Recidual and risk assessment of petroleum hydrocarbons in the oyster, fish and shrimp along Guangdong coast

In order to explore the effect of oil pollution on the food security of aquatic products in Guangdong coastal waters, a risk grade method of petroleum residue was first proposed, petroleum hydrocarbons(PH) in the oysters (Crassostrea rivularis) collected during 2001~2010 were determined by spectrofluorometry, and the PH level in fish and shrimp was speculated.The results indicated that PH contents in our oyster samples ranged from < 0.2×10^-6 to 36×10^-6(wet weight), and might not make oil taste.The mean content of PH was 9.4×10^-6 which was relatively lower in the oysters from coastal waters in China, but higher than the historical data (6.7×10^-6)during 1989~1992.PH were detectable in 99.3 percents of our samples.16.7 percents of our samples contained more PH than the limit value (15×10^-6, Chinese standard).The annual PH average and the over standard rate in our samples trended to decline during 2001~2006, but slightly rebounded after 2007, especially in the samples from the Pearl River Estuary and from industry-translation areas.Based on the data of this survey and other literature, wededuced that the PH contents in fish and shrimp in Guangdong coastal waters were probably lower than 15×10^-6, seldom higher than 30×10^-6, and also might be lower than above limit or oil taste threshold.