4,4'-Methylenediphenyl diisocyanate (MDI) is the most widely used isocyanate in the manufacture of polyurethanes.
MDI has been implicated as one of the major causes of occupational asthma.
Hydrolysis of MDI can yield 4,4'-methylenedianiline (MDA), which is a suspected human carcinogen.
Thus the need to monitor occupational exposure to MDI is of great significance.
The use of air monitors alone has been found to be insufficient and there is a need for sensitive markers of recent and long-term exposure.
We obtained biological samples from a group of 20 workers exposed to MDI vapor during the manufacture of polyurethane products.
The air levels of MDI in the factory were measured using personal, work room and work station monitors.
In most cases the levels were below detection limits.
The blood and urine samples were analyzed for the presence of adducts and metabolites using GC-MS methods.
Urinary base-extractable metabolites were found above control levels in 15 of the 20 workers and ranged from 0.035 to 0.83 pmol MDA/ml.
The level of the acetylated metabolite N'-acetyl-4,4'-methylenedianiline (AcMDA) ranged from 0.13 to 7.61 pmol/ml.
The amount of MDA released after acid hydrolysis was on average 6.5 times higher than the amount of free MDA and AcMDA present in urine.
MDA was detected as a hemoglobin (Hb) adduct in all of the 20 subjects.
The level ranged from 70 to 710 fmol/g Hb.
In one individual the Hb adduct of AcMDA was detected.
Mots-clés Pascal : Isocyanate organique, Uréthanne polymère, Industrie matière plastique, Industrie caoutchouc, Exposition professionnelle, Maladie professionnelle, Asthme, Homme, Adduit moléculaire, Albumine, Hémoglobine, Métabolite, Urine, Surveillance biologique, Protéine, Appareil respiratoire pathologie, Bronchopneumopathie obstructive, Plasma sanguin, Diphénylméthane(4,4p-diisocyanato)
Mots-clés Pascal anglais : Organic isocyanate, Polyurethane, Plastics industry, Rubber industry, Occupational exposure, Occupational disease, Asthma, Human, Molecular adduct, Albumin, Hemoglobin, Metabolite, Urine, Biological monitoring, Proteins, Respiratory disease, Obstructive pulmonary disease, Blood plasma
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 95-0594048
Code Inist : 002B03L06. Création : 01/03/1996.