The foul odour caused by hydrogen cyanide (HCN) from a lime stone factory in Myanmar has affected four villages in the Mae Sai district of Chiang Rai province.
The factory,registered as Ban Lom It 999, is located in Myanmar’s border town of Tachileik, opposite Mae Sai.
According to reports, the toxic gas emitted from the site sent a foul odour adrift, upsetting about ten nearby villages in tambon Mae Sai and Koh Chang.
Mr. Narongphol Khid-arn, the district chief of Mae Sai, has established an emergency operation centre to alert village leaders to the toxic gas in adjacent tambons. He also advised residents to wear masks and close their windows at night.
HCN gas is a colourless, highly toxic gas that is commonly used in pest control and gold mining. Direct contact may harm the bronchi, lungs, brain, heart, and blood vessels.
The pollution has affected 4 Chiang Rai villages in tambon Mae Sai: Muang Daeng Tai, Wiang Hom, San Sai, and San Sai Mai.
The Environmental and Pollution Control Office 1 (Chiang Mai) used a portable gas detector, which revealed that the HCN level had increased to 0.5 parts per million (ppm) from 0 ppm, which is considered harmful to the respiratory system.
The odour spread to Bang Chong in tambon Pong Pha on Wednesday night, about 13 kilometres from the Myanmar – Chiang Rai border.
Through the Thai-Myanmar Township Border Committee, the Chiang Rai Department of Provincial Administration and the army coordinated with Myanmar authorities.