Dietary uptake of polybrominated diphenyl ethers (PBDEs), occurrence and profiles, in aquacultured turbots (Psetta maxima) from Galicia, Spain

Polybromodiphenyl ethers (PBDEs) are one of the many toxic chemicals present in the environment and in the food we eat every day, being fish one of the main sources of persistent organic pollutants in our diet; like other lipid-related contaminants, they are of concern since they can bioaccumulate and biomagnify through the trophic chain. We published a study focused on the dietary uptake of dioxins and furans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) in a set of samples of Spanish farmed turbot (Blanco et al., 2007). In the present paper, we extend the study to PBDEs to provide more information about the uptake and transfer from feed to fish of halogenated contaminants. PBDEs in the feeds (2.35-4.76 ng g(-1)) were reflected in turbot fillets (0.54-2.05 ng g(-1)): predominant congeners were tetra-BDE 47, penta-BDEs 99 and 100. It is remarkable that tetra-BDE 49, accounting for only 2% in the feed, contributed to 15% of total PBDEs in turbot fillets. Dietary net accumulation values, 30-45%, showed that tri-, tetra-, penta- and hexa-BDEs were as efficiently transferred into turbot as dl-PCBs and tetra- and penta-chlorinated PCDD/Fs. Lipid-normalized biomagnification factors relating concentration in fish and in feed, BMFs>1 were obtained, except for BDE 209. BDE 49 accumulation, 90%, was possibly contributed by metabolism of higher brominated BDEs. Implication in aquaculture management is a need for uncontaminated fish feed to offer safe products.     

Sociodemographic, reproductive and dietary predictors of organochlorine compounds levels in pregnant women in Spain

Organochlorine pesticides and polychlorinated biphenyls (PCBs) are consistently found in human tissues. Serum levels of organochlorine compounds (OC) in pregnant women in particular have raised concern about possible harm to humans in the early phases of physical and behavioural development. The objective of the present study was to evaluate the association between concentration of OCs in serum of two cohorts of pregnant women from Gipuzkoa and Sabadell in Spain and socioeconomic, reproductive and dietary variables. Concentration of polychlorinated biphenyls (PCBs: 28, 52, 101, 118, 138, 153 and 180), hexachlorobenzene (HCB), beta and gamma-hexachlorocyclohexane (β-HCH and γ-HCH), heptachlor epoxide, dichlorodiphenyl dichloroethylene (p,p'-DDE) and dichlorodiphenyl trichloroethane (p,p'-DDT) were measured in the serum of 1259 pregnant women. Associations between OCs and potential predictor variables were assessed using linear regression models adjusted for potential confounders. The compounds most commonly found in the serum were p,p'-DDE (99% of the samples) and PCB-153 (95% of the samples). Geometric means of serum concentrations (ng g?1 lipid) of organochlorine pesticides were 110.0, 19.1, and 33.5 for p,p'-DDE, β-HCH, and HCB respectively, while the geometric means of PCBs were 21.8, 38.9 and 26.9 for PCB 138, 153, and 180 respectively. The levels of all OCs increased with age. BMI was positively associated with the concentration of organochlorine pesticides but inversely related to PCB concentrations. The serum levels of OCs fell only after a cumulative period of breastfeeding of over a year. Levels of PCBs were related to fish intake, but in general dietary factors did not improve the explained variability of the concentrations of OCs. Overall, the levels of OCs found in the study are at the lower end of the range reported in Spain and other countries.     

Printed wiring boards for mobile phones: characterization and recycling of copper

The popularization of mobile phones, combined with a technological evolution, means a large number of scrap and obsolete equipment are discarded every year, thereby causing economic losses and environmental pollution. In the present study, the printed wiring boards scrap of mobile phones were characterized in order to recycle some of the device components, using techniques of mechanical processing, hydrometallurgy and electrometallurgy. The use of the techniques of mechanical processing (milling, particle size classification, magnetic and electrostatic separation) was an efficient alternative to obtain a concentrated fraction (mainly iron in the magnetic fraction and copper in the conductive fraction) and another fraction containing polymers and ceramics. At the end of mechanical processing, a concentrated fraction of metals could be obtained with an average concentration of 60% copper. This concentrated fraction in metals was dissolved in aqua regia and sent to electrowinning to recover 92% of the dissolved copper. The obtained cathodes have a copper content above 95%, which demonstrates the technical feasibility of recovery of copper using the techniques of mechanical processing, hydrometallurgy and electrometallurgy.     

The Properties of Poly(<Emphasis Type="SmallCaps">l</Emphasis>-Lactide) Prepared by Different Synthesis Procedure

Different synthesis methods were applied to determine optimal conditions for polymerization of (3S)-cis-3,6-dimethyl-1,4-dioxane-2,5-dione (l-lactide), in order to obtain poly(l-lactide) (PLLA). Bulk polymerizations (in vacuum sealed vessel, high pressure reactor and in microwave field) were performed with tin(II) 2-ethylhexanoate as the initiator. Synthesis in the vacuum sealed vessel was carried out at the temperature of 150 °C. To reduce the reaction time second polymerization process was carried out in the high pressure reactor at 100 °C and at the pressure of 138 kPa. The third type of rapid synthesis was done in the microwave reactor at 100 °C, using frequency of 2.45 GHz and power of 150 W at the temperature of 100 °C. The temperature in this method was controlled via infrared system for in-bulk measuring. The solution polymerization (with trifluoromethanesulfonic acid as initiator) was possible even at the temperature of 40 °C, yielding PLLA with narrow molecular weight distribution in a very short period of time (less than 6 h). The obtained polymers had the number-average molecular weights ranging from 43,000 to 178,000 g mol⁻¹ (polydispersity index ranging from 1 to 3) according to the gel permeation chromatography measurements. The polymer structure was characterized by Fourier transform infrared and NMR spectroscopy. Thermal properties of the obtained polymers were investigated using thermogravimetry and differential scanning calorimetry.     

Forecasting model to assess the potential of secondary lead production from lead acid battery scrap

Environmental Science and Pollution Research - Lead acid battery (LAB) scrap management is an important issue both environmentally and economically. The recovery of lead from battery scrap leads to...     

Ovariectomy predisposes female rats to fine particulate matter exposure’s effects by altering metabolic,oxidative, pro-inflammatory,and heat-shock protein levels

Environmental Science and Pollution Research - The reduction of estrogen levels, as a result of menopause, is associated with the development of metabolic diseases caused by alterations in...     

Biochar as low-cost sorbent of volatile fuel organic compounds: potential application to water remediation

Pyrolysis of waste materials to produce biochar is an excellent and suitable alternative supporting a circular bio-based economy. One of the properties attributed to biochar is the capacity for sorbing organic contaminants, which is determined by its composition and physicochemical characteristics. In this study, the capacity of waste-derived biochar to retain volatile fuel organic compounds (benzene, toluene, ethylbenzene and xylene (BTEX) and fuel oxygenates (FO)) from artificially contaminated water was assessed using batch-based sorption experiments. Additionally, the sorption isotherms were established. The results showed significant differences between BTEX and FO sorption on biochar, being the most hydrophobic and non-polar contaminants those showing the highest retention. Furthermore, the sorption process reflected a multilayer behaviour and a relatively high sorption capacity of the biochar materials. Langmuir and Freundlich models were adequate to describe the experimental results and to detect general differences in the sorption behaviour of volatile fuel organic compounds. It was also observed that the feedstock material and biochar pyrolysis conditions had a significant influence in the sorption process. The highest sorption capacity was found in biochars produced at high temperature (>?400 °C) and thus rich in aromatic C, such as eucalyptus and corn cob biochars. Overall, waste-derived biochar offers a viable alternative to be used in the remediation of volatile fuel organic compounds from water due to its high sorption capacity.

     

Simultaneous removal of metronidazole and Pb(II) from aqueous solution onto bifunctional activated carbons

Environmental Science and Pollution Research - In this work, it was analyzed the behavior of three commercial activated carbons with different textural and chemical properties to adsorb...     

High CO2 adsorption on improved ZSM-5 zeolite porous structure modified with ethylenediamine and desorption characteristics with microwave

Journal of Material Cycles and Waste Management - Synthesized zeolite Socony Mobil-5 (ZSM-5) with large pore surface structures and modified with ethylenediamine were used to achieve high CO2...     

PCBs,PBDEs and dioxin-related compounds in floor dust from an informal end-of-life vehicle recycling site in northern Vietnam: contamination levels and implications for human exposure

Floor dusts from Vietnamese end-of-life vehicle (ELV)-processing households were investigated to elucidate the contamination levels and exposure risk of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and dioxin-related compounds (DRCs). The concentrations were in order of PBDEs (260–11,000, median 280 ng/g overall) > PCBs (19–2200, median 140 ng/g) > dioxin-like PCBs (8.8–450, median 22 ng/g) ? polybrominated dibenzo-p-dioxin/dibenzofurans (PBDD/Fs, 2000–28,000, median 8500 pg/g) > polychlorinated dibenzo-p-dioxin/dibenzofurans (PCDD/Fs, 440–4100, median 1800 pg/g) > MoBPCDD/Fs (1.9–1200, median 250 pg/g). Concentrations of PCBs and DRCs were higher than those reported for Vietnamese urban houses, indicating ELV processing as a significant source of these contaminants. Higher concentrations of PCBs relative to PBDEs suggest the abundance of old electrical capacitors/transformers in ELVs. The PBDD/F and PCDD/F profiles were indicative of DecaBDE-containing materials and combustion sources, respectively. PBDFs, PCDFs and DL-PCBs were the most important dioxin-like toxic equivalent (TEQ) contributors. The estimated PCB and TEQ intake doses from dust ingestion approached or exceeded the reference doses for children living in some ELV-processing households, indicating potential health risk. More comprehensive risk assessment of the exposure to PCBs and DRCs is required for residents of informal ELV recycling sites.