Smooth pursuit eye movements among storage battery workers.
Eleven male workers in a battery storage plant with lead and erythrocyte protoporphyrin blood actual levels greater than 50 and 100 micrograms %, respectively, and 18 male controls without lead exposure were tested by a clinical pendular eye tracking test (PETT). Each worker underwent a series of lead absorption measurements including blood lead, urinary lead, erythrocyte protoporphyrin, delta-aminolevulinic acid dehydratase activity, and urinary delta-aminolevulinic acid. The SPEMs were evaluated by an eye tracking technique. The subjects followed a horizontally moving target which, in the form of a luminous spot on a dark background, was projected onto a screen placed 1 m from the subject. The maximum predicted eye movement velocity during tracking was about 30 degrees/s. Skin electrodes were applied on the outer canthi of both eyes and SPEM were plotted on a polygraph, recording both the actual eye movements and the corresponding first derivative. Our findings suggest that lead workers display a disorder of motor coordination of SPEMs system, and the PETT is useful, when associated with biochemical data, to evaluate the degree of subclinical damage of nervous system during lead poisoning.
D000328:Adult; D005133:Eye Movements / Q000187:drug effects*; D006801:Humans; D007854:Lead / Q000097:blood / Q000633:toxicity*; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced*; D011524:Protoporphyrins / Q000097:blood
D011524:Protoporphyrins; D007854:Lead