Distribution Of Organophosphorus Flame Retardants In Sediments And Aquatic Organisms From The Pearl River Delta

Organophosphorus flame retardants(PFRs) have been widely utilized as flame retardants, plasticizers, antifoaming agents, hydraulic fluids, and lubricants by various industries, including textiles, electronics, building materials, and chemicals. The consumption of alternative PFRs has increased sharply along with the gradual phasing out of brominated flame retardants. As most PFRs are physically added into and mixed with, rather than chemically-bounding to the materials, leaching and releasing could occur throughout the lifetime of these products. It has been reported that PFRs were ubiquitous in diverse environmental media, such as air, dust, water, sediment, soil, and biota samples. Furthermore, it cannot be ignored that PFRs have some harmful effects on human health, such as carcinogenicity,neurotoxicity, reproductive toxicity, and hemolytic effects, etc.The Pearl River Delta(PRD) is an important manufacturing industry base in southern China, and, there is widespread use of large amounts of chemicals because of the prosperous manufacturing industry in the region. Reports have indicated that high concentrations of halogenated flame retardants have been found in this region. In the present study, analytical method for the determination of 12 PFRs in the sedimental samples was developed. The concentrations of 12 targeted PFRs were determined in 65 sediments and a 44-cm depth sediment core from the rivers and the estuary in the PRD, with the aim of investigating their spatial and vertical distributions, the environmental behaviors, potential sources, and the fate of PFRs. In addition, PFRs were also determined in eight aquatic biota samples in order to preliminarily investigate the levels of PFRs in the aquatic organisms.The concentrations of PFRs of the surface sediments from the PRD ranged from 0.54 to 470 ng/g dry weight(dw), with a median of 48 ng/g dw, which were compared with the global figures. TPhP, TCPP, TEHP, TBEP, and TCEP were the main compounds of the PFRs, the composition of which in the surface sediments varied across the different sampling area, reflecting the different sources of PFRs. The principal components analysis(PCA) was conducted. TDCP, EHDPP, TBEP, TCrP, TnBP, and TCEP can be contributed to the industrial sources of PFRs, while TPhP and TCPP can be contributed to the e-waste source. In the estuary, the PFRs mainly derived from the Dongjiang River, Xijiang River, and the Shunde sections, followed by Guangzhou. The halogenated PFRs in the sediments exhibited concentrations similar to those in sludge, but the concentrations of the non-halogen PFRs were significantly lower than were those in the sludge samples, indicating the different environmental behaviors between the halogen-containing and the halogen-free PFRs.The levels of PFRs in the sediment core from the PRE ranged from 4.0 – 96 ng/g dw. The main compounds of PFRs were TPhP, TCPP, TEHP, and TCEP, similar to those in the surface sediments. In the upper segments of the sediment core, increased concentrations of three halogenated PFRs have been observed. Conversely, relatively high levels of non-halogen PFRs were observed in the lower segments of the core, indicating different environmental behavious or usage patterns between the halogen-containing and halogen-free PFRs in the study area.The concentrations of PFRs in the aquatic biota samples ranged from 4.8 × 10-3 – 17.3 ng/g lipid wt, which was fairly low compared with the global figures. The dominant PFRs were TPhP, TCPP, EHDPP, and TnBP, similar to the other patterns reported in the aquatic organisms.