Introduction: Rail maintenance workers may be exposed to chromium, nickel, zinc, aluminum during curved-rail grinding. There is a case of asthma in rail maintenance worker who performed rail-grinding work for 4 years. He claimed a workers' compensation to Korea Workers' Compensation & Welfare Service(KCOMWEL). As worker's request, we conducted investigation whether his asthma related to rail-grinding work or not.
Methods: Numerous metals including chromium, nickel, zinc and aluminum can be emitted to air-borne during rail-grinding work from curved-rail itself and grinding stone. We analyzed metal composition of curved-rail and grinding stone and measured the metal concentration of the air-borne during curved-rail grinding work. All medical record as well as performed peak expiratory flow rate(PEFR) test, airway hyper-responsiveness test, non-specific and specific bronchial provocation test were undertaken.
Results: There is 14∼16% chromium in curved-rail samples, but not in straight-rail. And grinding stones used in rail maintenance included in chromium(43 ppm). The results from metal concentration of the air-borne during curved-rail grinding work is 0.9 μ/m3 at chromium. After he stopped rail grinding work(4 years later), there was negative result of methacholine provocation test. But, there was positive result of chromium provocation test. After chromium exposure(11 day after), there was positive result of methacholine provocation test.
Conclusions: Rail maintenance workers can expose chromium during curved-rail grinding. The positive results of test supported that the asthma occurring in rail-maintenance worker was work-related asthma causing from chromium exposure.