Bangkok is forecast to experience a resurgence of PM2.5 dust from now until the end of the month. An environmental chemistry expert at the National Institute of Development Administration (NIDA) has expressed the view that volatile weather in Thailand is compounding the dust situation.
Prof. Siwatt Pongpiachan, director of NIDA’s Center for Research & Development for Disaster Prevention & Management, said meteorological factors are the controlling factors for PM2.5 concentrations. He explained that regardless of whether dust sources increase or remain the same, meteorological conditions favoring the accumulation of dust would result in high levels of airborne particulate matter. He noted there is little rain at the end and beginning of the year and this means dust in the atmosphere is not washed away. Meanwhile, the lack of winds during this same period exacerbates the impacts of farm stubble burning.
For Bangkok, Dr. Siwatt said wind speeds change from day to day and PM2.5 levels vary depending on the wind speed. This means PM2.5 airborne dust is not swept away at the same rate each day despite dust sources in Bangkok remaining the same.
Dr. Siwatt suggested the government establish standard thresholds for cancer-causing substances in the atmosphere and in PM2.5 dust. These would also include determining the heavy metal content in the air, aside from the lead content. He noted Thailand is lacking these analyses, which would enable the public to be informed. He added that cancer-causing substances and heavy metals directly impact everybody who breathes in the air. (NNT)