According to this website

Civil Code 1942 gives you the option of moving out... or fixing the things yourself, and deducting the cost from your next rent.

This website states

A landlord can be held liable for damages resulting from a mold-related illness if a violation of the building code of the source of the problem. Examples may be:

• deficient bathroom or kitchen ventilation

So if your bathroom or kitchen doesn't even have ventilation, I don't think the building is done to code. Usually rental unit matters are determined at state level. Good luck!

According to this website

Civil Code 1942 gives you the option of moving out... or fixing the things yourself, and deducting the cost from your next rent.

This website states

A landlord can be held liable for damages resulting from a mold-related illness if a violation of the building code of the source of the problem. Examples may be:

• deficient bathroom or kitchen ventilation

You mention each room has a window so at least it's done to code, but maybe you can see if the bathroom window is smaller than an allowable limit. Usually rental unit matters are determined at state level. Good luck!