The principles and procedures for the assessment of the safety/risk of chemical used by the relevant WHO and EPA expert groups are outlined. The assessment in terms of acceptable daily intakes (ADIs) and reference doses (RfDs) of 25 pesticides is listed. The pesticides assessed are acephate, alachlor, amitrole, azinphos-methyl, benomyl, biphenthrin, bromophos, chlordane, chlorthalonil, cyhalothrin, DDT, EPTC, ethion, folpet, fosetyl-al, glyphosate, isofenphos, methomyl, methyl mercury, paraquat, phosphamidon, systhane, terbutyn, tribultyltin oxide, and vinclozin. In addition, their critical effects, the no-observed-effect levels and the size of the safety/uncertainty factors used are also listed to illustrate the diversity of the toxic effects and the resulting assessments. Furthermore, the enormous amount of data reviewed and the complex scientific judgement involved are also indicated. Considering the various uncertainties existing, the ADIs and RfDs do not differ appreciably in most instances. However, marked differences exist between the ADIs and RfDs of DDT and chlordane. It is suggested that re-evaluation be done on these, and perhaps other, chemicals.
Title: Zinc chloride-diphenylamine reagent for thin layer chromatographic detection of some organophosphorus and carbamate insecticides Sevalkar MT, Patil VB, Katkar HN Ref: J Assoc Off Analytical Chemistry, 74:545, 1991 : PubMed
Zinc chloride-diphenylamine reagent, whose use has been reported for the detection of organochlorine insecticides by thin layer chromatography, was further studied for its ability to detect the organophosphorus insecticides phorate, phosphamidon, DDVP, and phosalone and the carbamate insecticide carbaryl and aldicarb. These insecticides give intense blue-green spots with this reagent. The procedure can be applied to the detection of the insecticides in biological materials and thus has a potential use in forensic toxicology.
Title: Isolation and concentration of organophosphorus pesticides from drinking water at the ng/L level, using macroreticular resin LeBel GL, Williams DT, Griffith G, Benoit FM Ref: J Assoc Off Analytical Chemistry, 62:241, 1979 : PubMed
A screening method has been developed for determining organophosphorus pesticides at ng/L levels in drinking water. Sixteen organophosphorus pesticides, diazinon, diazinon-oxon, dimethoate, ronnel, beta-phosphamidon, methyl parathion, ethyl parathion, malathion, chlorpyrifos, fenitrothion, ruelene, methidathion, ethion, EPN, phosalone, and phosmet, were extracted by Amberlite XAD-2 resin from 100 and 200 L drinking water previously spiked with these pesticides. The pesticides were eluted from the XAD-2 resin with acetone-hexane (15+85). The concentrated extract was analyzed by gas chromatography using a nitrogen-phosphorus selective detector and by gas chromatography-mass spectrometry using selected ion monitoring. Recoveries at the 10 and 100 ng/L spiking levels were greater than 90%, except recoveries for dimethoate and phosphamidon were 37 and 42%, respectively. The analysis of 300 L Ottawa tap water showed no detectable amounts (less than 1 ng/L) of any of the 16 organophosphorus pesticides.
1 lessTitle: Apoptosis in male germinal line cells of rat in vivo: caused by phosphamidon Akbarsha MA, Sivasamy P Ref: Cytobios, 91:33, 1997 : PubMed
When Wistar strain male albino rats were fed on drinking water containing phosphamidon at 35 ppm concentration for 30 days, the spermatogenic compartment of the testis underwent histopathological changes. Differentiating spermatids and fully differentiated spermatozoa were rare or absent. Uni- and multinucleate giant cells appeared in the epithelium as well as the lumen. Semithin sections of resin-embedded tissues revealed that such cells had a typical apoptotic morphology. These cells were traceable to the caput and cauda epididymidal duct, and in the latter they appeared to fragment into apoptotic bodies. The male reproductive toxicity of phosphamidon leading to death and removal of the spermatogenic line cells through apoptosis is described. It is suggested that plastic embedding and semithin sectioning are appropriate methodologies to identify apoptotic cells in histological preparations viewed by light microscopy.
Title: Safety/risk assessment of pesticides: principles, procedures and examples Lu FC, Dourson ML Ref: Toxicol Lett, 64-65:783, 1992 : PubMed
The principles and procedures for the assessment of the safety/risk of chemical used by the relevant WHO and EPA expert groups are outlined. The assessment in terms of acceptable daily intakes (ADIs) and reference doses (RfDs) of 25 pesticides is listed. The pesticides assessed are acephate, alachlor, amitrole, azinphos-methyl, benomyl, biphenthrin, bromophos, chlordane, chlorthalonil, cyhalothrin, DDT, EPTC, ethion, folpet, fosetyl-al, glyphosate, isofenphos, methomyl, methyl mercury, paraquat, phosphamidon, systhane, terbutyn, tribultyltin oxide, and vinclozin. In addition, their critical effects, the no-observed-effect levels and the size of the safety/uncertainty factors used are also listed to illustrate the diversity of the toxic effects and the resulting assessments. Furthermore, the enormous amount of data reviewed and the complex scientific judgement involved are also indicated. Considering the various uncertainties existing, the ADIs and RfDs do not differ appreciably in most instances. However, marked differences exist between the ADIs and RfDs of DDT and chlordane. It is suggested that re-evaluation be done on these, and perhaps other, chemicals.
Title: Zinc chloride-diphenylamine reagent for thin layer chromatographic detection of some organophosphorus and carbamate insecticides Sevalkar MT, Patil VB, Katkar HN Ref: J Assoc Off Analytical Chemistry, 74:545, 1991 : PubMed
Zinc chloride-diphenylamine reagent, whose use has been reported for the detection of organochlorine insecticides by thin layer chromatography, was further studied for its ability to detect the organophosphorus insecticides phorate, phosphamidon, DDVP, and phosalone and the carbamate insecticide carbaryl and aldicarb. These insecticides give intense blue-green spots with this reagent. The procedure can be applied to the detection of the insecticides in biological materials and thus has a potential use in forensic toxicology.
Title: Isolation and concentration of organophosphorus pesticides from drinking water at the ng/L level, using macroreticular resin LeBel GL, Williams DT, Griffith G, Benoit FM Ref: J Assoc Off Analytical Chemistry, 62:241, 1979 : PubMed
A screening method has been developed for determining organophosphorus pesticides at ng/L levels in drinking water. Sixteen organophosphorus pesticides, diazinon, diazinon-oxon, dimethoate, ronnel, beta-phosphamidon, methyl parathion, ethyl parathion, malathion, chlorpyrifos, fenitrothion, ruelene, methidathion, ethion, EPN, phosalone, and phosmet, were extracted by Amberlite XAD-2 resin from 100 and 200 L drinking water previously spiked with these pesticides. The pesticides were eluted from the XAD-2 resin with acetone-hexane (15+85). The concentrated extract was analyzed by gas chromatography using a nitrogen-phosphorus selective detector and by gas chromatography-mass spectrometry using selected ion monitoring. Recoveries at the 10 and 100 ng/L spiking levels were greater than 90%, except recoveries for dimethoate and phosphamidon were 37 and 42%, respectively. The analysis of 300 L Ottawa tap water showed no detectable amounts (less than 1 ng/L) of any of the 16 organophosphorus pesticides.
