No abstract

The urinary excretion rates of diethyl phosphate and diethyl phosphorothioate and changes in blood cholinesterase activities were studied in fifteen persons self-poisoned either by the organophosphorus pesticide quinalphos (twelve persons) or by chlorpyrifos (three persons). The organophosphate poisoning was always indicated by a significant depression of serum and/or red blood cell cholinesterase activities. The return of serum cholinesterase activity in the range of referent values took more than 30 days and had a different course in different persons. The most rapid increase in red blood cell acetylcholinesterase activity was noted within 24 h after the first treatment with oximes Pralidoxime and/or HI-6. None of the spot urine samples, collected daily after admission of persons to hospital, contained measurable quantities of the parent pesticide. There was no correlation between the maximum concentration of total urinary diethylphosphorus metabolites normalized to creatinine and the initial inhibition of blood cholinesterase activities measured in samples collected on the day of admission to hospital. The excretion of metabolites followed the kinetics of a biphasic reaction. The half-time of urinary metabolites concentration decrease in the fast excretion phase in quinalphos poisoned persons was 5.5-14.2 h (eight persons) and 26.8-53.6 h (four persons) and in chlorpyrifos poisoned persons 3.5-5.5 h. The half-time for the slow excretion phase ranged from 66.5 to 127.9 h in all persons and for both compounds. For a given person, the rates of excretion of diethyl phosphate and diethyl phosphorothioate were about the same. However, in quinalphos poisoned persons the proportions of single metabolites in total diethylphosphorus metabolites varied with the initial maximum concentration of total metabolites.(ABSTRACT TRUNCATED AT 250 WORDS)

Polychlorinated biphenyls (PCBs), organochlorine pesticides and chlorophenols were measured in samples of rain and snow collected at urban and suburbadsemi-rural locations in the Zagreb City area, Croatia. PCBs and organochlorine pesticides were extracted with hexane from filtered aqueous samples and from particulate matter isolated by filtration. Chlorophenols were accumulated from rain and snow water by C18 reversed-phase adsorption. All samples were analysed by capillary gas chromatography using an electron-capture detector. Polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs) in rain and snow water were checked by gas chromatographic-mass spectrometric analysis of combined hexane extracts. PCBs were detected in all water (4-203 ng 1-1) and particle (40-4155 ng g-1) samples. The only organochlorine pesticide present in all rain and snow water (1-36 ng 1-1) and in particle (7-512 ng g-1) samples was y-hexachlorocyclohexane as a consequence of the regular local usage of lindane. A positive correlation was found between its concentration in the water phase and the average air temperature during the sampling period. Compounds of the DDT-type, trace amounts of which were detected in only two rain water samples, were determined in most particle samples. The DDE : DDT median concentration ratio in particles was lower than unity and indicated a recent input of DDT into the atmosphere. The incidence and concentrations of di-, tri-, tetra-and pentachlorophenols were higher in snow (single compound concentration 11-527 ng 1-1) than in rain (single compound concentration 2-171 ng 1-1). A quadratic decrease in chlorophenol concentrations in snow and rain with increasing air temperature was observed. Trace amounts of PCDDs and PCDFs were detected in both rain and snow water samples and the highest concentrations were measured for octa-CDD (2 pg 1-1 in snow and 6 pg 1-1 in rain).