RESUMEN
The results of formation of stable products of organochlorinated pesticides (OCP) under gamma-irradiation (dose 10 kGy, dose rate 0.026, 0.14 kGy/min) are discussed in the article. The model solutions of alpha-,gamma-hexachlorocyclohexane (alpha-,gamma-HCH), p,p-dichlorodiphenyl-trichloroethane (p,p-DDT) and p,p-dichlorophenyl-dichloroethylene (DDE), with initial concentrations of 1.0-0.1 ppm, were exposed to gamma-radiation. Among the products of OCP radiolysis such compounds as DDE, 2,2-di(chlorophenyl)-1-chloroethylene, dichlorophenyl-dichloroethane and various isomers of HCH were found. It was shown that taking in account the whole data on the formed metabolites the toxicological characteristics of pesticide solutions cannot be improved by exposure to gamma-radiation.
Asunto(s)
Contaminación de Alimentos/prevención & control , Rayos gamma , Insecticidas/efectos de la radiación , Insecticidas/toxicidad , Residuos de Plaguicidas/análisis , Tejido Adiposo/química , Animales , Cromatografía Líquida de Alta Presión , Radioisótopos de Cobalto/farmacología , DDT/análisis , DDT/química , DDT/efectos de la radiación , DDT/toxicidad , Diclorodifenil Dicloroetileno/análisis , Diclorodifenil Dicloroetileno/química , Diclorodifenil Dicloroetileno/efectos de la radiación , Diclorodifenil Dicloroetileno/toxicidad , Contaminación de Alimentos/análisis , Cromatografía de Gases y Espectrometría de Masas , Hexaclorociclohexano/análisis , Hexaclorociclohexano/química , Hexaclorociclohexano/efectos de la radiación , Hexaclorociclohexano/toxicidad , Humanos , Insecticidas/análisis , Insecticidas/química , Dosificación Letal Mediana , Dosis de Radiación , Soluciones , Factores de TiempoAsunto(s)
DDT/análogos & derivados , Diclorodifenil Dicloroetileno/síntesis química , Dicofol/efectos de la radiación , Insecticidas/efectos de la radiación , Benzofenonas/efectos de la radiación , Cromatografía de Gases , Cromatografía en Capa Delgada , DDT/efectos de la radiación , Diclorodifenil Dicloroetileno/efectos de la radiación , Contaminantes Ambientales/efectos de la radiación , Espectroscopía de Resonancia Magnética , FotoquímicaRESUMEN
DDE and DMDE, degradation products of the pesticides DDT and methoxychlor, rapidly undergo an unusual photoisomerization in solution when exposed to sunlight. The isomerization involves the exchange of a vinyl chlorine and an ortho aromatic hydrogen. Other photoproducts identified were corresponding benzophenones and 1,1-diaryl-2-chloroethylenes. Quantum yields for the reactions were measured and then used to compute sunlight photolysis half-lives for DMDE and DDE. Although both compounds absorb only the short-wavelength ultraviolet component of sunlight, their photolysis was found to be surprisingly rapid. During summer at latitude 40 degrees N, the photolysis half-lives near the surface of a water body are one hour and one day for dissolved DMDE and DDE, respectively. Photolysis of the DDE photoisomers is about an order of magnitude slower than that of DDE, suggesting that they may accumulate under environmental conditions. The DDE photoisomers photocyclize to form chlorinated dibenzofulvene and dichlorofluorenone. Neither DDE nor its photoisomers photoreact in solution to form PCB's. The environmental significance of these results is discussed, and its is suggested that the persistence of DDE in inland surface waters may be related to its tendency to sorb onto sediments and biota where not light is present.