That's what we call PAHs. Again, those are known or probable human carcinogens, and again, the bottom line is that it's always about the concentrations, right?
As an environmental chemist, I can tell you that if I have good enough detection limits, the chances are that I could detect just about everything in any media. Just because something is showing up in your water or in the air it's not necessarily a huge concern. It's all about the dose, the concentrations. We need long-term monitoring data to see the concentrations and to see how long a specific human population or ecosystem is exposed to that.