Search

Physicochemical characterization of particulate matter fractionated into eight samples by size from 10 to 0.43 microm was performed by HS-SPME/GC-MS for the organic (semi-)volatile components and SEM X-ray microanalysis (SEM/EDX) for analysis of the elemental composition. The HS-SPME technique was shown to be efficient with respect to requiring an extremely low amount of material, being selective and clean and avoiding use of any solvents. Particulate matter was collected at four sites characterized by particular environmental locations and different pollution levels around the city of L'Aquila in central Italy. The results reveal a tight correlation between the particle composition, size, and the emission source. The analyses show also that the finer the particle, the higher its content of elemental carbon and organic compounds. Well-known carcinogens such as PAHs were detected among the identified organic compounds from both the rural and highly polluted sites.

Bu çalışma, Uludağ Üniversitesi Fen Bilimleri Enstitüsünde Tülay Özcan'ın danışmanlığında Pınar Aydınol tarafından yazılan "Farklı dumanlama tekniklerinin Füme Çerkez peynirinin özellikleri üzerine etkisi" adlı yüksek lisans tezine dayanılarak hazırlanmıştır. The objective of this study was to determine the effects of natural smoke and liquid smoke application methods on quality characteristics of smoked Circassian cheese. The microbial counts of liquid smoked cheeses were found to be higher than naturally smoked cheeses. It can be concluded that although natural smoke inhibited the growth of micro-organisms more than liquid smoke application, benzo[a]pyrene, an indicator component for polycyclic aromatic hydrocarbons (PAH), was detected on the outer surface of naturally smoked cheeses. Therefore, liquid smoking could be used as an alternative method for smoked Circassian cheese production.

Benzo(a)pyrene (B[a]P) can induce somatic mutations, whereas its potential to induce germ cell mutations is unclear. There is circumstantial evidence that paternal exposure to B[a]P can result in germ cell mutations. Since DNA adducts are thought to be a prerequisite for B[a]P induced mutations, we studied DNA adduct kinetics by P-32-postlabeling in sperm, testes and lung tissues of male mice after a single exposure to B[a]P (13 mg/k9 bw, by gavage). To investigate DNA adduct formation at different stages of spermatogenesis, mice were sacrificed at Day 1, 4, 7, 10, 14, 21, 32, and 42 after exposure. In addition, DNA repair deficient (Xpc(-/-)) mice were used to study the contribution of nucleotide excision repair in DNA damage removal. DNA adducts were detectable with highest levels in lung followed by sperm and testis. Maximum adduct levels in the lung and testis were observed at Day I after exposure, while adduct levels in sperm reached maximum levels at similar to 1 week after exposure. Lung tissue and testis of Xpc(-/-) mice contained significantly higher DNA adduct levels compared to wild type (Wt) mice over the entire 42 day observation period (P < 0.05). Differences in adduct half-life between Xpc(-1-) and Wt mice were only observed in testis. In sperm, DNA adduct levels were significantly higher in Xpc(-1-) mice than in Wt mice only at Day 42 after exposure (P = 0.01). These results indicate that spermatogonia and testes are susceptible for the induction of DNA damage and rely on nucleotide excision repair for maintaining their genetic integrity. Environ. Mal. Mutagen. 51:123-129, 2010. (C) 2009 Wiley-Liss, Inc.

Solid-phase extraction with Tenax® is one of the most used methods for determining the fraction of a pollutant that desorbs rapidly from sediment and thus is available for living beings. In the present study, this technique has been applied to sediment contaminated in the laboratory with polybrominated diphenyl ethers (PBDEs) and dichlorodiphenyltrichloroethane, dichlorodifenyldichloroethylene, and dichlorodifenyldichloroethane (generically, DDXs). The amount of chemical retained in sediment during the time of the experiment fit well with a three-phase exponential desorption model. The ratios between the rapidly desorbing fraction and the fraction desorbed during a fixed time (6 or 24 h) were calculated. The fraction desorbed in 6 h was lower than the rapidly desorbing fraction for most of PBDEs, whereas the fraction desorbed in 24 h exceeded the rapidly desorbing fraction for both groups of compounds. However, variability of these data suggests, when possible, a long time measure of desorption in order to achieve a more accurate estimation. Both the extent and the velocity of desorption were inversely related with the bromination degree and, consistently, with hydrophobicity and molecular size. In this way, low brominated PBDEs and DDXs showed a high availability relative to high brominated PBDEs.

8 pages, 4 figures, 4 tables., Since the 1980s, brominated flame retardants (BFRs) have been detected in air, sewage sludge, sediment, fish, shellfish, birds, and mammals, including humans. However, model studies regarding BFR food-chain accumulation are scarce. In the present study, the accumulation of hexabromocyclododecane and brominated diphenyl ethers (BDEs) 47, 153, 154, and 183 in benthivorous barbel (Barbus graellsii) and pelagic bleak (Alburnus alburnus) from four locations in the Ebro river basin in Spain was modeled using a first-order, one-compartment model with sediment interaction. The model accounted for BFR uptake from water, ingested sediment, and food; release via water and feces; growth; and in situ binding of BFRs to black carbon. Rate constants were derived from allometric regressions. For most BFRs, dynamically modeled biota–sediment accumulation factors (BSAFs) were close to measured values, whereas steady-state model BSAFs were too high, especially for BDEs 153, 154, and 183. Differences between BSAFs for individual fish were explained by differences in age, growth, and feeding behavior. On average, modeled BSAFs for barbel were 50% higher than those for bleak because of extra BFR uptake through sediment ingestion and older age of barbel specimens., The authors thank Caroline Moermond, John Beijer, Agustina de la Cal, and Demetrio Raldua for their contributions to this work. This research project was partly funded by the European Union under the Global Change and Ecosystems (FP6) Water Cycle and Soil Related Aspects (AQUATERRA, project 505428, subprojects TREND and BASIN).