Exposure of ruminants to persistent organic pollutants and potential of decontamination

Human activities are emitting persistent organic pollutants (POPs) to the environment. These compounds have raised concerns about the risk of transfer through the food chain via animal products. They are characterized by a strong persistence in environmental matrices and a lipophilicity which may lead to their accumulation in fat tissues. In EU Regulations (no. 1881/2006, 1259/2011), maximum acceptable levels for polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs), and dioxin-like or nondioxin-like polychlorinated biphenyls (PCBs) in food of animal origin have been set. Transfer rates from contaminated fodder to milk have been established: for PCBs, the rate of transfer varies from 5 to 90 % and for PCDD/Fs from 1 to 40 %. The differential transfer of the compounds towards milk is related to the hydrophobicity of the pollutants and to their metabolic susceptibility. According to numerous authors, soil is the major reservoir for POPs, and its involuntary ingestion by farm animals reared outdoors may be the main cause of animal product contamination (meat, milk, or eggs). Recent studies seem to indicate that soil is a real risk matrix in terms of transfer of pollutants to the food chain. A POP crisis management is extremely difficult, since it impacts many farmers located in the contaminated area. The question arising is to know if livestock contaminated by POPs may be decontaminated and further used for their initial purpose. Recent data demonstrate that the decontamination process appear feasible and depends on initial level of contamination or the physiological status of the animals.     

Relative bioavailability of tropical volcanic soil-bound chlordecone in laying hens (Gallus domesticus)

The former use of chlordecone (CLD) in the French West Indies has resulted in long-term pollution of soils and of food chains. CLD may be transferred into eggs of hens reared outdoors, through polluted soil ingestion. Tropical volcanic soils display variable capacities of pollutant retention: CLD is less available and more persistent in andosol than in nitisol. The impact of soil type on CLD bioavailability to hens was tested through a relative bioavailability study. The deposition of CLD in egg yolk and in abdominal fat was measured in 42 individually housed laying hens fed with diets containing graded levels of CLD from polluted andosol, nitisol, or spiked oil during 23 days. Within each ingested matrix, the concentration of CLD in yolk and in abdominal fat linearly increased with the amount of ingested CLD (P < 0.001). However, the response to andosol diets and to nitisol diets was not different from the response to oil diets (P > 0.1), indicating that CLD was equally bioavailable to laying hens, irrespective of the matrix. This suggests that the hen's gastrointestinal tract efficiently extracts CLD from the two tropical volcanic soils, regardless of their retention capacity. Thus, hens reared on polluted soils with CLD may lay contaminated eggs.     

Removal of chloride from ethylene glycol solution using alumina/zeolite membrane as a physical boundary between the organic and aqueous phases

The permeation of Cl^? ions from a NaCl/ethylene glycol (EG) solution during electrodialysis was investigated using alumina and alumina/zeolite membranes. Voltage changes had very little effect on Cl^? permeation through the alumina membrane, suggesting that the driving force for the permeation was concentration-gradient-induced diffusion, and not the electric field. Solvation of the Na⁺ ions by EG resulted in EG migration through the membrane. Replacement of the deionized water (electrolyte) in the anodic cell with NaOH resulted in increased Cl^? permeation, although a greater amount of EG migrated into the NaOH solution as well. No notable difference was observed in Cl^? permeation through the alumina and alumina/zeolite membranes, but EG migration decreased when using the latter membrane, suggesting that EG migration was prevented by the zeolite layer. The proposed alumina/zeolite membrane is, hence, useful for solvent recovery by electrodialysis, but its mechanical stability must be improved for industrial applications.     

Electrodialysis for NaCl/EG solution using ion-exchange membranes

A new concept for the recycling of poly(vinyl chloride) (PVC) has been introduced, including the dehydrochlorination of PVC in ethylene glycol (EG) with NaOH as a reactant, the subsequent separation of NaCl from EG by electrodialysis, and the recovery of chlorine for the synthesis of new PVC. In this work, the separation of NaCl by electrodialysis was investigated. About 98 % of the salt were recovered from EG, with less than 10 % of the EG permeating the membranes after 5 h.     

PCB and dioxin-like PCB in indoor air of public buildings contaminated with different PCB sources--deriving toxicity equivalent concentrations from standard PCB congeners

Data on dioxin-like PCB in indoor air of buildings with PCB-containing materials and on possible correlation between toxicity equivalent concentrations (TEQ) and levels of non-dioxin-like standard PCB is sparse. As part of a larger survey on indoor-air contamination with PCB, the connection between the concentration of standard PCB congeners and the dioxin-like toxicity expressed as TEQ was investigated. Indoor air samples (n=8) were collected in four public buildings with known PCB sources and total PCB levels in the range from 715 to 2250 ng/m3 and analyzed for the six non-dioxin-like standard PCB (congeners 28, 52, 101, 138, 153, 180), the twelve dioxin-like PCB congeners according to WHO and the 17 2,3,7,8-substituted PCDD/PCDF congeners. In three buildings where PCB were used as flame retardant coatings of acoustic ceiling tiles, PCB 101 had the maximum level among the six standard PCB, while in the building with permanent elastic sealants as PCB source, congeners 28 and 52 dominated the pattern by far. In the case of permanent elastic sealants as PCB source (n=3) a total PCB concentration of 1000 ng/m3 corresponded to a total TEQ level of 0.3-0.6 pg/m3. In contrast, in rooms with acoustic ceiling tiles as PCB source, 1.8-4.7 pg TEQ/m3 per 1000 ng total PCB/m3 were found. Linear regression analysis between PCB and TEQ indicated that PCB 118 might be used to calculate the total TEQ of dioxin-like PCB and PCDD/PCDF. By means of such a correlation it is possible to estimate TEQ by extrapolation from the results of less sophisticated analytical methods. It is tentatively recommended to use PCB 118 for screening purposes or re-evaluation of standard PCB indoor-air measurements. If only the six non-dioxin-like PCB standard congeners are available, a regression algorithm using the sum of PCB 101, 138, 153 and 180 might be used instead.     

Effects of the parasiticide ivermectin on the cladoceran Daphnia magna and the green alga Pseudokirchneriella subcapitata

Although widely used for the treatment of endo- and ectoparasites in livestock and pets, very few data on chronic effects on aquatic organisms are available for the parasiticide ivermectin. In the present study, toxicity of ivermectin to two freshwater organisms, the cladoceran Daphnia magna and the green alga Pseudokirchneriella subcapitata was investigated. For D. magna, a mean LC(50) 48 h of 5.7 ngl(-1) was derived from 10 acute tests. Chronic toxicity of ivermectin to D. magna was extremely high: with 0.001 and 0.0003 ngl(-1), respectively, nominal LOEC and NOEC based on growth and reproduction were far below the analytical limit of detection for this compound. P. subcapitata was considerably less sensitive to ivermectin than D. magna. For both growth rate and yield, EC(50) was >4,000 microgl(-1), LOEC was 1,250 microgl(-1) and NOEC 391microgl(-1). In view of the high toxicity to D. magna, the use of ivermectin might pose a risk to local aquatic ecosystems. Further studies should be carried out to investigate the effects of ivermectin and its degradation products on pelagic and benthic freshwater invertebrates.     

Tetrodotoxin prevents copper-induced bradycardia in gastropod limpets

Acute exposure to waterborne copper is followed by a reduction in heart rate in gastropod limpets. In order to understand the mechanism of this effect, exposure to copper (0.25 or 0.5 mg l(-1); for 3 and 6 h) was combined with an injection of tetrodotoxin (TTX, 20 microl, 0.5 or 1 microM), a natural toxin that inhibits the propagation and transmission of impulses in excitable tissues. Experiments were performed on the Mediterranean limpet Patella caerulea, using a non-invasive method for the recording of cardiac activity. TTX did not affect the bradycardic effect of the cholinergic agonist carbachol. However, this toxin significantly antagonized the bradycardia induced by 0.25 and 0.5mg l(-1) of copper exposure and prevented the acardia observed in some limpets exposed to 0.5mg l(-1) of copper for 6h. These results are consistent with the hypothesis that the inhibitory action of copper on limpet cardiac activity involves an extrinsic, cholinergic neuronal control.     

Determining the role of the method used to recycle polypropylene waste materials from automotive industry using sepiolite and zeolite fillers

Journal of Material Cycles and Waste Management - In this work, the effectiveness of a rapid recycling method of waste polypropylene (WPP) with the addition of inorganic fillers was investigated....     

Alkaline hydrolysis of PVC-coated PET fibers for simultaneous recycling of PET and PVC

Journal of Material Cycles and Waste Management - Polyvinyl chloride (PVC)-coated poly(ethylene terephthalate) (PET) woven fibers are one of the hardest-to-recycle polymeric materials. Herein we...     

Thermal decomposition of tetrabromobisphenol-A containing printed circuit boards in the presence of calcium hydroxide

Journal of Material Cycles and Waste Management - Recycling of printed circuit boards (PCBs) is complicated by the presence of flame retardants containing halogen and phosphorus, as the degradation...