Probe into household cancer risks

Cansa said it would measure the concentration of "known andemerging carcinogens" in food, drinking water and polluted air.These chemicals are tasteless, odourless and invisible but "pose areal but unnoticed cancer threat".

In April, Canada announced a move to ban polycarbonate baby bottlesand declared BPA, which mimics the hormone oestrogen, "toxic"because it migrates into food and water.

Cansa said studies showed exposure to boiling water boosts the rateof migration 55 times from polycarbonate drinking bottles,especially those used by babies.

There is similar concern around certain clingwrap plasticisers,which migrate into fatty food such as minced meat, chicken andcheese. This process is speeded up when meat is thawed in amicrowave oven, according to Cansa.

It said more than 100 studies since the late 1990s had linkedlow-level exposure of BPA with breast and prostate cellspredisposed to cancer, early puberty and behavioural problems.

Cansa said it would test for the possible transfer of BPA from thelining of certain tinned foods or beverages, as well as runningtests on water and milk heated in plastic and polycarbonate babybottles for the release of BPA, and on the presence of BPA in tapand bottled drinking water.

David Hughes, the chief executive of the Plastics Federation ofSouth Africa, said it supported the early-warning system thatfollowed from research into "any potentially nasty chemicalcomponents of plastics".

The Canadian government said the "preliminary assessment tells usthe public need not be concerned [about BPA]" and the focus was onhealth impacts on newborns and infants, he indicated. "There is nocause for alarm until further scientific, peer-review study hasbeen completed into BPA."

In the coming weeks Cansa will independently test the synthetictrans-fat content of all margarines. It said the consumption oftrans-fats - plant oils created industrially through partialhydrogenation - not only increases the risk of coronary heartdisease but was also associated with a higher risk of prostatecancer and breast cancer among post-menopausal women.

Albrecht said: "I don't think anyone in South Africa has ever hadall our margarine analysed and made the information available tothe public. We spent a lot of time getting legal opinion, but we'renot just running off on a tangent. We're doing this for the publicgood.

"The manufacturers need to ask themselves how long they can keepthis up. We're just looking at ways to reduce the incidence ofcancer. It's better to fight it at the beginning, and it costsless."

Cansa said environmental factors account for 90 percent of cancerswhile just 10 percent are caused by genes. However, limitedattention had been given to reduce the carcinogenic risk of certainsynthetic chemicals in "close and constant proximity" to people inindustrialised cities.

It estimates the total cancer risk involving industrial chemicals,infections, dietary contamination, obesity and ultraviolet lightaccount for 60 percent to 70 percent of cancers. "If this is so, itmeans 30 percent to 40 percent of the cancer risk remainsunaccounted for. It's possible that man-made chemicals in theenvironment could largely fill this gap, accounting for allcarcinogens man is exposed to.

"This argument raises the ominous possibility that man-madechemicals in our immediate environment could be causing breast andprostate cancers or at least making a major contribution to thecarcinogenic process involved. Chemicals may be interacting witheach other in such a complex manner to cause cancer that scientistsdo not yet fully comprehend what's going on."

Albrecht said top laboratories, including the Council forScientific and Industrial Research, would use the "best technologyavailable" in the study, which would also focus on othersubstances, including the chemical dioxin, asbestos, andcarcinogens in water.


This article was originally published on page 2 of The Star on June 07, 2008