Dhaka has once again become one of the most polluted cities in the world, according to a recent air quality index prepared by the US Environmental Protection Agency.
According to the index prepared early this year, Dhaka ranked fourth in a list of the most polluted cities in the world with an index value of 195. Kathmandu was rated the most polluted with a value of 208.
The air pollution level across the world varies from hour to hour and day to day. In late February this year, according to the index, Dhaka ranked as the most polluted city in the world with a score of 339 and its air was classified as "very unhealthy."
The index has six categories indicating growing levels of public health hazards. An air quality value over 300 indicates hazardous air while below 50 is considered to be healthy air. Statistics of the Department of Environment (DOE) show that the air quality index had the highest score of 501 in Dhaka on March 11. It was 338 in Gazipur and 308 in Narayanganj on the same day.
Medical analysts say, dust concentration in the air usually increases five times during the dry season, and dust particles from construction sites worsen the situation. Inhaling dust can severely damage the respiratory system and cause various lung diseases as well as viral and bacterial infection.
Along with the air pollution, noise pollution, also known as sound pollution, has turned acute in the capital city as it always goes far beyond the permissible level, putting public health at risk. The survey, conducted at 70 points of the city, reveals that sound pollution has reached the highest 120-130 decibels (dB) at many points -- almost double the permissible level.
The survey shows that noise pollution has increased alarmingly at different parts of the capital. The highest noise level recorded at the city's Farmgate area was 130.2dB during daytime and the lowest 65.7dB at night.
Sound pollution is the disturbing noise with harmful impacts on the activity of human or animal life. The source of ambient sound worldwide is mainly caused by machines and transportation systems, motor-vehicles engines and construction works as well.
According to the World Health Organisation (WHO), generally 60dB sound can make a man deaf temporarily and 100dB sound can cause complete deafness. It causes mental and physical illness among people.
It causes high blood pressure, headache, indigestion, ulcer, and also affects sleep. If one experiences sound pollution for a long time, his or her hearing capacity will dwindle gradually, and at one point of time he or she will be sound impaired.
According to a survey, about 10 per cent of city dwellers are now hearing impaired and 35 per cent are suffering from low-hearing problem due to high noise pollution. Although the government announced the Noise Pollution (Control) Rules 2006 to protect public health from sound pollution, it totally failed to enforce the rule putting the health of people at risk.
Noise pollution in the city has undesirably gone beyond control due to lax enforcement of the Noise Pollution Control Rules 2006 by the authorities concerned and lack of awareness among the people about the rules. The mobile courts of the traffic police can impose a fine of Tk 100 as per the Motor Vehicles Ordinance 1983 against a vehicle for violating various traffic related offences.
The drivers of vehicles unnecessarily use their hydraulic horns to create blaring noise. People of the city, predominantly students, can't concentrate on their studies and are unable to sleep due to unbearable sound of horns.
However, there is a provision of sentencing a person to a minimum of one month's jail term and Tk 5,000 fine or both and a maximum of six moths' jail term and Tk 10,000 fine or both for causing noise pollution violating noise pollution control rules as per a recent legislation. But such rules are hardly followed.
Various studies on noise pollution level in the city suggest that in reality sound is three times higher than the level set in the noise pollution control rules. The rules set a maximum 130 decibel sound during the off-peak hour between 9:00 pm and 6:00 am while it is maximum 127 decibel in the silent zone after 9:00 pm. The standard has been set for silent zone at 50 decibel during the day-time while it is 40 decibel at night.
Any vehicle that generates more than 85 decibel sound after starting the engine will, according to the Motor Vehicles Ordinance 1983, not get the clearance certificate while it is totally forbidden to install hydraulic horn in the transports. But maximum number of bus and trucks has been using hydraulic horns threatening public health.
There is no denying that unplanned diffusion of communication system, industrialisation and lack of awareness among drivers, use of loud-speakers at different festivals and indifference of the authorities to the problem are causing concerns. Now, it is necessary to formulate laws regarding specific sound limits for industries, transports and social programmes. Sound of vehicles and industries must be kept at a tolerable level.
According to the Environment and Forestry Protection Law-1997, there is a designated silent area within 100 metres of any hospital, educational institutions and some government-fixed institutions. There is prohibition on the use of microphones and horns. But, none follows the rules.
Around 25 per cent of the surveyed people of Dhaka city suffer from lung function abnormalities due to higher extent of air pollution. Such lung function abnormalities cause different types of airborne diseases, like bronchiolitis, pneumonia, asthma and chronic obstructive pulmonary disease (COPD).
Reports say air pollution is a major issue around the world and kills seven million people annually -- one in every eight people around the world. And, of course, air pollution is a well-known and much-complained-about malady in Bangladesh. Few major global cities suffer from air pollution worse than Dhaka.
During the dry season, when dust is especially harmful, pollution levels can reach up to 16 times higher than the World Health Organisation's (WHO) air quality guideline.
On its part, the government needs to conduct extensive awareness campaign on health-related issues caused by noise pollution and become more active in enforcement of the law. Use of the vehicular hydraulic horns at any place of the city should be banned. Monitoring teams should be deployed at main traffic points to check whether the vehicles follow the rules or not.
