Total PBDE Research Articles

Levels, Distribution and Ecological Risk Assessment of PBDEs in Soils and Plants Around the Engineering Plastics Factory.

This study systematically investigated the pollution levels and migration trends of PBDEs in soils and plants around engineering plastics factory, and identified the ecological risks of PBDEs in the environment around typical pollution sources.The results showed that 13 kinds of PBDEs were widely detected in the surrounding areas, and the concentration level was higher than the general environmental pollution level. The total PBDE concentrations (∑13PBDEs) in soils ranged from 14.6 to 278.4ng/g dry weight (dw), and in plants ranged from 11.5 to 176ng/g dw. Both soil and plant samples showed that BDE-209 was the most important congener, the pollution level in soil and plant was similar, and the composition of PBDEs congener was similar. In the soil column (50cm), the radial migration of PBDEs was mainly concentrated in the 0-30cm section. Except for BDE-66, which was mainly located in the 20-30cm soil layer, the concentration of PBDEs was the highest in the 0-10cm region. Furthermore, the environmental risks of PBDEs in soil and plants were evaluated by hazard quotient method, and the HQ values were all < 1, which did not exhibit any ecological risk. The evaluation results also showed that the ecological risk of PBDEs in soil was higher than that of plants, especially penta-BDE, which should be paid more attention.

Prenatal exposure to polybrominated diphenyl ethers and birth outcomes

BackgroundPolybrominated diphenyl ethers (PBDEs) were used as flame retardants and from their end-use products they can be released to accumulate within indoor environments. This may result in exposures to pregnant women with potential adverse effects on the developing fetus. While studies have shown associations between prenatal PBDE exposure and poor birth outcomes, research has mainly focused on birth weight and gestational age and may miss important indicators of newborn size. MethodsThe sample included a cohort of Dominican and African American mother-child pairs from New York City recruited from 1998 to 2006. PBDE congeners (BDE-47, BDE-99, BDE-100, and BDE-153) were measured in cord serum at birth and dichotomized into low (<80th percentile) and high (>80th percentile) categories. Weight, length, head circumference, and gestational age were measured at birth and the ponderal index (birth weight/length x 100), size for gestational age, and population-based z-scores were calculated (n = 305). Separate regression analyses were conducted to estimate associations between PBDEs or PBDE sum (ng/g lipid) and birth outcomes. Quantile g-computation was performed to estimate the effect of total PBDE mixture. We also assessed effect modification by sex and ethnicity. ResultsAdjusting for relevant covariates, the high exposure category of BDE-153 was associated with lower birth weight z-score (−0.25, 95% CI: −0.5, 0.0) and longer gestation (0.43 weeks, 95% CI: 0.07, 0.79). The high exposure category of BDE-99 was associated with lower birth length z-score (−0.55, 95% CI: −0.98, −0.12). There was a negative association between the overall PBDE mixture and birth length z-score (−0.10, 95% CI: −0.21, 0.00) per 1 quintile increase in PBDEs. There was no effect modification by sex or ethnicity. ConclusionsThese results suggest that prenatal exposures to BDE-153, BDE-99, and total PBDE mixture are associated with birth outcomes in a cohort of Dominican and African American newborns.

Prenatal exposure to polybrominated diphenyl ethers and BMI Z-scores from 5 to 14 years

BackgroundPolybrominated diphenyl ethers (PBDEs) are flame-retardant compounds widely used in household products until phase out in 2004. PBDEs are endocrine disruptors and are suggested to influence signaling related to weight control. Prenatal exposures to PBDEs may alter childhood adiposity, yet few studies have examined these associations in human populations.MethodsData were collected from a birth cohort of Dominican and African American mother-child pairs from New York City recruited from 1998 to 2006. PBDE congeners BDE-47, − 99, − 100, and − 153 were measured in cord plasma (ng/μL) and dichotomized into low (< 80th percentile) and high (>80th percentile) exposure categories. Height and weight were collected at ages 5, 7, 9, 11, and an ancillary visit from 8 to 14 years (n = 289). Mixed-effects models with random intercepts for participant were used to assess associations between concentrations of individual PBDE congeners or the PBDE sum and child BMI z-scores (BMIz). To assess associations between PBDEs and the change in BMIz over time, models including interactions between PBDE categories and child age and (child age)2 were fit. Quantile g-computation was used to investigate associations between BMIz and the total PBDE mixture. Models were adjusted for baseline maternal covariates: ethnicity, age, education, parity, partnership status, and receipt of public assistance, and child covariates: child sex and cord cholesterol and triglycerides.ResultsThe prevalence of children with obesity at age 5 was 24.2% and increased to 30% at age 11. Neither cord levels of individual PBDEs nor the total PBDE mixture were associated with overall BMIz in childhood. The changes in BMIz across childhood were not different between children with low or high PBDEs. Results were similar when adjusting for postnatal PBDE exposures.ConclusionsPrenatal PBDE exposures were not associated with child growth trajectories in a cohort of Dominican and African American children.

Occurrence and distribution of persistent organic pollutants in the liver and muscle of Atlantic blue sharks: Relevance and health risks

Blue shark score among the most abundant, widely distributed and worldwide consumed elasmobranchs. In this work contents of PCBs, PCDD/Fs and PBDEs were studied by means of GC-HRMS in muscle and liver of sixty blue sharks from the North East Atlantic sampled in 2019. Concentrations relatively similar were found for PCBs and PCDD/Fs in comparison with those in Atlantic specimens from the same area sampled in 2015. In contrast, PBDE loads doubled, likely mirroring the increased environmental presence of these pollutants. This, together with the different congener profiles reported for the same species in other geographical areas, highlighted the blue shark's potential as bioindicator of the degree and fingerprints of regional pollution by POPs. Interesting dissimilarities between muscle and liver concentrations were detected, most likely ascribed to distinct toxicokinetics involved for the different pollutants. Whereas most POPs preferentially accumulated in liver, some did the opposite in muscle. BDE-209 was the most prominent example, being almost negligible its presence in liver (0.3%) while accounting for ca. 14% of the total PBDE content in muscle. Different findings in this regard described for other shark species call for focused research to ascertain the role of the species in this apparent favored metabolization of BDE-209 in the liver. From a consumption perspective, the concentrations found in muscle -the most relevant part in the human diet-for PCBs and dioxin-like POPs were below the EU maximum allowed levels in foodstuff. Conversely, in liver about 58% and 78% of samples overpassed the European levels for tolerable intake of i-PCBs and dioxin POPs, respectively. Concentrations of PBDEs exceeded EQS (0.0085 ng/g w.w.) established by the European Water Framework Directive in 100% and 92% of liver and muscle samples, respectively, which adds to the open debate of such as a reduce value for this current EQS.

New Insights into Human Biotransformation of BDE-209: Unique Occurrence of Metabolites of Ortho-Substituted Hydroxylated Higher Brominated Diphenyl Ethers in the Serum of e-Waste Dismantlers

Extremely high levels of decabromodiphenyl ether (BDE-209) are frequently found in the serum of occupationally exposed groups, such as e-waste dismantlers and firefighters. However, the metabolism of BDE-209 in the human body is not adequately studied. In this study, 24 serum samples were collected from workers at a typical e-waste recycling workshop in Taizhou, Eastern China, and the occurrence and fate of these higher brominated diphenyl ethers (PBDEs) were investigated. The median concentration of the total PBDEs in the serum was 199 ng/g lipid weight (lw), ranging from 125 to 622 ng/g lw. Higher brominated octa- to deca-BDEs accounted for more than 80% of the total PBDEs. Three ortho-hydroxylated metabolites of PBDEs─6-OH-BDE196, 6-OH-BDE199, and 6'-OH-BDE206─were widely detected with a total concentration (median) of 92.7 ng/g lw. The concentrations of the three OH-PBDEs were significantly higher than their octa- and nona-PBDE homologues, even exceeding those of the total PBDEs in several samples, indicating that the formation of OH-PBDEs was a major metabolic pathway of the higher brominated PBDEs in occupationally exposed workers. An almost linear correlation between 6-OH-BDE196 and 6-OH-BDE199 (R = 0.971, P < 0.001) indicates that they might undergo a similar biotransformation pathway in the human body or may be derived from the same precursor. In addition, the occurrence of a series of penta- to hepta- ortho-substituted OH-PBDEs was preliminarily identified according to their unique "predioxin" mass spectral profiles by GC-ECNI-MS. Taken together, the tentative metabolic pathway for BDE-209 in e-waste dismantlers was proposed. The oxidative metabolism of BDE-209 was mainly observed at the ortho positions to form 6'-OH-BDE-206, which later underwent a consecutive loss of bromine atoms at the meta or para positions to generate other ortho-OH-PBDEs. Further studies are urgently needed to identify the chemical structures of these ortho-OH-PBDE metabolites, and perhaps more importantly to clarify the potentially toxic effects, along with their underlying molecular mechanisms.

Plasma concentrations of lipophilic persistent organic pollutants and glucose homeostasis in youth populations

BackgroundExposure to lipophilic persistent organic pollutants (POPs) is ubiquitous. POPs are metabolic disrupting chemicals and are potentially diabetogenic. MethodsUsing a multi-cohort study including overweight adolescents from the Study of Latino Adolescents at Risk (SOLAR, N = 301, 2001–2012) and young adults from the Southern California Children's Health Study (CHS, N = 135, 2014–2018), we examined associations of POPs and risk factors for type 2 diabetes. SOLAR participants underwent annual visits for a median of 2.2 years and CHS participants performed a single visit, during which a 2-h oral glucose tolerance test was performed. Linear mixed models were used to examine associations between plasma concentrations of POPs [4,4′-dichlorodiphenyldichloroethylene (4,4′-DDE), hexachlorobenzene (HCB), PCBs-153, 138, 118, 180 and PBDEs-154, 153, 100, 85, 47] and changes in glucose homeostasis across age and pubertal stage. ResultsIn SOLAR, exposure to HCB, PCB-118, and PBDE-153 was associated with dysregulated glucose metabolism. For example, each two-fold increase in HCB was associated with approximately 2 mg/dL higher glucose concentrations at 30 min (p = 0.001), 45 min (p = 0.0006), and 60 min (p = 0.03) post glucose challenge. Compared to individuals with low levels of PCB-118, individuals with high levels exhibited a 4.7 mg/dL (p = 0.02) higher glucose concentration at 15 min and a 3.6 mg/dL (p = 0.01) higher glucose concentration at 30 min. The effects observed with exposure to organochlorine compounds were independent of pubertal stages. PBDE-153 was associated with the development of dysregulated glucose metabolism beginning in late puberty. At Tanner stage 4, exposure to PBDE-153 was associated with a 12.7 mg/dL higher 60-min glucose concentration (p = 0.009) and a 16.1 mg*dl−1*hr−1 higher glucose AUC (p = 0.01). These associations persisted at Tanner 5. In CHS, PBDE-153 and total PBDE were associated with similar increases in glucose concentrations. ConclusionOur results suggest that childhood exposure to lipophilic POPs is associated with dysregulated glucose metabolism.

Human health risks from brominated flame retardants and polycyclic aromatic hydrocarbons in indoor dust

Exposure to dust particles containing toxic compounds is linked to serious health outcomes, including cancer. The purpose of this study was to determine if indoor dust from houses and cars contained harmful levels of brominated flame retardants (polybrominated diphenyl ethers, PBDEs) and polycyclic aromatic hydrocarbons (PAHs), and to assess their potential toxicity to adults and children. In Kuwait, the median concentration of total PBDEs (Ʃ14- PBDEs) was 408.55 μg PBDEs/kg dust in houses and twice as high in cars (838.52 μg PBDEs/kg dust), while total PAHs (Ʃ16-PAHs) were similar in houses (992.81 μg PAHs/kg) and cars (900.42 μg PAHs/kg). The PBDEs and PAHs concentrations in indoor dust were related to house age and square footage, car model year, and natural ventilation. Furthermore, a higher PBDEs concentration was associated with electronic devices that operate continuously, furniture containing foam treated with PBDEs, and cars that are parked outdoors, since PBDEs tend to be volatilized under these conditions. The PAHs concentration in indoor dust increased with smoking and proximity to major roads and industrial facilities, which are major PAHs sources. The hazard quotient and total cancer risk for PBDEs in indoor dust were within safe limits, but indoor dust with higher PAHs concentrations had hazard quotients from 5.51 to 11.23 and total cancer risk of 10−3 for adults and children. We conclude that exposure to PAHs-contaminated indoor dust from houses and cars where smoking occurs can increase the cancer risk of adults and children.

Halogenated and organophosphorus flame retardants in cetaceans from the southwestern Indian Ocean

PBDEs, HBCD, DBDPE, PBEB and HBB, dechloranes and OPFRs, as well as natural MeO-PBDEs were monitored in muscle tissue of three dolphin species from the southwestern Indian Ocean (Delphinus delphis, Sousa plumbea and Tursiops aduncus) collected between 2012 and 2015. The mean PBDE concentration was 416 ± 333 ng g−1 lw. BDE-47 was found in all samples and was almost half the total PBDE contamination. BDE-209, BDE-100 and BDE-99 were present in ≥85% of the samples. HBCD was detected in just two samples at 20 and 330 ng g−1 lw. PBEB and HBB were not detected, while DBDPE was in all samples but always below its limit of quantification. Dec 602 was the only quantifiable dechlorane at 232 ± 549 ng g−1 lw. Mean OPFR concentration was 10452 ± 11301 ng g−1 lw. TBOEP was found in all samples making up most of the total OPFR contamination. MeO-PBDEs were detected in all samples at 114 ± 137 ng g−1 lw. Data on flame retardants in biota and environmental samples from the southwestern Indian Ocean are scarce and, as a result, comparisons are difficult. However, data from other marine predators in the region, such as penguins, suggest that further studies are needed to determine if these concentrations are the consequence of a high local contamination or widespread thoughout the Indian Ocean.

The complex issue of chemicals and microplastic pollution: A case study in North Pacific lanternfish

Marine plastic debris, including microplastics (<5 mm in size), comprises a suite of chemical ingredients and sorbed chemical contaminants. Thus, microplastics are a potential, and debated, source of anthropogenic chemicals for bioaccumulation and biomagnification. Several studies have investigated the role of microplastics as a vector of contaminants to marine organisms via modeling exercises, laboratory experiments, and field studies. Here, we examined relationships among chemical contaminants and microplastics in lanternfish (family Myctophidae), an important link in marine food webs, from the North Pacific Ocean as a case study from the field. We compared the body burden of several chemical groups (bisphenol A [BPA], nonylphenol [4-NP], octylphenol [4n-OP], alkylphenol ethoxylates [APEs], pesticides, polychlorinated biphenyls [PCBs], and polybrominated diphenyl ethers [PBDEs]) in fish caught within and outside the North Pacific Subtropical Gyre where plastic is known to accumulate. We also tested whether there was a relationship between chemical concentrations in fish and plastic density at each sampling location. Mean concentrations of common plastic constituents (BPA, 4-NP, 4n-OP, APEs, and total PBDEs) were comparable between myctophids collected within and outside the North Pacific Gyre. Pesticides were higher in lanternfish caught outside the gyre and were associated with lower plastic density. Total PCBs were also higher in fish outside the gyre. In contrast, lower chlorinated PCB congeners were higher in fish residing in the accumulation zone and were correlated with higher plastic density. This finding is consistent with other studies demonstrating an association between lower chlorinated PCBs and plastics in biota and suggests that microplastic may be a transport mechanism for some chemicals in nature.

Effects of β-cyclodextrin on phytoremediation of soil co-contaminated with Cd and BDE-209 by arbuscular mycorrhizal amaranth

Pot experiments were conducted to investigate the effects of a series of β-cyclodextrin (β-CD) on phytoremediation of soil co-contaminated with Cd and BDE-209 by amaranth (Amaranthus hypochondriacus L.) inoculated with arbuscular mycorrhizal fungus (AMF) – Rhizophagus intraradices. Results showed that the combination of mycorrhizal amaranth and 0.4% β-CD (RI+β0.4) significantly enhanced Cd concentrations and contents in shoots, total PBDEs concentration in roots, and BDE-209 dissipation in soil. Moreover, the RI+β0.4 treatment exerted the highest removal efficiency of both Cd and BDE-209. On the contrary, the xylem area, shoot Cd and BDE-209 concentrations and contents, and removal efficiency of Cd were markedly reduced in mycorrhizal amaranth with 0.8% or 1.2% β-CD treatments (RI+β0.8, RI+β1.2), compared with single inoculation treatment. The well-organized chloroplast and well-defined root anatomical structure were also observed in the treatment of RI+β0.4. Positive correlation was found between shoot biomass and chlorophyll concentrations. Shoot Cd or BDE-209 concentrations were positively correlated with xylem areas. In conclusion, mycorrhizal amaranth added with 0.4% β-CD could be used for the decontamination of soil polluted with mixture of Cd and BDE-209 due to the higher chlorophyll concentration and the larger xylem area.

Preliminary study of long-range transport of halogenated flame retardants using Antarctic marine mammals

Eight PBDE congeners, three emerging brominated flame retardants, five dechloranes and eight MeO-PBDEs were monitored in tissues (muscular, adipose, brain) and fur of southern elephant seal and Antarctic fur seal of the South Shetland Islands, Antarctic Peninsula. Total PBDEs and total dechloranes concentrations ranged between n.d.–6 ng/g lw. While PBDEs were not detected in brain tissue, Dec 602 was found in brain tissue of both seal species indicating that dechloranes —with potential neurological toxicity— could cross the blood-brain barrier. Emerging brominated flame retardants were not detected in any sample and only two MeO-PBDEs, which are of natural origin, were found. The presence of the detected compounds in biota from the Antarctic evidences their long-range transportation, being of special interest the detection of emerging compounds such as dechloranes. This is the first time that these contaminants have been detected in marine mammals from the Antarctic. BDE-47 concentrations were lower than previously reported for the same species, suggesting a successful effect of the existing regulation and bans on PBDEs. Capsule abstractHalogenated flame retardants were in tissues of Antarctic seals proving long-range transport. Dechloranes showed similar behaviour to PBDEs, additionally they crossed the BBB.

Ecological and human exposure assessment to PBDEs in Adige River

The interest for environmental issues and the concern resulting from the potential exposure to contaminants were the starting point to develop methodologies in order to evaluate the consequences that those might have over both the environment and human health. Considering the feature of POPs, including PBDEs, such as bioaccumulation, biomagnification, long-range transport and adverse effects even long time after exposure, risk assessment of POPs requires specific approaches and tools. In this particular context, the MERLIN-Expo tool was used to assess the aquatic environmental exposure of Adige River to PBDEs and the accumulation of PBDEs in humans through the consumption of possible contaminated local aquatic food.The aquatic food web models provided as output of the deterministic simulation the time trend of concentrations for twenty years of BDE-47 and total PBDEs, expressed using the physico-chemical properties of BDE-47, in aquatic organisms of the food web of Adige River. For BDE-47, the highest accumulated concentrations were detected for two benthic species: Thymallus thymallus and Squalius cephalus whereas the lowest concentrations were obtained for the pelagic specie Salmo trutta marmoratus. The trend obtained for the total PBDEs, calculated using the physico-chemical properties of BDE-47, follows the one of BDE-47.For human exposure, different BDE-47 and total PBDEs concentration trends between children, adolescent, adults and elderly were observed, probably correlated with the human intake of fish products in the daily diet and the ability to metabolize these contaminants. In detail, for the adolescents, adults and elderly a continuous accumulation of the target contaminants during the simulation's years was observed, whereas for children a plateau at the end of the simulation period was perceived.

Brominated flame retardant (BFRs) and Dechlorane Plus (DP) in paired human serum and segmented hair

Brominated flame retardants (BFRs) and Dechlorane Plus (DP) were measured in both human hair and paired serum samples from a cohort of university students in South China. Segmental analysis was conducted to explore gender difference and the relationships between the hair and serum. The concentrations of total PBDEs in the hair and serum samples were in a range of 0.28–34.1ng/g dry weight (dw) and 0.16–156ng/g lipid weight (lw), respectively. Concentrations of ∑DPs (sum of the syn-DP and anti-DP isomers) in all hair samples ranged from nd-5.45ng/g dry weight. Concentrations of most PBDEs and decabromodiphenylethane (DBDPE) in distal segments (5–10cm from the scalp) were higher than those in the proximal segments (0–5cm from the scalp) (t-test, p < 0.05), which could be due to the longer exposure time of distal segments. The proximal segments exhibited a unique congener profile, more close to that in the serum rather than the distal segments of hair. An obvious gender difference was found in the levels of ∑PBDEs using integrated hair samples, while the difference disappeared when considering alone the proximal segments of hair (0–5cm from scalp) for both genders. This paper provides supplement to the current knowledge on sources of BFRs and DPs in hair and declares the importance of segmental analysis.

Phytoremediation of soil co-contaminated with Cd and BDE-209 using hyperaccumulator enhanced by AM fungi and surfactant

Pot experiments were conducted to investigate the uptake and translocation of both Cd and decabromodiphenyl ether (BDE-209) in Solanum nigrum, under the treatments of two arbuscular mycorrhizal fungi [AMF, Funneliformis mosseae (FM) and Rhizophagus intraradices (RI)] and surfactant β-cyclodextrin (β-CD). Results showed that S. nigrum treated with either FM or β-CD significantly elevated shoot biomass and Cd concentrations and contents in shoots. The concentrations of BDE-209 in shoots and the dissipation and debromination efficiencies of BDE-209 in soil were significantly enhanced in S. nigrum treated with β-CD, inoculated with or without AMF. Moreover, significant positive correlations were found between the BDE-209 dissipation efficiency, the BDE-209 concentrations and contents in roots, and the soil enzymatic activities (polyphenol oxidase or dehydrogenase activities) and between the Cd and BDE-209 contents in shoots or roots. Higher concentrations of lower-brominated products and total PBDEs were detected in shoots than in roots suggesting that BDE-209 might be initially absorbed by roots, then translocated to shoots, and then degraded into lower brominated products in shoots. Considering the plant uptake of Cd and BDE-209 and the efficient removal of those chemicals in soils, the combination of S. nigrum and β-CD inoculated with or without AMF may be viable alternatives for phytoremediation of the co-contaminated soil.

Anthropogenic (PBDE) and naturally-produced (MeO-PBDE) brominated compound levels in Bizerte Lagoon clams (Ruditapes decussatus): Levels and human health risk assessment

Information on the occurrence of organobrominated compounds in bivalves from Tunisia is scarce. To the best of our knowledge, this is the first report of these compounds in clams from Tunisia. The aim of this study is to measure natural and synthetic organobrominated compound concentrations and evaluate congener distribution and pollution sources in a clam species (Ruditapes decussatus) from three sites of the Bizerte Lagoon. Total synthetic organobrominated pollutant levels in clam ranged from 34.8 to 188ngg−1lw. For natural organobrominated compounds, concentrations varied from 18.2 to 49.5ngg−1lw. Total PBDE and MeO-PBDE concentrations in clams from the Bizerte Lagoon were similar or slightly lower than those reported for other species from other locations around the world. The health risks associated with the consumption of this species were assessed and posed no threat to public health concerning PBDE intakes.

Bioindication of PBDEs and PCBs by native and transplanted moss Pleurozium schreberi

PBDEs and PCBs are toxic, persistent organic pollutants (POPs), and the use of PCBs is forbidden, but they are still present in many environments and biota. 90-day assays were conducted with the moss Pleurozium schreberi transplanted from an uncontaminated control site to ten sites (rural and urban) selected in one of the most polluted regions of Upper Silesia in Poland. Native P. schreberi mosses were collected from the same ten polluted sites. Concentrations of PBDEs (28, 47, 66, 85, 99, 100, 153, 154, 183 and 209) and PCBs (28, 52, 101, 118, 138, 153, 180) were determined in all native and transplanted P. schreberi from all sites. Native P. schreberi contained the highest ΣPBDE and ΣPCB levels (63.6ngg−1 and 4.47pgg−1, respectively) when collected in the vicinity of a steel smelter. After 90 days of the experiment native and transplanted P. schreberi contained the highest concentrations of the same BDE 209 congener (88–91% of total PBDEs in the native mosses and 85–90% of the total PBDE burden in the transplants). The native and transplanted mosses from the industrial sites after 90 days of exposure contained significantly higher concentrations of all the examined PBDE and PCB congeners (except for 153 and 180) than mosses from rural sites. PBDE and PCB values were higher in native than in transplanted mosses after 90 days of exposure in both rural and industrial sites.

PBDE Emissions during the Start-up Procedure of an Industrial Waste Incinerator by the Co-Combustion of Waste Cooking Oil and Diesel Fuel

ABSTRACTThis study examined the effect of using waste cooking oil (WCO) as an alternative of diesel on PBDE emissions during the start-up of an industrial waste incinerator (IWI). The co-combustions were designed with 0, 40, and 60% WCO injection and become D100, W40D60, and W60D40 multi-fuel combustions. The flue gas was sampled during 4 temperature stages of the furnace: Stage A ( 850°C). The highest PBDE level was found in Stage A and sharply declined in Stage B by using diesel. The reduction of total PBDE was a competitive result between residue releasing and thermal decomposition in Stage B. The WCO were found to slightly increased the PBDE emissions during the Stage C and D, which provided the suitable temperature for PBDE formation (600–800°C). Therefore, the viscosity became an important control factor when the WCO were utilized as an alternative fuel in IWI operation. The accumulated PBDE emissions during the start-up procedure were 1,099, 1,253, and 1,207 µg by using D100, W40D60, and W60D40, respectively. Additionally, the annual PBDE emissions contributed by start-up procedures increased up to 4.60%, 5.47%, and 5.20% by three fuel combinations, respectively, if the IWI restarted once per month, and became a noticeable issue. Therefore, avoiding unnecessary start-ups was an essential criterion for IWI operation. The small increases (< 1%) of PBDE emissions by altering 40% and 60% diesel with WCO provided a useful information for WCO treatment. This new disposal for waste oil also created a good demonstration of Circular Economy. The overall life-cycle analysis was suggested to be investigated in the following research.

Dioxin-like activities, halogenated flame retardants, organophosphate esters and chlorinated paraffins in dust from Australia, the United Kingdom, Canada, Sweden and China

The concentrations of organic flame retardants (FRs) and dioxin-like activities in dust collected from five countries were investigated. The correlations between the concentrations of the different groups of FRs and dioxin-like activities were examined. Chlorinated paraffins (CPs, C9 to C31) were found in the highest concentration (median ∑CP 700 μg/g, range 280–4750 μg/g), followed by organophosphate esters (median ∑13OPEs 56 μg/g, range 21–110 μg/g), halogenated flame retardants (median ∑17HFRs 3.3 μg/g, range 0.87–14 μg/g) and polybrominated diphenyl ethers (median ∑17PBDEs 2.8 μg/g, range 0.46–11 μg/g). There were no significant differences in concentrations of the FRs among the countries but differences in PBDE and CP congener profiles were found. BDE209 predominated in dust from Australia, the UK, Sweden and China, ranging from 50 to 70% of total PBDEs. The lowest percentage of BDE209 was found in the dust from Canada, representing only 20% of total PBDEs. For CPs in dust from Sweden, the long-chain CPs (especially C18 congeners) predominated, while for other countries, medium-chain CPs (especially C14 congeners) predominated. The dioxin-activities of the dusts ranged from 58 to 590 pg CALUX-TEQ/g, and had a median of 200 pg CALUX-TEQ/g. There were significant positive correlations between concentrations of PBDEs and CPs with dioxin-like activities. The dioxin-like activity may be due to the presence of polychlorinated or polybrominated dioxin/furans (PBDD/DFs) or polychlorinated naphthalenes (PCNs) in the dust. The PBDD/DFs are known impurities and degradation product of the penta-BDE mixture, and PCNs are known impurities of CPs which exhibit dioxin-like activities.

Association between serum concentrations of persistent organic pollutants and gestational diabetes mellitus in primiparous women

BackgroundThere is growing evidence that persistent organic pollutants (POPs) may play an important role in increasing the risk of gestational diabetes mellitus (GDM). ObjectivesThe aim of this study was to examine the association between polychlorinated biphenyls (PCBs, 10 congeners) and polybrominated diphenyl ethers (PBDEs, 8 congeners) and GDM in primiparous women with no family history of diabetes in first-degree relatives during the third trimester of pregnancy. MethodsThis case-control study was performed among the three university hospitals of Tehran University of Medical Sciences. Serum samples were collected from cases (n=70) that were diagnosed with GDM and from controls (n=70) with a normal pregnancy that attended the same hospital for a routine prenatal visit. Pollutant levels were analyzed by Gas Chromatography Mass Spectrometry (GC/MS). ResultsLogistic regression analyses manifested the positive association between total POPs (sum of total PCBs and PBDEs) (Odds ratio (OR)=1.61, 95% CI: 1.31–1.97, p-value <0.0001) and total PCBs (OR=1.75, 95% CI: 1.35–2.27, p-value<0.0001) and GDM considering confounding variables (age, gestational age, pre-pregnancy body mass index (BMI), and total maternal serum lipid). In addition, we found a positive association between total PBDEs and GDM (OR =2.21; 95% CI: 1.48–3.30, p-value <0.0001). Finally, we found a positive association between Ln PCB 187, 118 and Ln PBDE 99, 28 with GDM. Meanwhile a negative association between Ln PCB 28 and GDM was established. ConclusionOur data suggest that exposure to certain POPs (PCBs and PBDEs) could be a potential modifying risk factor for GDM.

Spatial distribution and temporal trends of farmland soil PBDEs: processes and crop rotation effects.

The concentration and temporal trend of PBDEs in farmland soil during a circle of crop rotation period within an e-waste dismantling area of South China were investigated. The averaged current concentration of total PBDEs in the farmland soil was averaged 19.1 ± 20.7ng/g dry weight, which was much lower than the PBDE level in roadside soil and in topsoil near e-waste dismantling sites. Spatial distribution of total PBDEs concentration in the study area showed higher level at the field near e-waste workshops and lower at the distanced farmland area. Soil organic carbon content was significantly correlated with concentration of BDE209 (r = 0.704, p < 0.01), but not related with the sum concentration of other PBDE compounds (r = 0.097, p > 0.1). During the whole crop rotation circle, the temporal concentration of PBDEs in the farmland soil was highest (25.3 ± 11.4ng/g dry wt.) in April when early paddy had been transplanted for 1 or 2weeks. When the crop rotated to autumn peanut in August and the land is turning dry, the PBDEs concentration in farmland soil reached the lowest level which was 8.1 ± 1.2ng/g dry wt. The temporal trend of PBDEs in farmland soil was not consistent with that of atmospheric PBDEs and soil total organic carbon (TOC) content during the rotation cycle. It was concluded that the dynamics of PBDEs in the farmland soil is influenced by multiple, interacting factors, and not clearly related to neither the atmospheric deposition nor the organic carbon content of the soil, but possibly related to the micro-environmental conditions changed by crop rotation process.