Amid health scares about genetically modified food, BSE, salmonella and E coli, it's no surprise that consumers have turned to organic produce.
However, having an organic label may not be any final proof of purity from harmful chemicals. The Soil Association (SA), the UK's leading organic certification body, concedes
that it has granted licences for some 50 additives to be allowed into organic food. Francis Blake, the SA's director of technical standards, claims that many of these, such as chalk or vitamin C, are innocuous or even beneficial.
But the SA has lately approved sodium nitrite for use as a preservative in bacon to prevent the development of food borne pathogens, such as salmonella and botulism. In large quantities, sodium nitrite has been implicated in cancers of the gastrointestinal system.
Nitrites react with amines, a group of chemicals found in food, to create nitrosamines, most of which have been shown to be carcinogenic. As nitrosamines have been shown to increase the risk of stomach and bowel cancers, legislation has been introduced in some countries to restrict nitrate levels in water, foods and cured meats. Sodium nitrite, as a food additive, is banned in Holland and Germany.
So why does the Soil Association allow the use of this preservative in organic meat, which to many consumers signifies "chemical free"? Could the SA guardians of food safety have caved in to pressure from Sainsbury plc, which wanted to stock organic products with a shelf life equivalent to normal processed foods?
Critics point out that the supermarket chain did provide donations to the SA last year. The SA itself admits that the sponsorship, totalling lb20,000 about 1 per cent of the SA's income for 1998 helped to fund a trade conference and to produce technical leaflets. The chairman of the association has also recently concluded a deal to sell organic sodium nitrite treated bacon to Sainsbury for the first time.
"There is no question that financial sponsorship of any kind would ever influence the decision making process of our standards committees," says Blake.
"The Processing Standards Committee accepted the proposal on the grounds that use of nitrites would promote a safe and reliable curing process," says Blake. The proposal was put to the UK Register of Organic Food Standards a government agency which determines organic food and was accepted last May.
"We are aware of the potential carcinogenic risk, but it's a matter of choosing the lesser of two risks: the very small one from cancer, or the greater risk from E coli and botulism," Blake adds.
The decision to permit sodium nitrite in processed bacon would seem to be backed by scientific research at the Aberdeen University Centre for Organic Agriculture and Department for Medicine and Therapeutics, which has investigated the safety of sodium nitrite for five years.
The epidemiological association of dietary nitrate with the incidence of stomach cancer over the last 20 to 30 years has been contradictory, says Dr Carlo Leifert.
He claims evidence increasingly suggests that dietary nitrate uptake is "protective" against cancer and gastrointestinal diseases in animals and man.
Because vegetarians have a much higher intake of nitrate (from green, leafy vegetables) than non vegetarians, Leifert says they should be at increased risk of gastric cancer if nitrate is a critical factor. However, the contrary appears to be true (Comp Biochem Physiol, 1997; 118a: 939-48).
Nevertheless, there are many potential weaknesses in that type of study; vegetarians, for instance, are being compared with meat eaters, who may actually have a higher intake of nitrates in their diet. It also flies in
the face of long held evidence in the US that nitrites converted into nitrosamines are a major human carcinogen (Nature, 1970; 225: 21-3), producing tumours in many organs. Twenty five years ago, a US government advisory group recommended that the meat industry be given three years to find replacements for nitrites in meats.
The association has been shaken by the "unexpected controversy" surrounding the sodium nitrate issue, and may be forced to make its decision making policies more transparent. In future, the association will seek wider consultation by placing a notice in their magazine Living Earth.
Swaddles Green Farm, an organic farm in Devon, is horrified by these disclosures, viewing them as the "thin edge of the wedge". Swaddles Green, like other organic farms, finds salt an effective disinfectant and preservative.
"This all smacks of big business to me," says Charlotte Reynolds of Swaddles Green. "Once you allow some chemicals in, what's to stop you from allowing in all the rest, so that there's no difference between organic and ordinary meat?"