Controlling sound pollution is not possible only by executing a law; building awareness and educating people is a necessity to get better results, said speakers at a discussion yesterday.

"We have to educate people on the issue then and only then it is possible," said Prof Pran Gopal Dutta, a former vice-chancellor of Bangabandhu Sheikh Mujib Medical University, at his keynote presentation at the capital's LGED-RDEC auditorium, organised by the department of environment (DoE).

He said noise-induced hearing loss is one of the most pervasive occupational health problems and causes serious damage since it is so gradual, which usually goes unnoticed but the hearing loss is permanent.

"Sound pollution increases blood pressure, enhances the rate of autism among children, and create obstacles to their growth," Dutta warned.

In USA, the ratio of autism among children was 1:212 earlier, now 1:88 due to excessive sound pollution, he added.

If a person talks in mobile phone for 16 to 20 minutes continuously, his brain temperature will be 102 degree Fahrenheit (around 39 degree Celsius), which is very harmful.

"The level of sound pollution in most of the areas of Dhaka city is 13 to 40 decibels extra than the permissible level," said Farid Ahmed, programme director of Coordinated and Partnership based Programme to Control Noise Pollution.

"According to the noise pollution control guideline-2006, in quiet areas the sound level should be restricted to 50 decibels during daytime and 40 at night, in residential areas 55 decibels at day and 45 at night, in mixed areas it should be 60 during daytime and 50 at night, commercial areas should be 70 and 60, and industrial areas 75 and 70," he said.

DoE has taken an initiative to make a survey at 645 spots in the country to measure the rates of the noise pollution and will conduct awareness programmes and offer training to raise awareness, he added.

"If everyone realises the negative effects of the noise pollution, it is possible to control it," said Raisul Alam Mondal, director general of DoE.