Role of toxicants

ReuberMD. 1981. The role of toxicity in the carcinogenicity of endosulfan. Sci Total Environ 20 23-47. 

Winyard, P.G., Perrett, D., Harris, G. and Blake, D.R, (1992). The role of toxic oxygen species in inflammation with special reference to DNA damage. In Biochemistry of Inflammation (eds. J.T. Whicher and S.W. Evans) pp. 109-129. MTP Press, Lancaster. 

But in most cases detailed experimental studies to support the hypothesis for a role of toxicity in production of neoplasia are not available, so regulators rule with caution. 

Uriz, M.J., Turon, X., Becerro, M.A., and Galera, J., Feeding deterrence in sponges. The role of toxicity, physical defenses, energetic contents, and life-history stage, J. Exp. Mar. Biol. Ecol., 205, 187, 1996. 

In 1982, the American Chemical Society sponsored a symposium at its annual meeting in Kansas City entitled MXenobiotics in Foods and Feeds,w and 23 major contributions were presented (65.). The fact that the ACS is again presenting a major symposium on this subject in 1984 clearly indicates that the role of toxic substances in the food we eat is of major concern to both the lay public and the scientific community. 

Various examples exist of the use of msPAF in multiple-stress analysis to acknowledge the relative role of toxicant mixtures in shaping ecological communities. Mulder et al. (2004) studied the decline of butterfly populations in a nature reserve in The Netherlands. It appeared difficult to establish associations between decline and the major environmental parameters, such as pH and water relationships. 

Analysis of benzene dosimetry in animal studies suggests that the metabolic pathways leading to the production of the putative toxic metabolites appear to be low-capacity, high-affinity pathways that are saturated at relatively low-exposure concentrations (Henderson et al. 1992). The authors suggest that this could also be true for humans. Additional dosimetry studies are necessary to further define the role of toxic metabolites in the development of benzene-related leukemia. 

G. Grummer, "The Role of Toxic Substances in the Interrelationships Between Higher Plants", in F. L. Mltthorpe, ed.. Mechanisms In Biological Competition. Academic Press, New York (1961), pp. 224-225. 

In addition to detection of toxicity in samples containing cyanobacteria and/or their toxins (i.e. screening), quantification and identification of the toxins present are necessary on occasions. Physicochemical methods of toxin analysis fulfil both these roles, often requiring a comparison of the test sample with purified... 

Solidification/Stabilization technologies are techniques designed to be used as final waste treatment. A major role of these processes is posttreatment of residuals produced by other processes such as incineration or chemical treatment. In some cases, solidification/ stabilization processes can serve as the principal treatment of hazardous wastes for which other detoxification techniques are not appropriate. High volume, low toxicity wastes (such as contaminated soils) are an example of this application. 

Kaufman, J. W. (1999). The role of upper airway heat and water vapor exchange in hygroscopic aerosol deposition iii the human airway. In Toxicity Assessment Alternatives Methods, Issues, Opportunities (H. Salem and S.A. Katz, Eds.), pp. 63-70. Humana Press Inc., Totow a, NJ. 

Persistent activation of PPARa can induce the development of hepatocellular carcinoma in susceptible rodent species by a nongenotoxic mechanism, i.e., one that does not involve direct DNA damage by peroxisome proliferator chemicals or their metabolites. This hepatocarcinogenic response is abolished in mice deficient in PPARa, underscoring the central role of PPARa, as opposed to that of two other mammalian PPAR forms (PPARy and PPAR5), in peroxisome proliferator chemical-induced hepatocarcinogenesis. Other toxic responses, such as kidney and testicular toxicities caused by exposure to certain phthalate... 

Overall the results reported in this review indicate that water scarcity might increase metal exposure (due to low dilution), metal uptake (due to higher retention under low flow), and metal toxicity and/or accumulation (depending on the dose and time of exposure), but also might cause opposite effects depending on the source of pollution. In addition, water scarcity will influence nutrient loads and will also modulate the fate and effects of metals. Thus, future studies addressing the role of environmental stress on the effects of toxicants at community scale are key to predict the impact of toxicants in the aquatic ecosystems. 

Chambers JE, Ma T, Boone JS, et al. 1994. Role of detoxication pathways in acute toxicity levels of phosphorothionate insecticides in the rat. Life Sci 54 1357-1364. 

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