3)if a person gets exposed to large amount of urine through cuts or mucous membrane . is it hiv risk??

Because of publicity about "contact with blood" as an HIV risk, many people have come to fear that ANY blood contact is a risk. It is not. You are worried about theoretical risks that have little basis in reality. Your statement at the end of question 2 is correct:  to my knowledge, there has never been a single case of HIV that was caught by contact with blood in the environment -- at construction sites, in homes, etc. Even in the busiest HIV/AIDS clinics, virtually all patients have traditional risks: unprotected sex with infected partners, shared drug injection needles, etc. Those who claim to not have such exposures always turn out to have either lied or were exposed to partners who they did not know were at risk (e.g. the spouse of a deeply closeted male partner who has sex with othe rmen). To your quesitons:

1) For the reasons above, this isn't a risk to worry about. Even if you have co-workers with HIV, you are not at risk.

2) In theory, the right kind of exposure in the environment could transmit the virus. But if there has never been a known case, obviously the risk is virtually zero.

3) Urine does not carry HIV and exposure to urine is not considered a risk for HIV.

So no risk at all and no need for worry. I hope this information has been helpful. Let me know if anything isn't clear.

Best wishes--  HHH, MD

1) sir, u mean even though people get  frequent cuts from construction site and if their cuts or mucous membrane get exposed other people blood everyday there is virtually no risk.

2) This is speculative. But for example, IF there were a large amount of very fresh, wet blood (which you would easily see) on a sharp object, AND that object  caused a major injury (not a minor prick), AND if the person who bled had HIV, the virus MIGHT be transmitted. Obviously the chance of all this happening is almost zero, and there has never been a known HIV infection acquired from exposure to blood in the environment.

3) Probably not. The amount of blood in urine probably would rarely be enough to carry any risk of transmitting HIV.

Please do your best to stop worrying about this. In the United States, the risk any particular person will die in the next year in an accident (auto wreck, drowning, falls, etc) is roughly one in 2,000. It's higher in many countries (I don't know where you are). That risk is thousands of times higher than the chance you'll catch HIV due to your construction work -- in fact, it's probably thousands of times higher than the risk of death from a construction accident. So my advice is to a) wear your seatbelt when driving, b) follow all safety precautions in your work (e.g. helmets, securing yourself if there is risk of falling), and c) stop worrying about HIV!

That concludes this thread. Best wishes.