Asthma, Climate Change and Planetary Health
Asthma is a common non-communicable disease with a large global burden. There is urgency and severity in the threat of climate change and planetary risk factors and it is important to understand the immediate and long term consequences of these on the burden of asthma. There are many aspects of climate change that directly impact on the health of people with asthma, including air pollutants, allergens, and high temperatures. The ecological impacts of climate change affect the planet unequally and disproportionately fall on people who already have fewer resources, increasing local, regional and planetary inequities, further reducing their resources.
Frequently, climate change is attributed to temperature increases, more extreme weather events, hot weather and heat. Excessively hot air can increase exacerbations of asthma that can result in asthma emergency hospitalisations. Warmer temperatures favour exposure to ozone, a major pollutant especially in the cities, leading to irritation of the airways that renders asthma severe. The burning of fossil fuels, waste burning, and suspension particles or sulphur dioxide (including all forms of PM2.5) are important contributors. It is vital to understand how pollutants and allergens are being altered by climate change and how these affects people, especially those with asthma.
As the climate changes, natural disasters, rising temperatures, changes in rainfall patterns, photochemical reactions from heat waves creating ozone and more, are already making life challenging and more dangerous for millions of people living with asthma. Climate change can affect mental health, which in turns worsens asthma, as extreme weather events cause stress, fear, anxiety and depression. In addition, increase in pollen and other allergens related to increase in temperatures occurs with climate change. Longer pollen seasons as well as transmission of allergens to areas that have not experienced pollen exposure in the past is a problem, especially to asthma patients who are allergic.
There is evidence around an increased risk of asthma due to indoor air pollutants (e.g cooking on an indoor open fire) or outdoor air pollutants (e.g waste burning, suspension particles or sulphur dioxide) but this is less clear and consistent than for tobacco smoke. The burning of fossil fuels is a contributor to air pollution and climate change. The mechanism of air pollution on asthma is well known with continuous inhalation of particles leading to oxidative stress, inflammation and sensitisation that can lead to increased risk of developing asthma. Air pollution also worsens the life of patients especially during short exposures, such as walking in dense traffic, which can lead to emergency hospitalisation and death. According to the World Health Organization, through birth, adolescence and beyond, air pollution principally driven by fossil fuels, and exacerbated by climate change damages the lungs and every other vital organ.
The disruption caused by climate change to our current lives, lifestyles, economies, societies and policies could have a serious effect on access to affordable, quality-assured, essential asthma medicines which currently do not reach many people with asthma (Chapter 15). The aspects which may be adversely affected include national procurement systems, supply chains and their continuity, and affordability (costs of medicine related to income of person with asthma). As the COVID-19 pandemic has illustrated, major crises can also disrupt health systems and the availability of healthcare.
Human contributions to climate change by producing excessive greenhouse gases harm the planet and health of asthmatics. Every day billions of people are breathing polluted air and raising their risk of succumbing to a pollution-caused illness such as asthma. The Global Asthma Report demonstrates that asthma already has an impact on the lives of large numbers of people. In addition, climate extreme events and rise in temperature will threaten food production. Also, elimination of forest in favor of farmland has contributed to the expansion of desert areas and worsening droughts that will worsen life for all people. Climate change is a crisis threatening the very existence of people around the world.
There is an urgent need for mitigation, adaptation and advocacy actions to curb these numerous climatic and planetary risk factors causing or worsening asthma or threatening access to asthma management. Health professionals are often recognised as being amongst the most trusted professionals in society. Their role in speaking about asthma care in relation to climate change and planetary health to the public, and decision makers can be extremely influential in support of policies that promote planetary health. Patients suffering from asthma need to be involved to support the wider transformation needed towards ending stigma from asthma and a ‘net carbon-zero’ economy and future planetary health.