Action against hazardous dust particles

The new measures will control the emission of dust particles to 2.5 micron - a standard used in the US and Europe, Dr Suphat Wangwong, director-general of the Department of Pollution Control, said at a press conference yesterday.

Citing a department study, he said the current standards that allowed emissions of 10-micron particles could be blamed for 1 to 3 per cent of deaths associated with heart-related and respiratory diseases. Particles smaller than 10 micron can be inhaled and cause permanent physical damage.

The main source of dust particles smaller than 10 micron are car emissions caused by incomplete combustion in both diesel and benzene vehicles, while the second source is smoke and debris from wildfires.

The 2.5-micron minimum size, which was set by the World Health Organisation, is being followed in the US and several European countries. WHO is planning to have more countries enforce this dust-particle size policy within the next five years, thought the size may vary depending on certain factors including environmental conditions.

In Bangkok, people living in the Din Daeng area are most exposed to dust particles and toxic emission, according to a Thailand Research Fund study of four locations in Bangkok surveyed in March. The other areas exposed to such risk are Somdej Chao Phya on the Thon Buri side, Chandra Kasem area and Bang Na.

Researcher Nares Chuesuwan said another study conducted between 1992 and 1996 found that deaths reported in Bangkok varied according to the density levels. Particle-dust density levels attributed to deaths caused by heart-related and respiratory diseases, which have risen by up to 2 per cent and 6 per cent, respectively.