Ambient mixing ratios of chlorofluorocarbons, hydrochlorofluorocarbons and hydrofluorocarbons in 46 Chinese cities

Air samples in 46 cities all over China were collected in October and November 2010, and the levels of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) were measured and are discussed in this work. In most cities, the ambient mixing ratios of CFCs were within 20% enhancements of the background values, while the levels of HCFCs and HFCs were significantly higher than the background values (P < 0.01). Compared with the results of previous research conducted in 2001 and other single-city studies, the levels of CFC-11, CFC-12 and CFC-113 have decreased since then, while the levels of HCFCs and HFCs have increased rapidly. The results are consistent with the fact that CFCs have been replaced by the interim replacements (HCFCs and HFCs) in compliance with the Montreal Protocol.