Hazard
A hazard was potential source of danger or risk that could cause harm or damage. It could be used to describe a variety of situations or conditions that might pose a threat to safety.
In 2268, Montgomery Scott informed Captain James T. Kirk by saying, "We've not been able to get through to Starfleet Command. All subspace frequencies have been blocked, and there's too much radiation coming from that Klingon ship. It's a hazard to the vicinity." (TOS: "Day of the Dove")