Modern WX radars have a very short hazard range. Our supplier (Collins) said once that it was 2 m. This applies for array radars with digital circuitry. There are still a lot of old fashioned radars around, in old DC-9s, 737 and Russian planes. They produced the rays in a tube, consuming lots of energy. It was basically an x-ray machine.
Still I wouldn't believe the numbers, since the very same people would also say that hand phones are not dangereous...
There is still no proof or disproof of all these things.
There is also a wide spread misconception about radar rays and their influence on biological tissue: Unlike radioactice rays, they are not "stored" in the tissue. It all depends how much you receive this very moment. If it's too much, you might encounter cell decay. It's basically a microwave oven. If it's too long, it's cooked.
Dani