Abstract
The contents of intermediates of porphyrin in the urine and blood were examined in lead-exposed rats in the workshop of lead glass factory to study relationship between metabolism of porphyrin and air-borne particles containing lead, and the following results were obtained. The concentration of lead in air-borne particles were 0.83 μg/m3/hr in places producing primary particles (ground materials, etc.) and 2.45 and 3.27 μg/m3/hr in places producing secondary particles (fumes, etc.). These air-borne particles were found to mainly consist of particles below 1μ. The contents of both δ-aminolevulinic acid and coproporphyrin in the urine and of protoporphyrin in the blood of rats exposed to air-borne dust containing lead increased over their levels in control rats. Free protoporphyrin in erythrocyte is suggested to be important as an index of chronic lead poisoning, and such a biological examination was demonstrated to be valuable from this experiment as an index of environmental quality in workshops.
