BIOLOGICAL MONITORING AND POSSIBLE HEALTH-EFFECTS IN WORKERS OCCUPATIONALLY EXPOSED TO METHYL-METHACRYLATE

Monitoring by means of blood and urine analysis for methanol was succe ssfully applied in 32 male workers who were exposed to methyl methacry late (MMA) monomer at 6 ppm as a geometric mean and at 112 ppm as the maximum. Measurement of time-weighted average (TWA) intensity of the v apor exposure was successfully conducted with a diffusive sampler with activated carbon cloth as an adsorbent. Methanol concentrations in wh ole blood, serum, and urine samples were measured by headspace gas chr omtography. The methanol concentrations in the three biological sample s collected at the end of 8-h workshifts related linearly with the TWA MMA vapor concentrations, with correlation coefficients of 0.8-0.9. Q uantitative evaluation of MMA in vapor and of methanol in urine sugges ts that only 1.5% of MMA inhaled will be excreted in urine as methanol . There were no significant clinical symptoms or abnormal hematologica l or serum biochemical findings at this exposure level, except that so me workers complained throat irritation and frequent cough and sputa. The results indicate that biological monitoring by analysis for methan ol is sensitive enough to detect MMA exposure at levels at which no se rious health effects are to be expected.