Start with the output power of the WAP. Factor in the distance, intervening walls, and the inverse-cube drop off... you're getting tiny fractions of a milliwatt of exposure, unless you somehow managed to swallow your wifi hotspot.
Eating farmed fish (mercury) or making microwave popcorn (microwaves leak enough power to completely drown out local 2.4GHz spectrum communications) will probably kill you long before the WAP does. If sun exposure, the american diet, or tripping over your own two feet don't get you first.
Basically, everything under the sun, including the sun, does damage to you and your cells, dna, etc. The trick, if you can call it that, is to do a small enough amount of damage that you can heal yourself faster than the damage is being done.