Slow poisons

Slow poisoning can occur in several different ways. In some cases, chemicals or their metabolites may slowly accumulate in the body -rates of excretion are lower than rates of absorption - until tissue and blood concentrations become sufficiently high to cause injury. Delayed toxicity can also be brought about by chemicals that do not accumulate in the body, but which act by causing some small amount of damage with each visit. Eventually, these small events, which usually involve... 

There are, however, two broad classes of exceptions to this conclusion. The first comes with the slow reaction of a gas with a very porous solid. Here reaction can occur throughout the solid, in which situation the continuous reaction model may be expected to better fit reality. An example of this is the slow poisoning of a catalyst pellet, a situation treated in Chapter 21. 

Short, K., 1994. Quick Poison, Slow Poison Pesticide Risk in the Lucky Country. South-wood Press, Sydney, Australia. 

Immediately Observable Adverse Effects, but That Produce Effects Only After Repeated Dosing for Large Fractions of a Lifetime. This statement avoids the false impression conveyed by a title that suggests there are two categories of chemicals, those that are acutely toxic and those that are slow poisons. From the principles discussed so far, it should be obvious that all chemicals can be both fast and slow poisons, depending upon the size, duration, and other conditions of dosing. Slow poisoning is perhaps a better title. 

Knowledge of which mechanism of delayed toxicity is operating in specific cases can not usually be gained from the animal test additional studies of ADME, and of interactions of the chemical with cellular components, are necessary to understand mechanisms of delayed toxicity. This chapter addresses mostly the ways slow poisoning is detected, the types of adverse effects that can appear, and some of the chemicals that can produce it. Mechanisms of toxic action come under review later, in Chapter 8. 

This chapter deals with slow poisons, but this title, while conveying a message that has a popular meaning, is a little misleading. A more accurate title might be Identifying the Toxic Properties of Chemicals When They are Administered at Doses That Do Not Give Rise To... 

Some specific examples of chemicals causing toxicity at various targets will be introduced at this point. Most can produce slow poisoning, but the discussion also includes some acute responses as well. The toxic properties of the chemicals to be discussed have been learned by the types of general and specialized animal tests just discussed. In many cases they have also been learned from epidemiological studies and case reports. Carcinogens, as we have already mentioned, are excluded until the next chapter. 

Hence the effect of poisoning is proportional to — a that is, it is less than a linear effect. This situation, corresponding to a slow poisoning reaction and a fast (large OJ main reaction, was termed antiselectivepoisoning by Wheeler. 

Ascher et al. (1967) found that triphenyl tin hydroxide (fentin hydroxide, 34) and triphenyltin acetate (fentin acetate, 35), already known for their fungicidal and insect antifeedant effect, also show insect sterilising activity. They assumed that the sterilisation of male insects is brought about by a slow poisoning of the sperm. 

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