Health in the city represents both a challenge and an opportunity to rethink our environments and raise the quality of life. Urban life provides access to services, culture and opportunities, as well as vibrant social vibrancy; however, environmental factors such as air pollution, extreme heat and noise have a direct impact on the well-being of city dwellers.

According to the World Health Organization (WHO), around 23% of global mortality - approximately12.6 million deaths per year -is linked to environmental factors. In Europe, air pollution causes the loss of some 270,000 lives each year, while in Spain, four of the five leading causes of death are related to environmental risks. These data highlight the urgent need to take care of the urban environment to protect public health.

Air quality is essential for well-being
Cities are affected by pollutants such as nitrogen dioxide (NO₂), ozone (O₃) and fine particles (PM2.5 and PM10). The WHO guide recommends an annual limit of 5 µg/m³ for PM2.5, while in Spain this threshold is 20 µg/m³. It has been determined that a 10 µg/m³ increase in PM2.5 is associated with a 5-7% increase in mortality from cardiovascular and respiratory diseases. This demonstrates that more stringent environmental policies could significantly improve the health of the population.

The urban heat island
Climate change has intensified both the frequency and intensity of heat waves, aggravated in cities by the "urban heat island" phenomenon. This effect raises temperatures and increases the risk of heat stroke, alterations in blood pressure and medical emergencies, especially among the most vulnerable groups, such as the elderly and those with pre-existing illnesses. For example, the summer heat wave of 2022 was associated with 61,672 deaths in Europe, highlighting the urgency of redesigning urban spaces to mitigate these thermal risks.

Urban noise also affects physical and mental health
In Spain, limits of 45 to 55 decibels (dB) have been established in residential areas; however, continuous exhibition to levels above 85 dB can irreversibly damage the sensory cells of the ear, impair hearing and trigger stress, sleep disorders and cardiovascular problems. In addition, noise from traffic and industrial activity affects the quality of rest and is linked to alterations in the nervous system, reinforcing the need to effectively manage noise pollution.

Strategies to Improve the Quality of Life in Cities
Urban planning and the incorporation of green spaces are emerging as essential strategies for improving the quality of life in cities. The creation of parks, gardens and green corridors not only financial aid to filter the air and reduce temperatures, but also promotes physical activity, fosters social cohesion and improves mental well-being. Several programs of study indicate that spending at least 120 minutes a week in natural environments is associated with a significant reduction in stress. In addition, encouraging the use of active means of transportation, such as walking or cycling, not only reduces pollutant emissions, but also promotes healthy lifestyle habits. It has been proven that walking 30 minutes a day can increase life expectancy by up to 11% and reduce the risk of cardiovascular disease.

Other key aspects include update and tightening urban and environmental regulations, which must be integrated into a strategic plan for the transformation of cities. Initiatives such as the "15-minute city", which seeks to decentralize services, and the promotion of the use of electric vehicles, which reduce both air and noise pollution, are examples of actions that promote more resilient urban environments. Likewise, the implementation of emerging technologies for real-time monitoring of pollutants and intelligent traffic management are key to anticipating and mitigating critical episodes.

Finally, the transformation of cities requires a collective commitment and the update regulations. partnership between governments, urban planners and citizens is essential to develop resilient and healthy environments. Projects such as the conversion of underutilized areas into green spaces and the implementation of green roofs increase vegetation cover, reduce the concentration of polluting particles and mitigate the heat island effect, which translates into fewer hospitalizations and improved sleep quality.

On this World Health Day, an unavoidable question arises: what concrete actions are we willing to take to build healthier and more resilient cities? The Chair Sanitas de Salud y Medioambiente of the University of Navarra was created with the real commitment to foster innovation, promote sustainability and encourage citizen participation. We believe that, working together-authorities, experts and citizens-we can transform our urban environments into spaces that prioritize the health and well-being of all.

 

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Jesús Miguel Santamaría Director of the Biodiversity and Environment Institute BIOMA and Full Professor at the University of Navarra. Ana Sánchez-Ostiz Researcher at the Biodiversity and Environment Institute BIOMA and Full Professor at the University of Navarra. 15.04.2025