Multiple peer-reviewed studies establish that both biological (such as genetics, epigenetics, and immune mechanisms) and environmental factors (including pollution, diet, and allergen exposures) significantly affect the development, progression, and severity of allergic reactions.
The claim is specific and falsifiable, passing Step 0. The retrieved literature extensively documents how various biological elements (genetics, mast cells, DNA methylation) and environmental factors (pollutants, smoke, diet, allergen presence) impact allergic reactions. Every relevant paper confirms that biological and environmental factors alter allergic severity and disease presentation. Therefore, the verdict is SUPPORTED.