Top-down estimates of benzene and toluene emissions in the Pearl River Delta and Hong Kong, China
Benzene (C6H6) and toluene (C7H8) are toxic to humans and the environment.They are also important precursors of ground-level ozone and secondary organic aerosols and contribute substantially to severe air pollution in urban areas in China.Discrepancies exist between different bottom-up inventories for benzene and toluene emissions in the Pearl Rive