The impact of metropolitan's Air Quality Policies on air pollution improvement in Taiwan

In recent years, the impact of air quality on health has drawn significant attention. The World Health Organization has highlighted that prolonged exposure to high concentrations of PM_2.5 can increase the incidence and mortality rates of cardiovascular and respiratory diseases, as well as elevate the risk of premature death, particularly among highly sensitive populations. Therefore, reducing air pollution levels and developing air quality policies require collaborative efforts from both the government and the public.

This study uses the WRF-CMAQ model to evaluate the inter-regional interactions of PM_2.5 and to assess the emission reduction benefits of the State Implementation Plan (SIP) implemented by Taiwan's six major cities. Taipei City, New Taipei City, Taoyuan City, Taichung City, Tainan City, and Kaohsiung City are Taiwan's primary urban centers, and their air pollution control efforts are essential for improving environmental quality nationwide.

The SIP measures in the six metropolitan focus on three major sources of pollution. For stationary sources, the policies include stricter standards for large emitters such as factories and coal-fired power plants, along with the promotion of low-pollution technologies. For mobile sources, the measures involve phasing out high-polluting vehicles, increasing the adoption of electric vehicles, and improving public transportation systems. For non-stationary sources, efforts are directed at strengthening the monitoring and control of construction dust and agricultural burning.

The policy's effectiveness is reflected in significant emission reductions: Taipei reduced PM_2.5 emissions by 283 tons; New Taipei, by 72 tons; Taoyuan, by 599.4 tons; Taichung, by 73.3 tons; Tainan, by 2,150 tons; and Kaohsiung, by 2,043 tons. For instance, in Taichung, the latest SIP measures are expected to reduce PM2.5 concentrations from 16.8 μg/m³ to 15.7 μg/m³, a 7% improvement.

Despite these achievements, inter-regional pollutant transport continues to affect the six metropolitan, particularly in southern Taiwan. Future policies must balance regional pollutant transport, climate change, and economic development needs. Moreover, collaboration with neighboring countries will be essential to reduce transboundary pollution.

Overall, the SIP policies implemented in Taiwan's six metropolitan areas have successfully improved air quality and offer valuable insights for reducing air pollution. However, continuous adjustments and strategic refinements will be necessary to address emerging challenges and ensure the long-term effectiveness of these policies.