Single Chemical Teratogens

There are several excellent new books on safety in general (ref. 14-17). Although they usually do not single out teratogens from among other toxic chemicals, they are very worthwhile as the reference safety books. 

The results of the last study point out the difficulties in associating specific pesticide exposures to end results. As discussed in Chapter 14, pesticides are almost always applied admixed with solvents, surfactants, and other chemicals that aid in their solution, distribution, and adsorption. More times than not, mixtures of different pesticides are applied to achieve multiple effects. Such pesticide mixtures contain multiple lipophiles and hydro-philes and the mixtures produce effects that are greater than those anticipated from the individual components. Accordingly, it should not be surprising that the teratogenic effects of pesticide mixtures should exceed those of the single species and produce enhanced detrimental outcomes in offspring. 

Pyrrolizidine alkaloids (PAs) occur in about 5% of all flowering plants. They are esters of a basic moiety ( Necine ) and esterifying acids ( necic acids ). Up to now, about 500 different PAs are described. PAs can be hazardous to man and domestic animal. They can show cancerogenic, mutagenic, teratogenic, and fetotoxic properties. Many intoxications by PAs are described. The level of the toxicity of each single PA is dependent from its concrete chemical stmcture. This chapter gives an overview about the chemistry, biosynthesis, and toxicity of PAs. 

---