A UK study has linked thyroid disease with human exposure to the chemical used in most non-stick cookware, fast-food packaging, and stain and water-resistant coatings for carpets and clothes.

The chemical is perfluorooctanoic acid (PFOA), a persistent organic chemical used in many industrial and consumer goods, such as Teflon pans, stain-resistant carpet, stain-resistant fabric sprays, and flame retardant chemicals used on children’s clothing.

Vacuuming carpet that contains a stain-resistant coating can release these chemicals into the air to be circulated in the home.

The study by the University of Exeter and Peninsula Medical School included nearly 4000 adults aged 20 and older whose blood serum was sampled between 1999 and 2006 for PFOA.

The researchers found that the individuals with the highest PFOA concentrations were more than twice as likely to report current thyroid disease.

Thyroid disease, if left untreated, can lead to heart disease, infertility, muscle weakness, osteoporosis and, in extreme cases, coma or death. Exposure to these toxic chemicals is likely one reason why thyroid disorders are becoming so widespread.

Non-stick cookware, when heated, has proven to be a primary source of PFOA.

PFOA and other similar chemicals are used to create heat-resistant and non-stick coatings on cookware, as well as grease-resistant food packaging and stain-resistant clothing and furniture and other fabrics. Studies have linked these chemicals to a range of health problems, including thyroid disease, infertility in women, and developmental and reproductive problems in lab animals.

Non-stick pans quickly reach temperatures that cause the non-stick coating to begin breaking down, releasing toxins into the air. When the pan reaches a hot cooking temperature, which takes about three to five minutes of heating, at least six toxic gases are released. If the pan gets extremely hot, the coatings on the cookware break down and release an even more toxic chemical called PFIB.

These chemicals are easily absorbed by the human body, and have been linked to a growing number of health concerns, meaning healthy, home-cooked meals can become toxic when prepared in unsafe non-stick cookware.

In the US, the Centre for Disease Control and Prevention last year issued a major report, the National Report on Human Exposure to Environmental Chemicals, which is considered the most comprehensive assessment to date of the exposure of the US population to chemicals in our environment. It had detected not one but 12 types of PFOA-type chemicals in people.

This group of chemicals was among 75 that had never before been measured in the US population, but are now is showing up with great frequency. No similar study has been undertaken in Australia.

In Australia, as in the US, non-stick cookware has become enormously popular because of its convenience factor; foods don’t stick to the surface, and the classic example is the sunny-side-up eggs that slide right out of the pan.

Now, about 70 percent of cookware contains a non-stick coating.

PFOA chemicals have also been linked to lower birth weights among newborns, with the US Environmental Protection Agency stating that PFOA ‘poses developmental and reproductive risks to humans’.

PFOA has even been associated with tumors in at least four different organs in animal tests, and has been associated with increases in prostate cancer in PFOA plant workers. The EPA has also ruled this class of chemicals as ‘likely carcinogens’.

An entirely voluntary program for companies to reduce PFOA emissions and products by 2010, and eliminate them entirely by 2015, has been introduced by the US EPA. No similar program has been initiated in Australia.

The UK research study was published in the journal Environmental Health Perspectives, in January this year.