The landlord needs to provide habitable premises. If you feel like anyone is getting ill, then you need to seek medical attention and ask for temporary housing elsewhere until landlord fixes the problem.
If you are significantly ill from it, then you might consider getting the place tested for types of mold and concentration.
Jeff Merrick, Oregon Trial Attorney
Injury & Employment Law
The above is not legal advice. I cannot give you sound advice without knowing more information. It is intended to raise some issues for you to discuss with your own lawyer.
Check out this great guide from the Community Alliance of Tenants -
If you need a lawyer, call their renters' rights hotline at (503) 288-0130. They can refer you to a lawyer who will give you a free consultation.