Effects of diesel exhaust on neurobehavioral and pulmonary functions.

Ten railroad workers and 6 electricians referred for shortness of breath also had slowness of response, memory loss, and disordered sleep, all of which suggested neurobehavioral impairment. The hypothesis was that diesel exhaust causes central nervous system impairment. Six electricians worked within enclosed concrete walls and roofs that trapped diesel exhaust from trucks. Seven railroad mechanics had tuned diesel engines indoors for 15-50 y, and 3 crewmen rode in locomotives. Neurobehavioral and visual functions were measured with a 26-test battery. Compared with unexposed men, the 16 in this study had significantly impaired reaction time, balance, blink reflex latency R-1, Culture Fair, peg placement, trail making, and verbal recall. Thirteen men had abnormal visual fields, and 11 had abnormal color confusion indices. Nine men had airways obstruction. The author could not attribute abnormalities to confounding factors or bias. Severe neurobehavioral impairment was associated with exposure to confined diesel exhaust. In additional studies of diesel-exposed workers, especially drivers of locomotives and trucks, investigators should use sensitive neurobehavioral methods.