Processed meats like bacon, sausages, hot dogs, pepperoni, ham, lunch meat, and more contain nitrates and nitrites. According to this source, they are what make the meat pink, rather than an unappetizing gray. They have been linked to colon cancer, stomach cancer, pancreatic cancer, decreased lung function, and for children born to mothers that eat a lot of processed meats--brain tumors.
So, check your labels, look for SODIUM NITRITE in the list of ingredients. This is where turkey hot dogs aren't necessarily better for you. They have it, too.
But the good news is that at some stores you can find uncured products. They don't have nitrates and nitrites. I've been buying my family bacon and hot dogs from Whole Foods and they taste great. In some parts of the country you will find uncured items in your regular grocery store. I haven't seen them in mine, here in Oklahoma.
I will check back in at the end of 7 days and report on my findings.
Why Avoid Nitrates and Nitrites
About.com - Nitrates and Nitrites