Please pick one of the theories and explain if you agree or disagree that it is a major cause

The incidence of asthma is increasing in the United States. There are many theories as to why this is happening. Please research this on the internet and share your research with the class. Please pick one of the theories and explain if you agree or disagree that it is a major cause. (Hint: increased pollution, genetics, too much cleanliness, etc.)

explain in no less than 200 words