Characterization and distribution of polybrominated diphenyl ethers in shellfish in Shenzhen coastal waters and assessment of human health risks.

This study aims to investigate the profiles of polybrominated diphenyl ethers (PBDEs) in shellfish obtained from Shenzhen coastal waters and assess the potential health risks. We analyzed 74 shellfish samples from eight different species for PBDEs (BDE-28, -47, -99, -100, -153, -154, -183, -209). The concentrations of total PBDEs in different shellfish species ranged from 2.02 to 360.17 pg g-1 wet weight, with the highest levels found in Pectinidae, Babylonia areolate, Ostreidae, Perna viridis, Haliotis diversicolor, Corbiculidae, Pinctada margaritifera, and Veneridae in descending order. Among the PBDE congeners analyzed, BDE-47 was the most abundant, followed by BDE-154 and BDE-153. Furthermore, the estimated daily intake of PBDEs through shellfish consumption for Shenzhen residents were between 0.11 and 0.19 ng kg-1(bw) day-1. To our knowledge, this is the first study to systematically investigate the profiles of PBDEs in eight different shellfish species from Shenzhen's coastal waters and evaluate the potential human health risks associated with shellfish consumption.

Body burden and influencing factors of polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) in male workers from a municipal waste incineration plant in China.

Emissions of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) from municipal solid waste incinerators (MSWIs) have aroused public concern around the world. However, biomonitoring evidence regarding the influence of MSWIs on the human body burden of PCDD/Fs is scarce. The aim of this study is to investigate the human body burden levels of PCDD/Fs in MSWI workers and to further explore the potential influencing factors, including duration of occupation and dietary habits, on the PCDD/F levels. A total of 98 paired serum samples from MSWI workers and non-MSWI workers were collected. Seventeen 2,3,7,8-chlorine substituted PCDD/Fs in the serums were analyzed using an isotope dilution high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS). The results showed that the mean levels of toxic equivalent (TEQ)-PCDD/Fs for the MSWI workers and the control group were 18.28 pg TEQ g-1 lipid and 5.81 pg TEQ g-1 lipid, respectively. Significantly higher concentrations of PCDD/Fs existed in the incinerator workers compared with the control subjects after adjustment of the confounding factors. OCDD was the most abundant congener in both the MSWI workers and the control subjects, accounting for 82.2% and 89.4% of the ∑17PCDD/Fs, respectively. The serum levels of PCDFs in the MSWI workers increased with the duration of occupation (ß = 0.498, P = 0.031), and a higher total concentration of PCDD/Fs were present in senior workers classified as production supervisors than routine operation staff (ß = 8.809, P = 0.008). No significant relationship was found between the PCDD/F concentrations and dietary habits. This study was the first to explore the associations between the body burden of PCDD/Fs and occupational exposure as well as dietary intake of MSWI workers in China. The findings provide scientific information for health risk assessments of human exposure to PCDD/Fs.

[Establishment the method for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans determination in human serum].

OBJECTIVE: To establish the determination method for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans(PCDD/Fs) in human serum, and further to provide an operable and scientific determination protocal and basis for conducting human health risk assessment for PCDD/Fs. METHODS: The serum samples were pretreated by C18 column solid phase extraction, acid silica gel column and activated carbon column purification, separated by DB-5 MS capillary column(60 m×0. 25 mm×0. 25 µm), and PCDD/Fs was quantitative analyzed by high resolution mass spectrometry. RESULTS: The method detection limit was in the range of 0. 35-3. 26 pg/g lipid. This method was further validated using international serum standard reference material sample SRM 1958. According to the reference mass fraction values given for SRM 1958, the concentrations of 17 PCDD/Fs monomers were all in the range of reference mass fraction values, and the relative standard deviation was 2%-19%(n=3). This method was further applied to determination PCDD/Fs in actual serum of human body. The result showed that the recovery rate of isotope labeled PCDD/Fs internal standards were in the range of 61%-135%. CONCLUSION: The performance of the method is highly sensitive, stable and highly accurate, which meets the requirements for the determination of PCDD/Fs in human serum and the method can be applied to human health risk assessment for PCDD/Fs in the future.

Hexabromocyclododecanes in breast milk from residents in Shenzhen, China: Implications for infant exposure.

Hexabromocyclododecanes (HBCDs) are widely used as flame retardants for various products and have become ubiquitous pollutants in environmental media. However, little is known about HBCD exposure for humans, especially in China. This study aimed to investigate the levels and profiles of hexabromocyclododecanes (HBCDs) in human breast milk and to estimate the daily HBCD intake for infants in Shenzhen, China. Levels of the HBCD diastereoisomers α-, ß-, and γ-HBCD in 180 breast milk samples collected from primiparas in Shenzhen were measured. The concentrations of α-, ß-, and γ-HBCD (ΣHBCDs) ranged within 0.103-15.1ng/g lipid and had a median of 1.82ng/g lipid. ΣHBCDs levels in milk in the present study are comparable to those in milk from other countries and regions but are markedly higher than those for most populations in other regions of China. Among the diastereoisomers, α-HBCD was predominant, accounting for 97.6% of the concentration of ΣHBCDs. The estimated daily intake of ΣHBCDs via breast milk for infants in Shenzhen ranged from 0.481 to 100ng/kgbw/day with a median of 8.40ng/kgbw/day, however, which was unlikely to raises a health concern based on the margin of exposure (MOE) approach. The duration of residence was found to have a significant positive correlation with the HBCD levels in the human breast milk (p<0.05). To our knowledge, this is the first report on HBCD levels in breast milk from Shenzhen residents.

Spatiotemporal variability of polybrominated diphenyl ether concentration in atmospheric fine particles in Shenzhen, China.

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants for various products and have become ubiquitous pollutants in environmental media. However, little is known about PBDE levels in Shenzhen, a manufacturing center of electronic products. This study aimed to investigate spatiotemporal variability of PBDE concentration in atmospheric fine particles (PM2.5) and to estimate the daily inhalation exposure doses for local residents in Shenzhen, China. A total of 36 samples were collected and 8 PBDE compounds (BDE-28, 47, 99, 100, 153, 154, 183 and 209) were analyzed by isotope dilution high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS). Mean concentrations of Σ8PBDEs and BDE-209 in PM2.5 in Shenzhen were 33.47 pg/m3 and 24.75 pg/m3, respectively, which were lower than those for other reported cities from China. The mean concentration of Σ8PBDEs was higher in the winter + spring than that in summer + autumn, and both concentrations of BDE-28 and BDE-47 in PM2.5 were significantly higher in winter + spring than those in summer + autumn. Among the 8 congeners, BDE-209 was predominant, accounting for 73.9% of the Σ8PBDEs concentrations. Traffic area, industrial area, residential area and discharge of electronic industries had significant positive influences on PBDE concentrations in PM2.5. Both vegetation area and water area were significantly negatively correlated with PBDE levels in PM2.5. Significantly negative correlation was also found between PBDE concentrations in PM2.5 and the relative humidity. The ranking of estimated inhalation exposure doses of PBDEs via PM2.5 inhalation were toddlers (1.74 pg/kg b.w./day) > children (1.33 pg/kg b.w./day) > adults (1.26 pg/kg b.w./day) > teenagers (0.64 pg/kg b.w./day), and toddlers had a highest risk to expose to PBDEs by PM2.5. To our knowledge, the present study is the first to reveal the spatiotemporal variability of PBDEs in PM2.5 of Shenzhen, China.

Toxaphene levels in retail food from the Pearl River Delta area of South China and an assessment of dietary intake.

Limited literature exists on toxaphene contamination in food worldwide, particularly in mainland China. In this study, three toxaphene congeners, Parlar 26 (B8-1413), Parlar 50 (B9-1679) and Parlar 62 (B9-1025), were analyzed in five different food categories from the Pearl River Delta Area in China using isotope dilution high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS), and toxaphene levels in food were reported and toxaphene dietary intake by local residents estimated. The results showed that fish contained the highest toxaphene level with a median of 12.87 pg/g wet weight (ww), followed by poultry meat, egg products, livestock meat and vegetable, which had median levels of 5.8, 2.2, 1.89 and 0.67 pg/g ww, respectively. Parlar 50 and Parlar 26 were the predominant characteristic congeners in fish, and Parlar 26 was the predominant congener not only in poultry products and eggs, but also in livestock and vegetable. The estimated average daily intake found by local residents was 35.57 pg/kg body weight/day. Overall toxaphene levels and estimated dietary intake in the Pearl River Delta Area of South China are far lower than the European Maximum Residue Limits (EU MRLs), the German MRL for fish, and other international literature data. Therefore, the risk of adverse health effects from dietary intakes of toxaphene for the local residents is not considerable at the current time, but follow-ups are warranted to study dynamic changes of toxaphene in food in this area.

[Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans in airborne fine particulate matter and inhalation risk assessment for local residents of Shenzhen].

OBJECTIVE: To explore the levels and congener profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in airborne fine particulate matter (PM25) in Shenzhen and roughly discuss its correlations between PM25 concentration and meteorological factors. METHODS: The high volume air samplers were used to collect the samples in six sampling sites in respective winter and spring phase and summer and autumn phase. Referring to the US EPA TO-9A for dioxins detection methods, the concentrations of the 17 polychlorinated dibenzo-p-dioxins and dibenzofurans in airborne fine particulate matter were determined by HRGC/HRMS. RESULTS: The total concentrations of PCDD/Fs ranged from 0.32 to 9.35 pg/m3, with average of 2.45 pg/ m3. The TEQ concentrations ranged from 0.006 to 0.388 pg I-TEQ/m3, with average of 0.095 pg I-TEQ/m3. The four abundant congeners were found to be OCDD (36.49%), 1, 2, 3, 4, 6, 7, 8-HpCDF (14.89%), OCDF (13.34%) and 1, 2, 3, 4, 6, 7, 8-HpCDD (10.92%). 2, 3, 4, 7, 8-PeCDF was the dominant contributor to toxicity equivalent (TEQ), accounting for 34.65%. Positive relationship was found between the levels of fine particle-bound PCDD/Fs and PM2.5 concentration (r(s) = 0.794, P = 0.006), whereas no correlation was observed for temperature, humidity and atmospheric pressure. Inhalation exposure to PCDD/Fs were 0. 023 pg I-TEQ/(kg · d) for adult and 0.035 pg I-TEQ/(kg · d) for children during winter and spring and relatively higher than those during summer and autumn (0.014 pg I-TEQ/(kg · d). for adult and 0.021 pg I-TEQ/(kg · d) for children respectively). CONCLUSION: The levels of PCDD/Fs in airborne fine particle-bound samples collected in Shenzhen were lower than those in Hangzhou and Beijing.

[Determination of hexabromocyclododecanes diastereoisomers in human breast milk by HPLC-MS/MS].

OBJECTIVE: A method for the determination of ac, 3 and γ-hexabromocyclododecanes (HBCDs) in human breast milk was developed by HPLC-MS/MS. METHODS: 3 -5 g human breast milk powder was spiked with '3C-HBCDs and then been extracted using Soxhlet extraction. The extract was dried and dissolved in 6ml of cyclohexane/ethyl acetate (1:1 ), then purified by gel permeation chromatography (GPC). The effluent was concentrated with rotary evaporation and then re-dissolved in hexane. 2ml of sulphuric acid was added to remove the fat for further clean-up. After drying under nitrogen, the supernatant was dissolved in 100 µl of methanol and finally determined by HPLC-MS/MS. RESULTS: The linear range for the three diastereoisomers of HBCDs was in 1 - 50 µg/L, with correlation coefficients ranging from 0. 9997 to 0.998. The detection limits of the three diastereoisomers ranged from 0. 12 to 0. 22 µg/L. The recoveries for three spiking levels ranged from 82. 80% to 110. 60% . The intra-day and inter-day relative standard deviations (RSD) were all less than 9. 4%. CONCLUSION: The developed method was simple, convenient and sensitive. It was suitable for the determination of or, P3 and y-HBCDs in breast milk and other matrix in the future.

[Evaluation of nutrient level and its factors of breast milk in Shenzhen City].

OBJECTIVE: To investigate the nutrient level for Fat and Nutrient Elements (Ca, K, Na, Mg, Fe and Zn) in Breast Milk and its factors in Shenzhen, China. Eventually we can evaluate the nutrient study for local infants and provide a more reasonable basis for infants breast-feeding. METHODS: 235 breast milk (1 - 2 months postpartum) samples were collected in three districts of Shenzhen during the year of 2011 to 2013. Fat content was analyzed by Soxlet Extraction System, and elements contents were determined by ICP - OES. RESULTS: The average content of fat was 3.73 g/100 ml. The average concentrations of Ca, K, Na, Mg, Fe and Zn in breast milk from Shenzhen were 296.55, 531.45, 188.96, 28.22, 0.27 and 2.36 mg/L, respectively. CONCLUSION: The average contents of fat and elements of Ca, K in the breast milk from Shenzhen were within the reference ranges provided by the World Health Organization (WHO). However, the levels for element of Fe and Mg were much lower than the reference ranges, and the levels for Na and Zn were relative higher when compared with the standard. No significant difference in six nutrients among three districts in Shenzhen were found, however, the significant difference in each element was found compared with that from other cities or countries. Furthermore Zinc daily intake for local infant reached the level of recommended nutrient intake (RNI), however other nutrients were under the adequate intake level (AI) which was set by Chinese nutrition society (CNS).

[Levels for toxaphene in three categories of animal originated food in Pearl River Delta area].

OBJECTIVE: To explore the present contamination status and profile of toxaphene in fish, chicken and meat samples in Pearl River Delta area. METHODS: Totally 60 independent samples including fish, chicken, meat were collected from Huizhou,Guangzhou,Dongguan,Jiangmen of Pearl River Delta area in Guangdong by purposive sampling from Oct 2010 to Jun 2011. Toxaphene monomer Parlar26, Parlar50 and Parlar62 levels in three various categories of foods were quantitatively and qualitatively analyzed referencing international authoritative standard methods by utilizing isotope dilution high-resolution gas chromatography/high-resolution double-focusing magnetic mass spectrometry (HRGC-HRMS). The levels of pollution and characteristics were compared. RESULTS: The concentration of toxaphene median(M) in fish, chicken and meat were 12.87, 5.8 and 1.89 ng/kg (gross weight) , respectively and the difference was significant(H = 14.29, P = 0.001). The toxaphene level in seafish (M = 32.07 ng/kg) was significantly higher than that in freshwater fish (M = 10.63 ng/kg, Z = -2.52, P = 0.012). The profile analysis showed that Parlar50 and Parlar26 were the predominant characteristic monomers in fish, which contributed about 44% (9.91/22.60, ng/kg) and 39% (8.89/22.60, ng/kg) to total concentration, and Parlar62 and Parlar26 were the two predominant congeners in poultry products, the two congeners accounted for 42% (5.03/11.90, ng/kg) and 38% (4.58/11.90, ng/kg). Furthermore Parlar26 and Parlar62 made up about 57% (3.45/6.08, ng/kg) and 26% (1.58/6.08, ng/kg) of total concentration in livestock meat respectively. CONCLUSION: Toxaphene levels in all tested food samples are far lower than the limited standard stipulated by the European Food Safety Authority (EFSA) in 2002, which was 0.1 mg/kg. The congener characteristic difference in the three categories food indicated that the different enrichment ability in Toxaphene in different animal species.