There have been no reports of hypersensitivity pneumonitis caused by metal working fluids in Korea, despite their existence in other countries. Here, we report the first such case, along with an assessment of work-relatedness through exposure assessment.

A 64-year old male patient visited the hospital with dyspnea after metal pipe cutting for about a year. He was diagnosed with hypersensitivity pneumonitis from the evidence of specific exposure history, clinical symptoms, and radiologic findings. The air exposure levels of the oil mist, endotoxin, total bacteria and fungus in the work environment was TWA(8-hr) 0.531 mg/m3, 6.33 EU/m3, 100 CFU/m3 and 75 CFU/m3, respectively. The concentrations of the endotoxin, total bacteria and fungus within the metal working fluid was 1.5x10(4) EU/mL, 4.6x10(5) CFU/mL and 1.8x10(5) CFU/mL, respectively.

Although the patient did not receive a specific precipitating antibody test, the microbial concentration within the metal working fluid was higher than normal and similar to previous case reports, The oil mist level in the air exceeded the NIOSH REL and ACGIH NIC, and were similar or higher than previous cases. By excluding other causes of hypersensitivity pneumonitis, we concluded that the disease developed from exposure to microbial antigens in the metal working fluid.