Allergies Increase as Ragweed and Mold Increase as Well

Most of us have either experienced or know someone who has been experiencing allergy problems this year. For those with allergies, it may seem like the issue is more troublesome this year than most, and this is in fact, true. According to the results of a national report titled Allergies Across America, it appears that sensitization to a number of allergens has definitely increased, however, the increase in allergies this year can be blamed on mostly mold and ragweed.

Based on research, it seems as though the increasing allergy troubles are correlated to changes in our climate. Allergies Across America is a Quest Diagnostics Health Trends Report is has been the biggest cross-sectional study ever conducted in our country regarding allergies. The results of this study are based upon almost 14 million blood tests that have been given for 11 basic and relatively common allergens including mold, ragweed, dust mites, dogs, cats, and five different types of food. This study also involved over 2 million visits by patients.

The individuals involved in the study ranged in age from newborns to those 70 years of age and included people from all of the states as well as the District of Columbia. The blood test for allergies that was used in the study was the ImmunoCAP specific IgE test. IgE can be described as an antibody that our bodies produce that results as a direct response to the existence of allergies, whether it be to one or several.

The results of blood tests were compiled over the course of four years and it showed that sensitivity to the ragweed allergen has actually increased by 15% across the country while mold also increased, by 12%. In total, sensitivities to all of the 11 allergens involved increased by 5.8% combined.

Medical director, Stanley Naides noted that he and his fellow researchers believe that this study is the largest on a national level that was able to prove the growing trend of allergies. This theory had been suggested by other types of studies and is believed to be mainly due to changes in our climate that are leading to increases in environmental allergens.

Nearly 20% of all people in the United States have a sensitivity to ragweed, which is a very hardy plant related to sunflowers. There are 41 various species of ragweed, all which have a tendency to thrive on dry weather.

Because the climate is now warmer, it allows the blooming season to last even longer than expected and will in turn lead to an increase in environmental allergens that will also continue to grow.

Also affected by the changes in the climate, mold has also been seen to increase as the temperatures increase.

Those who have severe allergy issues and are allergic to ragweed in particular may be interested in a specific report that it out which ranks the top 30 cities within our country that have a definite sensitivity to ragweed itself. The top five of the worst cities to live with bad allergies are Phoenix, Kansas City, Las Vegas, Dallas, and Riverside-San Bernardino.

This study shed light on the reality that global warming will have side effects on our planet that involve increasing allergens across the country and therefore leading to increases to sensitivity to things such as mold and ragweed. Based on this information, further research needs to be done to fully be able to understand our warming climate and what implications there will now be for the future of public health.


Quest Diagnostics. 2011. Health Trends Report.

Mitchell, D. 2011. Rise in Allergies Due Mostly to Ragweed and Mold.