When describing environmental factors in an ecological definition it can include the air, water, minerals, organisms, and all other external factors surrounding and affecting a given organism at any time. Given what causes allergic reactions, it is easy to assume that environmental factors are the major contributing factor to their severity.
If anybody has seen the movie Erin Brockovich, you would see first hand how environmental factors can cause cancer. Notice how cities have higher asthma rates than rural counties because of the toxins coming from automobiles. There are a lot of environmental factors that cause health problems all across the spectrum. Allergies have to be among them.
Yes, the environment plays a key role in the severity of allergic reactions. If the person lives or works in an environment where he is constantly bombarded by allergens that cause an immune response then the subsequent exposure to those allergens will cause a heightening of his immune system. As is often seen with allergies to food, flowers, animals, et cetera, the more one is exposed to those triggers the greater subsequent allergic reactions will be.
Yes, I believe environmental factors can contribute to the severity of an allergic reaction. Allergies are a very complex area of medicine. It's like trying to solve a Rubik's Cube, where one small shift can cause your conditions to do unexpected things. We have a long way to go before we completely understand allergies.
Yes, I believe that environmental factors can contribute to the severity of an allergic reaction, because allergies are sensitive. Even how much moisture is in the air, or how much moisture is in a person's skin can make a difference. The weather is another big factor. Social issues as well, such as how parents or others around react to the allergies can also make a mental difference.