The Pearl River Delta (PRD) is one of the largest fast-developing economic zones in China. Hong Kong and the mainland part of the PRD differed in socio-economic development history and chemical management policies. Polyurethane foam (PUF)-passive air sampling (PAS) was deployed at 21 regional air quality monitoring stations across the PRD in summer and winter, respectively. Dichloro-diphenyl-trichloroethane (DDT), chlordane and hexachlorobenzene (HCB) were analyzed with GC-MS. High total DDT (240-3700 pg m(-3)) and chlordane (100-2600 pg m(-3)) concentrations were observed. Concentrations of DDTs and chlordane were higher in summer than winter; HCB vice versa. Spatially, the mainland part of the PRD generally displayed higher DDT concentrations than Hong Kong. Antifouling paint for fishing ships in coastal China was suggested to be an important current DDT source in the coast. The reason is unknown for the very low trans-/cis-chlordane (TC/CC) ratios (0.27) found in the mainland in winter. HCB concentrations were relatively uniform across the PRD, and long range transport of HCB from inland/North China to the PRD in winter was suggested.
An intensive field campaign including measurements from the environmental monitoring network and from two super sites took place in the Pearl River Delta region in summer 2006. Using routinely measured O 3 and NO x concentrations, the spatial and temporal variation of O 3 and of the total oxidant concentrations was characterized. According to the spatial variability of NO 2 /NO, the two super sites were found to be representative of polluted urban and downwind suburban conditions. In addition, both sites were located in high O 3 regions. In-depth diagnostic of photochemical ozone production processes and their key controlling factors are achieved with an observation-based model (OBM) to gain regional perspectives. Budget analysis and sensitivity model runs show that aldehyde and HONO chemistry had significant impacts on local photochemical ozone production rates. The analysis of calculated Relative Incremental Reactivities shows that photochemical ozone production rates are mainly sensitive to anthropogenic hydrocarbons (HCs) in the polluted urban areas. In the suburban areas, sensitivity to nitrogen oxide (NO) concentrations dominated. Key anthropogenic HCs in both areas are alkenes and aromatics. Significant differences of ozone production efficiencies are identified between the urban and suburban regions, consistent with the OBM diagnosed results. ozone, Pearl River Delta, photochemical ozone productions, HONO, relative incremental reactivity
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.