Taipei: Taiwan will start trials to monitor ultrafine PM0.1 air particles in Taichung and Kaohsiung starting in 2026 to help develop a stable foundation for monitoring the pollutants, the Ministry of Environment (MOENV) said Wednesday.

According to Focus Taiwan, Deputy Environment Minister Shen Chih-hsiu reported to the Legislative Yuan that PM0.1 particles, which have a diameter of 0.1 micrometers or less, remain relatively unstudied and unmonitored in Taiwan. He highlighted that their sources and characteristics are not fully understood by the ministry, prompting the need for these trials.

The Ministry of Environment has included this initiative in its Air Quality Policy White Paper, marking it as a key focus of air quality management over the next decade. PM0.1 particles are about one-700th the width of a human hair, making them challenging for the body to defend against and potentially harmful to human health, Shen noted.

According to the World Health Organization, which incorporated ultrafine particles into its global air quality guidelines for the first time in 2021, exposure to such particles may heighten the risk of systemic inflammation and cardiovascular or lung diseases. It identifies road traffic and other forms of transportation, such as aviation and shipping, as primary sources of the particles. Additionally, emissions from industrial sources, power plants, residential heating, and biomass burning also contribute.

Shen emphasized that research indicates PM0.1 concentrations vary significantly across urban areas and fluctuate throughout the day, such as during rush hour versus off-peak times. This behavior contrasts with PM2.5, which tends to be more evenly distributed. Currently, Taiwan’s air quality monitoring system includes PM2.5 and PM10 particulates.