Allergens

Allergens are a special type of antigen that are responsible for clinical symptoms in allergic people. Antigens are foreign substances that induce an immune response in normal individuals. A person may be exposed to an allergen by inhalation, ingestion, or penetration of the skin.
Allergens that are inhaled can be either indoor or outdoor varieties, although the two environments appear to be intimately related. Indoor allergens occur primarily in the home and the workplace. The most important allergens in this category are house dust, mites, animal danders, feathers, mold spores, and pollen. The indoor environment is affected by air-conditioning and heating systems, by humidifiers, people’s personal habits, and their hobbies. The work environment is affected by such factors as smoking, the type of job or industry, degree of ventilation and humidification. A person’s occupation may be the only source of exposure to the allergens responsible for his or her symptoms.

Sources:
Allergy Be Gone	American College of Allergy, Asthma & Immunology	Auckland Allergy Clinic
Eallergy.net	American College of Allergy, Asthma & Immunology	bbc.co.uk Health

Books on Allergies

Safe Sex in the Garden: And Other Propositions for an Allergy-Free World

Editorial Reviews
In Safe Sex in the Garden there are many tips for living allergy-free. The horticulture is excellent too and it is completely clear that the author is a botanist of considerable standing. I looked him up on a Google search and found that he has landscaped an American Lung Association headquarters (in Richmond, VA), that the USDA urban foresters use his plant/allergy scale, and that county asthma coalitions hire him to produce pollen-free landscapes at elementary schools. This a very fine book and I intend to recommend it to all my friends who garden, who enjoy exciting botany, and certainly to anyone with asthma or allergies.

Reader Review - Most interesting book on asthma and allergies I've seen.
I have allergies and I found this book fascinating! I heard the author, Tom Ogren, interviewed on NPR's Weekend Edition with Linda Werthheimer. After hearing that interview I immediately wanted to read this book. It was every bit as good as I expected, better. It is a very clearly written book, but there is so much new information in it that I may have to read it three or four times for it all to sink in. The title of this book comes from the discovery that male plants, especially male street trees, are raining allergenic pollen on us all. Male plants are used since they don't make seeds. Female plants, which are all pollen-free, are shunned. The chapter on "How to tell the boys from the girls," is great!