Taipei, April 19 (CNA) The air quality was poor throughout western Taiwan on Wednesday, reaching levels seen as unhealthy for groups most sensitive to air pollution, according to the Environmental Protection Administration's (EPA's) Taiwan Air Quality Monitoring Network.
As of 11 a.m., the air quality in most parts of the northern cities of Taipei, New Taipei and Taoyuan, Taichung and Changhua in central Taiwan, and Yunlin, Chiayi, Tainan, Kaohsiung and Pingtung in the south flashed orange, signaling unhealthy air for young children, the elderly and people with chronic diseases.
The air quality indexes in the outlying islands of Kinmen and Matsu also showed orange.
The monitoring station in Taoyuan flashed red with very high levels of PM2.5 and PM10 particulates, meaning the air was unhealthy for everybody.
In other parts of western Taiwan, found mostly in Miaoli, Nantou, Chiayi and Kaohsiung, the air quality flashed yellow, meaning it was fair, network data showed.
The air quality in the eastern counties of Yilan and Hualien and the outlying island of Penghu also flashed yellow.
Only two monitoring stations around the country -- in Hengchun near Taiwan's southernmost tip and in Guanshan in Taitung County -- flashed green as of 11 a.m., indicating good air quality.
For Thursday, the air quality is expected to flash orange in central and southern Taiwan, and yellow in northern and eastern Taiwan.
The EPA's six-color scale takes into account ozone, PM2.5 and PM10 particulates, carbon monoxide, sulfur dioxide and nitric oxide concentrations in the air.
Green represents good air quality with an index reading of 0-50; yellow indicates moderate with a reading of 51-100; orange means unhealthy air quality for sensitive groups with a reading of 101-150; red indicates unhealthy quality with a range of 151-200; purple signifies very unhealthy levels at 201-300; and maroon represents hazardous levels at a reading of 301-500.
(By Elaine Hou)