[14]

The thing you need to be careful with using a cast iron pan is to not go too high heat. Since they can withstand a higher heat from other pans there is a risk when doing so as it creates a carcinogenic compound.

There's some concern that because cast-iron pans can sustain high heat, they may produce chemicals known as heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), which are linked to an increased risk of cancer. These chemicals form when meat, including beef, pork, fish and chicken, are cooked using high-temperature cooking techniques, like pan-frying and grilling over an open flame, according to the National Cancer Institute.

Not sure how much the increased risk is but just something to consider.

[Robotbeat]

Indeed. Any kind of burning or charring of food is causing really complex chemistry, and with organic molecules will likely produce aromatics, etc. (benzene is the prototypical aromatic and is present in cooking oil fumes: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4029104/ ). I think about this a lot when we’re cautioned about the presence of extremely minuscule amounts of industrial chemicals, some of the same that are present in charred food.

[14]

What I find odd is usually our bodies are extremely good at warning us of a lot of dangers. Things that are bitter don’t eat. Things that smell very fowl maybe don’t want to eat. But barbecued food smell and taste so good with a slight char on the outside. Our senses let us down if they truly are bad for you.

[Robotbeat]

They’re not very bad for you, though. (Compared to, say, salmonella, as the other person said.)

The dose makes the poison.

[tedunangst]

Well, they're better for you than salmonella.