There are concerns that anxiety about what might cause cancer could be diverting attention from proven anti-cancer strategies.
Smoking, drinking too much alcohol, obesity and sun exposure are the big four proven causes of cancer.
Cancer researcher Professor Bernard Stewart, who specialises in public health, says anxiety about chemicals in food and consumer products is unfounded and potentially distracting.
He gives the example of people who worry about cancer being caused by car interiors, minute quantities of carcinogens in food, or certain cosmetic contaminants.
"Fears of these things can, it seems, overwhelm consciousness of cancer causation and cancer prevention methodologies that involve basic changes in behaviour rather than avoiding dangerous carcinogens," he said.
"There is evidence published in reputable journals in which it's apparent that people who are aware of lots of causes of cancer tend to be less likely to do the things that some of us may have thought were absolutely obvious, like stopping smoking."
Audio: Professor Bernard Stewart talks to AM (AM)
Professor Stewart says confusion can stop people from taking measures that do prevent cancer, such as quitting smoking, cutting back on alcohol, getting into shape and avoiding sunburn.
"The idea of someone saying 'I'm not giving up smoking but I'm going to make sure we eat organic food from now on' - without in any way being disparaging of people who want to absolutely minimise their intake of pesticides, that option is not known to prevent a burden of cancer, whereas stopping smoking certainly does prevent a burden of cancer.
"So if our criteria is actually preventing cancer then we can forget about many of these reports that involve very low levels of exposure."
He says modern society fears cancer above any other disease.
"The media can't be blamed for delivering to the community what the community wants, namely information about every last possible cause of cancer," he said.
"But detection of low levels of carcinogens in any context doesn't necessarily mean that in that context they actually cause cancer.
"So whereas we get reporting of possible cancer risks, the actual known causes and the proven preventive measures tend to take a back seat because it's old news."
Professor Stewart has published his concerns in the Lancet Oncology magazine.