There have been some fumes in every apartment I've been in.
Once me and my father went outside somewhere around 8pm. He said "See? You have air here. There's wind."
I couldn't agree with him. I felt like I don't have an apartment because of the fumes and what he said. It feels like being homeless. You don't have enough oxygen in your apartment. This is why when I wake up early in the morning I go outside on my balcony for a few minutes. It's always after 5 am and no one has raised any complaints so far.
If you are able to, please let everyone know. This is why. This is the reason. There is nothing suspicious and I wouldn't say fire if there's no fire.
I think everyone should be informed of this. If it's not allowed call me on the phone and I'll wait until 6 or 7 am to do it.
Yatsufusa
You can look up details on this in your own time, but unless there's a large crowd staying in your place (or you have _no_ windows), you won't get issues with breathable air. Even 'modern' houses aren't exactly hermetically sealed. You could go a over a week without opening a window and you would be "fine" (which I "tested" in my teenage years).
That being said, 'quality' of the air in any given house will improve if you air out the house 3 times a day and it will prevent trouble with mold.
Hope this helps.
As for the "fumes"... Sorry, I do not know what you are talking about there, but it is 'possible' that you might benefit from talking about that to a medical professional - either a family doctor or somebody who specializes in respiratory issues.