PM2.5 – airborne particles less than 2.5 micrometres in diameter – can cause health risks, especially for young children, pregnant women, the elderly, and people with chronic lung disease. Thailand’s safety level for PM2.5 is 50 micrograms per cubic metre of air (μg/m3).
The navy said the machines, built at its Naval Dockyard Department, are based on the prototype developed by Rajaprajanugroh Foundation and were placed in 13 areas of the city that reported high levels of air pollution over the past few days.
Each machine can filter five cubic metres of air per second, the navy said. Lab results show that each machine can lower the PM2.5 level in an area of 144 cubic metres to below 50 μg/m3 in 30 minutes.
“The machines can also filter most germs, bacteria and viruses, including the Covid-19 virus, as well as aromatic hydrocarbons in nearby areas within 30 minutes,” the navy said, adding: “They have been tested for safety by the Naval Medicine and Naval Science departments.”
The Bangkok Metropolitan Administration on Saturday morning reported that the PM2.5 level in the past 24 hours ranged from 28 to 58 μg/m3 and that overall air quality was “good”.
The districts that reported the highest levels of PM2.5 – from 49-58 μg/m3 – are in eastern Bangkok. They are Nong Chok, Lat Krabang, and Bueng Kum.