The phrase "alarming levels" means that something has reached a very worrying or concerning point. It implies that there is a high level of danger, risk, or seriousness involved. Full definition
It was reported many popular brands add alarming levels of cancer causing lead particles. (drbradyhurst.com)
There is no doubt that the level of pollution attained on the planet has reached alarming levels threatening our health and the environment. (hawaiinaturopathicretreat.com)
As the markets began to crash, values in real estate started to rise and the demand for homeownership started to grow, at almost alarming levels. (investopedia.com)