I’ve been thinking about this section for a while: information about air-borne allergies. Not everyone has severe reactions to air-borne allergens, but I suspect a great many people have reactions to dust and mould without realizing it. Some people, like myself, are allergic to these allergens and know it, but I believe such allergens are often ignored, except in severe cases such as asthmatics or others with severe reactions.
I think that improving air quality helps everyone feel better.