of cardiac risk among profe ssional drivers. Scand J Work Environ Health 1994;20:73-86.This literature review indicates that professional drivers have excess cardiac risk that is not fully explained by standard risk factors. The contributi on of occupation is suggested by two independent methods and by psychophysiological studies during on-the-job driving. Driving has been conceptualized as a threat-avoidance task. Stimuli encountered in traffic are not inherently aversive but become so by association with driving experie nce, a formulation corroborated by laboratory studies in which stimuli such as car headlights elicit cardiovascular hyperreactivity and electroencephalographic signs of arousal in professional drivers. More-advanced neurophysiological methods (event-related potentials) show higher cortical electrone gativity to imperative signals among professional drivers than among nondriver referents. These data are viewed in light of reports of possible associations between event-related slow potentials and cardiac risk. A clinically and ecologically relevant neurocardiological model is proposed, and preventive strategies, including workplace interventions, are suggested.K EY TERMScardiova scular disease, event-related potentials, glare, neurocardiology, professional drivers, review, work stress.Of the numerous studies performed in va rious countries on cardiovascular disease and professional driving over a sp an of almost three de cades, ne arly all have shown an exce ss ri sk of cardiovascular di sease among professional drivers. Despite rigorous se lection against these disorders at hiring and during periodic medical foll ow-up ( 1-4), a risk of hyp ertension, ventri cu lar arrhythmias, myocardial infarction, and other ischemic heart disease ha s been ob served in 28 of the 32 reports found to consider thi s question (1-32). (No ns ig nifica nt findings have be en reported in references 13, 18, 19, and 23.) Of particular note in many of these studies is the close relation between the number of work years as a driver and the untowardly yo ung ag e at which these ev e nts occur (l , 5, 7, 9 17, 26, 29, 32). For example, in studies of young myocardial infarct ion patients, fo r whom profession was determined, an unexpectedly high percentage (up to 40 %) comprised professional dri vers (9,17,26,29,32). While standard ri sk-factor status tends to be high in thi s population, these fa ctors have not been clearly shown to distinguish professional drivers from other lo wer ri sk groups (1 , 15, 16,33-35) (tab le I). Rece ntly , Ro sengren and her co-workers (27) demonstrated that the excess risk of coronary he art disease among middle-aged bus and tram drivers occurred independently of sta ndard ri sk-factor status .Thus the quest ion ari ses as to how this excess cardiac risk oc curs for professional drivers. A growing co nse ns us indicates that occupational factors must be gi ven ca reful consideration (1-3). A focus on neural mech anisms pr omises to offer meaningful insig hts into the problem (3,36,37). In...