Quote Quoting llworking
Ok, let me make sure that I fully understand your complaint...

You are stating that someone is smoking outside, no windows or doors are open, and somehow smoke is getting into your unit? Do you otherwise have a serious problem with drafts and other insulation issues?

Smoke is going to follow the path of least resistance. The amount of smoke that could possibly enter your unit (unless there are serious drafts) should not be enough to give you headaches, serious fatigue or a higher risk for cancers. Even with serious drafts, the person would have to be literally smoking right next to the draft area.

What you might want to do is see if you can figure out what the point of entry is. If there is a draft area somewhere that could be rectified it might not only solve that problem, but might reduce your heating and cooling costs as well.
Your understanding is correct. I appreciate your helpful advice about looking for point(s) of entry where smoke (or any other unwanted odors) are coming in. I get the impression that you're trying to gently tell me that - notwithstanding a maintenance issue - there really is no corrective action a tenant could take in this situation.

If it makes a difference: there is approximately five feet (or basically, one of me minus eight inches lying on the ground, lol) between our doors, which are side by side within a wall. When the new tenant moved in, she situated two chairs (it's like those fold-up seats you can get from Walmart) to take up all the space between our doors. Both chairs are within three feet of my door, and the one closest to it is less than a foot away.

Taking a closer look at the area, the walls seem fine; they are stone. However, I do see what look like "cracks" toward the bottom and to the right of the door when shut. It's like an "uneven" part of the wooden surface where a part of it was "shaved" somehow; when the sun is out, light actually shines through that part of the door, but I always thought the "cracks" (or whatever you might call them) were so small that they would not have made a difference on anything.

Then again, since I live alone in a one bed/one bath, the air conditioner is in the same room as the kitchen and close to the door previously mentioned, and my electric bill during the summer months averages $150, perhaps your suggestions need to be taken seriously. I will have to look into that. Assume for the purposes of this thread, however, that this issue remains unresolved even after addressing the potential maintenance issue.

Quote Quoting llworking
Smoke is going to follow the path of least resistance. The amount of smoke that could possibly enter your unit (unless there are serious drafts) should not be enough to give you headaches, serious fatigue or a higher risk for cancers.
The Centers for Disease Control and Prevention and American Cancer Society cite numerous studies and reliable references (including the US Department of Health and Human Services) that indicate that brief and/or long-term exposure to even "low" amounts of secondhand smoke can have serious impacts to cardiovascular and respiratory health. Thus, there is no "non-serious" level of exposure for secondhand smoke. This is something that is fully-controllable and preventable, as secondhand smoke is generated only by people who make the choice to smoke.

So, unfortunately, I must disagree here. As stated previously, what others do on their own time is their own business, and they are certainly free to damage their own bodies to the fullest extent possible. Heck, I'll even stop using that entrance and go outside through the vestibule from now on - even though the entrance previously mentioned is supposed to be a part of a shared space. I just don't want something known to claim 40,000 lives per year to be in the same place in which I sleep and prepare food.

Quote Quoting Taxing Matters
Whether a landlord would have any responsibility for this and to what extent depends on the applicable state law, and so far you have not indicated in what state you live. As there are 50 states, DC, and several territories in the U.S., each with their own laws that can differ significantly, knowing the state makes a big difference.
You're right. I just didn't mention it because the Warranty of Habitability and Covenant of Quiet Enjoyment - both of which I thought were a matter of common law - were the two implied parts of the lease that could potentially be impacted by this issue.

My state is Florida, where there aren't extensive statutory protections for tenants compared to some of the other states. There's § 83.20, but I will have to double check my lease to see if it is "silent" on the matter of maintenance and repair of the rental property. Even if it is, this section would only appear to apply if a lack of maintenance made the property "wholly untenable."

I'm not sure if secondhand smoke would make the property "wholly untenable," but it is my opinion that a phenomenon known to contain tens upon tens of carcinogens and thousands of toxic chemicals might have an impact on the habitability of the property or my ability to enjoy it in peace.