I live in an apartment with an forced air heating system. The air that is blown out has a bad smell as from paint or solvents. Why can that happen and what can I do?

I wish I knew the answer - I am having the same problem. My landlady is being cooperative but we can't seem to fix the problem. She did discover a leak in the line that pooled on the floor. All leaks were fixed but my guess is there is another one somewhere and the oil that leaked on the floor evaporates when the furnace comes on and causes the smell. But it is sooo horrible. I'm very close to calling the city and reporting it - it has been almost a month now.