasing sediment waste in the river without refining it. Due to the waste of the dockyard, river traversing vessels, launches, steamers, trawlers, coal and oil, solid waste and sewage by the ascending, chemicals which are used for agricultural purpose and unplanned sanitation system and household waste, Livestock construction etc. are also responsible for river pollution. In this year, a study by Department of Environmental Science, Stamford University Bangladesh in associate with Poribesh Bachaw Andolon (POBA) jointly analyzed that the parameter of five rivers (Buriganga, Dhaleshwari, Shitalakhya, Balu and Turag) in around of Dhaka. Tested parameters are Temperature, PH, DO, TDS, EC and Salinity parameter. Nevertheless, some of the parameters of sample water were incompatible with Environmental Quality Standards (ECA 1995). To solve this problem we should use STP, ETP / CETP to treat sewage and industrial effluents.

Unplanned Waste Management

Hotel and restaurant waste, waste from industrial factories, medical waste, kitchen waste, vegetable wastes, blood from slaughterhouse, printing press etc. are the main sources of waste in the city. Among these, medical waste is more hazardous. Medicals wastes include samples of saline bags, syringes, blood, stools, urine, cough, sputum etc. including some parts of the body's diseased organs. These phenomena are highly contagious and dangerous. Projects in Agriculture, Rural Industry, Science and Medicine, Prism Bangladesh manage the medical waste. Different NGOs and specific areas waste collecting workers complete secondary work and finally City Corporation disposal the waste. People are openly dumping solid and medical waste which is contaminating air and causing soil pollution, along with creating the bad smell in the surrounding area. Mosquitoes, flies and insect pests are growing in this place. Wastes are not being removed on time during the rainy season that causes surface and groundwater pollution. Wastes are decomposed and released lichen which is made of waste liquid. This lichen contaminates groundwater and the river. As a result, this causes water-borne diseases and various health problems. A survey conducted by Department of Environmental Science of Stamford University Bangladesh found that 1.80 to 2 tons of medical wastes are produced from only Dhaka Medical College Hospital, out of which 65 percent of the waste is hazardous. The people who are working as cleaner in the hospitals and most of those involved in the waste discharges work without any safety material such as gloves, gumboot, mask etc. The workers often suffered severe injuries during the collection of sharp wastes (broken glass, needle). Not only will the city corporation's initiative be required, as well as awareness is needed, in order to prevent these hazards.

Environmental pollution is so much involved in our lives that we are not really aware about the pollution anymore. Every day there is some news related to environmental pollution, in the newspaper. But we are unaware of it. We should reduce pollution to keep, ourselves and the future generations alive. We must build some common habits to prevent pollution.

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