RESUMO
Background: It is widely known that carbon dioxide (CO2) arc welding generates carbon monoxide (CO). However, to the best of our knowledge, no case reports have been published regarding CO poisoning in CO2 arc welders. Therefore, we aimed to report a case of CO poisoning-induced encephalopathy in a CO2 arc welder in the Republic of Korea to inform about the dangers of CO exposure among CO2arc welders. Case presentation: A 40-year-old man working as a CO2 arc welder for 15 years visited a local hospital with a tremor, involuntary urination, and speaking gibberish, on April 9, 2019. He stated that he had intermittent headache and forgetting symptoms for the last 5 years, and had been lost on the way to work several times. On April 9, 2019, he was diagnosed with CO poisoning-induced encephalopathy through brain magnetic resonance imaging. He received hyperbaric oxygen therapy, and some of his symptoms improved. According to the exposure assessment of his work environment, he was continuously exposed to high concentrations of CO for 15 years while operating CO2 arc welding machines. Conclusions: After evaluating the patient's work environment and evaluating his medical history, we concluded that his encephalopathy was caused by CO exposure during CO2 arc welding. Thus CO2 arc welders must be aware of the risk of CO poisoning and strive to avoid CO exposure.