Association between humidifier disinfectant use duration and lung cancer development in the Republic of Korea.

Objectives: This study was conducted to assess the association between the duration of humidifier disinfectant use and lung cancer development.

Methods: We analyzed data from 3,605 applicants registered for compensation from the Korean government due to health conditions related to humidifier disinfectant exposure. Among these individuals, 121 were diagnosed with lung cancer at least 4 years after their initial exposure (through December 2021). Hazard ratios (HRs) and 95% confidence intervals (CIs) for lung cancer incidence were estimated according to the duration of disinfectant use using Cox proportional hazards models.

Results: Compared with <5 months of use, the HRs for lung cancer were 1.81 (95% CI, 0.41 to 7.97) for 5-14 months, 2.45 (95% CI, 0.58 to 10.41) for 15-29 months, and 4.61 (95% CI, 1.12 to 18.91) for ≥30 months. Using never smokers with <15 months of use as the reference category, the HRs were 2.97 (95% CI, 1.34 to 6.56) for never smokers with ≥15 months of use, 2.73 (95% CI, 0.94 to 7.95) for current or former smokers with <15 months of use, and 4.74 (95% CI, 1.94 to 11.61) for current or former smokers with 15 months of use.

Conclusion: Our study provides some of the first robust epidemiological evidence that prolonged humidifier disinfectant use contributes to lung cancer development. Future studies-particularly those including unexposed populations-are needed to confirm these findings.