Asthma risks on the rise due to climate change
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Key takeaways:
- Multiple outcomes of climate change contribute to asthma development and worsening.
- Disparities in asthma care are widening with climate change.
Climate change has resulted in higher pollution levels, more wildfires and warmer temperatures, all of which come together and increase the risk for asthma, according to a paper published in Frontiers in Science.
“Climate change is impacting our immune system, and that is tied to almost everything health related,” Mary Margaret Johnson, MD, PhD, principal research scientist at Harvard T.H. Chan School of Public Health and author on this paper, told Healio. “It’s really important to be aware of that.”
In this paper, Johnson and colleagues discuss how climate change has led to a rise in immune-mediated diseases and what mitigation and adaption efforts should be taken to clean up the air and help those more susceptible to the impacts of climate change.
Healio spoke with Johnson to learn more about how climate change is specifically impacting patients with asthma, ways that climate change is contributing to health disparities and what actions everybody can take against climate change.
Air pollution
As a result of climate change, pollution from manmade sources like industry and transportation is on the rise, and this in turn has heightened the risk for asthma and asthma exacerbations.
Johnson specifically noted that since children are more vulnerable, they face a higher risk for asthma if they reside in places with elevated levels of pollutants including particulate matter (PM), ozone and nitrogen oxides.
“A child who gets asthma at a young age is going to have a whole lifetime of health care needs that would not have otherwise been necessary had that air quality been in an acceptable range,” she said.
As Healio previously reported, a high risk for asthma in children was linked to increased levels of fine PM and nitrogen dioxide exposure in the first 3 years of life.
In addition to children, the paper highlighted that pregnant women are vulnerable to air pollution. Maternal exposure to high fine PM levels during developmental windows before and after pregnancy increased the risk for childhood asthma, as well as wheezing.
According to the paper, it does not matter whether the exposure to pollution is long- or short-term because multiple studies have shown that both lead to poor outcomes.
In one systematic review including 67 studies, researchers observed a heightened risk for emergency room visits and hospital admissions for asthma exacerbations per 10 µg/m3 rise in short-term daily pollutant exposure.
Wildfires, thunderstorms, flooding
Other outcomes from climate change include increases in heat, wildfires, thunderstorms and flooding. Each of these elements negatively impact patients with asthma, Johnson said.
As Healio previously reported, asthma outcomes only get worse with rising temperatures as heat has been shown to lead to more hospitalizations.
Compared with exposure to PM2.5 from industry/transportation sources, Johnson said wildfire smoke pollution has been linked to poorer health outcomes.
“It is thought that wildfire smoke exposure is more ‘toxic’ for a variety of reasons,” she said.
The 24-hour standard for PM2.5 is 35 µg/m3 in the United States; however, researchers of this paper found that wildfire PM2.5 can go over this standard by 10- to 15-fold.
Johnson noted that wildfire smoke is particularly harmful and costly for adults born premature.
“Babies who are born prematurely often have difficulty as an adult when they’re exposed to wildfire smoke because their lung capacity has never reached normal since they were premature,” she added. “They have decreased lung capacity, and things like that increase health issues and costs.”
In terms of thunderstorms, being outdoors prior to and during this event can impact both those with and without asthma. According to Johnson, when a thunderstorm is coming, pollen bursts into small pieces, becoming easily inhalable. The result of breathing in this pollen is severe exacerbations and emergency room visits.
An event that often follows this extreme weather condition is flooding. With these large amounts of water and dampness comes mold production and mold spores, both of which place patients with asthma at danger, Johnson said.
“Mold can be a very triggering stimuli to people with asthma,” she told Healio.
In addition to mold, other indoor sources that can trigger asthma include gas stoves, fireplaces, dust, pet dander and hair spray.
“You can see an increase in the volatile organic compounds in your home when you use hairspray,” Johnson said, “and this is linked to upper airway and asthma symptoms.”
Health disparities
Due to climate change, Johnson said disparities in asthma care are widening.
Patients who live in underserved areas are at a major disadvantage when extreme weather events and wildfires occur because they do not have extra money to spend on home renovation or air purifiers.
“The underserved are typically more at risk because they tend to live in older homes and not have the resources to do home weatherization, such as sealing the house and making sure there is appropriate ventilation,” Johnson said.
Non-English speakers are another community of individuals who face a greater risk for negative outcomes after climate change-related events. A lack of accessible resources and education on this topic can harm those with asthma by placing them at a risk beyond what they know.
“Creating a clean air room, using an air filter or using an N95 mask all may be missed by populations that are not English speaking,” Johnson said.
Taking action
To slow down climate change and prevent the harmful events related to it, researchers of the paper stressed the importance of reducing pollution and emission levels.
An example of how lower pollution levels impact asthma can be seen through southern California. According to the paper, as ambient nitrogen dioxide and PM2.5 levels went down between 1993 and 2014, so did asthma incidence among children.
One of the main ways individuals can lower pollution is through transportation. In addition to buying zero-emission vehicles and carpooling, Johnson said one way to reduce emissions daily is to stop idling your car, which is frequently seen in pickup lines for schools.
“Schools can take an initiative and do pickup and drop off in such a way that there’s not car idling,” she said.
When asked how clinicians can act against climate change, Johnson emphasized the importance of education.
Clinicians should make sure they discuss how climate change impacts asthma with their patients, so they are more aware of the risks. In turn, this could even inspire patients to advocate for standards that clean up the air and slow down climate change.
Another way to combat climate change is to educate clinicians early. Johnson said medical school education should feature courses on climate change so that clinicians are educated on the topic and its impact on health.
For more information:
Mary Margaret Johnson, MD, PhD, can be reached at mjohnson@hsph.harvard.edu.
References:
- Agache I, et al. Front Sci. 2024;doi:10.3389/fsci.2024.1279192.
- Scientists call for urgent action to prevent immune-mediated illnesses caused by climate change and biodiversity loss. https://www.frontiersin.org/news/2024/04/04/scientists-call-for-urgent-action-to-prevent-immune-mediated-illnesses. Published April 4, 2024. Accessed April 4, 2024.