Distribution Of Phthalic Acid Esters (PAEs) In Surface Sediments Of The Yellow Sea And The East China Sea

Phthalic Acid Esters (PAEs) are carcinogens, teratogens, mutagens, and can beenriched in organisms through the food chain, mainly from artificial synthesis. PAEsare one kind of persistent organic pollutants (POPs), which exist in almost all parts ofthe environment. They have significant potential hazards for human health andecological environment. After released into the environment, of that type of pollutantswill transport for long through the atmosphere, at present, PAEs pollution has becomea subject of concern of global environmental problems.The Yellow Sea (YS) and the East China Sea (ECS) with many rivers input arelocated on the wide continental shelf in East China, where the coastal economicdeveloped. In addition, the study area also is in downwind of the East Asian Monsoon.Therefore, the YS and the ECS receive large particulate artificially generatedpollutants fluxes every year, including those PAEs. After transferring into the marineecosystem through sewage discharge, atmospheric deposition and other approaches,because of their hydrophobic, PAEs and other persistent organic pollutants tend toadsorbing on the surface of suspended particulate matters, and ultimately deposit insediments at the bottom. Hence the surface sediments are likely to record and preservea lot of information about these organic pollutants.Four kinds of PAEs in surface sediments collected from the YS and the ECSwere extracted by ultrasound-assisted extraction (UAE) with silica gel-aluminacolumn for separation and then were determined by gas chromatography-flameionization detector (GC-FID). The factors that affect the distribution were discussed,and a preliminary assessment of the ecological risk was made.The result showed that total concentration range of PAEs in surface sediments ofthe Yellow Sea was311.4~6156.5ng/g, with an average value of1636.3ng/g, andhigh value areas were in central part of the YS. Di-butyl phthalate (DBP) presented the highest concentration that ranged from159.7ng/g to5499.3ng/g. Theconcentration of di-n-octyl phthalate (DnOP) was the lowest (2.2~81.1ng/g). Theaverage concentrations of dimethyl phthalate (DMP) and diethyl phthalate (DEP)were159.5ng/g and74.2ng/g, respectively. The distribution characteristics of thefour kinds of PAEs were different, but the high value areas were mainly located in thecentral part of the SYS for all of them. TOC content in sediments was an importantfactor affecting the distribution trends.Total concentration range of PAEs in surface sediments of the ECS was180.3~4897.6ng/g, with an average value of1435.0ng/g. High value areas concentrated inthe southeast of the Yangtze estuary, Fujian coastal and the southwest part of ChejuIsland mud area, and the secondary high value area distributed in Zhejiang coast. Thecontent of inshore and offshore mud area were similar, with average value of1433.8ng/g and1438.4ng/g. DBP presented the highest concentration that ranged from55.6ng/g to4349.53ng/g, which was much higher than the others. On the contrary, theconcentration of DnOP was the lowest (0.1~90.1ng/g). The average value of DMPand DEP were122.1ng/g and132.5ng/g, respectively. There was a slightly differencein distribution among different components. Otherwise, a poor correlation betweenPAEs concentration and TOC showed the particularity and complexity of the studyarea.PAEs were detected in all of the samples, suggesting that human activities havehad a significant impact on the mud areas of the YS and the ECS. The PAEs wererelatively lower compared to those of the other areas including some rivers, lakes andoceans. Ecological risk assessment results showed that only DBP concentration wasabove the criteria value, but the highest value was still less than ERL (effects rangelow), indicating that the potential ecological risk of the PAEs was relatively low.