METHODS

Sub j ects. Out of 44 male workers in a battery storage plant, 11 were chosen according to lead (Pb B) and erythrocyte protoporphyrin (FEP) blood actual levels greater than 50 and 100 pg%, respectively, and were tested by PETT. A list of biochemical data is reported in Table 1. The control group consisted of 18 male workers in the same factory who were not exposed to lead and who showed Pb B and FEP levels less than 50 and 100 pg%, respectively. In Table 2 are displayed the average ages and the average length of employment of the two groups. No overt signs of nervous disorder nor opthalmological deficit were found in any of the subjects. dular moving target suspended to eye level at a distance of 1 m. corresponding to an amplitude of 20" of visual angle, and maximum eye velocity during perfect tracking would be 31.4"/s. The subject was in-