The health risks associated with eating well-done meat may have been underestimated, researchers say.

It has long been known that cooking of food, as in grilling or frying, can lead to the formation of carcinogenic substances, the so-called food mutagens. But a new study has found that the harmful effects of consuming well-done meat may have been underestimated.

In a study funded by the Norwegian Research Council, researchers used a mouse with human enzymes inserted to examine whether humans may be more sensitive to certain carcinogenic substances from heat-treated foods. The experiment aimed to study the tumor development in the intestines of the "human-like" mice, and compare it with tumor development in normal mice given the same food mutagen.

The results showed that the incidence of intestinal tumors increased from 31 per cent to 80 per cent in "human-like" mice that consumed substances from well-done meat crust.

Aside from well-done meat, some of the more known carcinogens are cigarettes, asbestos and smoked meat.

But there are some suspected carcinogens which you have probably never heard of but are part of everyday life. Surge Desk listed potential cancer causers not many of us know.

1. Styrene

Styrene, and its chemical compound colleague styrene-7,-8-oxide, which is found in cigarettes, marijuana and styrofoam food packaging.

2. Tetrachloroethylene

Also known as PCE or PERC, this chemical compound, which is used in metal finishing plants, dry cleaners or taxidermy shops, has already been shown to cause liver cancer and leukemia in rats, and epidemiological studies have linked it to esophageal and cervical cancer and non-Hodgkin's lymphoma.

3. Titanium Dioxide

One of the least studied, titanium dioxide has been established as a cancer-causing agent in several animal studies, and is mostly found in manufacturing facilities. It's also an ingredient in cosmetics, paints, varnishes, lacquers, paper, plastics, ceramics, rubber or printing ink.

4. Diesel Exhaust

This has been linked to lung cancer in many animal studies and a few small evaluations of truck drivers and others in the automotive industry.