MDA in plasma as a biomarker of exposure to pyrolysed MDI-based polyurethane : correlations with estimated cumulative dose and genotype for N-acetylation.
The object of this study was to investigate whether exposure of pipe-layers to thermal degradation products of diphenylmethane diisocyanate (MDI) could be assessed by analysing 4,4-methylenedianiline (MDA) in hydrolysed plasma and urine, and whether the genotype for N-acetylation affected these biomarker levels.
Blood and urine samples were drawn from 30-pipe-layers who had been welding polyurethane (PUR) insulated pipes during the preceding 3 months.
MDA in hydrolysed plasma and urine was determined with a gas chromatography-mass spectrometry technique, and genotype for N-acetylation was analysed with a polymerase chain reaction technique.
MDA in plasma was detected in 18 of the 30 pipe-layers.
Their plasma concentrations of MDA varied from 0.05 to 8.48 g/l. There was a significant negative correlation between time since last welding of PUR-insulated pipes and P-MDA (r#Bs=0.50, P=0.005).
There was also a significant positive correlation between the estimated number of welded PUR-insulated pipes during the preceding 3 months and P-MDA (r#Bs=0.68, P=<0.001).
No significant association between genotype of N-acetylation and P-MDA was observed in a multiple regression analysis when adjustment was made for the estimated cumulative exposure to thermal degradation products of MDI.
MDA in urine was detected in only four of the 30 pipe-layers.
These four subjects had been welding PUR pipes on the same day as the sampling, or on the day before.
The present results ...
Mots-clés Pascal : Diphénylméthane(4,4p-diisocyanato), Diisocyanate organique, Uréthanne polymère, Exposition professionnelle, Pose canalisation, Homme, Marqueur biologique, Produit dégradation, Dégradation thermique, Acétylation, Toxicogénétique, Médecine travail, Surveillance biologique
Mots-clés Pascal anglais : Organic diisocyanate, Polyurethane, Occupational exposure, Pipe laying, Human, Biological marker, Degradation product, Thermal degradation, Acetylation, Toxicogenetics, Occupational medicine, Biological monitoring
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 96-0151116
Code Inist : 002B03L06. Création : 199608.