Cold air and pollution aggravate respiratory risks

With the arrival of winter, Temperatures drop, humidity increases and the air becomes denser. These changes, which for many mark the beginning of cold season, also directly affect the lungs. Cold air irritates the airways and makes it difficult for the lungs to function normally, something that is especially noticeable in people with asthma, bronchitis or Chronic Obstructive Pulmonary Disease (COPD).

In this context, the report Influence of the urban environment on people’s health, prepared by the BIOMA Institute, for the Sanitas Chair of Health and Environment of the University of Navarra, warns that the Spanish population currently presents a lower tolerance to low temperaturesafter years of progressive adaptation to milder thermal conditions. This is causing an increase in the adverse effects of cold on respiratory health even at moderate temperatures, especially during winter, although in autumn they already begin to manifest.

“The cold reduces the lung capacity and alters natural defenses of the respiratory system, which facilitates the appearance of infections such as the flu or bronchitis. If exposure to pollutants is added to this, the inflammation worsens and the symptoms appear earlier and with greater intensity,” explains Alfonso Marco Sanz, head of Emergencies at the Sanitas La Moraleja University Hospital.

During the fall, air pollution tends to concentrate due to reduced ventilation and air stability. Fine particles (PM₂,₅ and PM₁₀), nitrogen dioxide (NO₂) and benzpyrenereach higher concentrations in the environment due to the poor dispersion of these pollutants, which aggravates the irritation of the respiratory tract and enhances the effects of the cold. Although these processes usually begin in autumn, they intensify during winter, when thermal inversions further reduce air renewal. This accumulation increases exposure and health risk: according to the European Environment Agency, at least 239,000 deaths in the EU in 2022 were attributable to exposure to fine particles (PM2.5).

“Clean air is essential not only for public health, but also to mitigate climate change. The main greenhouse gases are carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O), responsible for retaining heat in the atmosphere and altering weather patterns. Reducing their concentrations requires promoting renewable energies, improving efficiency
energy and promote more sustainable mobility,” says Jesús Miguel Santamaría, director of the BIOMA Institute at the University of Navarra. Given this panorama, researchers from the Health and Environment Chair recommend adopting preventive measures that help protect the lungs during the coldest months in urban environments:

• Avoid outdoor exposure on high pollution days: During pollution peaks, especially in urban areas, it is important to limit time outdoors and pay attention to the most vulnerable groups (children, the elderly and patients with respiratory diseases) who are more sensitive to poor air quality.

• Protect the respiratory tract from cold air: Covering your nose and mouth with a scarf or mask helps warm and humidify the air before it reaches your lungs, reducing irritation.

• Use indoor air purifiers: These devices help reduce the presence of pollutants in closed spaces, such as fine particles (PM2.5) and harmful gases. Having a purifier equipped with a HEPA filter is an effective measure to improve air quality in the home or workplace. Properly ventilate interior spaces: renewing interior air is
important to maintain good environmental quality, but should be done only when outdoor pollution levels are low. In cities, the most suitable times are usually early in the morning or at night, when traffic and industrial activity decrease.

• Keep flu and pneumococcal vaccination up to date: in patients with chronic respiratory diseases, these vaccines are essential during periods of greatest exposure, since they are part of the preventive approach and help reduce complications derived from respiratory infections.