Carcinogens From Barbequing

I highly recommend this book, "Positively Ageless" by Cheryl Forberg, RD
(from her book)

Don't overcook your meats!
There are 2 types of chemicals that can develop when cooking over high heat, I am talking about barbecuing. HCAs (heterocyclic amines) and PAHs (polycyclic aromatic hydrocarbons)... HCAs are formed in muscle meats at high temperatures. PAHs result from fat dripping on to hot coals during grilling or barbecuing, which creates smoke and fire that then collects on the meat. Both of these chemicals are suspected to be carcinogenic in humans. To reduce the amount of these chemicals in your food, stick with cooking methods that don't char your food. When you do use a grill, drain and blot away any excess oil if marinating the meat. Place your food on foil to prevent fat from dripping on the coals, and cut off any portion of food that gets blackened from fire and smoke.

I know that is a bit discouraging since we all BBQ quite a lot, but just make sure not to place meats directly over the flames or cook 'indirect' on the grill.