 The level of nitrosamines in bacon is so high that these carcinogens have been discovered even in the vapors from fried bacon. You know the smell of frying bacon that everyone loves so much? Well, one of the more potent carcinogenic nitrosamines is in those fumes. You're breathing it in. In fact, if you're going to cook something like bacon and eggs, the barbecue people have the right idea. Do it outdoors in the fresh air. The amount of deposited particles deep into the lung of an individual indoors exceeded by up to 10 times the amount received by an individual at the same time period outdoors. Just don't run around or play frisbee or anything near the grill, as the number of deposited particles significantly increases with exercise, just because you're inhaling greater lung volumes. It's kind of the second-hand smoke of the meat world. What about tempeh bacon? Tempeh is probably the closest plant-based thing to cured meat. It's a fermented soybean product. Airborne mutagens produced by frying beef, pork, and a soy-based food. What do you think they found? Airborne cooking byproducts from frying burgers, bacon, and tempeh were collected, extracted, and tested for mutagenicity, the ability to damage and mutate DNA. Fumes generated by frying pork and beef were mutagenic, especially the bacon, found 15 times worse than the beef, but no mutagenicity was detected in fumes from frying tempeh burgers. The researchers suggest that this may explain both the increased risk of respiratory tract cancer among cooks, as well as the lower proportion of deaths from respiratory diseases and lung cancer among vegetarians.