Chlorinated Phenolic Compounds in Bleaching Filtrates from a Mixed Eucalyptus and Acacia Pulp Using Different Sequences (original) (raw)
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Mutation Research/Genetic Toxicology and Environmental Mutagenesis, 1997
The genotoxicity of effluents collected from a conventional 5-stage softwood kraft pulp bleaching process was studied in Ž . Ž . Chinese hamster ovary CHO cells in vitro. Spent liquor from the first chlorination stage CrD , where elemental chlorine and chlorine dioxide had been used in equal proportions, was shown to induce a dose-dependent increase in sister chromatid Ž . Ž . exchanges SCEs without metabolic activation 4-h treatment , with a maximum increase of 1.6 times over the control level at 204 mlrml; this dose also induced 15.5-and 20.5-fold increases in cells with chromatid-type chromosomal aberrations after 4-h and a 20-h treatment, respectively. Another CrD stage spent liquor from a process where the ratio of elemental chlorine and chlorine dioxide had been 9:1 produced a 40.5-fold elevation of cells with chromatid-type aberrations at 204 Ž . Ž m l r ml 20-h treatment . This sample clearly increased chromosomal aberrations also when tested as a concentrate 4-h . treatment , which showed that the observed clastogenicity was not unspecifically due to the relatively large volumes used in the treatments with the unconcentrated liquors. In general, the use of rat liver S9 mix reduced the genotoxicity of the spent liquors. The results agree with earlier findings on the Salmonella mutagenicity of the same CrD samples: both the prokaryotic and eukaryotic assays showed a reduction in genotoxicity when the amount of elemental chlorine in the bleaching process was reduced. An effluent sample collected from the alkaline stage of the process was not clastogenic with or without metabolic activation. Methanesulfonyl chloride, a new compound identified in bleaching plant air, was found to be induce chromosomal aberrations in the presence of S9 mix.
Brazilian Journal of Biology, 2012
Toxicity and genotoxicity tests were performed on root cells of Allium cepa in order to evaluate wastewater quality following an ECF cellulose bleaching process. The results revealed a toxic effect of the effluent, with inhibition of meristem growth and generally lower values of metaphase, anaphase and telophase indices at pH 10.5 than pH 7 for all effluent concentrations. The genotoxicity effect was different from the toxic effect given that the micronucleus and the chromosomal aberration tests in anaphase-telophase cells were low over all ranges of the studied effluent concentrations.
Objectives: To explore the acute toxicity of major aquatic pollutants like mercuric chloride (HgCl2) and polychlorinated by phenyls (PCB) and their effects based on the haematology of fresh water fish Danio rerio (Zebra fish). Methods: Zebra fish (Danio rerio) were exposed to progressive concentrations of HgCl2 and PCB. The fishes were exposed to various concentrations of 5, 10, 20, 30, 40, 50 and 60 µg/L of mercury and PCB for a period up to two weeks. Haematological tests (total RBC, WBC count and haemoglobin concentration) were carried out on each concentration as well as control for a period of 2 weeks. Results: It was observed that, in exposure time from 0, 7 and 14 days, the total erythrocyte (RBC), leucocytes (WBC) haemoglobin (Hb) values decreased. The exposure to sub lethal doses of Mercury and PCB for 1, 7 and 14 days exposure period causes significant(Values are expressed as means ± SD. Significant difference between groups were compared to control, *p <0.01, **p <0.05) time and dose dependent alterations in total RBC, WBC and haemoglobin count compared to the control values. Conclusions: Haematological parameters constitute one of the important methods to access the health or ill health of an organism, subjected to intoxication. This demonstrates the physiological dysfunction of the haemopoietic system. Hgcl2 is a heavy metal that causes symptoms in human like and gastrointestinal disturbances, anaemia, anorexia, loss of weight, chronic inflammations of kidneys. PCB exposure in animals has been reported to develop Wasting syndrome, reduced body weight, immune toxicity, vitamin A deficiency, and thyroid hormone deficiency, reproductive effects in offspring like reduced birth weight, abnormal gonad development. It also affect the central nervous system which results in slowed learning and memory loss, and also responsible for other behavioural changes. Thus toxicity bioassay is the basic tool for the detection, evaluation and abatement of water pollution
A Possible Relationship Between Toxicity and Carcinogenicity
Journal of the American College of Toxicology, 1986
Carcinogenic response is compared to noncarcinogenic toxicity in that group of chemicals tested by the National Cancer Institute (NCI) and National Toxicology Program (NTP) between 1976 and 1982 and reported in the Carcinogenesis Technical Report Series. A positive finding of carcinogenicity in the bioassay is correlated with the degree of noncarcinogenic chronic toxicity of the dose applied. Comparisons of acute toxicity (LDSo) with carcinogenic potency show that they are correlated, but the correlation may in part be an artifact, since doses used in the NCI/NTP carcinogenesis bioassays are toxic and because reliable measures of potency can only be derived for positive carcinogenic responses, The high correlations for certain classes of chemicals and the relationship of chronic toxicity to positive carcinogenic finding suggest that these relationships are more than spurious. Since toxicities in different species are highly correlated, these findings imply that carcinogenicities in different species are also correlated.
The Journal of Toxicological Sciences
The oral intubation of chlorpyrifos, an extensively used organophosphate insecticide, was tested for its capability to induce in vivo genotoxic upshot in blood lymphocytes of 24 male and female Wistar rats using biomarker of genotoxicity. Rats were orally administered with daily doses 3 and 12 mg/kg body weight (BW) of chlorpyrifos (CPF). The blood lymphocytes were harvested after 7 and 14 days of treatment and subjected to bi-nucleus (BN), multi-nucleus (MN) and single cell gel electrophoresis (comet assay) to evaluate the extent of DNA damage. Other than BN and MN assay, damage to DNA was assessed through comet length, height, area, head diameter, head DNA percentage and tail DNA percentage along with tail movement. A significant boost was noticed in the frequency of BN cells formation after 12 mg/kg BW CPF treatment. However, the propensity to produce MN cells was significantly more (P ≤ 0.05) in males than that of females. Likewise, the frequency of comet formation, mean comet length, height and area were more (P ≤ 0.05) in males than females even with 12 mg/kgBW. Comet head DNA % and tail length remained non-significant. Olive movement also revealed a significant increase (P ≤ 0.05) in males than females. The study inferred that the CPF can induce DNA damage in both male and female subjects but more pronounced in the male individuals.
Environmental Health Perspectives, 2009
for comments on the manuscript. J.P.M. is CEO/chief scientist for Environmental Health Sciences (EHS), a not-for-profit organization that receives support from several private foundations (listed at http://www.environmentalhealthnews. org/about.html) to support EHS's mission to advance public understanding of environmental health sciences. In addition to serving on the faculty of the University of Missouri, F.v.S. is CEO of XenoAnalytical LLC, a small private laboratory that performs assays of xenobiotic compounds. R.T.Z. declares he has no competing financial interests.
Toxicological effects of major environmental pollutants: an overview
Environmental Monitoring and Assessment, 2013
The last quarter of the twentieth century had witnessed a global surge in awakening against the unabated menace of environmental pollution. Among the various types of environmental pollution, water pollution is an age-old problem but it has gained an alarming dimension lately because of the problems of population increase, sewage disposal, industrial waste, radioactive waste, etc. Present scenario of water pollution calls for immediate attention towards the remediation and detoxification of these hazardous agents in order to have a healthy living environment. The present communication will deal with the toxicological effects of major environmental pollutants, viz. heavy metals, pesticides, and phenols.