Why asthma increasing - causes and triggers discussed

The Collaborative on Health and Environment reports that recent research suggests some reasons that asthma is increasing:
* Exposures to herbicides and pesticides before birth and during infancy
* Breastfed infants are less likely to develop asthma and allergies compared to those fed infant formula. Breast-feeding enhances immune function.
* Indoor air quality has deteriorated
* ozone and fine particle pollution from diesel engine exhaust remain problems.
* Exposure to second-hand smoke before and after birth
* Interactions between different exposures
(read the full article for a more detailed explanation about the possible causes of asthma)

What triggers an attack?
Triggers include second-hand smoke, dust mites, cockroach feces and exoskeleton dust, mold and pets. Outdoor triggers include ozone, nitrogen oxides, diesel exhaust and pollen, infections, occupational exposures, some drugs (such as aspirin), and sulfites (food additives used in dried fruit, wine, dehydrated potato products, shrimp, etc.).

Occupational exposures linked to asthma attacks include wood dust, grain dust, bacterial toxins, and chemicals such as isocyanates (used in polyurethane foams, plastics, paints, and varnishes), methacrylates (used in orthopedic surgery and dentistry as a bonding cement), some metals in a dust or aerosol form, and some pesticides.

The "too clean" hypothesis is also discussed in the article.