Herbicides, safe

It Is now a relatively straightforward matter to analyze commercial pesticide mixtures for nitrosamlne contamination as part of the normal quality control process (2.18). and, as Illustrated above, some of the major contamination problems have begun to be solved by means of technological Improvements. If further research brings about the circumstance In which there Is no detectable N-nItroso compound In any pesticide sold an here, will that mean that pesticide use Is safe from nitrosamlne-formatlon problems I believe that considerably more research must be done before a responsible answer to this question can be given. To elaborate on this position, let me focus on the herbicides for a moment. 

Phenylalanine ammonia-lyase (PAL EC 4.3.1.5) is a pivotal enzyme in controlling flow of carbon from aromatic amino acids to secondary aromatic compounds (Figure 1) (28). PAL primarily deaminates phenylalanine to form t-cinnamic acid, however, in many species, it also less efficiently deaminates tyrosine to form -coumaric acid. Because PAL is restricted to plants and is an important enzyme in plant development, Jangaard (29) suggested that PAL inhibitors might make safe and effective herbicides, however, in his screen of several herbicides, he found no compound to have a specific effect on PAL. This was also the case in studies by Hoagland and Duke (30, 31.) in which 16 herbicides were screened. 

In the book The Safe Use of Pesticides While Intensifying Agricultural Production [21], the paragraphs on polychlorpinen in beet fields were lost among data linked to OCP contamination of breast milk in Japan, the USA, and Sweden the dangers to the inhabitants of Italy from herbicide contamination of the Po river the poisoning of the inhabitants of the USA and Canada by watermelon from a plantation treated with pesticides and many other facts. Here is the text on the beet fields ... 

In the production of the herbicide 2,4,5-T (2,4,5 tetrachlorophenoxyacetic acid), a dioxin (2,3,7,8 tetrachlorodibenzodioxine) is often formed. Not only has it been called the second most lethal chemical ever discovered but it can also produce birth defects. During the early 1970s there were court battles over whether 2,4,5-T should be banned because of the possible presence of the dioxin. The Dow Chemical Company maintained that no detectable dioxin was produced in its process and that therefore its product was safe and should not be taken off the market. In this instance, the removal and hence concentration of the dioxin would pose problems of such a magnitude that the only feasible reaction conditions are the ones that produce no dioxin. 

Wallington, T.J. and Kurylo, M.J. Flash photolysis resonance fluorescence investigation of the gas-phase reactions of OH radicals with a series of aliphatic ketones over the temperature range 240-440 K, J. Phys. Chem., 91 (9) 5050-5054, 1987. Wallnoefer, P.R., Safe, S., and Hutzinger, 0. Microbial demethylation and debutylation of four phenylurea herbicides, Pestic. Biochem. Physiol., 3 253-258, 1973. 

Refined borax (Na B Op is an additive in laundry products such as soaps and water-softening compounds. Also used for cosmetics, body powders, and the manufacture of paper and leather. Borax is an environmentally safe natural herbicide and insecticide. 

Amino Acid Pathways Absent in Mammals Offer Targets for Safe Herbicides Chorismate Is a Common Precursor of the Aromatic Amino Acid Family... 

Three herbicides considered to be safe. These compounds all act on an enzyme required for branched amino acid biosynthesis. Since this enzyme is not present in mammals, the herbicides are considered to be harmless to humans. 

Amino Acid Pathways Absent in Mammals Offer Targets for Safe Herbicides... 

This book is about the revolutionary impact of the triazines herbicides, likely the most important class of agricultural chemicals ever developed. For five decades the triazines have provided weed control in more than 50 crops around the world and have helped farmers boost yields and produce enough food to feed a rising global population. The triazine herbicides, and especially atrazine, are the most well-researched herbicides in history, with thousands of scientific studies on their safety to humans and the environment. Data from studies on the triazines have been evaluated extensively by regulatory authorities around the globe to ensure their safe use. 

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