Association between ambient temperature and respiratory health

Area of Science:

• Environmental Health
• Pulmonology
• Climate Change Research

Background:

• Rising global temperatures and increased temperature variability due to climate change pose risks to respiratory health.
• Existing research on the short-term effects of temperature on lung function is conflicting, and long-term impacts remain largely uncertain.

Purpose of the Study:

• To investigate the short-, mid-, and long-term effects of ambient temperature on lung function and respiratory symptoms.
• To analyze these effects in a nationally representative population using detailed exposure data.

Main Methods:

• A cross-sectional analysis of 10,819 participants from the Korean National Health and Nutrition Examination Survey (KNHANES) between 2016-2018.
• Individualized temperature exposures were estimated using high-resolution atmospheric models.
• Generalized additive models (GAM) and distributed lag non-linear models (DLNM) were employed to assess effects across different time scales (lag days 0-14, moving averages of 30-180 days, and 1-5 years).

Main Results:

• Short-term exposure to high temperatures (e.g., 29.7°C) was linked to reduced forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC), with cumulative effects lasting over 14 days.
• Long-term heat exposure (e.g., 5-year moving average at 13.7°C) was associated with a decline in FEV₁, particularly at higher temperature extremes.
• Chronic sputum production showed a significant association with long-term heat exposure (1- to 5-year moving averages).

Conclusions:

• Both short- and long-term exposure to heat significantly impair lung function.
• The adverse effects on lung function are more pronounced at higher ambient temperatures.
• Long-term heat exposure is also linked to an increased likelihood of chronic sputum production.