Biological monitoring of workers exposed to 4,4'-methylene-bis- (2-orthochloroaniline) (MOCA). II. Comparative interest of "free" and "total" MOCA in the urine of exposed workers.
The objectives of the study were to investigate the best urinary marker of exposure to MOCA in urine samples of exposed workers and to study its applicability in exposure evaluation in polyurethane resin production plants.
In addition, our intention was to contribute to the question of biological target value in order to reduce exposure levels.
Urinary MOCA markers were measured in urine samples collected at the end of the workshifts. 40 workers from four factories were observed for three consecutive days in the same week. « Free » MOCA in non-acid-stabilized urines, « total » MOCA in urines after alkaline hydrolysis, « acid-labile » MOCA in sulfamic or citric acid-protected urines were measured in all urine samples.
MOCA liberated by heating the non-acid-stabilized urines ( « heat-labile » MOCA) was also measured in 17 urine samples of exposed workers.
The median value of « free » MOCA was lower than that of « sulfamic acid-labile » MOCA : 6.0 and 12.5 mug/l respectively.
The difference between « free'and » total MOCA was statistically significant (Mann-Whitney test, P=0.023) for the urine samples collected without acid.
Correlations between urinary MOCA concentrations in hydrolysed and non-hydrolysed urine samples were high (r=0.984,0.966 and 0.950 ; P<0.001) for urine samples with sulfamic acid, with citric acid and without acid respectively. (...)
Mots-clés Pascal : Exposition professionnelle, Médecine travail, Homme, Diamine, Composé aromatique, Surveillance biologique, Urine, Liquide biologique, Analyse quantitative, Forme libre, Forme liée, 4,4p-Méthylènedianiline(2,2p-dichloro)
Mots-clés Pascal anglais : Occupational exposure, Occupational medicine, Human, Diamine, Aromatic compound, Biological monitoring, Urine, Biological fluid, Quantitative analysis, Free form, Bound form
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0437540
Code Inist : 002B03L06. Création : 22/03/2000.