Exposure to polybrominated diphenyl ethers and tetrabromobisphenol A among computer technicians

This study investigates exposure to polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA), which are used as flame retardants in electronic equipment, in a group of technicians with intense computer work. Thirteen PBDE congeners and TBBPA were quantified in serum from 19 computer technicians. Previously investigated groups of hospital cleaners with no computer experience, and clerks working full-time at computer screens were used for comparison. The computer technicians had serum concentrations of BDE-153, BDE-183 and BDE-209 that were five times higher than those reported among hospital cleaners and computer clerks. The median levels observed among the computer technicians were 4.1, 1.3, and 1.6 pmol/g lipid weight, respectively. In contrast, for BDE-47 there was no difference between the computer technicians and the others. BDE-100, BDE-203, and three structurally unidentified octa-BDEs and three nona-BDEs, were present in almost all samples from the computer technicians. Further, TBBPA was detected in 8 out of 10 samples. The levels of BDE-153, BDE-183, and one of the octa-BDEs were positively correlated with duration of computer work among technicians. On a group level an exposure gradient was observed, from the least exposed cleaners to the clerks, and to the highest exposed group of computer technicians. A dose (duration of computer work)-response relationship among computer technicians was demonstrated for some higher brominated PBDE congeners. Thus, it is evident that PBDEs used in computers and electronics, including the fully brominated BDE-209, contaminate the work environment and accumulate in the workers tissues.     

Environmental factors in debromination activity of polybrominated diphenyl ethers by hepatic microsomes of freshwater fish

Although the debromination of polybrominated diphenyl ethers (PBDEs) in fish species has been studied, environmental factors, such as chemical contamination and habitat temperature, have not been well understood. This study compared debromination of BDE209 by hepatic microsomes of wild and cultured fish. PBDE concentrations in muscle tissue were lower in cultured fish than in wild fish. Debromination activity was high in wild common carp, followed by cultured common carp, moderate in cultured ayu sweetfish, and low in two cultured fish (rainbow trout and cherry salmon) and wild Japanese sea bass. Although common carps have been known as the species which have higher debromination ability, there were differences between wild and cultured common carps. First, wild common carp debrominated much more BDE209 than cultured common carp. Second was debromination of BDE209 lasted 96 h in wild carp but only 24 h in cultured carp. Wild carp were collected from warm wastewater effluent with consistently high concentrations of micropollutants. Cultured carp were collected from colder clean waters. Therefore, environmental factors in debromination include contamination or ambient temperature. To investigate the effects of habitat environment on debromination of PBDEs, we collected wild carp in summer and winter at two different locations with similar PBDE contamination levels. Carp collected from the natural river in winter had the highest BDE99 debromination activity. Although the results indicated seasonal difference of debromination of BDE209, we could not confirm whether habitat temperature or physiological cycle of carp affected to debromination ability. Thus, further investigation such as in vivo experiment is required.

     

Correction to: Environmental factors in debromination activity of polybrominated diphenyl ethers by hepatic microsomes of freshwater fish

Environmental Science and Pollution Research - The corrected Electronic Supplementary Material is presented in this paper.     

Risk assessment for human consumption of perfluorinated compound-contaminated freshwater and marine fish from Hong Kong and Xiamen

Perfluorinated compounds (PFCs) are man-made fluoro-surfactants that are identified as global pollutants and can pose health risks to humans and wildlife. Two aspects of risk assessment were conducted in this study, including exposure and response. Exposure was estimated by using the concentrations of PFCs in fish and applying standard exposure factors. Among different PFCs, PFOS, PFOA, PFNA, PFDA, PFUdA and PFTrDA were detected. Total concentrations of PFC in fish ranged from 0.27-8.4 ng g⁻¹ to 0.37-8.7 ng g⁻¹ respectively in Hong Kong and Xiamen. The calculated hazard ratio (HR) of PFOS for all fish was less than 1.0. However, the HR for mandarin fish in Hong Kong and bighead carp, grass carp and tilapia in Xiamen, had HR values of approximately 0.5, indicating that frequent consumption of these 4 more contaminated fish species might pose an unacceptable risk to human health. Our data support the notion that the released/disposed chemical pollutants into water systems make fish a source of environmental toxicants to humans. The risks and potential effects of PFCs to health of coastal population in the Pearl River Delta are of concern.     

Occurrence, bioaccumulation and potential sources of polybrominated diphenyl ethers in typical freshwater cultured fish ponds of South China

To determine the potential input sources of polybrominated diphenyl ethers (PBDEs) to fish farming environments in South China, samples of seven various environmental matrices were collected from October 2006-September 2007. Tri- to deca-BDEs were detected in all samples analyzed, with mean concentrations (±standard deviations) at 5.7 ± 3.6 ng/L in pond water, 15 ± 11 ng/g dry wt. in pond sediment, 12 ± 3.8 ng/g dry wt. in bank soil, 21 ± 20 ng/g lipid wt. in fish, and 93 ± 62 ng/g lipid wt. in fish feeds. In addition, BDE-209 was the major constituent in all samples except fish and BDE-47 was predominant in fish samples. Relatively high abundances of BDE-49 were detected in all the samples compared to those in the penta-BDE technical products. Several bioaccumulation factors were evaluated. Finally, statistical analyses suggested that fish feed, as well as pond water at a lesser degree, may have been the major source of PBDEs in freshwater farmed fish.     

Organochlorine pesticides, polychlorinated biphenyls and polybrominated diphenyl ethers in Singapore's coastal marine sediments

Persistent organic pollutants (POPs) are ubiquitous pollutants in the marine environment, particular in coastal areas affected by industry and shipping traffic. POPs are known for their recalcitrance and toxicity in the environment, and there is increasing concern over their global distribution and impact upon wildlife. Marine surface sediment samples taken within 6 km of the coastline of Singapore were analyzed to determine prevailing concentrations of organochlorine pesticides (OCPs), polychlorinated biphenyl (PCBs) and polybrominated diphenyl ethers (PBDEs). Total PCB concentrations varied widely from 1.4 to 329.6 ng/g (average 73.9 ng/g), where high concentrations were detected at sample locations closest to industrial areas with intensive shipping traffic. Total DDT concentrations ranged from 2.2 to 11.9 ng/g (average 6.7 ng/g) and were lower than the concentration range of 3.3-46.2 ng/g measured for total HCH (average 18.1 ng/g). Ratios of DDT/(DDE+DDD) in sediments do not indicate recent inputs of DDT into Singapore's marine environment, but high concentrations of alpha-HCH and gamma-HCH show evidence for the usage of HCHs in Southeast Asia. Peak concentrations of cis- and trans-Chlordane were 10 ng/g. Among the PBDE congeners BDE 47, 99, and 100 only BDE 47 could be detected at a range of 3.4-13.8 ng/g (average 6.2 ng/g). The levels of OCPs, PCBs and PBDEs were compared to available data for other countries in Asia, and indicated relatively moderate levels of contamination. Peak concentrations of PCBs, HCH isomers, Chlordane, Heptachlor, Heptachlor epoxide and Dieldrin have the potential to induce ecotoxicological impacts based on levels specified in the sediment quality standards of the USEPA and Canadian Council of Ministers of the Environment.     

Brominated-chlorinated diphenyl ethers formed by thermolysis of polybrominated diphenyl ethers at low temperatures

Polybrominated diphenyl ethers (PBDEs) are a group of brominated flame retardants (BFRs) used mainly as additives in different kinds of plastic material. Various PBDEs are found in all environmental compartments as well as in tissue and blood serum of animals and humans due to their persistence and tendency to bioaccumulate. Emission of PBDEs into the environment can occur during recycling of PBDE-containing plastic material or during their uncontrolled or insufficient combustion as e.g. in accidental fires or landfill fires. Under these circumstances, PBDEs can also function as precursor molecules for the formation of polybrominated dibenzodioxins (PBDDs) and dibenzofurans (PBDFs). In this study, we qualitatively investigated the reaction of two PBDE congeners, 2,2′,4,4′-tetrabromo diphenyl ether (BDE 47) and 2,2′,4,4′,5,5′-hexabromo diphenyl ether (BDE 153), as well as hexabromobenzene (HBB), a flame retardant used in the past, when exposed to temperatures between 250 °C and 500 °C. The formed reaction products were analysed by high resolution gas chromatography–low resolution mass spectrometry (HRGC-LRMS). Among others brominated–chlorinated diphenyl ethers were formed by chlorodebromination of the PBDEs. In addition, thermolysis of BDE 47 and BDE 153 in the presence of tetrachloromethane as model substance for an organic chlorine source was studied. Thermal treatment of HBB resulted in the formation of brominated–chlorinated benzenes.     

Sorption-desorption behavior of polybrominated diphenyl ethers in soils

Polybrominated diphenyl ethers (PBDEs) are flame retardants that are commonly found in commercial and household products. These compounds are considered persistent organic pollutants. In this study, we used 4,4′-dibromodiphenyl ether (BDE-15) as a model compound to elucidate the sorption and desorption behavior of PBDEs in soils. The organic carbon-normalized sorption coefficient (K_OC) of BDE-15 was more than three times higher for humin than for bulk soils. However, pronounced desorption hysteresis was obtained mainly for bulk soils. For humin, increasing concentration of sorbed BDE-15 resulted in decreased desorption. Our data illustrate that BDE-15 and probably other PBDEs exhibit high sorption affinity to soils. Moreover, sorption is irreversible and thus PBDEs can potentially accumulate in the topsoil layer. We also suggest that although humin is probably a major sorbent for PBDEs in soils, other humic materials are also responsible for their sequestration.     

Sodium borohydride reduction of individual polybrominated diphenyl ethers

Many chemicals in use today lack appropriate documentation on their environmental properties, fate, and effects. To counteract this lack of documentation it is vital to thoroughly investigate a compound’s fate in the environment before it comes into use. The present study is describing a novel method for assessing the reduction potential of polybrominated diphenyl ethers (PBDEs), as a part of a project aimed to create an experimental model for determination of chemical persistence. The reductive transformation of 15 PBDE congeners using sodium borohydride was determined. Pseudo-first-order reaction rate constants of the transformations were determined by monitoring the disappearance of the investigated congeners. The reductions lead primarily to formation of lower brominated PBDEs. Each PBDE congener was tested in a total of ten replicates which showed a relative standard deviation of 31% or less. The decaBDE, BDE-209 was approximately 3 times as prone to reductive transformation as BDE-207. The three nonaBDEs, BDE-206, BDE-207, and BDE-208, showed similar reductive potential. The reactivity of the tested octaBDEs was quite variable, from 5% to 24% of the reactivity of BDE-209 for BDE-196 and BDE-198, respectively. The heptaBDEs studied were in the range of the less reactive octaBDEs, except for BDE-181 which was as high as 13% of the reactivity of BDE-209. The results presented give a method for measuring the propensity of PBDEs, and possibly similar compounds, to undergo reductions. They indicate a potential route to a vital piece of information in the assessment of environmental persistence of chemicals.     

Pine needles as passive bio-samplers to determine polybrominated diphenyl ethers

Eight polybrominated diphenyl ethers (PBDEs) were determined in pine needles of three species (Pinus halepensis, Pinus pinea and Pinus nigra) collected in the NE Spain in an attempt to use this matrix for the biomonitoring of airborne PBDEs. The method used was based in ultrasonic extraction followed by alumina and Florisil clean-up and determination by gas chromatography coupled to mass spectrometry in negative chemical ionization. Recoveries were between 99% and 138%, limits of detection between 0.011 and 0.070 ng g⁻¹-dw (0.232 ng g⁻¹-dw for BDE 209) and repeatability lower than 13%. PBDE levels ranged between 0.027 ng g⁻¹-dw and 13.04 ng g⁻¹-dw, with predominance of BDE 209, followed by BDEs 47. P. halepensis was the species with the highest PBDE levels and P. nigra, the least, according to their widespread and remote distribution, respectively. The presence of PBDEs in pine needles was attributed to the release of in-use PBDEs, transport through atmosphere and adsorption upon lipid rich pine needles. Given the easy collection of pine needles, its ample distribution and its potential to accumulate airborne contaminants, this matrix is proposed as passive bio-sampler to be used in PBDE monitoring programs.

Capsule

Pine needles can be used to biomonitor airborne PBDEs.     

Determination of polybrominated diphenyl ethers (PBDEs) in fish samples from rivers and estuaries in Taiwan

Polybrominated diphenyl ethers (PBDEs) have been used extensively over the past two decades as flame retardants in many types of polymers, and have been found to be a class of contaminants of concern. Measurements of PBDEs in various environmental matrices from Sweden, Holland, Japan, North America, and elsewhere have been reported. We report data of PBDEs in fish samples taken from six rivers and three estuaries in Taiwan. Seven PBDE congeners were observed in all sixty samples. BDE-47 was found to be the dominant congener in all waters, and BDE-154 contributed more than BDE-99 and BDE-100. Nonetheless, BDE-154 and BDE-183 were the predominant congeners in some species studied. These results are somewhat different from those from other countries, where the pattern is typically BDE-47 > 99 >100 >154, 153, and is postulated to be due to the extensive use of octa-BDE rather than penta-BDE in Taiwan. The average concentration distribution across all samples of the sum of PBDE congeners ranged from 30.6 ng/g lipid to 281 ng/g lipid. The concentrations of PBDEs in fishes reported here are higher than those reported from European countries, but lower than those from the United States.     

Spatial distribution of polybrominated diphenyl ethers in coastal marine sediments receiving industrial and municipal effluents in Kuwait

Polybrominated diphenyl ether (PBDE) concentrations were measured in surficial sediments from coastal sediments receiving industrial and municipal effluents in Kuwait. The summation PBDE concentrations varied by two orders of magnitude ranging from 80 to 3800 pg g(-1)dw. The congener distribution was dominated by BDE 183, with minor contributions from BDEs 154 and 153. The similarity between the congener profile to that of the technical octa formulation (Bromkal 79-8DE) suggests a source of this product in Kuwait. The observed gradient in concentration distribution, with high summation PBDE concentrations near the shore and an exponential decrease seaward, indicates that wastewater discharge from industrial activities in the study area is the primary source of these compounds in the sediments.     

Polybrominated diphenyl ethers and polybrominated biphenyls in Australian sewage sludge

This paper presents a brief review of the international scientific literature of polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls (PBBs) in sewage sludge and a survey of these compounds in sewage sludge from 16 Australian wastewater treatment plants (WWTPs). The SigmaPBDE mean concentration in the Australian study was 1137microgkg(-1) dry weight (d.w.) (s.d. 1116) and ranged between 5 and 4 230microgkg(-1)d.w. The urban mean of 1308microgkg(-1) (s.d. 1320) and the rural mean of 911microgkg(-1) (s.d. 831) are not statistically different and are similar to levels in European sludges. Principal components analysis was performed on the data set and revealed that 76% of the data variation could be explained by two components that corresponded to overall concentration of the pentaBDE and the decaBDE commercial formulations. An analysis of variance was performed comparing PBDEs levels at three WWTPs over the years 2005 and 2006, finding differences between treatment plants (BDE-47) but no significant difference in PBDE levels in the years 2005 and 2006. Low levels of BB-153 were detected in all samples of this survey (n=16); mean 0.6microgkg(-1)d.w. (s.d. 0.5). This compound has rarely been reported in any other study of sewage sludges undertaken outside Australia. This work highlights the need for a risk assessment of PBDEs in sewage sludge when used for land application, taking into account typical levels found in Australian sludges and soils.     

Levels and distribution of polybrominated diphenyl ethers (PBDEs) in marine fishes from Chinese coastal waters

Concentrations of polybrominated diphenyl ethers (PBDEs) in yellow croakers (Pseudosciaena crocea) and silver pomfrets (Pampus argenteus) collected from nine coastal cities along the eastern China coastline were investigated. PBDE congeners with mono- to hexa-brominated substitutions were detected in the samples, indicating their ubiquitous distribution in the marine environment of China. The total PBDE concentration averaged 3.04 ng g⁻¹ lipid wt, a level that was relatively lower than in other regions of the world, especially North America where Penta-BDE was extensively used. Geographically, the highest concentration of PBDEs was found in Xiamen, and the PBDE levels in yellow croakers were significantly higher than those in pomfrets in most of the selected cities, a pattern which may be related to the different feeding habits of the two species. The congener profiles of PBDEs were found to be different from the commonly detected pattern in fishes from other regions of the world (i.e., BDE47 > BDE99, BDE100 > BDE153, BDE154). BDE47 and BDE154 were the predominant congeners in both species, accounting for more than 60% of the total PBDE concentrations. The reasons for the relatively high proportion of BDE154 may be due to the debromination of higher brominated congeners such as BDE183 and BDE209 by these two species.     

Environmental pollutants in the Swedish marine ecosystem, with special emphasis on polybrominated diphenyl ethers (PBDE)

Levels of polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and perfluorinated organic compounds (PFCs) were analysed in whole herring (Clupea harengus) and sprat (Sprattus sprattus), eggs from common eider (Somateria mollissima) and eggs and livers from herring gull (Larus argentatus) from the Swedish west coast. The contaminant values obtained were compared with published values from the Arctic marine ecosystem. Tetra- and penta-brominated PBDEs were detected at low levels in herring, sprat and common eider (ΣPBDE 0.3-2.0 ng g⁻¹ ww), while the levels were higher in the herring gull samples (ΣPBDE 1.3-29.9 ng g⁻¹ ww). Hexa-decaBDEs were also found in samples from herring gulls. Eggs from herring gulls from the sub-Arctic contained four times more PBDE than the Swedish herring gulls eggs. Fish samples from the Arctic had two times higher levels of PBDEs and DDTs than similar samples from Sweden. The higher levels of contaminants in fish and seabirds from the Arctic reflect differences in transport processes, feeding ecology (reflected by trophic levels) and metabolism. PBDEs contributed to <10% of the total contaminant load in all investigated samples. The relative contribution of DDTs was higher in fish and bird samples from the Arctic when compared to Swedish samples, e.g. 65% in glaucous gull livers compared to 10% in herring gull livers. This study shows that even though the Swedish west coast is more urban than the Arctic, higher pollutants levels are found in seabird species from the Arctic.     

Occurrence and distribution of polybrominated diphenyl ethers (PBDEs) in the dissolved and suspended phases of the sea-surface microlayer and seawater in Hong Kong, China

This study reports the first data on the concentration and distribution of polybrominated diphenyl ethers (PBDEs) in the sea-surface microlayer (SML), and their enrichment relative to bulk seawater, for coastal waters in the marine environment of Hong Kong, China. Samples were collected in March 2005 at five sample locations and analysed for eight congeners of primary interest, i.e. BDE 28, 47, 99, 100, 153, 156, 183 and 209. Concentration ranges of summation operatorPBDE in the dissolved phase (DP, defined as sum of truly dissolved and colloidal phase) and suspended particulate matter (SPM) of seawater were 31.1-118.7 pg/l (mean 70.7 pg/l), and 25.7-32.5 pg/l (mean 28.1 pg/l), respectively. Concentrations in the SML were generally higher by factor of 1.3-3.6 in the DP (concentration range from 40.2 to 228.2 pg/l, mean 149.2 pg/l) and by 0.3-2.1 in the SPM (concentration range 8.1-69.1 pg/l, mean 38.2 pg/l). Concentrations of PBDEs were general low and below detection limits in samples of an oceanic character and highest in the sheltered waters of Victoria Harbour. The congeners BDE 28, 47, 100 and 183 were most abundant, where BDE 209 was detected only in trace amounts. It is suggested that Hong Kong's marine waters show relatively low levels of PBDE contamination, and these compounds may originate from the disposal of electronic waste in southern China, as well as untreated discharge of wastewater locally.     

Residual levels of DDTs and PAHs in freshwater and marine fish from Hong Kong markets and their health risk assessment

Axial and ventral muscle from 10 each species of freshwater and marine fish purchased from markets in Hong Kong were analyzed for dichlorodiphenyltrichloroethane (total DDTs including DDE, DDD and DDT) and polycyclic aromatic hydrocarbons (PAHs). Among the 10 freshwater fish species, rice field eel (Monopterus albus) showed significantly higher levels of DDTs in both ventral (125 ng/g wet wt) and axial muscle (127 ng/g wet wt) than the other species. The highest concentration of PAHs was detected in catfish (Clarias fuscus), with 24.8 ng/g in ventral muscle and 9.1 ng/g in axial muscle. As to marine fish, snubnose pompano (Trachinotus blochii) showed significantly higher levels of DDT and its metabolites (1018 ng/g in ventral and 409 ng/g wet wt in axial tissues) than all other marine fish species. The overall concentrations of PAHs in marine fish species were 15.5-57.0 ng/g (axial muscle) and 18.1-118 ng/g wet wt (ventral muscle) where yellow seafin (Acanthopeyrus latus) and golden threadfin bream (Nemipterus virgatus) exhibited the highest concentrations of PAHs in the axial and ventral muscles, respectively. In general, results showed that levels of PAHs in Hong Kong market fish was low and do not expect to cause any concern for human consumption. However, the levels of DDTs in fish samples ranged from 1.10 to 1018 ng/g wet wt, and based on a fish consumption rate of 142.2g/day to calculate the screening value of 14.4 ng/g wet wt for human consumption (USEPA, 2000. Guidance for assessing chemical contaminant, data for use in fish advisories, vol. 1: fish sampling and analysis, third ed. EPA 823-R-95-007. Office of Water, Washington, DC), there were 9 out of 20 (45%) muscle samples of freshwater fish species and 14 out of 20 (70%) muscle samples of marine fish species had elevated levels of DDTs exceeded the screening value. It was also suggested to use ventral muscle for detecting concentrations of persistent organic pollutants in fish.     

Spectral characterization of two bioaccumulated methoxylated polybrominated diphenyl ethers

Two methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were isolated from a True's beaked whale (Mesoplodon mirus) and identified by NMR (1H, 1H-1H and 1H-13C) and high resolution mass spectrometry as 2-(2',4'-dibromophenoxy)-3,5-dibromoanisole (6-MeO-BDE47) and 2-(2',4'-dibromophenoxy)-4,6-dibromoanisole (2'-MeO-BDE68). Previously the structures of these bioaccumulated compounds have been determined by comparison of their mass spectra and gas chromatographic (GC) retention times with those of authentic standards. While this method is accepted and generally successful, NMR of the isolated compounds allows us to definitively identify the congeners. Our characterizations are consistent with those made for MeO-PBDEs in other organisms, identified by chromatographic methods.     

State of polybrominated diphenyl ethers in China: an overview

Polybrominated diphenyl ethers (PBDEs), extensively used as flame retardants, are ubiquitous environmental contaminants that are found in both abiotic and biotic environmental samples. Sufficient evidence shows that PBDEs have been rapidly accumulating in the environment of China, especially in the Southeast regions. This paper summarizes and critically reviews the published scientific data on PBDEs in China, including the levels of PBDEs in the air, soil, water, sediment, the terrestrial and marine organisms, and human samples in China. The data preliminarily reveal the state of PBDEs in China.