Air quality improves but ozone concentration increases: EPA

Taipei, The Air Quality Index (AQI) flashed 282 red alerts in 2018, an improvement ahead of the annual government forecast for next year, but the overall concentration of ozone rose, the Environmental Protection Administration (EPA) said Thursday.

The EPA released 2018 air quality data on Thursday, which shows 282 red alerts up to Dec. 19, meaning unhealthy for the general public, a marked improvement on the annual forecast of 698 red alerts for 2018.

The reduced number of red alerts enabled the government to reach its 2015 target, halving alerts from 997 in 2015 to 499 by 2019, ahead of schedule.

Fewer red alerts were recorded across the island except in the north, Hsinchu, and Miaoli, the EPA said.

Less precipitation, fewer rainy days, and more days with low wind speed in those areas could have worsened air quality there, but the exact reasons have not yet been determined, it said.

Meanwhile, Chang Shuenn-chin , director of the EPA's Department of Environmental Monitoring and Information Management, said most major air pollutants have decreased over the past five years, though overall ozone volume concentration rose in 2018.

Chang said air quality monitoring stations in Kaohsiung and Pingtung recorded more days of ozone orange alerts - which is less severe than red alerts but still unhealthy - than the rest of Taiwan, and pollutants brought by northeasterly winds caused a significant increase in ozone concentration in the outlying Matsu and Penghu islands.

Chang added that in addition to overseas pollutants, the administration will also focus on reducing domestic ozone caused by volatile organic compounds (VOCs), which react with nitrogen oxide (NOx) to form ozone.

The EPA's air quality index takes into account ozone, PM2.5 and PM10 particulates, carbon monoxide, sulfur dioxide and nitric oxide concentrations in the air.

Source: Focus Taiwan News Channel