Toxicologie environnementale et analytique

An investigation has been made to ascertain the effect of tannery effluent associated with seasonal variation on river water samples collected from confluence point, upstream and downstream located near Jajmau area at Kanpur. All the samples analyzed for physico-chemical parameters including estimation of chromium. The pH at confluence point (Q) was significant (P<0.05) alkaline (7.9±0.13) during summer as compared to upstream point P3 due to dumping of untreated tanneries effluent, which suggested that utilization of salts for leather tanning process. Study shows that a significant (P<0.05) decrease in DO values (3.79±0.101 mg/L) at summer, although the higher level of
DO (6.76±0.13) during monsoon season might be attributed to the dilution of the effluent by rain water. The level of BOD (41.07±1.268 mg/L) shows a significant (P<0.05) increase at confluence point during as compared to upstream point (P3) during summer. Although the level of COD at different sampling points affected with seasonal variation but it was not significant. However this study also revealed a significant negative correlation showing that as BOD and COD increases in values DO decreases with correlation of r = -0.944 (t= 6.978, P<0.05 for BOD) and r = -0.970 (t= 9.696, P<0.05 for COD). These correlation between BOD, COD and DO suggest a similar cause. The correlation analysis of TDS versus BOD and COD gives a positive correlation (r =0.9408 & r =0.8667 respectively) showing that as TDS increase BOD and COD also increases. Theses correlation analysis shows that levels of TDS, BOD and COD are highly correlated with each other in sampling area during different seasonal variation. Chromium levels were high (52.12±15.52 mg/L) in almost all sampling points with seasonal variation, thus tanneries effluent with seasonal variation showed highly adverse effect on river Ganga.

This study aims to demonstrate the exposure of artisanal miners to the contents of mineralised gangue and to assess whether the different workstations and their related operating processes potentiate such exposure. The population sampled (n=100) consisted of artisanal miners operating in the mine of Ruashi, in the south of the Katanga copper belt. We made use of hair as a biomarker and performed our analyses using ICP-MS. According to recommendations from the Agency for Toxic Substances and Disease Registry, we have compared our results to those of an unexposed population living in the same area in order to point out the occupational origins of such exposure. In our hair analysis, we identified and quantified 22 elements. For almost all of these elements, the artisanal miners had much higher values as compared to the control population. In addition, non-diggers had higher levels than diggers for almost all of the elements that could be directly linked to those present in the mineralised gangue. Median values obtained for the artisanal miners were systematically higher than those of the control population, reflecting a higher than normal exposure. Such differences between the two sample populations can only be explained by the occupational (mining) origin of exposure, since the living environment, hair nature, sampling method, and analysis techniques were the same for both populations. Medians within the miner samples showed different exposure profiles for non-diggers versus diggers, resulting from the fact that non-diggers were more exposed to the mineralised gangue. The results attest to the reality and the large extent to which artisanal miners in Katanga Province are exposed to chemical components of mineralised gangue. This exposure is more significant within the workstations related to the raw mineral processing phase as opposed to the extraction phase.

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 current research makes a comparative analysis between the biodegradation of polythene and plastic by five different types of soil sample collected from different sources. The five soil sample (A, B, C, D, E) were indigenous to locations: (A) Medicinal Garden soil, (B) Sewage Water Soil, (C) Energy Park soil, (D) Sludge Area soil, (E) Agricultural Soil, respectively. The ability of these soils in degrading polythene and plastic was investigated. And pure culture with sample, incubate for one week and sub culturing is done in every week, for bacteria and fungi, for the purpose of biodegradation. The initial and final dry weight of polythene and plastic before and after incubation in the culture medium were compared and the % of degradation was calculated. Among all the treatments various species of bacteria and fungi such as Bacillus subtilis, Aspergillus niger, Aspergillus nidulance, Aspergillus flavus, Aspergillus glaucus, Penicillum species, Pseudomonas sp., Staphylococcus aureus., Streptococcus lactis, Proteus vulgaris, Micrococcus sp. were found to degrade polythene and plastic efficiently. However various species of fungi and bacteria isolated from different soil sample. Overall polythene gave rapid biodegradation as compare to plastic. The active enzymes produced by the bacteria and fungi caused weight loss in the sample of polythene and plastic.

Poisons, those silent weapons capable of destroying life mysteriously, secretly and without violence, have ever had a peculiar fascination for mankind. The plant originated weapons or “BOTANICAL WEAPONS (BW)” were also used by criminals in burglary, rape and murder cases. The Botanical weapons are may be the part of the toxic and poisonous plants or may be the toxic constituents of plants.
In India, there are so many cases were available where criminal by mixing it in food material or contact of the irritating toxic parts of the plants to victim’s body in the buses/trains. Poisonous plants are those biological weapons which cause serious problems or even death occur.
These weapons are first choice of professional poisoners in toxi-crime because they are easily available and having no cost. They have played so large a part, in romance as well as in crime, that the subject is one which claims the attention of even student of human nature. Through this article authors have studied some toxic and poisonous plants of India, which are generally used by the criminals to commit the crimes. In this paper, all the toxicological substances of these plants are also mentioned, which provide a prefect database for the forensic toxicologists.

Photocatalysis offers low cost and durable treatment to dyes polluted effluent. But sometimes photocatalyzed dye intermediates appear to be more toxic than parent dye molecule. Present investigation uses suspended TiO2 nanoparticles and sunlight irradiation for photocatalytic treatment of Giemsa dye at optimum pH. Giemsa dye has wide applications in molecular biology, cytology and histology laboratories across the world. Surplus and used dye is discharged in sink drain which is likely to cause hazardous concerns to environment. Paper analyzes toxicity concerns of treated and untreated Giemsa dye. Bioassays incorporating agar well diffusion assay and seed germination were employed to check the toxicity of water. Significant changes were noted in alkalinity, BOD, COD, Ca2+ , Mg2+, NO3-, SO42- ion concentration, hardness, temperature, turbidity and pH; and compared with standards for drinking water, World Health Organization. HPTLC of treated waste water confirmed that photocatalyzed dye intermediates exhibited increased absorbance in visible range of spectrum. At pH 2 various investigated parameters were found to match WHO standards for drinking water. Environmental risk assessment reveals that treated water possessed toxicity at pH 7 and was not found suitable for irrigation and potable purposes. Beside photocatalytic treatment, waste disposal methodology still needs to be accompanied with secondary treatment of water.

The fluoride content in 419 groundwater samples from different sources in Rameswaram area, Southern India was determined in addition to the other physico-chemical parameters. From the results, it was evaluated that about 15% of the groundwater samples were found to contain the F content greater than the WHO recommended limit of 1.5 mg/l. The dental fluorosis survey among the school children also revealed that the percentage of boy victims was greater than the girl victims. The correlation values between Total Alkalinity (TA) and Fluoride (F) is evident for the leaching of Fluoride into the groundwater of the study area.

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.

Oxidative stress is one of the molecular mechanisms involved in chlorpyrifos (CPF) and lead poisoning. The present study investigated the role of vitamin C in mitigating the biochemical alterations induced by co-administration of CPF and lead. Forty adult male Wistar rats divided into 4 groups of 5 animals in each group were used for this study. Group I was dosed with corn oil (2 ml/kg) while group II was given vitamin C (100 mg/kg). Group III was co-administered CPF ( 4.25 mg/kg~ 1/20th LD50) and Pb (225 mg/kg~1/20th LD50) while group IV was pretreated with vitamin C (100 mg/kg) and then co-administered with CPF (4.25 mg/kg) and Pb (225 mg/kg), 30 min later. The regimens were administered once daily by oral gavage for a period of 9 weeks. The rats were sacrificed and sera obtained from the blood samples were analyzed for the total proteins, albumin, globulin, electrolytes (Na+, K+, Cl-), urea and liver malonaldehyde concentrations. The activities of serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase and lactate dehydrogenase were evaluated. The result showed that alterations in the biochemical parameters induced by co-exposure to CPF and lead were mitigated by pretreatment with vitamin C.