Outdoor allergy, Scientific article

Climate change and allergies

Influence of climate change

Climate change is not simply an environmental issue, it is also a threat to the global public health, as it dramatically impacts the severity and duration of symptoms for allergy and asthma sufferers. 

Extreme weather events, such as droughts and heat waves, are becoming increasingly common. These weather events can lead to a lack of air flow in which the air becomes stagnant, and the air quality worsens. When air does not flow, pollutants react together in the heat and sun and increase the ground-level ozone.  

Urban smog consists of ground-level ozone; higher levels of air pollution and smog cause higher levels of carbon dioxide (CO2), which then again results in warmer temperatures. A vicious cycle that keeps on continuing, as rising CO2 levels also increase the pollen count in the air, which triggers asthma and allergy symptoms.  

Top 20 allergy capitals of 2021 & increased temperatures since 1970


Rank  Metropolitan area  Average Spring temperature (°F) increase since 1970  Average Fall temperature (°F) increase since 1970 
1  Scranton, PA  2.5  2.6 
2  Richmond, VA  2.1  1.9 
3  Wichita, KS  3.0  2.8 
4  McAllen, TX  3.6  3.7 
5  Pittsburgh, PA  2.8  2.0 
6  Hartford, CT  0.7  2.3 
7  Springfield, MA  0.7  2.3 
8  New Haven, CT  1.8  1.9 
9  Oklahoma City, OK  1.9  1.6 
10  Bridgeport, CT  1.8  1.9 
11  Albany, NY  2.4  3.0 
12  Virgina Beach, VA  2.3  1.1 
13  Buffalo, NY  1.4  2.3 
14  San Antonio, TX  2.4  2.7 
15  Dayton, OH  2.0  1.5 
16  Riverside, CA  3.3  5.4 
17  Las Vegas, NV  6.5  6.0 
18  Memphis, TN  1.6  1.8 
19  Dallas, TX  2.9  3.0 
20  Louisville, KY  3.7  2.7 
Source: Climate Central temperature data, February 2021 

Rising temperatures due to the rising level of CO
lead to elongated growing seasons for grasses, trees and weeds producing pollen during Spring and Summer. 

The data collected by researchers shows that in many cities, the last freeze is occurring earlier in the year, which signals the beginning of Spring. The earlier Spring starts, the more time is given to plants to grow and produce pollen. The chart above demonstrates that on average, Spring across the U.S. has become warmer by 2 °F over the past fifty years, while Fall has become 2.5 °F warmer on average, leading to a longer lasting summer season.  

This cycle presents a huge problem to the world population, including US citizens. Not only will the number of people suffering from allergies continuously increase, but pollen production will also get worse the warmer and longer Spring and Summer seasons become. People may also be exposed to new allergens that they have not experienced before.  

Allergy and asthma patients should consult their doctor or allergy specialist for advice on how to avoid situations and places that could possibly trigger and worsen symptoms of allergic reactions.  

AirNow offers a helpful tool for US citizens wanting to check the air quality on any given day, showing the pollution levels of the air in your area. This way, allergy and asthma sufferers can prepare themselves better and plan accordingly before they venture outside. 

Lastly, it is also important to advocate for policy makers to act now and slow down climate change by reducing CO2 emissions and their drastic impact on human health.  

Sources: aafa.org (123)



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