Toxins in your bread
Across the globe countries are taking action against a herbicide that the World Health Organisation says might cause cancer.
Here in South Africa, the weed killer is widely used and is found in bread and maize meal.
Colombia has suspended the aerial spraying of illegal coca plantations with glyphosate because several studies - including one by a research arm of the WHO - suggest that the herbicide is likely to be carcinogenic to humans.
European countries, including the Netherlands, Denmark and Sweden, have banned or restricted the use of glyphosate.
In South Africa, a position on its continued use is unclear, with the Department of Agriculture, Fisheries and Forestry failing to respond to queries yesterday.
The WHO study, published in the journal The Lancet Oncology, said there was limited evidence that the herbicide caused non-Hodgkin's lymphoma in humans, although there was sufficient evidence that it caused cancer in animals.
Non-Hodgkin's lymphoma is a cancer that attacks the lymphocytes that form part of the immune system.
The study found that glyphosate had been detected in the blood and urine of agricultural workers, suggesting absorption.
In South Africa, the use of glyphosate - an active ingredient in Monsanto's Roundup herbicide, which is used on genetically modified crops - has been growing.
According to the African Centre of Biodiversity, an activist organisation, half of South Africa's maize crop and 100% of the soya crop is genetically modified, meaning it has to be grown with the use of glyphosate.
According to Christo Joubert, from the market economic research centre at the National Agricultural Marketing Council, the country consumes nearly 27000 tons of maize daily.
It is unclear what portion of this is genetically modified maize.
In 2012, the African Centre for Biodiversity conducted a study of glyphosate levels in maize and soya in South Africa.
"We found traces of glyphosate, but it was below the maximum residue levels permitted," said Gareth Jones, one of the researchers.
What concerned the organisation was that it had to get the tests done in France because none of the laboratories in South Africa could perform the analysis.
"There is no testing facility in South Africa, so there is no active monitoring,'' said the centre's Zakiyya Ismail.
Last year, the centre tested the amount of genetically modified soya flour used in the making of bread and discovered glyphosate traces in the output of seven of eight big manufacturers of bread in the country.
Jones said even though the levels were within legal South African limits, there has not been sufficient tests on the long-term effects of low exposure to the pesticide.
Attempts to get clarity on the government's policy on glyphosate had been unsuccessful, he said.
"For six to nine months at the time of the study we tried to get information from the Department of Agriculture, but we couldn't get a response," he said.
The Department of Agriculture, Fisheries and Forestries told The Times it would respond to queries only today.
Rhodes University has tested the affect of glyphosate on aquatic animals. The herbicide is known to effect the embryonic development of frogs.
Professor Tally Palmer, of the Rhodes Institute for Water Research, said glyphosate was used to control a number of aquatic weeds. But to test the amount of glyphosate in South Africa's waterways would be expensive.
A concern, she said, was that because genetically modified crops are resistant to glyphosate, farmers have a tendency to over-spray plants, releasing more of the weed killer into the environment.
The South African Consumer Protection Act requires all food containing 5% or more genetically modified content to be labelled.
Monsanto has said the WHO's research was biased.
"We are outraged with this assessment," said Dr Robb Fraley, Monsanto's chief technology officer.
"This conclusion is inconsistent with the decades of ongoing comprehensive safety reviews by the leading regulatory authorities around the world that have concluded that all labelled uses of glyphosate are safe for human health. [The WHO] result was reached by 'cherry picking' of data and is a clear example of agenda-driven bias."
He said that repeated safety assessments had formed "the foundation for the long history of safe, highly effective use of this important agricultural tool in more than 160 countries around the world."
Additional reporting by Farren Collins