I. Lead Concentrations in the Air of Printing Department and the Results of a Medical Examinations on the Workers Regarding the Lead Poisoning. The auther measured lead concentrations in the air of respective printing department of four big newspaper offices and made medical examinations on men working there regarding the lead poiosning. The results are as follows: 1) Process of the work and equipments in these offices are similar to each other. The lead concentration in the air sometimes rises above the threshold limit value (0.2mg/m³) on the metal pot, in the stereotype foundry and in the flatplate foundry only for a short period. It is low and below the threshold limit value in the other parts. 2) Values of blood specific gravity (GB.), hemoglobin content (Hb) and red blood cell counts (Er.) of the lead workers are low compared with those of normal Japanese as well as those of the control in the present study (non-lead workers). 3) Frequency of appearance of basophillic stippled cells (Bp.), coproporphyrin (copro.) in in urine, δ-aminolevuric acid and porphobilinogen in urine is high. There is no marked difference between the lead concentrations in blood and urine of lead workers and those of the city inhabitants hitherto reported. But, they show higher values than those of the control. 4) Subjective and objective symptoms are frequently encountered in digestive and nervous systems. 5) Persons who needed therapy were found in 9% of the male lead workers and in 23% of the female. 6) Female workers have a higher rate of symptoms of lead-poisoning than male workers. II. Difference of Symptoms of Lead-poisoning in the Printing Department. Cases of lead-poisoning in the workers stated in I were examined according to exposure conditions and routes of invasion into the body. 1) Cases of lead-poisoning occur in about the same frequency in various parts of the printing depertment, but they occur in slightly higher frequency in the stereotype foundry, in the flatplate foundry and the distribution. 2) Workers who inhale relatively large amounts of lead dust tend to show more coproprophyrin in urine and higher lead concentrations in blood. Workers whose hands are more liable to be contaminated by lead or to be exposed to painting-ink show about the same frequency of occurrence of the lead poisoning in spite of less inspiration of lead dust. The workers in the distribution are more liable to have their hands contaminated by lead and to be exposed to printing-ink. As such workers are mostly female, special precautions are required. III. Specific Gravity and Hemoglobin Content of the Blood According to Age Groups Blood specific gravity and hemoglobin content of lead workers in newspaper offices were examied according to the duration of employment and their age. The values were compared with those of the control, i.e. workers in a steam power plant. 1) Blood specific gravity and hemoglobin content show a similar pattern of increase and decrease according to the duration of employment and the age. Two stages of anemia are found before and after 21 to 30 years of age, or 5 to 9 years of the duration of employment. 2) The first stage appears in lead workers as well as in non-lead workers. Recovery is incomplete in the former. The second stage of anenia starts 10 years earlier in lead workers than in non-lead workers. IV Change of Blood Symptoms with Time in Each Individual 1) In lead workers abrupt decreases of blood specific gravity (GB.) and hemoglobin content (Hb.) and increases of coproporphyrin in urine and basophilic stippled cells occur after the onset of work. Anemia is restored to the normal value after 19 months, while Hb. is frequently lower than before the onset of work. 2) Though GB. and HB. do not show marked difference before and after the 6 year period in general, there are marked differences in individual cases. GB. shows an increase or a decrease in persons younger than 40 years of age.

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