Toxicologie environnementale et analytique

ABC transporters belonging to the subfamilies ABCB (MDR/TAP) and ABCC (CFTR/MRP) are likely to play a role in the detoxification of metallic pollutants. We made an inventory of the transcriptional response of 10 abcb and 9 abcc gene members in zebrafish Danio rerio exposed for 7 days to ionic cadmium (89 nM), zinc (7.3 μM), or a blend of both metals. These concentrations correspond to those found in a polluted tributary of the Lot River, France. The general trend was that cadmium is rather an up-regulator (but for high accumulation factors only) whereas zinc is rather a repressor. In muscles the expression pattern of ABC genes in response to metals appeared unpredictable since there was no relationship between differential expression and metal accumulation. Although no increase of zinc burden was observed in fish muscles and gills exposed to zinc, that metal repressed 9 and 4 ABC genes in muscles and gills, respectively. Despite a 3-fold increase in zinc burden in brain, it triggered the down-regulation of 3 ABC genes. Also, despite an accumulation factor of 7 in muscles, cadmium repressed 2 ABC genes in muscles. However, in gills and liver cadmium exposure caused the up-regulation of 4 and 6 ABC genes linked to accumulation factors of 33 and 25, respectively. Beside MDR- and MRP-transporter encoding genes, metals up regulated other genes encoding zebrafish homologues of TAP2 (abcb3 and abcb3L1), ATM1 (abcb7), M-ABC1 (abcb8), TAPL (abcb9), SUR1 (abcc8) and SUR2 (abcc9) transporters.

The aim of this study was to examine and compare the effects of different ethanol-containing solutions on a 3D oral mucosal model (OMM) with those of fresh oral mucosal biopsies and monolayer keratinocyte cultures. 3D OMMs were engineered by the air/liquid interface culture technique using human oral fibroblasts and keratinocytes. Fresh tissue biopsies were also obtained from patients and divided into small pieces. OMMs, fresh biopsies, and monolayer cultures were exposed to serial dilutions of ethanol in PBS (5% to 50%) for 30 secondss and 60 secondss. Biological response was evaluated using basic histology and the Alamar Blue tissue viability assay. Histological examination showed that the effects of ethanol on the OMMs resembled the fresh tissue biopsies. The 3D model was also able to detect the concentration-dependent and time-dependent effects of ethanol. The TC50 values for the monolayer cultures were significantly lower than those for the 3D models. It can be concluded that ethanol in high concentrations significantly affects the oral mucosal model’s viability and histological appearance. The response of the OMM to ethanol exposure was similar to the response of the fresh clinical biopsies. Monolayer keratinocytes are more sensitive to ethanol than 3D models or biopsies.

The present study was designed to investigate the disappearance of cyanobacterial mat from fish breeding lakes and to evaluate the phytotoxic effects of Penicillin, Ciprofloxacin, and Tylosin as single and as mixtures to cyanobacterial mats. Phytotoxic effects were measured as growth inhibition of cyanobacteria using spectrophotometer at 680 nm at low concentrations of antibiotics. Results showed potential phytotoxicity of the tested antibiotics with EC50 values of Penicillin, Ciprofloxacin and Tylosin of 0.13, 0.71, 5.28 mg/l respectively. Relative toxicity indicated that Penicillin and Ciprofloxacin were more toxic to cyanobacterial mats than Diuron (standard toxic material). EC50 values of binary mixtures are 0.077, 0.103, 0.292 TU, for (Penicillin+Tylosin), (Ciprofloxacin+Tylosin) and (Ciprofloxacin+Penicillin) respectively; whereas EC50 of the tertiary mixture is 0.034 TU. Statistical analysis of the results indicated significant differences between the toxic effects of compounds and their mixtures to cyanobacterial mats. Observation of toxicity of over time indicated that cyanobacterial mats were able to overcome the toxic effects after approximately 72 h of exposure time. It can be concluded that antibiotics exert dangerous toxic effects to cyanobacterial mat, an important organism in the eco-system. These results are considered the first of its kind in Palestine.

Heavy metals are very dangerous to environment and harm to all living organisms e.g. plants and animals etc. They enter the plant through soil and damage the internal mechanisms of plants. Chromium is very toxic to plants as well as animals. It has negative influences on plant growth, mineral nutrients and chlorophyll contents. Increasing its concentration causes reduction in plant growth, Chlorophyll contents and mineral nutrients in Wheat (Triticum aestivum L.). All the parameters were found to be reduced if there is increase in the concentration of chromium.

The effect of semi-static exposition of common carp (Cyprinus carpio L) to different concentrations (0, 10, 50 and 100 μg/L) of the pesticide carbofuran has been evaluated. The following biological responses were measured: (1) ethoxyresorufin-O-deethylase (EROD) and benzyloxy-4-[trifluoromethyl]-coumarin-O-debenzyloxylase (BFCOD) activities, as a phase I biotransformation parameters; and (2) uridine diphospho-glucuronosyltransferase (UDPGT) activity as phase II conjugation enzyme. A clear inhibition of both EROD and BFCOD activities was observed in fish exposed to carbofuran with respect to controls, whereas in the case of UDPGT activity, values of exposed animals showed a clear increase during the experiment with respect to controls.

In this study, investigated the possible mediatory role of salicylic acid (SA) in protecting Zea mays L. “Martha F1” seedlings from glyphosate toxicity. 0.5 mM SA was treated as preemergence and 17-145 mM glyphosate herbicide was treated postemergence to same groups. The effects upon Peroxidase (POD), Ascorbate Peroxidase (APX), Superoxide Dismutase (SOD), Catalase (CAT) reduced glutathione (GSH), Glutathione Reductase (GR), Glutathione S Transferase (GST), lipid peroxidation, total chlorophyll and total soluble carbohydrate content of this herbicide were investigated on the 1st, 5th and 10th days following the treatment.

Preliminary use of performance reference compounds (PRC) spiked into the silicone-membrane/γ-Fe2O3 sampler for in situ calibration has been demonstrated to improve the quantitative nature of water concentration estimates. Hydrophobic polycyclic aromatic hydrocarbons (PAHs), though they occur at significant levels in the environment, were used as PRC because of their relatively high fugacity from the silicone membrane and evidence of their isotropic exchange kinetics. In situ calibrations of silicone-membrane/γ-Fe2O3 sampler spiked with 16 PAHs and the resulting time weighted average (TWA) concentration estimates were compared with similar values of SPE extracts from grab samples. Calibration studies were successfully done and variable environmental conditions (e.g. effects of hydrodynamics and temperature) were found to affect their elimination rates from silicone-membrane/γ-Fe2O3 sampler. A significant increase of elimination rates with change of hydrodynamic conditions from static to turbulent was observed for all compounds under investigation. The technique has also been successfully applied to the detection of freshwater cyanobacterial toxins such as microcystins and cylindrospermopsin.

The study was conducted to evaluate the soil quality and impact of coal mining operations on different physicochemical parameters of soils of paddy fields, located in the vicinity of Raniganj coalfield, India. During the entire study period, bulk density of soil ranges from 1.2 to 1.4 gm/cc, pH varies from 5.2 to 7.4, while electric conductivity fluctuated between 120 – 527 μs /cm, organic carbon content and organic matter varied from 0.29 to 2.05%, 0.5% to 3.5% respectively. The average values of available nitrogen and phosphorus was 94.2 and 5.9kg/ha. Statistical analysis of the data showed positive co-relation of organic carbon with parameters like pH, electrical conductivity, organic matter, available phosphorus and available nitrogen. Bray Curtis similarity analysis shows that there is a similarity of 96.7% between Site VIII and II and 93.68% between site VI and V.

Background: Prenatal exposure to pesticides can adversely affect fetal health. This study aims to measure levels of some pesticides in meconium obtained from newborns whose mothers were exposed to pesticides, and to identify the effect of maternal exposure to pesticides on neonatal weight. Methods: This is a cross-sectional study. It was carried out on 190 cases (106 exposed and 84 non-exposed to pesticides). Nine pesticides (pretilachlor, DDT, lindane, chloropyrifos, diazinon, malathion, bioallethrin, α cyprmethrin and β cyfluthrin) were detected by Gas Chromatography/ Mass Spectrometry (GC/MS). Results: The frequencies of pesticides detection in the samples were: 54.7%, 57.4%, 50%, 35.8%, 53.7%, 49.5%, 34.7%, 41.1% and 21.5% respectively. Those who reported prenatal exposure to pesticides were four times more likely to work in agricultural work (OR=4.5, 95% CI= 2.1- 9.8). Moreover, those who reported prenatal exposure to pesticides were 1.6 times more likely to have babies with low birth weight (OR=1.59, 95% CI=1.2 - 6.3). Conclusions: Agricultural pregnant workers in our community were significantly more exposed to several types of pesticides and this was associated with impaired fetal growth.

Apiculture is one of the most widely spread agricultural subsectors making substantial contribution to household food security through providing income, quality foods and assets to the rural beekeepers in Ethiopia. Ethiopia is endowed with immense apicultural resources and long standing traditional beekeeping practices. Recently, there is a growing pesticides grievance on honeybee population and their products decline with considerable economic impacts on beekeepers. To ascertain the gripe, field assessment was conducted on pesticides use and its economic impacts on the apiculture subsector in three districts of Amhara region (Dangila, Guangua and Mecha) in April 2014. Random household survey was conducted on a total of 270 respondents (90 per district) of which 137 were beekeepers and 133 none beekeepers. From the total respondents, 147 uses pesticides and Dimethoate 40% EC, Ethiolathion 50%, Karate 5EC, 2,4-D were the most often used pesticides. March, June, July and September are identified as pesticides applications months. From the total pesticides users (147), 114 (78%) apply before flowering stage, 25 both before and during flowering stages and the rest applies whenever they feel pests and/ or weeds occur. Besides, more than 60% of the respondents know pesticides kill honeybees and results in dwindling and absconding. Three years trends analysis of honeybee colony number and honey yield indicated dramatic decline mainly attributed to indiscriminate applications of pesticides. This assessment revealed indiscriminate uses of pesticides caused fatalities on 22987 honeybee colonies and incurred economic loss amounting USD 819291.37. This study is appropriate and timely to develop and implement effective development and extension strategies to minimize and/or control the ill effects of accidentally using pesticides.

Ambient particulate matter (PM10 and PM2.5) and carbon monoxide (CO) due to domestic wood burning during the winter and summer months in the city of Escondido were investigated. The data collected from January 2000 to December 2010 from San Diego Air Pollution Control District's (SDAPCD's) collection station in Escondido were analyzed by both non-paired student's t-tests and Mann-Whitney U tests (significance of 0.05 for both tests). For all three pollutants, the significant differences in levels between the winter and summer months, the significant differences in levels during the days that were celebrated as holidays and normal days, and the significant differences in levels between weekends and weekdays were noted. Additionally, the significant differences in levels between night and daytime, early evening hours and night and during burning and smoldering fires were determined for hourly PM2.5 and CO data. For all emission types, traffic patterns did not match the levels of emissions on weekdays, weekends, evenings, or daytimes. Elemental and organic carbon species taken from PM2.5 data correlated with the original PM2.5 filter data. Results of our analysis suggest that wood burning is a source of PM10, PM2.5, and CO in the area.