Polybrominated diphenyl ethers (PBDEs) in aquatic biota from the lower reach of the Yangtze River, East China

Abstract

Sixteen species of aquatic biota from the lower reach of the Yangtze River including fishes, crabs and shrimps were collected and analyzed for 13 polybrominated diphenyl ethers (PBDEs) congeners. All the PBDEs congeners except BDE-17 were detectable in the samples indicating that the aquatic biota from the lower reach of the Yangtze River are widely exposed to these pollutants. The ∑₁₂PBDEs ranged from 3.52 to 603.69 ng/g lipid (0.032∼62.69 ng/g wet wt), with a mean of 44.04 ng/g lipid (2.69 ng/g wet wt). The PBDEs levels in the Yangtze River aquatic biota were low to average compared to PBDEs levels in aquatic biota around the world. The predominant congeners were BDE-47, BDE-28, BDE-154, BDE-100 and BDE-153. The proportion of BDE-28 seemed to be relatively high which was different from the result in other studies around the world but consistent with the results in China. The congener pattern of the sample was similar to the pattern in the sediment from the Yangtze River which implies that sediment may be an important PBDEs source for aquatic biota in the lower reach of the Yangtze River. Although the PBDEs levels in aquatic biota this area is comparable to or even lower than that in other areas in China, such as the Pearl River Delta and the Laizhou Bay, the increasing textiles, chemical and electronic industry may bring more and more PBDEs contamination to the Yangtze River Delta. The fact that PBDEs were detectable in all the biota samples from the lower reach of the Yangtze River should be an alarm for increasing risk in the Yangtze River Delta, East China.

Introduction

Polybrominated diphenyl ethers (PBDEs) are some of the most often used brominated flame retardants (BFRs) which are added in plastics, textiles, electronic circuitry and other materials to prevent fire (WHO, 1994). In 2001, the consumption of PBDEs around the world reached 67 440 tons, with about 37% of such consumption occurring in Asia (Tanabe, 2004). Because of the extensive use of PBDEs in recent decades and their persistence, PBDEs are now ubiquitous in the environment (Covaci et al., 2003). Besides their prevalence in environment, researchers have also studied their adverse effects. Animal studies have shown that PBDEs can cause thyroid hormone disruption, neurobehavioral deficits, and possibly even cancer (McDonald, 2002, Staskal et al., 2005). Recent researches also suggested that PBDEs may cause some adverse effects on humans (Branchi et al., 2003, Hites, 2004, Julander et al., 2005). As a result, PBDEs have become a hot spot in the realm of environmental science.

In China, PBDEs is one of the most frequently produced BFRs. The domestic demand of BFRs has increased at a rate of 8% per year in China (Mai et al., 2005). In 2002, the production of PBDEs in China was already 20 000 tons. The current production of PBDEs may far exceed the production in 2002. PBDEs are detectable in many different environmental samples, including water (Guan et al., 2007), air (Chen et al., 2006a, Chen et al., 2006b), soil (Zou et al., 2007), sediments (Zheng et al., 2004) and biota (Xiang et al., 2007), suggesting that China is suffering from PBDEs pollution. Thus far, most of the reports about PBDEs in China have been focused on the Pearl River Delta in South China. However, the Yangtze River Delta, which is located in East China, might be another site that should be paid attention too.

The Yangtze River Delta is located in the central coastal area of mainland China and has a population of 78 million. There are 16 large cities in the delta, 10 of which are amongst the cities with the strongest economic growth in China. In 2007, the gross domestic product (GDP) of the Yangtze River Delta reached 4667.2 billion yuan, which means that about 18.7% GDP of China comes from this area. The economy in the Yangtze River Delta develops rapidly and more than 400 of the Fortune 500 have set up branches in this area. The study area is focused on the lower reach of the Yangtze River in the Yangtze River Delta (Fig. 1). Jiangsu province, located in the lower reach of the Yangtze River, contains some BFRs production factories. At the same time, as it is a major production center for textiles and chemical industries, the annual consumption of PBDEs is very high (JCA, 2006). The rapidly developing electronic industry in Jiangsu province also brings PBDEs pollution to the Yangtze River Delta. For examples, Shen et al. (2006) has detected PBDEs in the surface sediments from the Yangtze River Delta. Xian et al. (2008) has also detected PBDEs in the freshwater fishes from the Yangtze River. Unfortunately, the current data regarding PBDEs in the Yangtze River Delta is far from enough. More understanding of the potential sources of PBDEs, their fate and behavior in the Yangtze River Delta are needed.

In this study, fishes, crabs and shrimps from the lower reach of the Yangtze River were collected and 13 PBDEs congeners were analyzed to understand their contamination status in the Yangtze River Delta. The main objective of the present study is to supply more valid data about PBDEs in aquatic biota and to elucidate the sources, fate and behavior based on assessment of specific congener profiles in the Yangtze River Delta.