Geography of Taiwan water supplies, and trade in endangered species. Though regulation of sulfate aerosol emissions from petroleum combustion is becoming stringent, acid rain remains a threat to the health of residents and forests. Atmospheric scientists in Taiwan estimate that more than half of the pollutants causing Taiwan's acid rain are carried from mainland China by monsoon winds. Geography of Taiwan Taiwan, formerly known as Formosa, is an island in East Asia; located some off the southeastern coast of mainland China across the Taiwan Strait. It has an area of , which includes other nearby islands such as Penghu (). The East China
Mainland China in English, is commonly applied by SAR governments to represent non-SAR areas of PRC, including Hainan province and coastal regions of mainland China, such as "Constitutional and Mainland Affairs" () and Immigration Departments. In the Mainland and Hong Kong Closer Economic Partnership Arrangement (as well as the Mainland and Macau Closer Economic Partnership Arrangement) the CPG also uses the Chinese characters "inner land", with the note that they refer to the "customs territory of China". In the United States' Taiwan Relations Act, the ROC-controlled islands of Quemoy and Matsu were excluded from the definition of "Taiwan". The House Foreign Affairs