環境および分析毒性学

In the present study, cytotoxic, genotoxic and mutagenic actions of different concentrations (1, 10, 100 and 1000 µg/L) of an azo dye (BDCP – Black Dye Commercial Product) were evaluated using different cytogenetic techniques [(conventional dye, C banding, NOR banding, base-specific fluorochrome banding and fluorescent in situ hybridization (FISH)] applied to the Allium cepa test-organism. The use of conventional cytogenetic staining allowed us to determine that the azo dye induced cell death, chromosomal aberrations, nuclear alteration and micronuclei. By means of chromosome bandings and the FISH technique, it was possible to notice both cell and nucleolar alterations induced by BDCP, whose effects, in a general way, were not specific for any chromosome sites. The abnormalities observed made it possible to infer both aneugenic and clastogenic actions caused by the dye analyzed. The cytotoxic, genotoxic and mutagenic effects of BDCP were not completely eliminated, even after the recovery treatment of the A. cepa roots in water, showing a cumulative potential effect of the referred dye. Due to these results, we could infer that the BDCP may be a dangerous contaminant to the environment and, consequently, to the lives of the organisms exposed to it.

Azo dyes pollution has attracted a major environmental concern due to their color and toxicity. In this study, we investigated a biocatalyzed electrolysis system (BES) with a bio-cathode seeding with enriched inoculum for the decolorization of a model azo dye, alizarin yellow R (AYR). The bio-cathode was inoculated with AYR autotrophic biodegrading consortium. Batch test results showed that the decolorization efficiency (DE) of AYR (100mg/L) reached to 93.2% within 58 hours with 0.5V power supplied and NaHCO3 (840 mg/L) as sole carbon source. Lower DEs of 83.5% and 70.7% were respectively observed in abiotic cathode BESs and bio-cathode BESs inoculated with mixed sludge. The result indicated that the enriched inoculum had a significant effect on the cathode performance. The azo bond cleavage of AYR resulted in the formation of p-phenylenediamine, p-nitraniline and 5-aminosalicylic acid. The decolorization efficiency was further enhanced under the optimized condition of pH (5.2), power supplied (0.5V) and initial AYR concentration (100mg/L), reaching up to 99.2 % within 48 hours with the bio-cathode BESs seeding with the enriched inoculum.

The aim of this study was to identify the pharmaceutical substances in the waters of the river Volturno in Campania and to identify the genetic alterations that they induce in fish. These vertebrates, living in water, are particularly sensitive to polluting substances dissolved in their water that interact with DNA leading to the formation of additions or breaks, as well as to the loss or chemical modifications of the bases, because they can conserve and concentrate the substances discharged into their natural habitat. A preventive chemical analysis was carried out on the waters of the river Volturno. The results showed the presence of various drugs, among which Carbamazepine, a known antiepileptic and Diclofenac, a non-steroid anti-inflammatory agent. The genotoxicity of these two compounds was evaluated in 155 individuals of Danio rerio using the Comet Test, the Diffusion Assay and RAPD-PCR. The alkaline version of the Comet Test was used for the erythrocytes of the zebrafish to evaluate the presence of DNA breaks of a single strand. Furthermore, the Diffusion Assay was used to estimate the number of apoptotic cells. The specimens were treated with Carbamazepine and Diclofenac at the same average concentrations found in the river Volturno and were killed after three, seven and fifteen days. The results of the Comet Test showed a statistically significant loss of DNA integrity after only three days of exposure to the drugs. Also the percentage of apoptotic cells reached its maximum values after three days of exposure to Carbamazepine and after one week to Diclofenac. By RAPD-PCR the genotoxicity was evaluated at the molecular level. The amplification products from the individuals exposed to the same concentrations of the environmental pollutants showed significant changes in their electrophoretic pattern with respect to the negative controls. The results of all three tests clearly show the genotoxicity of the compounds analyzed.

Soils contaminated with hydrocarbons are a serious problem in Nigeria and 70% of such soils are distributed in the Niger Delta. This pot experiment was conducted to determine the interactions of selected soil minerals with organic contaminants from oil spill site. V. subterranean, which potential for stimulating the biodegradation processes of petroleum hydrocarbons was established was employed under the application of two fertilizer types. Iron concentrations were greater than maximum permissible levels, MPL for plants grown in contaminated soil and showed significant variation (p > 0.05) compared to control. Poor zinc concentrations in oil –stressed regimes decreases ear size, slowed growth and maturity of specie. Both iron and manganese became less available at pH > 7 in the absence of organic matter and water (dehydrated due to oil – stress). Concentration of available P was sensitive to soil pH and was more available to Poultry manure – amended soil as pH correction was evident. Plant tissue analyses revealed significantly (p ≤ 0.05) higher increases in accumulation, in comparison with those grown in unpolluted (Control) regimes. Also, soils depleted mineral nutrients were replenished (> 30%) by test plant and best practice. These results indicated that soil minerals affect the dynamics and transformations of organic materials and metabolic processes even in a stressed soil type with modifications due to clean-up.

Distillery sludge is an easy source of plant nutrient but its fertilizer value can vary considerably. In the present study anaerobically digested distillery sludge was applied to agricultural soils and its effect on soil biological and biochemical properties was evaluated. The sludge treatments were comprises of 0, 10, 50, 100 and 150 t ha-1 as single application in an agricultural field and tested for six months. Microbial respiration, microbial biomass carbon, FDA hydrolysis, phosphatase, urease and dehydrogenase activity were evaluated temporally throughout the incubation time for different amount of distillery sludge amendments. These parameters were sensitive enough to show the effect of distillery sludge application on soil microorganisms. The results revealed that sludge application at different rates initially increased the microbial activity, its highest activity was found between 30 and 60 days after application when sludge was applied at the rate of 150 t ha-1 but afterwards the microbial activities decreases gradually. Results show that at high dose soil microbial number increases but the diversity of soil microbial population decreases. Aerobic heterotrophic and symbiotic nitrogen fixing bacteria seems to be more sensitive to sludge addition and shows a marked decrease in population on higher doses. The results also shows that the sludge from distillery wastewater treatment plant may have potential as a beneficial soil amendment up to certain extent for improving biological properties of the soil but at higher doses its contamination can create harm for the beneficial soil inhabitant microbial population and their activities