Spending time outdoors is a useful way to fight cabin fever, something many of us are dealing with right now as our lives have changed because of the COVID-19 pandemic. Being outside reduces the transmission of the virus because of the constant movement of air, and it is often easier to socially distance than it is indoors. However, more time outdoors is not so pleasant for the nearly 19 million Americans who suffer from allergic rhinitis, commonly known as hay fever.
Every spring, summer and fall, I have patients in my clinic concerned about their pollen allergies. Many have noticed that their symptoms are starting earlier in the year and seemingly getting worse. There are multiple reasons for this constellation of symptoms — runny nose, itchy eyes and sneezing — to progress. One of those reasons is most certainly climate change, and we see this every season.
Anyone who suffers from seasonal allergies is affected by global warming, which extends the freeze-free season. This is the season exempt from frost, when plants are able to grow. What this means for patients is that allergy symptoms often start earlier in the year and last longer. Compared to 1970, the growing season in New York City has increased by 21 days; in Washington, D.C., by 17 days; and in Atlanta by 27 days, according to Climate Central, an independent organization of leading scientists and journalists that study and report on the impacts of climate change. For those dealing with daily allergy symptoms, each additional week affects their quality of life at home, and also their performance at work and school. For some parts of the U.S., the increase in the growing season is more than one month long, and the number of days is only projected to increase with time as global warming continues.
It is not uncommon for patients to tell me that their allergy symptoms have become increasingly severe over the years. One reason for this may be the rise in seasonal pollen counts, as demonstrated by ragweed, one of the most common allergens in the United States. Studies show that higher levels of atmospheric carbon dioxide, which is produced when fossil fuels are burned for energy, leads to increased plant growth and pollen production. Between 1900 and 2000, the concentration of carbon dioxide rose from 280 to 370 parts per million, which correlates with a more than twofold increase in the production of ragweed pollen, with trends projected to increase fourfold in the next 40 years with continued unchecked carbon dioxide emissions. This escalation of seasonal pollen concentration does not only affect quality of life, it also has an economic impact, as those suffering from allergies spend more money on medicine to control and relieve their symptoms.
The Intergovernmental Panel on Climate Change special report found that the world has already warmed approximately 1 degree Celsius from preindustrial levels. Research shows that with rising temperatures, the spread of tick-borne diseases, such as Lyme disease, has changed, now appearing in places previously unaffected. Increasing global temperature also has the potential to lead to the development of pollen allergies. As the climate warms, plants are moving into new regions that were at one time not hospitable. This migration introduces new allergenic pollens to people previously not exposed, putting them at risk for developing allergy symptoms.
For those who are experiencing the familiar symptoms of sneezing, itchy eyes and stuffy nose, this is not just a “bad pollen” year. The world is warming and pollen is lasting longer and increasing in number around us. As with every unwelcome consequence of climate change, now is the time for action. We must aggressively act and support climate initiatives that address global warming and halt the undesired effects on pollen allergies.
Dr. Neelu Tummala (Twitter: @NeeluTummala) is an ENT physician at The George Washington Medical Faculty Associates in Washington, D.C., and a climate advocate with a special interest in the intersection of climate and health.