Phenolic endocrine-disrupting compounds in the Pearl River Estuary: Occurrence, bioaccumulation and risk assessment

STOTEN-21882; No of Pages 8 Science of the Total Environment xxx (2017) xxx–xxx

Contents lists available at ScienceDirect

Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv

Phenolic endocrine-disrupting compounds in the Pearl River Estuary: Occurrence, bioaccumulation and risk assessment Panpan Diao, Qi Chen, Rui Wang, Dong Sun, Zhuoping Cai, Hao Wu, Shunshan Duan ⁎ Research Center of Hydrobiology, Jinan University, P.R. China

H I G H L I G H T S

G R A P H I C A L

A B S T R A C T

• Occurrence of APs and BPA, in water, sediment and biota were determined. • Higher concentrations were detected for 4-NP than 4-t-OP and BPA in all matrixes. • The benthos were more likely to accumulate 4-NP than BPA based on BCF and BSAF. • Co-exposure showed low risk to aquatic organisms and human health.

a r t i c l e

i n f o

Article history: Received 16 October 2016 Received in revised form 12 January 2017 Accepted 25 January 2017 Available online xxxx Editor: Adrian Covaci Keywords: Phenolic endocrine-disrupting chemicals Aquatic environment Bioaccumulation Mixture risk assessment Human health

a b t s r a c t Three phenolic endocrine-disrupting compounds, 4-nonylphenol, 4-tert-octylphenol and bisphenol A, were determined in water, sediment and biota (fish, shrimp and mollusk) collected from sites along the Pearl River Estuary, China. The 4-nonylphenol, 4-tert-octylphenol and bisphenol A concentrations ranged from 1.20– 3352.86 ng/L in the water, b0.17–20.80 ng/g dw in the sediment and b1.49–237.12 ng/g dw in the biota. The concentrations of 4-nonylphenol were higher than those of 4-tert-octylphenol and bisphenol A in the water, sediment and organisms. Moreover, the bioconcentration factors (BCFs) and biota-sediment accumulation factors (BSAFs) of 4-nonylphenol and bisphenol A were calculated, and were found to be higher for 4-nonylphenol and in demersal organisms. To assess co-exposure to phenolic endocrine-disrupting compounds, the 4nonylphenol equivalent was employed to evaluate the potential risks to aquatic organisms and human health, and the results indicated a low risk. © 2017 Elsevier B.V. All rights reserved.

1. Introduction Endocrine-disrupting compounds (EDCs), with potential adverse effects on the endocrine system and even the reproductive system of organisms, have caused considerable concern in recent decades (Diamanti-Kandarakis, 2009). Phenolic EDCs, a major type of EDCs ⁎ Corresponding author. E-mail addresses: [email protected] (P. Diao), [email protected] (S. Duan).

primarily consisting of 4-nonylphenol (4-NP), 4-tert-octylphenol (4-tOP) and bisphenol A (BPA), have moderate estrogenic potency and extensive applications (Xiang-Li et al., 2007). 4-NP and 4-t-OP are important intermediates in the production and degradation of alkylphenol ethoxylates, which are widely used as nonionic surfactants in industrial, agricultural and household applications. BPA is the raw material used to produce resins and polymers, such as polycarbonate, epoxy and polyacrylate, which are widely used in food packaging, bottles and dental sealants that many humans are exposed to daily.

http://dx.doi.org/10.1016/j.scitotenv.2017.01.169 0048-9697/© 2017 Elsevier B.V. All rights reserved.

Please cite this article as: Diao, P., et al., Phenolic endocrine-disrupting compounds in the Pearl River Estuary: Occurrence, bioaccumulation and risk assessment, Sci Total Environ (2017), http://dx.doi.org/10.1016/j.scitotenv.2017.01.169

2

P. Diao et al. / Science of the Total Environment xxx (2017) xxx–xxx

Studies have shown that phenolic EDCs have been detected in air, water, sediment and organisms (Omar et al., 2016). Moreover, they could transfer to humans through skin contact, respiration and ingestion. Owing to their estrogenic potency, these chemicals could act competitively toward natural hormones by binding to estrogen receptors, thereby interfering with normal endocrine activity and causing cancer, diabetes, etc. (Kabir et al., 2015). Additionally, phenolic EDCs may have detrimental effects on aquatic organisms and higher trophic levels due to their accumulation characteristics (Staniszewska et al., 2014). Notably, 4-NP and 4-t-OP are more toxic, lipophilic, estrogenic and persistent than their parent substances and aquatic organisms show more sensitivity to these compounds, especially during the early developmental stages (Arslan and Parlak, 2007; Isobe et al., 2001). Considering the negative effects of phenolic EDCs, NP has been classified as a priority pollutant and limitation of its use has been recommended by the European Water Framework directive (WFD), whereas OP has not received this classification (Selvaraj et al., 2014). The European Union banned the use of plastic infant bottles containing BPA in 2011, a breakthrough decision intended to protect human health. However, most developing countries, including China, still lack the environmental monitoring and regulatory awareness to restrict the usage of phenolic EDCs (Duong et al., 2010). With respect to the adverse effects of phenolic EDCs, procedures have been developed to estimate the effects of individual chemicals, but little is known about the impacts of mixtures (USEPA, 2000). However, organisms are exposed to mixtures of chemicals much more frequently than single chemicals. A previous study has revealed that human estrogen receptor (hER) exhibits distinct transactivation properties in the presence of the combination of two weak environmental estrogens but not in the presence of any solitary chemical (Arnold and Mclachlan, 1996). To accurately evaluate the impacts of phenolic EDCs, the concentration addition (CA) model has been used to demonstrate their combined effects rather than their independent effects (Thorpe et al., 2005). The estradiol equivalent (EEQ), derived from the CA model, has been frequently applied in studies of estrogenic mixtures. In addition, the total EEQ has been calculated to estimate the estrogenicity of EDCs (Duong et al., 2010; Zhang et al., 2011), but there are limited reference values for determining whether total EEQ concentrations indicate a health risk (Yang et al., 2015). Considering the abundance studies on NP, the 4-NP equivalent, which is a modification of EEQ, was used to obtain an overview of the integrated effects of phenolic EDCs in the present study. The Pearl River Estuary connects the water in the Pearl River with that in the South China Sea; this area also has been called the Pearl River Delta. The Pearl River Delta is one of the most economically developed regions in China, with a population of 42.3 million within an area of 41,700 km2. Rapid agricultural, industrial, and urban development and the overuse of chemicals have resulted in increasingly severe environmental contamination. Polycyclic aromatic hydrocarbons (PAHs) and heavy metals have been shown to be present at high levels in sediment in the Pearl River Estuary due to rapid urbanization processes and anthropogenic pollution (Mai et al., 2002; Ye et al., 2012). In addition, studies have shown that phenolic EDCs have been detected in water, sediment, algae and wild carp bile in the Pearl River Estuary (Yang et al., 2014; Zhao et al., 2009). However, there are still limited systematic studies on phenolic EDCs in aquatic organisms and in their surrounding water and sediment, as well as their co-impacts on ecological security and human health, in the Pearl River Estuary. Fish, shrimp and mollusk are primary aquatic organisms consumed by human beings. Mugil cephalus, Parabramis pekinensis, Penaeuschinensis and Corbicula fluminea are common species in the Pearl River Estuary that are attractive for human consumption owing to their high nutritional values. Among them, M. cephalus has been widely used in biomonitorig studies conducted in coastal zone because it has a long gut, which favors highly efficient absorption of contaminants (Waltham et al., 2013). C. fluminea has also been used in toxicity

bioassays performed in environments with pollution, including metal pollution (Shoultswilson et al., 2010). Thus, the objectives of the present study were to evaluate the distribution characteristics of phenolic EDCs (4-NP, 4-t-OP and BPA) in water, sediment and aquatic organisms; to investigate the bioconcentration factors (BCFs) and biota-sediment bioaccumulation factors (BSAFs) of 4-NP and BPA in fish (M. cephalus and P. pekinensis), shrimp (P. chinensis) and mollusk (C. fluminea); and to conduct an ecological risk assessment and estimate the potential effects of these EDCs on human beings in the Pearl River Estuary based on the data collected in this study. 2. Materials and methods 2.1. Chemicals and materials Standards of 4-nonylphenol (a mixture with different isomers, analytical standard) and BPA (99%) were purchased from Aladdin, and 4-tOP (99.5%) was obtained from Dr. Ehrensorfer GMBH. Stock solutions of standard chemicals (1 g/L) were prepared with methanol and stored at −20 °C in the dark. HPLC grade acetone, formic acid, methanol, ethyl acetate, dichloromethane and n-hexane were acquired from Anpel. Glass fiber filters (GF/F, pore size 0.45 μm) were supplied by Whatman and baked at 500 °C for 4 h in a muffle furnace before use. Oasis HLB (500 mg/6 mL) and Sep-pak silica gel (500 mg/6 mL) solid phase extraction cartridges were obtained from Waters, and ProElut PSA (1 g/6 mL) solid phase extraction cartridges were purchased from Dikma. During all of the steps of analytic determination, the use of plastic products was avoided as much as possible. In addition, all of the glassware used throughout the procedure was successively washed with Milli-Q water, acetone and methanol and dried in an electric thermostatic drying oven before been used. 2.2. Sampling sites and sample collections The Pearl River system mainly consists of four tributaries that run through Guangdong Province - the Zhujiang River, East River, North River and West River - finally merging into the Pearl River Estuary in China. The Zhujiang River flows through Guangzhou, a highly developed metropolis, and the East River runs across Dongguan, where the manufacturing and processing industries are extremely developed. The Zhujiang River and the East River converge at the Shizhiyang Waterway, and they then flow into the Pearl River Estuary through the Humen outlet. The North River and West River run through undeveloped industrial areas that are sparsely populated, and they run into the Pearl River Estuary through the Jiaomen and Modaomen outlets and the Yamen outlet, respectively. Water, sediment and biota samples were collected in August 2015 in the Humen outlet (HM), Jiaomen outlet (JM), Modaomen outlet (MDM) the Yamen outlet (YM) (Fig. 1). Surface water samples (n = 3; each station) were obtained at a depth of 0.5 m in pre-cleaned 4-L amber glass bottles and stored at 4 °C before analysis. Sediment samples (n = 3; each station) were acquired from a depth of 5 cm using a stainless steel grab sampler and stored at − 20 °C until further analysis. Biota samples (n = 3 for P. pekinensis and P. chinensis, n = 4 for M. cephalus and n = 6 for C. fluminea; each station) were collected from the same sites using fishing nets and transported to the laboratory in an incubator with ice bags and then were stored at −20 °C before analysis. 2.3. Sample pretreatment The three phenolic EDCs were extracted from the water samples using a previously described method (Zhao et al., 2009). Briefly, 0.5-L water samples were filtered through glass fiber filters and then passed through HLB solid phase extraction cartridges to extract the target chemicals. Each final extract was filtered through a 0.22-μm membrane

Please cite this article as: Diao, P., et al., Phenolic endocrine-disrupting compounds in the Pearl River Estuary: Occurrence, bioaccumulation and risk assessment, Sci Total Environ (2017), http://dx.doi.org/10.1016/j.scitotenv.2017.01.169

P. Diao et al. / Science of the Total Environment xxx (2017) xxx–xxx

3

phenolic EDCs was performed with an electron spray ionization (ESI) source in the negative (ESI−) ion mode. All analyses were performed in the multiple reaction monitoring (MRM) mode. The optimized parameters are summarized in Supplementary material (Table S1). 2.5. Quality assurance and quality control Recovery, limit of quantification (LOQ) and limit of detection (LOD) were performed to validate the method. The recoveries were calculated through standard addition to blank samples. And the recoveries of the target compounds ranged from 80.53% to 102.58% for water, 84.09% to 99.96% for sediment, and 70.50% to 102.18% for biota (Table S2). The LOQs were calculated when the signal to noise ratio (S/N) was 10. The LOQs of the target phenolic EDCs ranged from 0.14 to 0.62 ng/L for water, 0.17 to 1.49 ng/g dw for sediment and 0.11 to 3.72 ng/g dw for biota. The LODs were calculated at S/N = 3 and were shown in the Supplementary material (Table S2). In addition, calibration curves were generated for the analytes, which showed good linear relationships (R2 N 0.99) between the LOD and 200 ng/L for the samples. Values below LOQ calculated as zero in statistical analysis. 2.6. Statistical analysis and calculation formula Fig. 1. Map of sampling sites in the Pearl River Estuary. HM, JM, MDM and YM were the abbreviation of Humen outlet, Jiaomen outlet, Modaomen outlet and Yamen outlet, respectively.

filter into a 1-mL amber glass vial and was stored at − 20 °C until analysis. In addition, all of the sediment samples were freeze-dried for 24 h, sieved through an 80-mesh (180 μm) stainless steel mesh, and then stored in a dryer. The phenolic EDCs were extracted from 1 g of each sediment sample with 10 mL of ethyl acetate by ultrasonic-assisted solvent extraction. The samples were then centrifuged at 2500 rpm for 5 min, and supernatants were collected, blown down to nearly dry under a gentle flow of nitrogen, and then redissolved in 2 mL n-hexane. The concentrated extracts were passed through a Sep-pak silica solid phase extraction cartridges that were pre-conditioned with 5 mL methanol, 5 mL ethyl acetate and 5 mL n-hexane. The target compounds were eluted using 3 × 2 mL ethyl acetate and 3 mL dichloromethane. The eluents obtained were blown down to nearly dry under a gentle flow of nitrogen and then redissolved in 1 mL methanol. The final extracts were filtered and stored in the same manner as the water samples. Further, extraction of the three phenolic EDCs from the biota samples was conducted according to a previously described method (Gu et al., 2014). The samples were dissected to obtain edible parts, namely muscles for the fish and shrimp without cephalosomes and mollusk without shells. The samples were freeze-dried and homogenized and then stored in amber glass bottles at − 20 °C in a refrigerator before analysis. The three phenolic EDCs were extracted from 0.5 g of each sample using acetonitrile, and the crude extracts were purified using a ProElut PSA solid phase extraction cartridge. The final extracts were then filtered and stored in the same manner as the water samples. 2.4. Analytical procedure All samples were analyzed by liquid chromatography tandem mass spectrometry (4000 Q TRAP® LC-MS/MS). The injection volume was set at 1 μL for each sample. The target compounds with different solubilities in methanol were separated by chromatographic analyses in methanol solutions of different concentrations at a flow rate of 0.25 mL/min. The mobile phases were Milli-Q water (A) and methanol (B), and the following gradient program was used: from 10% to 100% (B) over 1 min; maintenance at 100% (B) for 9 min; from 100% to 10% (B) over 0.1 min; and maintenance at 10% (B) for 9.9 min. Mass analysis of the

Statistical analysis was performed using SPSS 19.0 software (IBM, USA). Homogeneity and normality of data were checked by Levene's test and Shapiro-Wilk's test before analysis. Differences of the three compounds among the stations were conducted using Fisher's least significant difference (LSD) test by ANOVA. Differences were considered significant at a p b 0.05. Bioconcentration is a process by which a chemical substance is absorbed by an organism through respiratory and dermal surfaces, and the bioconcentration factor (BCF) was calculated as follows (Arnot and Gobas, 2006): BCF ¼ Cbiota Cwater

ð1Þ

where Cbiota (ng/g dw) is the concentration of phenolic EDCs in the biota sample, and Cwater (ng/L) is the concentration in water. The biota-sediment accumulation factor (BSAF) was also taken into consideration and calculated using the following equation (SalgueiroGonzalez et al., 2015): BSAF ¼ Cbiota Csediment

ð2Þ

where Cbiota (ng/g dw) is the concentration of phenolic EDCs in the biota sample, and Csediment (ng/g dw) is the concentration in the sediment. To perform a comprehensive risk assessment, the 4-NP equivalent (NPEQ), a modification of the EEQ, was calculated to evaluate mixtures of chemicals as follows: n

NPEQ t ¼ ∑ Ci •EEFi  0:00063 i¼l

ð3Þ

where NPEQt is the total NPEQ, Ci is the concentration of compound i, and EEFi is the 17β-estradiol equivalency factor. The EEFs of phenolic EDCs were determined as previously described (Zhao et al., 2011) and were 0.00063 for 4-NP, 0.00093 for 4-t-OP and 0.00011 for BPA. Aquatic organism risk assessment was performed based on ecological risk assessment (Leeuwen, 1996) by calculating the risk quotient (RQ) using the following formula: RQ ¼ MEC  PNEC

ð4Þ

where MEC is the measured environmental concentration, and PNEC is the predicted no-effect concentration. The MEC was represented as NPEQt and was measured in both water and sediment. The PNECs of 4-NP were deduced as 330 ng/L in water and 39 ng/g dw in sediment

Please cite this article as: Diao, P., et al., Phenolic endocrine-disrupting compounds in the Pearl River Estuary: Occurrence, bioaccumulation and risk assessment, Sci Total Environ (2017), http://dx.doi.org/10.1016/j.scitotenv.2017.01.169

4

P. Diao et al. / Science of the Total Environment xxx (2017) xxx–xxx

according to the European Union Risk Assessment Report (EU, 2002). When RQ N 1, it is considered a high risk; 0.1 b RQ b 1 is moderate risk; and RQ b 0.1 is low risk (Blair et al., 2013) With regard to human health impacts, the estimated dietary intake (EDI, ng/kg bw/day) of the mixture of phenolic EDCs in water and fish for adults was calculated using the following equation, modified from (He et al., 2015): n

EDINPEQ ¼ ∑ðCi •EEFi  0:00063•aÞ  bw

ð5Þ

i¼l

where Ci is the concentration of congener i in water (ng/L) and fish (ng/ g), a is the quantity of water (L/day) and fish (g/day) consumed daily, and bw is the body weight. Daily water intake is 1.4 L/day for adults according to the US Environmental Protection Agency (SalgueiroGonzalez et al., 2015). Dietary data for fish were obtained from a survey conducted in 2006 in coastal cities in Guangdong Province reporting that 57.4 g fish is consumed every day by adults (Tang et al., 2009). The average weight of an adult was considered to be 60 kg. The intake of phenolic EDCs from food was assumed to be a chronic exposure condition. The hazard quotient (HQ) was calculated to determine the potential risks of the mixtures of phenolic EDCs to human health as the follows: HQ ¼ EDINPEQ  RfD

ð6Þ

where RfD is the reference dose, which is synonymous with the tolerable daily intake (TDI). The TDI of 4-NP is 5 μg/kg bw/day according to the Danish Environmental Agency (Bradley, 2010). When HQ N1, it has been indicated that there would be a potential impact on human health (USEPA, 1989). 3. Results and discussion 3.1. Concentrations of the three phenolic EDCs in water The contamination situation of phenolic EDCs was surveyed and the results are displayed in Table 1. The three phenolic EDCs were all detected in water samples collected from all of the sampling sites, and 4-NP was the predominant compound, with concentrations ranging from 233.04 to 3352.86 ng/L. The concentrations of 4-t-OP and BPA were hundreds to thousands of ng/L b4-NP. These differences in concentrations of phenolic EDCs were consistent with previous findings (Selvaraj et al., 2014). 4-NP and 4-t-OP accounts for 80% and 20% of the total alkylphenol ethoxylates, respectively, and those compounds are widely used as detergents, emulsifiers and solubilizer. The water solubility values of 4-NP, 4-t-OP and BPA are 1.57, 12.6 and 120 mg/L, respectively, at 20 °C (Ying and Kookana, 2005). Although 4-NP and 4t-OP have lower water solubility values, they were detected at higher concentrations than BPA. Therefore, the actual emission load of alkylphenol ethoxylates could be much higher than the detected values.

Table 1 Concentrations of the phenolic EDCs in water and the sieved fraction of sediment. Surface water (ng/L)

HM JM MDM YM

Sediment (ng/g dw)

4-NP

4-t-OP

BPA

4-NP

4-t-OP

BPA

3352.86 898.92 700.88 233.04

3.99 1.56 1.20 2.07

12.75 62.78 12.41 29.51

20.80 19.50 7.85 7.55

b0.17 b0.17 b0.17 b0.17

13.16 7.01 7.36 2.31

HM, JM, MDM and YM were the abbreviation of Humen outlet, Jiaomen outlet, Modaomen outlet and Yamen outlet, respectively.

The three phenolic EDCs exhibited variable distributions among the different areas. 4-NP and 4-t-OP were present at relatively high concentrations in the Humen outlet, indicating heavy contamination with alkylphenol ethoxylates. The water flowing into the Humen outlet receives domestic and industrial sewage discharged from a bustling metropolis, Guangzhou, and a manufacturing-known city, Dongguan. Although there are many wastewater treatment plants (WTPs) along the rivers, the Humen outlet is also severely polluted. Studies have revealed that WTPs could not completely remove phenolic EDCs from water (Wang et al., 2005). The BPA concentrations in the Jiaomen outlet were higher than those in the other outlets. BPA is widely used to manufacture plastic products. Most of the rivers run through undeveloped areas, where are littered with plastic bags, and ultimately enter into the Jiaomen outlet. Agriculture activities and the use of personal care products might influence the distribution of phenolic EDCs. The detected concentrations of phenolic EDCs in water from the Pearl River Estuary were polluted seriously, compared with concentrations reported for other coastal areas. In Morro Bay, America, the 4-NP concentrations in water have been reported to be 100–900 ng/L (mean:420 ng/L) (Diehl et al., 2012). In addition, in Yundang Lagoon, Xiamen, China, NP, OP and BPA concentrations of 587.34–659.99 ng/L, 13.58–14.11 ng/L and 14.21–31.42 ng/L, respectively, have been detected (Zhang et al., 2011). Moreover, in the Thermaikos Gulf, Northern Aegean Sea, Greece, NP, OP and BPA concentrations were 22–201 ng/L, 1.7–18.2 ng/L and 10.6–52.3 ng/L, respectively, have been reported (Arditsoglou and Voutsa, 2012).

3.2. Concentrations of the three phenolic EDCs in sediment 4-NP and BPA were detected in all of the sediment samples, whereas, 4-t-OP was not detectable in any sampling site (Table 1). The low 4-t-OP concentrations in the water may be absorbed onto suspended particles, considering the hydrophobicity of phenolic EDCs and that there was not enough time for the suspended particle to precipitate, resulting in low 4-t-OP detection rate in sediment. Notably, NP could rapidly absorb onto suspended particles within 1 h, leaving sufficient time for the suspended particles to precipitate (Hou et al., 2006), likely similar to what occurs for OP. The NP, OP and BPA concentrations in sediment might be influenced by hydrodynamics based on the relationship between suspended particles and the flow velocity of water (Zhang et al., 2014). The re-suspension of phenolic EDCs from sediment would also affect the concentrations of these target compounds in sediment (Yang et al., 2016). The distribution of the phenolic EDCs in sediment was the same as when they were in water: 4-NP N BPA N4-t-OP. And the sieved fraction of sediment were also heavy contaminated by phenolic EDCs in Humen outlet. The concentrations of phenolic EDCs in suspended particles or sediment have been reported to increase with increasing concentrations of phenolic EDCs in the surface water in Lake Donghu, China (Jin et al., 2013). The contamination status of phenolic EDCs was similar between the water and the sieved fraction of sediment, indicating that human activities had significant impacts on the occurrence and distribution of phenolic EDCs. The concentrations of phenolic EDCs in sediment from the Pearl River Estuary were in the ranges of those sediments from the other areas. In Bay of Biscay, Southwestern Europe, NP, OP and BPA concentrations of b0.83–257.20 ng/g dw, b0.01–0.02 ng/g dw and b0.01– 0.04 ng/g dw, respectively, have been reported in sediment (b 120 μm) (Puy-Azurmendi et al., 2013). In addition, in Galicia coast, Spain, NP, 4-t-OP and BPA concentration of 190–1409 ng/g dw, 20.1– 38.9 ng/g dw and b 2.86–11 ng/g dw, respectively, have been detected in sediment (b250 μm) (Salgueiro-Gonzalez et al., 2014). Moreover, in estuarine sediments (b149 μm) from Mumbai, India, concentration of 4-NP, 4-t-OP and BPA have been reported to range from 234.56 to 537.78 ng/g dw, 107.35 to 268.89 ng/g dw and 16.3 to 35.79 ng/g dw, respectively (Tiwari et al., 2016).

Please cite this article as: Diao, P., et al., Phenolic endocrine-disrupting compounds in the Pearl River Estuary: Occurrence, bioaccumulation and risk assessment, Sci Total Environ (2017), http://dx.doi.org/10.1016/j.scitotenv.2017.01.169

P. Diao et al. / Science of the Total Environment xxx (2017) xxx–xxx

5

Table 2 Concentrations of the Phenolic EDCs in biota (ng/g dw). 4-NP

P. c C. f M. c P. p

4-t-OP

BPA

HM

JM

MDM

YM

HM

JM

MDM

YM

HM

JM

MDM

YM

36.49 137.25 86.22 112.76

86.03 168.24 36.04 31.77

17.48 237.12 24.16 57.40

60.12 54.86 58.31 31.41

0.12 b0.11 b0.11 b0.11

0.47 0.14 b0.11 b0.11

b0.11 b0.11 b0.11 b0.11

0.61 0.48 0.17 0.30

1.18 0.49 0.68 0.76

3.19 1.07 1.27 4.51

0.16 0.50 0.19 0.43

4.36 1.34 0.97 1.23

HM, JM, MDM and YM were the abbreviation of Humen outlet, Jiaomen outlet, Modaomen outlet and Yamen outlet, respectively. P.c, C.f, M.c and P.p are the abbreviations of P. chinensis, C.fluminea, M. cephalus and P. pekinensis, respectively.

3.3. Distribution of the three phenolic EDCs in biota The occurrence of 4-NP, 4-t-OP and BPA in shrimp (P. chinensis), mollusk (C. fluminea) and fish (M. cephalus and P. pekinensis) was also investigated in the Pearl River Estuary (Table 2). 4-NP and BPA were discovered in all biota samples from all sampling areas, and 4-t-OP was detected in all species at low concentrations but not at every sampling point. The occurrence and distribution of the phenolic EDCs were similar between water and sediment; 4-NP was present at the highest concentration, followed by BPA and 4-t-OP. High concentrations of the target compounds were observed in the Modaomen outlet and Yamen outlet, where the concentrations of phenolic EDCs in the water and sediment were relatively low. These results suggest that the concentrations of phenolic EDCs in organisms account for a large proportion of these compounds in the aquatic ecosystem. In addition, it could be inferred that the occurrence and distribution of phenolic EDCs in biota might be affected by their surrounding environment. Relatively high concentrations of 4-NP were detected in C. fluminea and high concentrations of 4-t-OP and BPA showed up in P. chinensis. The high concentration factor for toxicity compounds of C. fluminea might contribute to the high concentrations of 4-NP in C. fluminea. C. fluminea and P. chinensis live at the bottom of the water and feed on benthic algae, plankton and organic debris, indicating that phenolic EDCs are likely more bioavailable to such demersal organisms than to pelagic ones. P. chinensis and M. cephalus have similar trophic levels (2.33 (Xue, 2016) and 2.5 (available in http://www.fishbase.org)) and omnivorous eating habits. However, higher 4-t-OP and BPA concentrations were detected in P. chinensis, indicating that phenolic EDCs were metabolized at different rates in these organisms. Various metrics have been used to express the concentrations of EDCs in biota, such as ng/g wet weight, ng/g lipid weight and ng/g dry weight, but comparison of the levels of phenolic EDCs in different areas provides limited information. No comparison of the

concentrations of phenolic EDCs in P. pekinensis was performed in current study, considering the lack of information in literature. The fish examined in this study showed less contamination with phenolic EDCs than that described in a previous Iran study (Mortazavi et al., 2013). In contrast with Dianchi, China, another previous study has reported a higher concentration of 4-NP and relatively lower concentrations of 4t-OP and BPA in fish (Liu et al., 2011). In addition, lower concentration of phenolic EDCs have been reported in C. fluminea from the Minho River Estuary, NW Iberian Peninsula (Salgueiro-Gonzalez et al., 2015). 3.4. Bioconcentration factor (BCF) and biota-sediment accumulation factor (BSAF) in biota Bioconcentration factors (BCFs) were calculated by Eq. (1) and the results are shown in Fig. 2(a). The BCFs of 4-NP ranged from 10.88 to 257.99 in P. chinensis; 40.93 to 338.31 in C. fluminea; 25.71 to 250.23 in M. cephalus; and 33.63 to 123.96 in P. pekinensis. The BCFs of 4-NP were high in each tested species from the Yamen outlet in spatial distribution in correction with its low concentration in the water. The BCFs of 4-NP in the individual species were ordered as follows: C. fluminea N P. chinensis N M. cephalus N P. pekinensis. In addition, the BCFs of BPA ranged from 13.10 to 147.71 in P. chinensis; 17.03 to 45.53 in C. fluminea; 15.67 to 53.44 in M. cephalus; and 34.42 to 71.82 in P. pekinensis. The spatial distribution of the BCFs of BPA was similar to that of the BCFs of 4-NP, with relatively high values observed in Yamen outlet. The BCF of BPA in P. chinensis was higher than those in the other types of biota. A BCF of a chemical exceeding 5000 was generally considered indicative of bioaccumulation (Weisbrod et al., 2010). Notably, the BCFs of 4-NP and BPA were substantially lower than 5000, indicating no accumulation in the Pearl River Estuary and little impact on biota. The biota-sediment accumulation factor (BSAF) data are displayed in Fig. 2(b). The BSAFs of 4-NP ranged from 1.75 to 7.96 in P. chinensis; 6.60 to 30.19 in C. fluminea; 1.85 to 7.72 in M. cephalus; and 1.63 to

Fig. 2. (a) Bioconcentration factor (BCF) of 4-NP and BPA in biota; (b) Biota-sediment accumulation factor (BSAF) of 4-NP and BPA in biota. P.c, C.f, M.c and P.p are the abbreviations of P. chinensis, C.fluminea, M. cephalus and P. pekinensis, respectively.

Please cite this article as: Diao, P., et al., Phenolic endocrine-disrupting compounds in the Pearl River Estuary: Occurrence, bioaccumulation and risk assessment, Sci Total Environ (2017), http://dx.doi.org/10.1016/j.scitotenv.2017.01.169

6

P. Diao et al. / Science of the Total Environment xxx (2017) xxx–xxx

7.31 in P. pekinensis. The BSAFs of 4-NP in C. fluminea were higher than those in other biota, similar to BCFs, demonstrating the high affinity of this organism for phenolic EDCs. Among the BSAFs of 4-NP in C. fluminea, that for the Modaomen outlet was the highest; this finding was potentially influenced by difference life-stages and sizes of C. fluminea at different sampling areas and other factors. The BSAFs of BPA ranged from 0.02 to 1.88 in P. chinensis; 0.04 to 0.58 in C. fluminea; 0.03 to 0.42 in M. cephalus; and 0.06 to 0.64 in P. pekinensis. The BSAFs of BPA in P. chinensis were higher than those in the other biota, similar to the BCFs. The BSAFs of 4-NP were much higher than those of BPA, similar to the BCFs. In present study, a BSAF value of 4 as screening level for neutral organic compounds in assessing dredge materials has been referenced to evaluate accumulation (Wong et al., 2001). For the Pearl River Estuary most of the 4-NP BSAFs were N 4, indicating more 4-NP in biota, while the BPA BSAFs were below 4 and there was no significant bioaccumulation. In addition, the NP BSAFs were relatively high and the BPA BSAFs were lower in current study than those in Sacca di Goro, Italy, where the NP BSAFs ranged 0.11–0.48 and the BPA BSAFs ranged 0.46– 0.92 in C. fluminea (Casatta et al., 2015). Considering aquatic organisms simultaneously affected by water and sediment, the similarity of BCFs and BSAFs in single chemical were observed. And it had been concluded that 4-NP was more bioavailable than BPA in water and sediment to organisms, and that this increased bioavailability might be related to the different physicalchemical characteristics and faster metabolism of BPA in wild fish (Zheng et al., 2015). Moreover, demersal organisms (C. fluminea and P. chinensis) have been shown to have higher BCFs and BSAFs, which might be due to their specific living environments, dietary habits and metabolic characteristics. Because both C. fluminea and P. chinensis are crustaceans, the main way that 4-NP and BPA enter to these organisms might be through the diet, including the consumption of plankton and organic detritus. Studies have revealed that the composition of phytoplankton and zooplankton could affect the accumulation of phenolic EDCs in organisms in the Southern Baltic Sea (Staniszewska et al., 2016; Staniszewska et al., 2015). In addition, organic detritus, including dead organic material from organisms, might be loaded with 4-NP and BPA. 3.5. Risk assessment 3.5.1. Ecological risk assessment Phenolic EDCs were widely detected in the water, sediment and aquatic organisms from the Pearl River Estuary. Previous studies have demonstrated that phenolic EDCs have adverse effects on aquatic organisms. In the self-fertilizing fish Kryptolebias marmoratus, the vitellogenin concentration has been reported to dramatically increased at 24 h after exposure to NP, BPA, and OP (Kim et al., 2016). In addition, continuous exposure of Japanese Medaka (Oryzias latipes) to OP has been shown to result in decreased reproductive success, alteration of the sex ratio and development (Knorr and Braunbeck, 2002). Moreover, NP has been demonstrated to potentially influence the immunity of prawns (Macrobrachium rosenbergii) (Sung and Ye, 2009). Therefore, it may be necessary to estimate the potential risk of EDCs to aquatic organisms. Risk quotients (RQs) were calculated based on the predicted no-effect concentrations in water and sediment using Eqs. (3) and (4). As shown in Fig. 3, all RQs for the water were over 1, indicating adverse effects to aquatic organisms. The specific toxicity effects of lifetime exposure to phenolic EDCs on aquatic organisms in the Pearl River Estuary at different life stages should be determined. Phenolic EDCs in water might enter aquatic organisms mainly through respiration, which is an inevitable physiological process (Arnot and Gobas, 2006). Thus, reducing the concentrations of phenolic EDCs in water using physical, chemical and biological methods is important to protect aquatic organisms. The RQs for the sediment samples from the Humen outlet and Jiaomen outlet were over 1, consistent with high concentrations of

Fig. 3. Risk assessment of phenolic EDCs mixture for aquatic organisms in the Pearl River Estuary.

phenolic EDCs detected in the sediment samples. The precipitation of large amounts of inorganic and organic contaminants including heavy metals, xenobiotic, flame retardants and EDCs, has been observed in sediment in the coastal and marine ecosystems. In addition, sediments contains an abundance of benthic organisms, such as mollusks and polychaetes. This complex environment of sediment complicates risk assessment. To the authors' knowledge, several sediments quality guidelines have been established for the monitoring of sediment quality; however, barely guidelines have been established for EDCs (Fuhrman et al., 2014). Thus, the finding of the potential risk of EDCs in sediment, as indicated by RQs, just a preliminary result and further research is expected. 3.5.2. Human health risk assessment Studies of EDCs involving clinical observations and epidemiological analyses have indicated that those compounds can negatively affect the reproductive system, nervous system and can even cause cancer and obesity (Kabir et al., 2015). In addition, fetus or infants exposed to EDCs could develop dysfunction or diseases in later life (DiamantiKandarakis, 2009). Phenolic EDCs enter the human body mainly through oral consumption of food and water. In present study, the

Fig. 4. Risk assessment of Phenolic EDCs mixture obtained from water and fish (M. cephalus (M. c) and P. pekinensis (P. p)) for human health in the Pearl River Estuary.

Please cite this article as: Diao, P., et al., Phenolic endocrine-disrupting compounds in the Pearl River Estuary: Occurrence, bioaccumulation and risk assessment, Sci Total Environ (2017), http://dx.doi.org/10.1016/j.scitotenv.2017.01.169

P. Diao et al. / Science of the Total Environment xxx (2017) xxx–xxx

consumption of the target compounds reached 0.02–0.24 μg/kg bw/day in water, 0.09–0.33 μg/kg bw/day in M. cephalus and 0.09–0.32 μg/ kg bw/day in P pekinensis. The estimated intake of the target compounds in both water and fish were much lower than the reference dose (5 μg/kg bw/day), showing HQ values b1 (Fig. 4). Additionally, the highest total HQ for water and fish reached 0.89 in Humen outlet, approximately generating potential negative effects on human health. In short, the target compounds in the Pearl River Estuary have not indicated negative effects on human health. Nevertheless, the target compounds might exposure to human through packaging bags, cereals, cooking oils, and eggs (He et al., 2015). Thus, the risk posed by phenolic EDCs to human health following a long periods of exposure should be evaluated comprehensively. 4. Conclusions The present study determined the concentrations of 4-NP, 4-t-OP and BPA in water, sediment and biota (fish, shrimp and mollusk) from the Pearl River Estuary; in addition, BCFs and BSAFs were calculated to detect the possible accumulation of those EDCs; and their potential risks to aquatic organisms and human health were assessed. The concentrations of phenolic EDCs in all of samples were similar to, even higher than, ranges reported in other studies conducted worldwide. The BCFs and BSAFs did not indicate significant accumulation in the organisms studied. Taking co-exposure into account, the phenolic EDCs surveyed in the Pearl River Estuary are probably not harmful to aquatic organisms or human health. However, further investigation of phenolic EDCs in the Pearl River Estuary is needed to improve regulation for managing and monitoring the usage of phenolic EDCs. Acknowledgments This study was supported by the Natural Science Foundation of China-Guangdong Province Joint Key Project (U1133003), and the Natural Science Foundation of China (41176104). Appendix A. Supplementary data Supplementary data to this article can be found online at http://dx. doi.org/10.1016/j.scitotenv.2017.01.169. References Arditsoglou, A., Voutsa, D., 2012. Occurrence and partitioning of endocrine-disrupting compounds in the marine environment of Thermaikos Gulf, Northern Aegean Sea, Greece. Mar. Pollut. Bull. 64:2443–2452. http://dx.doi.org/10.1016/j.marpolbul.2012. 07.048. Arnold, S.F., Mclachlan, J.A., 1996. Synergistic activation of estrogen receptor with combinations of environmental chemicals. Science 272:1489–1492. http://dx.doi.org/10. 1126/science.272.5267.1489. Arnot, J.A., Gobas, F.A., 2006. A review of bioconcentration factor (BCF) and bioaccumulation factor (BAF) assessments for organic chemicals in aquatic organisms. Environ. Rev. 14:257–297. http://dx.doi.org/10.1139/a06-005. Arslan, O.C., Parlak, H., 2007. Embryotoxic effects of nonylphenol and octylphenol in sea urchin Arbacia lixula. Ecotoxicology 16:439–444. http://dx.doi.org/10.1007/s10646007-0417z. Blair, B.D., Crago, J.P., Hedman, C.J., Klaper, R.D., 2013. Pharmaceuticals and personal care products found in the Great Lakes above concentrations of environmental concern ☆. Chemosphere 93:2116–2123. http://dx.doi.org/10.1016/j.chemosphere.2013.07.057. Bradley, E.L., 2010. Nonylphenol in food contact plastics and migration into foods. http:// www.food.gov.uk/science/research/chemical-saftey-research/a03057 (accessed 2016.10.01). Casatta, N., Mascolo, G., Roscioli, C., Vigano, L., 2015. Tracing endocrine disrupting chemicals in a coastal lagoon (Sacca di Goro, Italy): sediment contamination and bioaccumulation in Manila clams. Sci. Total Environ. 511:214–222. http://dx.doi.org/10. 1016/j.scitotenv.2014.12.051. Diamanti-Kandarakis, E., 2009. Endocrine-disrupting chemicals: an endocrine society scientific statement. Endocr. Rev. 30:293–342. http://dx.doi.org/10.1210/er.2009-0002. Diehl, J., Johnson, S.E., Xia, K., West, A., Tomanek, L., 2012. The distribution of 4nonylphenol in marine organisms of North American Pacific Coast estuaries. Chemosphere 87:490–497. http://dx.doi.org/10.1016/j.chemosphere.2011.12.040.

7

Duong, Cuong N., Jin, S., Jaeweon, Kim, Sang, D., et al., 2010. Estrogenic chemicals and estrogenicity in river waters of South Korea and seven Asian countries. Chemosphere 78:286–293. http://dx.doi.org/10.1016/j.chemosphere.2009.10.048. EU, 2002. European Union Risk Assessment Report 4-nonylphenol (Branched) and Nonylphenol. Fuhrman, V.F., Tal, A., Arnon, S., 2014. Why endocrine disrupting chemicals (EDCs) challenge traditional risk assessment and how to respond. J. Hazard. Mater. 286C: 589–611. http://dx.doi.org/10.1016/j.jhazmat.2014.12.012. Gu, Y.Y., Yu, X.J., Peng, J.F., Chen, S.B., Zhong, Y.Y., Yin, D.Q., et al., 2014. Simultaneous solid phase extraction coupled with liquid chromatography tandem mass spectrometry and gas chromatography tandem mass spectrometry for the highly sensitive determination of 15 endocrine disrupting chemicals in seafood. J Chromatogr. B Anal. Technol Biomed Life Sci. 965:164–172. http://dx.doi.org/10.1016/j.jchromb.2014.06.024. He, D., Ye, X., Xiao, Y., Zhao, N., Long, J., Zhang, P., et al., 2015. Dietary exposure to endocrine disrupting chemicals in metropolitan population from China: a risk assessment based on probabilistic approach. Chemosphere 139:2–8. http://dx.doi.org/10.1016/j. chemosphere.2015.05.036. Hou, S.G., Sun, H.W., Gao, Y., 2006. Sorption of small metabolites of nonylphenol polyethoxylates in single and complex systems on aquatic suspended particulate matter. Chemosphere 63:31–38. http://dx.doi.org/10.1016/j.chemosphere.2005.07.069. Isobe, T., Nishiyama, H., Nakashima, A., Takada, H., 2001. Distribution and behavior of nonylphenol, octylphenol, and nonylphenol monoethoxylate in Tokyo metropolitan area: their association with aquatic particles and sedimentary distributions. Environ. Sc. Technol. 35:1041–1049. http://dx.doi.org/10.1021/es001250i. Jin, S., Yang, F., Xu, Y., Dai, H., Liu, W., 2013. Risk assessment of xenoestrogens in a typical domestic sewage-holding lake in China. Chemosphere 93:892–898. http://dx.doi.org/ 10.1016/j.chemosphere.2013.05.037. Kabir, E.R., Rahman, M.S., Rahman, I., 2015. A review on endocrine disruptors and their possible impacts on human health. Environ. Toxicol. Pharmacol. 40:241–258. http://dx.doi.org/10.1016/j.etap.2015.06.009. Kim, B.M., Lee, M.C., Kang, H.M., Rhee, J.S., Lee, J.S., 2016. Genomic organization and transcriptional modulation in response to endocrine disrupting chemicals of three vitellogenin genes in the self-fertilizing fish Kryptolebias marmoratus. J. Environ. Sci. (China) 42:187–195. http://dx.doi.org/10.1016/j.jes.2015.08.006. Knorr, S., Braunbeck, T., 2002. Decline in reproductive success, sex reversal, and developmental alterations in Japanese medaka (Oryzias latipes) after continuous exposure to octylphenol. Ecotoxicol. Environ. Saf. 51:187–196. http://dx.doi.org/10.1006/eesa. 2001.2123. Leeuwen, K.V., 1996. Technical guidance document on risk assessment in support of commission directive 93/67/EEC on risk assessment for new notified substances and commission regulation (EC) No1488/94 on risk assessment for existing substances part II. https://www.researchate.net/publication/286208518_Technical_guidancedocument_on_risk_assessment_in_support_of_commission_regulation_EC_ No148894_on_risk_assessment_for_ex (accessed 2016.10.01). Liu, J., Wang, R., Huang, B., Lin, C., Wang, Y., Pan, X., 2011. Distribution and bioaccumulation of steroidal and phenolic endocrine disrupting chemicals in wild fish species from Dianchi Lake, China. Environ. Pollut. 159:2815–2822. http://dx.doi.org/10. 1016/j.envpol.2011.05.013. Mai, B.X., Fu, J.M., Sheng, G.Y., Kang, Y.H., Lin, Z., Zhang, G., et al., 2002. Chlorinated and polycyclic aromatic hydrocarbons in riverine and estuarine sediments from Pearl River Delta, China. Environ. Pollut. 117:457–474. http://dx.doi.org/10.1016/s02697491(01)00193-2. Mortazavi, S., Bakhtiari, A.R., Sari, A.E., Bahramifar, N., Rahbarizadeh, F., 2013. Occurrence of endocrine disruption chemicals (Bisphenol A, 4-nonylphenol, and Octylphenol) in muscle and liver of, Cyprinus Carpino Common, from Anzali wetland, Iran. Bull. Environ. Contam. Toxicol. 90:578–584. http://dx.doi.org/10.1007/s00128-013-0964-0. Omar, T.F.T., Ahmad, A., Aris, A.Z., Yusoff, F.M., 2016. Endocrine disrupting compounds (EDCs) in environmental matrices: review of analytical strategies for pharmaceuticals, estrogenic hormones, and alkylphenol compounds. TrAC Trends Anal. Chem. 85:241–259. http://dx.doi.org/10.1016/j.trac.2016.08.004. Puy-Azurmendi, E., Ortiz-Zarragoitia, M., Villagrasa, M., Kuster, M., Aragon, P., Atienza, J., et al., 2013. Endocrine disruption in thicklip grey mullet (Chelon labrosus) from the Urdaibai biosphere reserve (Bay of Biscay, southwestern Europe). Sci. Total Environ. 443:233–244. http://dx.doi.org/10.1016/j.scitotenv.2012.10.078. Salgueiro-Gonzalez, N., Turnes-Carou, I., Muniategui-Lorenzo, S., Lopez-Mahia, P., PradaRodriguez, D., 2014. Analysis of endocrine disruptor compounds in marine sediments by in cell clean up-pressurized liquid extraction-liquid chromatography tandem mass spectrometry determination. Anal. Chim. Acta 852:112–120. http://dx.doi.org/10. 1016/j.aca.2014.09.041. Salgueiro-Gonzalez, N., Turnes-Carou, I., Besada, V., Muniategui-Lorenzo, S., Lopez-Mahia, P., Prada-Rodriguez, D., 2015. Occurrence, distribution and bioaccumulation of endocrine disrupting compounds in water, sediment and biota samples from a European river basin. Sci. Total Environ. 529:121–130. http://dx.doi.org/10.1016/j.scitotenv. 2015.05.048. Selvaraj, K.K., Shanmugam, G., Sampath, S., Larsson, D.G., Ramaswamy, B.R., 2014. GC-MS determination of bisphenol A and alkylphenol ethoxylates in river water from India and their ecotoxicological risk assessment. Ecotoxicol. Environ. Saf. 99:13–20. http://dx.doi.org/10.1016/j.ecoenv.2013.09.006. Shoultswilson, W.A., Unrine, J.M., Rickard, J., Black, M.C., 2010. Comparison of metal concentrations in Corbicula fluminea and Elliptio hopetonensis in the Altamaha River system, Georgia, USA. Environ. Toxicol. Chem. 29:2026–2033. http://dx.doi.org/10.1002/ etc.235. Staniszewska, M., Falkowska, L., Grabowski, P., Kwasniak, J., Mudrak-Cegiolka, S., Reindl, A.R., et al., 2014. Bisphenol A, 4-tert-octylphenol, and 4-nonylphenol in the Gulf of Gdansk (southern Baltic). Arch. Environ. Contam. Toxicol. 67:335–347. http://dx. doi.org/10.1007/s00244-014-0023-9.

Please cite this article as: Diao, P., et al., Phenolic endocrine-disrupting compounds in the Pearl River Estuary: Occurrence, bioaccumulation and risk assessment, Sci Total Environ (2017), http://dx.doi.org/10.1016/j.scitotenv.2017.01.169

8

P. Diao et al. / Science of the Total Environment xxx (2017) xxx–xxx

Staniszewska, M., Nehring, I., Zgrundo, A., 2015. The role of phytoplankton composition, biomass and cell volume in accumulation and transfer of endocrine disrupting compounds in the southern Baltic Sea (the Gulf of Gdansk). Environ. Pollut. 207:319–328. http://dx.doi.org/10.1016/j.envpol.2015.09.031. Staniszewska, M., Nehring, I., Mudrak-Cegiolka, S., 2016. Changes of concentrations and possibility of accumulation of bisphenol A and alkylphenols, depending on biomass and composition, in zooplankton of the southern Baltic (Gulf of Gdansk). Environ. Pollut. 213:489–501. http://dx.doi.org/10.1016/j.envpol.2016.03.004. Sung, H.H., Ye, Y.Z., 2009. Effect of nonylphenol on giant freshwater prawn (Macrobrachium rosenbergii) via oral treatment: toxicity and messenger RNA expression of hemocyte genes. Aquat. Toxicol. 91:270–277. http://dx.doi.org/10.1016/j. aquatox.2008.11.017. Tang, H.L., Guo, Y., Meng, X.Z., Shen, R.L., Zeng, E.Y., 2009. Nutritional status in dietary intake and pollutants via food in coastal cities of Guangdong Province, China—assessment of human exposure to persistent halogenated hydrocarbons and heavy metals. J. AgroEnviron. Sci. http://dx.doi.org/10.3321/j.issn:1672-2043.2009.02.020. Thorpe, K.L., Gross-Sorokin, M., Johnson, I., Brighty, G., Tyler, C.R., 2005. An assessment of the model of concentration addition for predicting the estrogenic activity of chemical mixtures in wastewater treatment works effluents. Environ. Health Perspect. 114: 90–97. http://dx.doi.org/10.1289/ehp.8059. Tiwari, M., Sahu, S.K., Pandit, G.G., 2016. Distribution and estrogenic potential of endocrine disrupting chemicals (EDCs) in estuarine sediments from Mumbai, India. Environ. Sci. Pollut. Res. Int. 23:18789–18799. http://dx.doi.org/10.1007/s11356-0167070-x. USEPA, 1989. Risk assessment guidance for superfund volume i human health evaluation manual (part A). https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid= 20533&CFID=78970654&CFTOKEN=18664055 (assessed 2016.10.01). USEPA, 2000. Supplementary Guidance for Conducting Health Risk Assessment of Chemical Mixtures. Waltham, N.J., Teasdale, P.R., Connolly, R.M., 2013. Use of flathead mullet (Mugil cephalus) in coastal biomonitor studies: review and recommendations for future studies. Mar. Pollut. Bull. 69:195–205. http://dx.doi.org/10.1016/j.marpolbul.2013.01.012. Wang, Y., Hu, W., Cao, Z., Fu, X., Zhu, T., 2005. Occurrence of endocrine-disrupting compounds in reclaimed water from Tianjin, China. Anal. Bioanal. Chem. 383:857–863. http://dx.doi.org/10.1007/s00216-005-0082-x. Weisbrod, A.V., Woodburn, K.B., Koelmans, A.A., Parkerton, T.F., Mcelroy, A.E., Borgå, K., 2010. Evaluation of bioaccumulation using in vivo laboratory and field studies. Integr. Environ. Assess. Manag. 5:598–623. http://dx.doi.org/10.1897/ieam_2009-004.1. Wong, C.S., Capel, P.D., Nowell, L.H., 2001. National-scale, field-based evaluation of the Biota–sediment accumulation factor model. Environ. Sci. Technol. 35:1709–1715. http://dx.doi.org/10.1021/es0016452. Xiang-Li, L.I., Luan, T.G., Yan, L., Wong, M.H., Lan, C.Y., 2007. Distribution patterns of octylphenol and nonylphenol in the aquatic system at Mai Po Marshes nature

reserve, a subtropical estuarine wetland in Hong Kong. J. Environ. Sci. 19:657–662. http://dx.doi.org/10.1016/s1001-0742(07)60110-7. Xue, YJCP-mF, 2016. Food habits and trophic levels for 4 species of economical shrimps in the Pearl River estuary shallow waters. J. South. Agric. 2016,47 (5):736–741. http:// dx.doi.org/10.3969/j:issn.2095-1191.2016.05.736. Yang, J., Li, H., Ran, Y., Chan, K., 2014. Distribution and bioconcentration of endocrine disrupting chemicals in surface water and fish bile of the Pearl River Delta, South China. Chemosphere 107:439–446. http://dx.doi.org/10.1016/j.chemosphere.2014. 01.048. Yang, Y., Cao, X., Zhang, M., Wang, J., 2015. Occurrence and distribution of endocrinedisrupting compounds in the Honghu Lake and east Dongting Lake along the central Yangtze River, China. Environ. Sci. Pollut. Res. 22:17644–17652. http://dx.doi.org/10. 1007/s11356-015-4980-y. Yang, L., Cheng, Q., Lin, L., Wang, X., Chen, B., Luan, T., et al., 2016. Partitions and vertical profiles of 9 endocrine disrupting chemicals in an estuarine environment: effect of tide, particle size and salinity. Environ. Pollut. 211:58–66. http://dx.doi.org/10.1016/ j.envpol.2015.12.034. Ye, F., Huang, X., Zhang, D., Tian, L., Zeng, Y., 2012. Distribution of heavy metals in sediments of the Pearl River estuary, Southern China: Implications for sources and historical changes. J. Environ. Sci. 24:579–588. http://dx.doi.org/10.1016/s1001-0742(11)60783-3. Ying, G.G., Kookana, R.S., 2005. Sorption and degradation of estrogen-like-endocrine disrupting chemicals in soil. Environ. Toxicol. Chem. 24:2640–2645. http://dx.doi. org/10.1897/05-074r.1. Zhang, X., Gao, Y., Li, Q., Li, G., Guo, Q., Yan, C., 2011. Estrogenic compounds and estrogenicity in surface water, sediments, and organisms from Yundang lagoon in Xiamen, China. Arch. Environ. Contam. Toxicol. 61:93–100. http://dx.doi.org/10. 1007/s00244-010-9588-0. Zhang, Y.Z., Meng, W., Zhang, Y., 2014. Occurrence and partitioning of phenolic endocrine-disrupting chemicals (EDCs) between surface water and suspended particulate matter in the north Tai Lake basin, eastern China. Bull. Environ. Contam. Toxicol. 92: 148–153. http://dx.doi.org/10.1007/s00128-013-1136-y. Zhao, J.L., Ying, G.G., Wang, L., Yang, J.F., Yang, X.B., Yang, L.H., et al., 2009. Determination of phenolic endocrine disrupting chemicals and acidic pharmaceuticals in surface water of the pearl rivers in South China by gas chromatography-negative chemical ionization-mass spectrometry. Sci. Total Environ. 407:962–974. http://dx.doi.org/10. 1016/j.scitotenv.2008.09.048. Zhao, J.L., Ying, G.G., Chen, F., Liu, Y.S., Wang, L., Yang, B., et al., 2011. Estrogenic activity profiles and risks in surface waters and sediments of the Pearl River system in South China assessed by chemical analysis and in vitro bioassay. J. Environ. Monit. 13:813–821. http://dx.doi.org/10.1039/c0em00473a. Zheng, B., Liu, R., Liu, Y., Jin, F., An, L., 2015. Phenolic endocrine-disrupting chemicals and intersex in wild crucian carp from Hun River, China. Chemosphere 120:743–749. http://dx.doi.org/10.1016/j.chemosphere.2014.10.049.

Please cite this article as: Diao, P., et al., Phenolic endocrine-disrupting compounds in the Pearl River Estuary: Occurrence, bioaccumulation and risk assessment, Sci Total Environ (2017), http://dx.doi.org/10.1016/j.scitotenv.2017.01.169