Effects of electrical accidents : occupational and health perspectives

Professionals working in the electrical industry are at risk of accidental injuries caused by electricity. Electrical accidents can cause persistent neurological symptoms, previously mainly described in patients whose injuries were initially extensive. The overall aim of this thesis was to study the prevalence of persisting, self-reported symptoms after electrical accidents and to explore their relationship to results obtained using clinical methods that are commonly used to study nerve function and hand-arm function. Another aim was to increase knowledge about the work situation and the safety culture of Swedish electricians and to describe the frequency with which electricians seek health care after electrical accidents. Study I was a retrospective survey of 523 Swedish male electricians. In study II, the electricians who reported persistent symptoms were further invited to undergo clinical examinations that included quantitative sensory testing (QST), assessment of fine motor skills and tactile gnosis. The most common self-reported symptoms were pain, reduced sensation and reduced muscle function. For a few, these symptoms persisted at the time of survey. Roughly half of the group exhibited abnormal warm and cold perception thresholds and tactile gnosis test values. Study III included 24 participants with persisting self-reported sensory symptoms, 1-5 years after an accident. Observations of nerve function; QST, laserevoked potentials (LEP) and nerve conductions studies, were performed. At least one neurosensory impairment was present- in at least one of the tests in 67% of the participants. The participants in study III were also evaluated in study IV, in which a control group of 24 healthy persons was added. Hand function was affected in many participants assessed with the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire as was tactil gnosis and manual dexterity, for the participants in the case group. Only a quarter of the participants in study I sought health care after their accidents, and the safety culture questionnaire revealed deficiencies, particularly in the reporting culture. The conclusions of this thesis are that self-reported neurosensory symptoms can persist for years after an electrical accident and that these symptoms can be evaluated using standard neurophysiological and functional tests that reflect changes in nerve function. Accordingly, hand function, examined using both objective and subjective measures, may be affected after work-related electrical accidents. This thesis highlights some aspects of safety culture and the work situations of professionals within the electrical industry. These areas need to be improved so that reporting routines provide opportunities to learn from and prevent accidents