1.This diagram shows the spatial distribution
of regional air pollution levels in the Pearl River Delta (PRD) area expressed in
terms of the Regional Air Quality Index (RAQI). The higher the index value, the
higher the regional air pollution levels.
2.“ RAQI is a composite indicator of
the aggregate level of four major regional air pollutants, namely respirable suspended
particulates (PM10), sulphur dioxide (SO2), nitrogen dioxide
(NO2) and ozone (O3).
3.Please refer to Frequently Asked Questions
for more details about the RAQI, and the differences between RAQI report and the
Air Pollution Index (API) reports issued by individual cities.