Allergens are impurities in the air that can bring on an allergic reaction. In an urban environment, a mixture of these allergens with other impurities present in the air – called adjuvant substances – such as Diesel Exhaust Particles (DEP’s) produced by engines and Volatile Organic Compounds (VOC’s) present in building materials, cosmetics, etc. can turn allergens into heavy allergens. These in turn can have increased negative health effects such as aggravated symptoms and the triggering of latent allergies.
