Yan-Ping Duan

Occurrence, sources, and inventory of hexabromocyclododecanes (HBCDs) in soils from Chongming Island, the Yangtze River Delta (YRD).

Hexabromocyclododecanes (HBCDs) is a concern due to their large usage combining with physico-chemical properties and toxicity to wildlife and human. However, very limited data were reported on HBCDs in soils, especially from rural area. In this study, 22 soil samples were collected from Chongming Island at estuary of the Yangtze River Delta, to investigate the level, diasteroisomer profile, potential sources, and mass inventory of HBCDs. The total concentrations ranged from not detected to 93.8pgg(-1) dry weight (dw) with a mean of 23.3pgg(-1)dw, which was at the low end of the global levels. The wide distribution of HBCDs in soils suggested that the local emissions of HBCD-containing materials and/or the inputs via atmospheric transport from other regions were two possible sources. Variation of HBCDs levels was observed in different types of soils. Woodland, tideland and road soils contained slightly higher HBCDs than those of farmland and grassland. Overall, γ-HBCD was the dominant diasteroisomer in soils, followed by α-HBCD and β-HBCD. Significant but weak correlations were only found between α-HBCD and β-HBCD versus TOC content in soils. Currently, the mass inventory of HBCDs in soils of Chongming Island was 5.3kg. Based on these data, we gave perspective on human intake of HBCDs via soil ingestion by age. Local residents intakes ranged from 15.5 to 97.8fgkg body weight(-1)d(-1), in which children are exposed more than adults.

Polybrominated diphenyl ethers in e-waste: Level and transfer in a typical e-waste recycling site in Shanghai, Eastern China

Very few data for polybrominated diphenyl ethers (PBDEs) were available in the electronic waste (e-waste) as one of the most PBDEs emission source. This study reported concentrations of PBDEs in e-waste including printer, rice cooker, computer monitor, TV, electric iron and water dispenser, as well as dust from e-waste, e-waste dismantling workshop and surface soil from inside and outside of an e-waste recycling plant in Shanghai, Eastern China. The results showed that PBDEs were detected in the majority of e-waste, and the concentrations of ΣPBDEs ranged from not detected to 175 g/kg, with a mean value of 10.8 g/kg. PBDEs were found in TVs made in China after 1990. The mean concentrations of ΣPBDEs in e-waste made in Korea, Japan, Singapore and China were 1.84 g/kg, 20.5 g/kg, 0.91 g/kg, 4.48 g/kg, respectively. The levels of ΣPBDEs in e-waste made in Japan far exceed the threshold limit of RoHS (1.00 g/kg). BDE-209 dominated in e-waste, accounting for over 93%. The compositional patterns of PBDEs congeners resembled the profile of Saytex 102E, indicating the source of deca-BDE. Among the samples of dust and surface soil from a typical e-waste recycling site, the highest concentrations of Σ18PBDEs and BDE-209 were found in dust in e-waste, ranging from 1960 to 340,710 ng/g and from 910 to 320,400 ng/g, which were 1-2 orders of magnitude higher than other samples. It suggested that PBDEs released from e-waste via dust, and then transferred to surrounding environment.

Occurrence and human health risk of wastewater–derived pharmaceuticals in a drinking water source for Shanghai, East China

Pharmaceuticals are heavily used to improve human and animal health, resulting in the frequent contamination of aquatic environments with pharmaceutical residues, which has raised considerable concern in recent years. When inadequately removed from drinking water in water treatment plants, pharmaceuticals can have potential toxic effects on human health. This study investigated the spatial distributions and seasonal variations of five pharmaceuticals, including ibuprofen (IBP), ketoprofen (KEP), naproxen (NPX), diclofenac (DFC), and clofibric acid (CA), in the Huangpu River system (a drinking water source for Shanghai) over a period of almost two years as well as the associated risk to human health for different age groups. All of the targets were ubiquitous in the river water, with levels decreasing in the following order: KEP (mean: 28.6 ng/L)≈IBP (23.3 ng/L)>DFC (13.6 ng/L)≈NPX (12.3 ng/L)>CA (1.6ng/L). The concentrations of all of the investigated compounds were at the low or medium end of the global range. The upstream tributaries contained lower IBP but higher NPX than did the mainstream and downstream tributaries. However, no significant variations were found in the levels of KEP, DFC, or CA at the different sampling sites. Except for CA in the mainstream, significantly higher pharmaceutical levels were observed in the dry season than in the wet season. Overall, a very low risk of the selected pharmaceuticals for human health via drinking water was observed, but future studies are needed to examine the fate and chronic effects of all pharmaceuticals in aquatic environments. To our knowledge, this is the first report to investigate the human health risk of pharmaceuticals in raw drinking water in China.

Multi-phase partitioning, ecological risk and fate of acidic pharmaceuticals in a wastewater receiving river: The role of colloids

The occurrence and multi-phase distribution of five pharmaceutical compounds were investigated in an urban wastewater treatment plant (WWTP) receiving river by analysis of pharmaceuticals in sediment, particulate matter, conventional dissolved phase (>0.7 μm), colloidal phase (5 kDa to 0.7 μm), and truly dissolved phase (<5 kDa) water. Diclofenac was found in all samples, followed by clofibric acid, ibuprofen, ketoprofen, and naproxen with the decreasing detection frequency. All targets in WWTP outfall site were higher than those in the upstream and downstream, indicating that the WWTP is an important input source of pharmaceuticals in the river. The colloidal phase contributed 10-14% of ketoprofen, 8-26% of naproxen, 17-36% of clofibric acid, 22-33% of diclofenac, and 9-28% of ibuprofen in the aquatic system, suggesting the colloids will play an important role as carrier to contaminants in the aquatic environment. Based on truly dissolved concentrations of pharmaceuticals in water, only the risk quotient (RQ) value for diclofenac towards fish was higher than 1, indicating it poses a potential risk to aquatic organisms. Finally, a Level III fugacity model was used to further assess the environmental fate of the selected pharmaceuticals (exemplified for clofibric acid and diclofenac). Both clofibric acid and diclofenac tend to accumulate in water compartment with the percentage of 99.7% and 60.6%, respectively. Advection in river is a significant loss process for clofibric acid (56.4%) and diclofenac (54.4%).

Removal of carbamazepine and clofibric acid from water using double templates-molecularly imprinted polymers.

A novel double templates–molecularly imprinted polymer (MIP) was prepared by precipitation polymerization using carbamazepine (CBZ) and clofibric acid (CA) as the double templates molecular and 2-vinylpyridine as functional monomer. The equilibrium data of MIP was well described by the Freundlich isotherm model. Two kinetic models were adopted to describe the experimental data, and the pseudo second-order model well-described adsorption of CBZ and CA on the MIP. Adsorption experimental results showed that the MIP had good selectivity and adsorption capacity for CBZ and CA in the presence of competitive compounds compared with non-imprinted polymer, commercial powdered activated carbon, and C18 adsorbents. The feasibility of removing CBZ and CA from water by the MIP was demonstrated using tap water, lake water, and river water.

Hexabromocyclododecane in consumer fish from South China: Implications for human exposure via dietary intake

Levels of hexabromocyclododecane (HBCD) were determined in 12 consumer fish species from South China. The concentrations of the sum of HBCD diastereoisomers (ΣHBCD) ranged from nondetectable to 194 pg/g wet weight, with a detectable frequency of 70%. This was at the low end of the concentration range globally observed. Carnivorous fish species contained higher HBCD concentrations than herbivorous and detritivorous ones, suggesting the potential for biomagnification of HBCDs via the trophic chain. Moreover, ΣHBCD concentrations were higher in both freshwater and seawater farmed fish than in wild marine fish, indicating that human activities were probably an important input source of HBCD in aquaculture. Among the three diastereoisomers, α-HBCD dominated in most samples, with a mean relative abundance of 70%. In agreement with previous studies, a difference in the diastereomer patterns was observed from commercial products and several environmental media to biota samples. For farm-raised snubnose pompano, the concentrations of ΣHBCD were moderately linearly correlated with lipid contents but were not significantly correlated with fish body lengths and weights. In the worst-case exposure, the mean estimated daily intake of ΣHBCD via fish consumption for residents of South China ranged from 13 to 16 pg/kg body weight/d for various age groups, much lower than its lowest observed adverse effect level derived from a two-generation reproductive toxicity study on rats.

Characterizing distribution, sources, and potential health risk of polybrominated diphenyl ethers (PBDEs) in office environment

This study evaluated the levels and spatial distribution of PBDEs in 9 typical offices in Shanghai, China through the sample analysis of air and settled dust (floor dust, desktop dust and dust in computer case). PBDEs in air ranged from 93 to 322 pg/m(3), while the PBDEs levels in dust varied from 247 to 3.3 × 10(4) ng/g. Spatial variability of PBDEs in office dust was evident and likely influenced by air exchange and the use of electronic devices. A significant positive linear correlation was observed between the power usage rate and PBDE levels in both office air (R(2) = 0.81) and settled dust (R(2) = 0.94). The PBDEs exposure via inhalation and dust ingestion were both analyzed to estimate the life-time cancer risk, which is 1.34 × 10(-22) to 7.16 × 10(-22), significantly lower than the threshold level (10(-6)). Non-cancer risk indicated by the hazard index (<1) is also low in current exposure conditions.

Polybrominated diphenyl ethers (PBDEs) in PM2.5, PM10, TSP and gas phase in office environment in Shanghai, China: occurrence and human exposure.

To evaluate risk via inhalation exposure of polybrominated diphenyl ethers (PBDEs) in office environment, thirty-six pairs air samples including PM2.5 (particles with aerodynamic diameter less than 2.5 μm), PM10 (particles with aerodynamic diameter less than 10 μm), total suspended particles (TSP) with matching gas phase were collected in office environment in Shanghai, China. The average concentrations of PM2.5, PM10 and TSP were 20.4, 27.2 and 50.3 μg/m3, respectively. Σ15PBDEs mean concentrations in PM2.5, PM10, TSP and gas phase were 51.8, 110.7, 148 and 59.6 pg/m3, respectively. Much more PBDEs distributed in fine fractions than coarse ones. PBDEs congener profiles found in PM2.5, PM10 and TSP (dominated by BDE-209) were different from that in gas phase (dominated by the tri- to penta-BDEs). Approximately 3.20 pg/kg/d PM2.5 bound PBDEs can be inhaled into the lung; 3.62 pg/kg/d PM10-PM2.5(particles with aerodynamic diameter of 2.5-10 μm) bound PBDEs tended to be deposited in the upper part of respiratory system, and the intake of PBDEs via gas-phase was 2.74 pg/kg/d. The exposure of PBDEs was far below the minimal risk levels (MRLs), indicating lower risk from PBDEs via inhalation in the studied office in Shanghai.

Transfer of PBDEs from TV Housing Plastics to Aqueous Media

To investigate the transfer of PBDEs from products into the aqueous media, experiments and analysis were carried out by contacting TV housing plastics with distilled and dissolved humic solution (DHS) in brown bottles in the artificial climate box. The leaching test conditions were a liquid-to solid ratio of 100:1, and a contact period of 1, 2, 4, 7, 10, 13, 16 and 20 day (s), with pH of 3, 5, 7, 9 and temperature of 15, 20, 25 °C. The leaching concentrations of PBDE increased with DHS rather than distilled water, and were found to be remarkably enhanced when TOC of DHS increased. Despite no detection of most of the lower BDEs in distilled water, most homologues could be detected in DHS, and their solubility increased according to the contact time; those of highly BDEs increased to 10 times their maximum solubility in distilled water. Temperature had limited influence for the limited range investigated. Lower pH generally resulted in higher transfer of PBDEs to aqueous phase.

Occurrence and Removal of Selected Pharmaceuticals in a Wastewater Treatment Plant

The occurrence and removal of selected pharmaceuticals have been investigated in a municipal wastewater treatment plant (WWTP) of Shanghai in this study. Ibuprofen (IBP), naproxen (NPX), ketoprofen (KEP), diclofenac (DFC), and clofibric acid (CA) were selected as target compounds. Results showed that all of these pharmaceuticals were detected in the influent samples with IBP showing the highest concentrations (1380 ng/L). The partition coefficient (logKd) between the particulate and the dissolved phase calculated for KEP, NPX, CA, DFC, and IBP ranged from 1.2 to 2.2 in the raw sewage and the treated effluent suggesting the weak tendency of the target pharmaceuticals being absorbed onto particles. Different compounds were removed to different extent in the WWTP treatment processes. The highest removal efficiency was observed for IBP and the lowest for CA, 87.2% and 36.7%, respectively. The results indicated that municipal WWTP cannot remove these pharmaceuticals efficiently.