Fate and transport of ethoprophos in the Jamaican environment

The hydrolytic half lives of ethoprophos in distilled, river, brackish and open sea water were 25, 133, 65 and 81 days, respectively. Under laboratory conditions, volatilisation of the residues after 12 h was 1.4 - 3.6, 2.3 - 4.5 and 6.5 - 20.2 percent from a sandy loam soil with 1, 10 and 20 percent moisture levels, respectively. Photolysis in soil was significantly faster (P< 0.05) in direct sunlight (T 1/2 of 12.3 days). The microbial degradation of ethoprophos from unweeded plantation soil at 23 degrees slope was significantly (P=0.015) less than at 38 degrees slope; the amounts lost after 9 weeks and 27.5 mm of rainfall were 89.4 and 91.2 percent respectively, of the applied amount from the two respective slopes. In the weeded plots, 93.6 and 92.4 percent of the applied insecticide were lost from 23 degrees and 38 degrees slopes, respectively. Under laboratory conditions, between 67.0 and 85.1 percent of ethoprophos leached through the soil columns. Under field conditions, after 9 weeks and 25 mm of rainfall, only 2.8 and 2.0 percent residues were recovered at a depth of 10-15 cm from unweeded and weeded slopes, respectively at 23 degrees slope, and 2.2 and 1.9 percent from the two respective plots at 38 degrees slope. (AU)

Environmental factors affecting paracetamol metabolism in London factory and office workers

Paracetamol elimination was measured, using serial saliva samples, in 114 London factory and office workers, 76 whites and 38 Asian immigrants. Use of social drugs such as alcohol, tobacco and the oral contraceptive varied considerably within the sample, being appreciably greater in white subjects. Paracetamol clearance was 21 percent slower in Asians than in whites and half-life 18 percent longer. The total range of clearance was 1.86-6.78 ml/min/kg. Clearance was slower in women than in men, increased with increasing alcohol intake and cigarette consumption, and was more rapid in those women using the oral contraceptive. The effects of alcohol and the oral contraceptive were also found in white subjects alone. The variable found to correlate independently with paracetamol clearance accounted for only 27 percent of the total sample variance, however, and are unlikely to be the major determinants of paracetamol elimination in man (AU)

Assessment of antipyrine kinetics by measurement in saliva

The half-life of antipyrine has been estimated from saliva samples in ten subjects by a gas chromatographic method. Half-life, apparent volume of distribution and total body clearance estimated from saliva and plasma concentrations of antipyrine are not significantly different. The concentration of antipyrine in saliva is independent of the flow rate within the range expected in healthy subjects in response to mechanical and sapid stimuli. Antipyrine estimation in saliva could facilitate many areas of pharmacokinetic research limited by the difficulty of obtaining serial plasma samples. (AU)