Air quality monitoring is an important basis to promote air quality protection and prevention. In order to effectively probe into air quality, we must operate and maintain a monitoring system on a long-term basis to acquire high-quality, comprehensive, representative, and reliable monitoring data.
Types of air quality monitoring stations:
The main objective of the monitoring stations is to monitor air quality and its long term trend in a larger area. After a cautious examination of data related to emission of pollutants, meteorological status and distribution of air quality concentration in each area, monitoring stations were designed and installed to serve their purposes. According to different monitoring purposes, monitoring stations are classified as general stations (60), traffic air quality monitoring stations (Fengshan, Sanchong, Zhongli, Yonghe, Fuxing and Datong, 6 in total), industrial air quality monitoring stations (Toufen, Xianxi, Mailiao, Taixi, Qianzhen, 5 in total), national park monitoring stations (Hengchun and Yangming; Hengchun is also a general station), background air quality monitoring stations (Wanli, Guanyin, Sanyi, Qiaotou and Cape Fugui; Wanli and Sanyi are also general stations), and other air quality monitoring stations.
General air quality monitoring stations：
General stations are installed in populous sites, or sites that are prone to higher pollution or can represent the distribution of air quality of a larger area, so that the data collected can reflect the air quality status of people's daily life.
Industrial air quality monitoring stations：
Industrial stations are installed in leeward side of the prevailing wind in industrial areas, so to understand the influence of industrial pollution. The monitoring stations should sit in populous areas where higher pollution is expected. If the height of a significant emission source is lower, the station should be installed on the edge of the leeward area immediately next to the source. If the emission comes from a high chimney, then the station should be installed in leeward side several kilometers away from the source.
Traffic air quality monitoring stations：
Traffic stations are installed at areas with heavy traffic so to reflect the air quality to which the pedestrians are exposed. The data collected will be used to evaluate effects of motorized vehicle control and the amount of exhaust gas that the pedestrians are exposed to.
National park monitoring stations：
National park stations are installed at appropriate sites in the national parks, so to understand the current states and future trends of air quality in these reserved areas. The location of the stations should not be anywhere close to sites that are prone to pollution, such as main roads, parking lots or ignition sources.
Background air quality monitoring stations：
Background stations are installed in areas with less pollution or in the windward side of the prevailing wind in the total quantity control zones, so to monitor the pollution amount brought by the wind in the windward area. These stations are installed purposefully in areas that can avoid the influence of pollution sources in the neighborhood, so to reflect the air quality at a larger scale and see if there is pollutant that has traveled a long distance from somewhere outside Taiwan.
Other air quality monitoring stations:
These stations are installed in Puli, Guanshan and other sites, serving special purposes. And there are some other special monitoring stations, including mobile monitoring vehicles and research-oriented stations.
Principles for locating monitoring sites：
- Types of the monitoring station
- Distribution and type of pollution source and pollutant concentration
- Topography, geography and climatic conditions
- Distribution of populations and traffic conditions
- Locations that can help evaluate effects of pollution countermeasures
- Urban planning, regional planning or other land exploitation planning
Principles for setting samplers：
- Not be influenced directly by pollution of flues and exhausting vents
- Airflow or pollution concentration around the sampler should not be interfered by obstacles nearby
- Pollution concentration around the sampler should not be interfered by the surface of constructions or obstacles nearby
- Determine the height of sampler based on the vertical distribution of pollutant concentration around the station
History of monitoring stations：
The air quality monitoring stations were completely installed in 1993. In 1999, the density of monitoring stations in every city and county were reviewed based on the principles governing the establishment of general monitoring stations stipulated in Article 11 of the Air pollution Control Act Enforcement Rules. The review led to several changes: Wanli, Sanyi, and Hengchu, originally had been back ground monitoring stations, were adjusted to also function as general stations; Taixi was adjusted to become an industrial monitoring station, and Fengshan was adjusted to become a traffic monitoring station.