Bioactivity and Persistence of Some Parathion Formulations in Soil2

Parathion: Residues in soil and water

“…GRIFFITHS and WALKER (1970) reported rapid degradation of parathion by a heat-labile agent, presumably of microbial origin, in soil percolation experiments, but the organisms responsible were not isolated. More recently, SACHER et al (1972) also noticed increased persistence of parathion in soils treated with methyl bromide as a soil sterilant. Moreover, more rapid degradation of parathion occurred in summer months with a half-life of 1.5 weeks than in winter months with a half-life of more than three weeks, presumably due to more intense microbial activity in summer months.…”

“…Similarly, under flooded conditions, heat treatment of the soils prior to flooding prevented the nitro group reduction (SETHUNATIIAN and YOSHIDA 1973 a) and hydrolysis (SETIlUNATIIAN 1973 b) of parathion. Increased persistence of parathion thus reported in soils sterilised by autoclaving, irradiation or anti-microbial agents presumably resulted from reduced microbial activity (NAUMANN 1970, LICHTENSTEIN et al 1968, GETZIN and ROSEFIELD 1968, SACHER et al 1972, SETIlUNATHAN and YOSHIDA 1973. More convincing evidence for microbial involvement in parathion degradation in the soil was obtained by correlating its degradation rate with microbial proliferation and!…”

Interactions between insecticides and soil microbes

“…Parathion, an organophosphorus insecticide introduced commercially in 1947, is like most other compounds in this group considered to be relatively nonpersistent on plants and in soil (EL-RAFAI and HOPKINS 1966, HARRIS 1969, SACHER et al 1972. LICHTENSTEIN and SCHULZ (1964) showed that parathion was most persistent in dry soil and least persistent in soils with high moisture content.…”

Μελέτη Της Υδρόλυσης Και Προσρόφησης Επιλεγμένων Οργανοφωσφορικών Φυτοπροστατευτικών Προϊόντων Σε Υδατικά Και Εδαφικά Συστήματα. Διερεύνηση Της Τοξικότητας Σε Θαλασσίους Φυτοπλαγκτονικούς Οργανισμούς

“…35d (Nofziger et al, 1988) ; 3-29d µε µέση τιµή 18d (Lichtenstein & Schulz, 1964;Sacher et al, 1971;Spencer et al, 1975). (Farm Chemicals Handbook, 1987;The Merck Index, 1989;Tomlin, 1997;Montgomery, 1997;Μπαλαγιάννης, 1994).…”