Toxins chlorinated compounds

In addition, chlorine derivatives are important as intermediates in the chemical industry, and there are numerous chlorine-containing pharmaceuticals for which no substitutes are presently available. Furthermore, organochlorine compounds, some very toxic, do occur naturally on a large scale. Clearly, however, we must endeavor to avoid adding unnecessarily to the natural load of toxins as the old adage goes, it is the dose that makes the poison.4 Certainly, problems exist that require an intelligent and chemically informed resolution, but the total ban advocated by some on the use of chlorine and chlorinated compounds is neither necessary nor acceptable. 

Organic compounds other than hydrocarbons and chlorinated substances Veterinary drugs and other toxins... 

Saito, M., Enomoto, M., and Tatsuno, T. 1971. Yellowed rice toxins Luteroskyrin and related compounds, chlorine-containing compounds and citrinin. In "Microbial Toxins" (A. Ciegler, S. Kadis, and S. J. Ajl, eds.), Vol. VI fungal toxins, pp. 299-380. Academic Press, New York. 

Chlorinated Aromatic Hydrocarbon Environmental Toxins. As a result of human endeavor, toxic compounds containing chlorinated benzene rings have been widely distributed in the environment. The pesticide DDT and the class of chemicals called dioxins provide examples of chlorinated aromatic hydrocarbons and structurally related compounds that are very hydrophobic and poorly biodegraded (Fig. 5.28). As a consequence of their persistence and lipophilicity, these chemicals are concentrated in the adipose tissue of fish, fish-eating birds, and carnivorous mammals, including humans. 

This chapter is divided into seven main sections. The first of these sections is focused on technological contaminants, namely heterocyclic amines, acrylamide, furan, chloropropanok and their fatty acid esters, polycycKc aromatic hydrocarbons, monocyclic aromatic hydrocarbons, nitroso compounds, and ethyl carbamate. Other sections deal with microbial toxins (mycotoxins and bacterial toxins), persistent organohalogen contaminants (such as polychlorinated biphenyls, dibenzodioxins and dibenzofurans), chlorinated ahphatic hydrocarbons, pesticides (persistent chlorinated hydrocarbons and modem pesticides), veterinary medicines and contaminants from packaging materials. Presented for each of these contaminants are structures, properties, occurrence and the main sources of dietary intake, mechanisms of formation, possibilities of food contamination, prevention and mitigation and health and toxicological evaluations. 

This process has aroused much interest and has led CIBA-GEIGY to build two plants operating on the wet cycle oxidation principle (300°C, 200 bars). Unfortunately the operating conditions are such that only compounds containing C, H, O and a little chlorine can be processed without causing rapid corrosion of the equipment. The residues must be pumpable or be placed in aqueous solution chlorine is only acceptable in very small quantities, and elements other than C, H, N, and P have to be avoided. To date, it appears that these tests have not been carried out with actual toxins. Although very attractive on paper, it seems unlikely that this process will ever see any application in the field of chemical toxin destruction. 

In insects poisoned by organic phosphorus compounds, assays for acetylcholinesterase show that this enzyme becomes increasingly inhibited dvuring the first hour and the levels of free acetylcholine rise sharply (Small-man and Fisher, 1958). This rise causes a great increase in spontaneous nerve activity (neuronal hyperexcitation), both autonomic and somatic. This state brings about liberation of tissue toxins, ion imbalance, with eventual paralysis, dehydration, and death this sequence is reminiscent of that caused by the chlorinated insecticides (see Section 7.6c for this comparison and for general information on biochemistry of the insect nervous system). 

---