Acid deposition in Hong Kong

A multi-year data set on rainwater composition obtained by the Royal Observatory, Hong Kong, as a contribution to the Global Atmosphere Watch of the World Meteorological Organization, has been reviewed in terms of data quality and evaluated for evidence of acidification due to anthropogenic emissions of acid precursors. Elevated levels of acidic sulphate and nitrate are evident in the data, which, when combined with a preliminary estimation of dry deposition fluxes of acidic gases, suggest a total acid deposition flux of approximately 160 meq m−2 yr−1. This value is sufficiently high so as to suggest the need for integrated assessment of acidic deposition and potential environmental consequences in the region.