Implication du polymorphisme d’enzymes de métabolisation et/ou de réparation dans le suivi de travailleurs exposés au styrène, à des solvants, des pesticides ou à l’arsenic

Les cancérogènes environnementaux sont convertis, par des enzymes de métabolisation dits de phase I ou de fonctionnalisation) et des enzymes de phase II ou de conjugaison), en métabolites réactifs pouvant se fixer à l’ADN. La plupart de ces enzymes sont polymorphes : le polymorphisme1 génétique est la base de la susceptibilité individuelle. Il est défini comme une différence par rapport au gène de référence, observée chez au moins 1 % des individus. Pour des expositions équivalentes, deux individus de même poids, même âge, même sexe peuvent avoir des taux plasmatiques2 de toxiques ou de métabolites variant de 1 à 1000 s’expliquant par des capacités d’absorption, de métabolisation et d’élimination différentes régulées génétiquement. La réponse toxique d’un individu vis-à-vis d’un contaminant va dépendre de ses capacités à transporter la substance, à la métaboliser et à réparer les lésions initiales sur l’ADN. Les enzymes de réparation sont aussi polymorphes. L’identification de certains variants alléliques3 de gène comme marqueurs de susceptibilité4 peut constituer un outil précoce de diagnostic et de pronostic

Exposition à des moisissures dans le milieu hospitalier et dans des usines de production de biogaz-Intérêt des protections individuelles et collectives

Les champignons filamenteux se développent de manière ubiquitaire sur de nombreux substrats organiques. Les spores se retrouvent dans les poussières et sont souvent inhalables. De plus en plus de données scientifiques pointent l’inhalation de moisissures comme cause d’allergie respiratoire ou cutanée aussi bien dans l’environnement (maisons insalubres) que dans le milieu du travail, notamment dans les industries de compostage de matière organique ou de fabrication de bioéthanol. La contamination peut aussi avoir lieu via les systèmes d’air conditionné. Les spores par elles-mêmes engendrent des effets toxiques à l’origine d’allergie. De plus, elles produisent des toxines. Les risques de développement de moisissures dans l’air inspiré sont bien connus en milieu hospitalier et plus particulièrement chez les personnes immunodépressives. Néanmoins, la présence des ces éléments fongiques en milieu de travail est responsable de rhinites, toux et problèmes dermatologiques, chez les travailleurs non immunodéprimés. Notre note portera sur la contamination de l’air en milieu hospitalier et dans un laboratoire de mycologie ainsi que sur les risques liés à l’air conditionné. Le dernier article relatera les effets subis par les travailleurs lors du compostage et de la fabrication de bioéthanol

Response to Comments of Peter G. Mantle

The apparently high yield of testis tumors (25%) in rats exposed long-term to Ochratoxin A (OTA) is uninterpretable without data on tumor yield in unexposed rats. Conversely, our demonstration that prenatal exposure to OTA induces DNA adducts in the testes of newborn mice and the absence of these adducts in the testes of mice not exposed prenatally to OTA, is evidence for the presumptive carcinogenicity of OTA in the testis. Together with recent data showing that prenatal exposure to OTA depresses expression of DMRT1, a tumor suppressor gene in the testis, our findings suggest that OTA may be a cause of testicular cancer

Effect of cytostatic drugs on the sludge and on the mixed liquor characteristics of a cross-flow membrane bioreactor: Consequence on the process

The influence of cyclophosphamide and its principal metabolites (CPs) on the physicochemical properties of the mixed liquor of a cross-flow membrane bioreactor and the consequences for membrane fouling were investigated. The influence of CPs was determined by comparing the performance of two bioreactors running in parallel, MBR-CPs (with CPs) and MBR-control (without CPs). The physicochemical properties of the mixed liquor were characterized by soluble extracellular polymeric substances (soluble EPS content), particle size distribution and specific cake resistance. Results suggested that the CP toxicity altered the characteristics of the biological matrix of the activated sludge. Micro-organisms exposed to CPs showed higher endogenous respiration rates than MBR-control micro-organisms. The accumulation of soluble EPS and the formation of small particles (in MBR-CPs after cross-flow velocity was raised) increased the resistance to filtration. The fouling potential of the supernatant seemed to be linked more closely to the concentration of polysaccharides than of proteins and humic substances. Modifications of the membrane performance were observed. Under operating conditions, membrane fouling was faster in MBR-CPs than MBR-control. Moreover, the membrane played an important role in the permeate quality and the overall performance of the process, making possible the biological treatment of such an effluen

Cytoxicity and cytostatic drug removal in a membrane bioreactor from wastewater

The growing use of antineoplastic drugs in cancer therapy is an emerging issue in environmental research. The presence of the anticancer drug cyclophosphamide (CP) in municipal wastewater raises several environmental problems. Besides its cytotoxic effects, CP possesses teratogenic and mutagenic properties and is a known human carcinogen. The application of membrane bioreactor (MBR) technology was investigated with the aim of evaluating its potential for cytostatic drug bioremoval. The toxicity removal was assessed from biomarkers tests and related to the choice of the reactor operating conditions. The influence of sludge retention times (SRT) on CP removal was suited but not significant effects were found for variation of SRT from 50 days to 70 days. CP removal up to 80% was achieved under studied operating conditions. In front of such pollution, evidence has been made about the use of MBR. Our study proofed that advances wastewater treatment using a MBR provides a suitable process for lowering CP concentrations before discharge into the aqueous environment. However, a tertiary treatment is necessary for the complete elimination of toxicity

Cyclophosphamide removal from water by nanofiltration and reverse osmosis membrane

The rejection of cyclophosphamide (CP) by nanofiltration (NF) and reverse osmosis (RO) membranes from ultrapure (Milli-Q) water and membrane bioreactor (MBR) effluent was investigated. Lyophilization–extraction and detection methods were first developed for CP analysis in different water matrices. Experimental results showed that the RO membrane provided excellent rejection (>90%) under all operating conditions. Conversely, efficiency of CP rejection by NF membrane was poor: in the range of 20–40% from Milli-Q water and around 60% from MBR effluent. Trans-membrane pressure, initial CP concentration and ionic strength of the feed solution had almost no effect on CP retention by NF. On the other hand, the water matrix proved to have a great influence: CP rejection rate by NF was clearly enhanced when MBR effluent was used as the background solution. Membrane fouling and interactions between the CP and water matrix appeared to contribute to the higher rejection of CP

Cyclophosphamide removal by nanofiltration and reverse osmosis membranes - effect of water matrix properties

The rejection of cyclophosphamide (CP) by nanofiltration (NF) and reverse osmosis (RO) membranes from ultrapure (Milli-Q) water and membrane bioreactor (MBR) effluent was investigated. Experimental results showed that the RO membrane provided excellent rejection (>90%) under all operating conditions. Conversely, efficiency of CP rejection by NF membrane was poor: in the range of 20-40% from Milli-Q water and around 60% from MBR effluent. Trans-membrane pressure, initial CP concentration and ionic strength of the feed solution had almost no effect on CP retention by NF. On the other hand, the water matrix proved to have a great influence: CP rejection rate by NF was clearly enhanced when MBR effluent was used as the background solution. Membrane fouling and interactions between the CP molecule and water matrix appeared to contribute to the higher rejection of CP

Cytotoxicity micropollutant removal in a crossflow membrane bioreactor

The application of membrane bioreactor (MBR) technology was investigated with the aim of evaluating its potential for cytostatic drug and cytotoxicity bioremoval. The toxicity removal was assessed from biomarker test. CP removal of up to 80% was achieved under the operating conditions studied (HRT of 48 h and a SRT of 50 days). The increase of TMP was associated with an increase of supernatant toxicity as if fouling led to retention of the toxicity. Peaks of supernatant cytotoxicity were correlated with peaks in supernatant humic acid contents. It may suggest that molecules with a toxic effect may be adsorbed or entrapped in humic acids substances. Our study then points out that advances in wastewater treatment using an MBR can provide a suitable process for lowering CP concentrations before discharge into the aqueous environment. However, a tertiary treatment is necessary if complete elimination of toxicity is targeted

Occurrence of ochratoxin A and citrinin in Czech cereals and comparison of two HPLC methods for ochratoxin A detection.

The aims of the study were to obtain information about the occurrence of ochratoxin A (OTA) and citrinin (CIT) in cereals harvested in the Czech Republic and to compare two analytical procedures for detecting OTA. A total of 34 cereal samples, including two matrix reference materials (R-Biopharm, Germany), were analysed. The results were compared with the limit for raw cereal grains used as a foodstuff according to Commission Regulation No. 1881/2006, which allows a maximum OTA level of 5 µg kg−1. Compared were two methods based on the high-performance liquid chromatography principle, one using the immunoaffinity columns OchraTest™ (VICAM) and the second based on solvent partition (PART), both followed by fluorescence detection. The highest OTA contents were found in two barley samples. According to the method employed, the results for the first sample (malting barley) were VICAM = 31.43 µg kg−1 and PART = 44.74 µg kg−1. For the second sample (feeding barley) they were VICAM = 48.63 µg kg−1 and PART = 34.40 µg kg−1. Two samples of bread wheat had an OTA content approaching the legal limit (VICAM = 4.71 µg kg−1 and PART = 6.03 µg kg−1; VICAM = 4.12 µg kg−1 and PART = 3.95 µg kg−1). CIT was analysed using the PART method only, and its highest content (93.64 µg kg−1) was found for the malting barley sample with high OTA content (44.74 µg kg−1 as analysed using PART)

Transfer of Ochratoxin A into Tea and Coffee Beverages

International audienceOchratoxin A (OTA) is nephrotoxic, hepatotoxic, immunotoxic, neurotoxic, reprotoxic, teratogenic, and carcinogenic (group 2B), being characterized by species and sex differences in sensitivity. Despite the fact that OTA is in some aspects a controversial topic, OTA is the most powerful renal carcinogen. The aim of this study was to make a small survey concerning OTA content in black tea, fruit tea, and ground roasted coffee, and to assess OTA transfer into beverages. OTA content was measured using a validated and accredited HPLC-FLD method with a limit of quantification (LOQ) of 0.35 ng/g. The OTA amount ranged from LOQ up to 250 ng/g in black tea and up to 104 ng/g in fruit tea. Black tea and fruit tea, naturally contaminated, were used to prepare tea infusions. The transfer OPEN ACCESS Toxins 2014, 6 3439 from black tea to the infusion was 34.8% ± 1.3% and from fruit tea 4.1% ± 0.2%. Ground roasted coffee naturally contaminated at 0.92 ng/g was used to prepare seven kinds of coffee beverages. Depending on the type of process used, OTA transfer into coffee ranged from 22.3% to 66.1%. OTA intakes from fruit and black tea or coffee represent a non-negligible human source