Climate change could be making everyday life harder for people struggling with allergies and asthma as the pollination season keeps growing, according to new research.

After analyzing the change in freeze dates in more than 200 cities, Climate Central researchers found that the pollen seasons are stretching longer in El Paso and other cities because of rising temperatures. The report joins a growing body of research that finds human-caused climate change could impact respiratory health.

The Climate Central analysis released Wednesday found that El Paso’s growing season has increased by 50 days since 1970. In Reno, Nevada, the season increased by 99 days, the longest of all the cities. While not all cities recorded longer growing seasons, the vast majority in the study did.

Trees, grasses and other flowering plants release pollen during the growing season, which is the period between the last and first freeze. Mold, another common allergen, is also growing for a longer time throughout the country.

For people who are more sensitized, constant exposure to allergens can lead to inflammation of the airways and the development of allergic asthma, said Dr. Jorge Cervantes, an assistant professor in microbiology and immunology at Texas Tech University Health Sciences Center El Paso.

Most patients with asthma test positive for allergies in skin tests. Allergies trigger the majority of asthma attacks in children and about half in adults, Cervantes said. All of this adds up in emergency department visits, medical expenses, and lost work days, he added. A year’s worth of immunotherapy to treat allergies in El Paso can cost upward of $1,000 out of pocket, with weekly and monthly appointments.

More than 60,000 children and adults in El Paso have asthma, according to the American Lung Association. More than 30,000 people have COPD, chronic obstructive pulmonary disease, which people can have concurrently with asthma and allergies.

People tend to think of climate change as something “big and nebulous” – something that affects other people, but not them personally, said Lauren Casey, a meteorologist at Climate Central.

“But it’s here and now, and impacting people’s everyday lives, and potentially has human health consequences,” Casey said. 

The ash tree, one of El Paso’s most popular landscaping trees for new constructions, produces a pollen that is most severe in the months of March and April. (Corrie Boudreaux/El Paso Matters)

Researchers also collected data on airborne pollen and mold spores, but monitoring stations are not evenly distributed across the country. The closest pollen counting stations to El Paso are in Midland, Texas, and Albuquerque, though air currents can carry pollen long distances.

Rainy days don’t provide the allergy relief people think they do either, Casey said.

“When we’re dealing with rainfall, you think rain cleanses the pollen, which is good at first,” Casey said. “But pollen, when it gets wet, breaks down and becomes tinier. Then it gets dispersed by wind and gets into your nasal passages.”

Warm winters, CO2 pollution stimulate allergen growth

Warmer winters are also creating more favorable conditions for mold in certain parts of the country, though more research is needed, according to the report. Numerous types of mold grow in the desert, despite the misconception that molds can’t thrive in dry climates.

“Mold loves warmth,” Casey said. “As you’re getting these warmer temperatures in each season – particularly in winter time, when you really wouldn’t see mold – you’re seeing that mold growth.”

To mitigate this trend, “we need to reduce our reliance on fossil fuels,” she said.

Greenhouse gas emissions from human activities are driving the heat. About three-fourths of greenhouse gas emissions from the United States come from burning fossil fuels for transportation, electric power generation and the industrial production of goods, according to the U.S. Environmental Protection Agency.

Increased levels of carbon dioxide can also stimulate plant growth, which intensifies pollen production and mold growth, according to the Climate Central report. 

Members of Eco El Paso display a poster advocating for stricter air quality standards in El Paso during a Texas Commission on Environmental Quality hearing on July 18. (Corrie Boudreaux/El Paso Matters)

Air pollution itself is a trigger for allergies and asthma. The American Lung Association gave El Paso an F, the worst rating, in ozone pollution in 2022. Ozone, which combined with particle pollution forms smog, irritates the lungs and airways, making it more difficult to breathe deeply, according to the Allergy and Asthma Foundation of America.

People can develop allergies and allergy-associated asthma as adults, even if they’ve lived in El Paso their entire life and been exposed to local allergens. Cervantes said risk factors for asthma include a family history of allergies, exposure to environmental pollution and low socioeconomic status, which can limit access to education, health care and anti-inflammatory medications.

Priscilla Totiyapungprasert is a health reporter at El Paso Matters and Report for America corp member. She previously covered food and environment at The Arizona Republic. You can follow her on social...