A NEW study from the Korea National Health and Nutrition Examination Survey (KNHANES) highlights the complex effects of humidity on respiratory health. Analysing data from over 10,000 individuals aged 40 and older between 2016 and 2018, researchers found that humidity influences lung function and respiratory symptoms in diverse and sometimes contradictory ways.
The study revealed that higher long-term relative humidity (RH) exposure was associated with a lower risk of restrictive lung disease, offering potential protective effects. For example, a 4-year moving average of higher RH reduced the likelihood of restrictive lung disease (odds ratio: 0.978). Additionally, mid-term RH exposure over 90 days correlated with a decreased risk of chronic cough and sputum production. These findings suggest that moderate humidity levels may alleviate certain respiratory symptoms.
However, the picture isn’t entirely positive. The study also showed that higher RH was negatively associated with the forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ratio, across various timeframes. This implies that elevated RH may exacerbate conditions linked to obstructive lung disease, countering its potential benefits.
These results underline the dual nature of humidity’s impact on respiratory health. While certain aspects of higher humidity may help reduce some symptoms, it can also pose risks to lung function and contribute to obstructive lung conditions. Healthcare professionals should consider environmental factors like humidity when advising patients with chronic respiratory diseases.
This research sheds light on the need for tailored strategies to balance humidity levels in living and working environments, optimising respiratory health outcomes for vulnerable populations.
Aleksandra Zurowska, EMJ
Reference
Seok J et al. Association between humidity and respiratory health: the 2016–2018 Korea National Health and Nutrition Examination Survey. Respir Res. 2024; DOI: 10.1186/s12931-024-03054-z.
