Context: Many environmental factors have been associated with asthma's development and exacerbation including allergens, air pollution, and other environmental chemicals. Smoking during pregnancy and after delivery is associated with a greater risk of asthma-like symptoms. Low air quality from factors such as traffic pollution or high ozone levels, has been associated with both asthma development and increased asthma severity. Exposure to indoor volatile organic compounds may be a trigger for asthma; formaldehyde exposure, for example, has a positive association. Also, phthalates in certain types of PVC are associated with asthma in children and adults.

Question: What are some of the enviromental factors that have been linked to asthma?
Answer: allergens, air pollution, and other environmental chemicals

Question: What two things are associated with a greater risk of asthma-like symptoms?
Answer: Smoking during pregnancy and after delivery

Question: What can cause symptoms and asthma serverity to change?
Answer: Low air quality from factors such as traffic pollution or high ozone levels

Question: Exposure to what compounds can also trigger asthma?
Answer: indoor volatile organic compounds

Question: What envoronmental factors are associated with early delivery when pregnant?
Answer: Unanswerable

Question: What two things are associated with a greater risk of symtoms from phtalates?
Answer: Unanswerable

Question: What can change symptoms of formaldehyde exposure and severity?
Answer: Unanswerable

Question: Exposure to what compounds can also trigger early delivery when pregnant?
Answer: Unanswerable

Question: What other compound is associated with early delivery?
Answer: Unanswerable