Hello, thank you in advance for taking my question and appreciate your efforts and all that you do.  I'm a maintenance man in a large building and received a call of blood on a ceiling tile in the women's washroom, I had spoken to our cleaning lady before removing the tile and replacing it with a new one and she had told me she was up there earlier that morning wiping down the stall wall with what at the time she didn't think was blood, but it almost certainly was, so a few hours had passed before I changed the tile. While removing the tile, and lifting it up, I had jarred some dust loose from what I believe to be from on top of the tile or the edge where it was a tight fight that wasn't exposed to the blood spatter, fell into my eye, and my coworkers who at the time were their had made a comment like oh boy here we go he's definitely got aids now, laughing it off I didn't think it was a big deal but now maybe my ocd is kicking in, but if there was a chance some of the tiny dried blood spots had come off while adjusting the tile to remove it got in my eye, could there be a potential for infection or hiv transmission? It bothers me how the blood even got up there, its probably a good 7-8ft high, and at first I was assuming it was drug use because in 16yrs I've never had a call like that and never seen anything like that, plus our building is an A tier building and the one tenant on the floor is small, and wouldn't guess anyone would be doing heroin in the bathroom. I think not knowing what it was weirds me out more than anything. I wore gloves to remove the tile, but unfortunately did not wear safety glasses. I'm almost sure none of the affected area flaked off during removal but it was dry and wish I knew for certain. Thanks again!

Welcome back to the forum. Thanks for your question.---

DR, Thank you for your reply, and I did read your blog response to a similar question. I've noticed from doing random google searches on related topics and seeing responses from yourself as well as other colleagues, that have also said quite adamantly the virus dies and or weakens after a few seconds or minutes once exposed to light and air, and starts to die once outside the host because it needs human to human direct cell contact in order to transmit, and considering its in small quantities it breaks up quite fast? Is it that the cdc doesn't back those statements, so its hard to make such educated opinions without consent? I really do value you and your colleagues opinions because I know how many years you have invested into this field. I've had a mild/moderate cold for the last week just like many others I know, but I sometimes correlate things like that which makes me suspicious of having a disease because this incident happened two months ago, and I've read that you can get the flu shortly after being infected. I don't have the flu but some symptoms of it, and my hypochondriac personality has kicked in to full gear now. Sorry to waste your time. I know that blood flakes didn't come off the tile, that is just a what if scenario and I have ocd issues I need to deal with. I just want to ease my mind, which seems impossible to do.

There have been studies of HIV survival in various environmental situations, and indeed the virus often dies or becomes inactive in many of the scenarios you describe. But my point is that it doesn't matter. Focusing on the biological reasons for low risk from environmental exposure is pretty much irrelevant. If such infections don't happen, who cares about the biology of it all? ---

Doctor H, I want to thank you again for everything that you do to help those who are searching for answers, as I have just one last question before you close this post. Would you think it would be safe to say that if a small collection of blood droplets that have been absorbed into a man made porous material and dried anywhere between say 6hrs and 48hrs that the blood in question would be deemed  potential hiv virus dead and non transmissible at that point? With the bathroom being 74 degrees Fahrenheit and just under 30% RH with constant exhaust pulling air out of the room and significant lighting being on... Sorry for back and forth, just trying to be as specific as possible so you know the conditions. I believe the stains were a darker brown/red at the time as well. Thanks again!

There are absolutely no data on whether any theoretical risk from environmental exposure might be higher or slower if it involves a porous versus other surfaces. I'll just repeat what I already said, this time trying an internet shout: IT DOESN'T MATTER! Whether or not there is HIV in such blood, and whether or not HIV is alive or dead, will make no difference in whether or not you will be infected. You will not. And if you really care so much, just clean the area with any standard household cleaner and then forget it. ---