There is a raging debate on the carcinogenicity of glyphosate, the active ingredient in Roundup and similar herbicides, and its use by the City of Cape Town in urban and environmentally sensitive areas.
The outcry was raised on CapeTalk recently when residents of Noordhoek questioned why a product with glyphosate was being sprayed in Noordhoek and Kommetjie during the western leopard toad mating season.
Caroline Cox, editor of the Journal of Pesticide Reform, describes glyphosate as a broad-spectrum herbicide widely used to kill unwanted plants both in agriculture and in non-agricultural landscapes.
Most glyphosate-containing products are either made or used with a surfactant, chemicals that help glyphosate to penetrate plant cells.
She said glyphosate-containing products are acutely toxic to animals, including humans, and lists symptoms which include eye and skin irritation, headache, nausea, numbness, elevated blood pressure, and heart palpitations.
She said the surfactant used in Roundup is more acutely toxic than glyphosate itself, and the combination of the two is yet more toxic.
City of Cape Town spokeswoman Priya Reddy said the City would not use a product that caused irreversible harm to residents, their pets and the natural environment.
“The City appoints contractors who must apply herbicides responsibly and all of the information available on any product is regularly reviewed,” she said.
She confirmed that the City’s contractor does use Roundup to control weed growth on hard surfaces such as on the edges of the surfaced roads and footways. However, she said a World Health Organisation (WHO) risk assessment had found glyphosate “exhibits low toxicity” and was not banned for use in herbicides.
According to the study, glyphosates “do not spread readily” but rather “cling to the surface to which they are applied”. The City was also not spraying herbicides on vast tracts of land but using “minimal and diluted” amounts on road verges.
Ms Reddy said the City’s regular contractor had been unable to spray in March as they usually did “due to unforseen circumstances”. This had led to a replacement contractor only spraying in Kommetjie and Noordhoek in June, outside the normal window.
Should glyphosate herbicides be banned, the City would heed such a restriction, said Ms Reddy. The City strived to to meet “standards of global best practice regarding the health of humans and the environment”.
The City has withdrawn the contractor from the known western leapoard toad breeding sites, including Noordhoek, as a precaution.
However the City’s assurances ring hollow for researcher, journalist and author Glenn Ashton . He told the Echo that in 2015 the WHO’s International Agency for Research on Cancer (IARC) found glyphosate probably causes cancer in humans, and that this year California intends listing it as a carcinogen under state law Proposition 65 (the Safe Drinking Water and Toxic Enforcement Act of 1986).
There was a wealth of published scientific evidence of the risks of glyphosate including risks to amphibia and other wildlife such as reptiles.
“The issue with scientific publications is that they are naturally conservative, and it is unusual for any scientific publication to state that any link is definite. This apparent lack of clarity is abused by manufacturers to create doubt about the risk of their products, which rely on manufacture’s proprietary and often confidential data that is not published and peer reviewed (the gold standard of scientific proof) data in order to gain permission for their products to be used,” he said.
He suggests readers look up the following links themselves for their own research:
http://www.ncbi.nlm.nih.gov/pubmed/27155487 – genotoxicity of glyphosate on lizard species
http://onlinelibrary.wiley.com.ez.sun.ac.za/doi/10.1002/etc.2268/full – questions on impact of glyphosate on ampibians.
He said another issue was that Roundup and other generic versions did not only contain the approved substance glyphosate but also several other chemicals, all of which came with their own risks – some examples are cited here:
Mr Ashton said the City’s use of Roundup on road verges was worrying because runoff ended up in the drains.
“This means that these chemicals enter the drainage system and go somewhere. In the case of Noordhoek and Kommetjie this somewhere is usually a wetland.”
The problem with that, he said, is that glyphosate is implicated in increasing the risk of the growth of toxic blue green algae when it enters such fresh water sources.
“In an area such as ours, where the largest relatively unspoiled wetland in the metropole exists, such risks are simply unacceptable, both to the health of the wetland and to the animals that live there, such as the western leopard toad and other amphibia, reptiles, insects and wildlife.”
Mr Ashton said manufacturers obviously claimed that glyphosate is safe. “They would, they make a profit from the stuff. While it may be a less dangerous chemical than many of the other alternatives, it is by no means inert or as safe as claimed by the manufacturers. Science is often slow to catch up to the realities of chemical pollution. After all, we considered DDT perfectly safe and acceptable until it was shown to have serious impacts on both wildlife and on humans and was subsequently banned and is now only allowed to be used under extremely strict criteria,” he said.
It was unnecessary to use this chemical to protect verges or roads, he said.
“There are many other ways to do so, including the use of low toxicity compounds such as vinegar – as well as using labour intensive methods to manage heavy weed infestation. The fact that the workers applying these chemicals to the local verges were given no protective clothing nor were briefed of the risk of using the chemical without the use of such protection shows two things: an unacceptable risk to their occupational health and safety that is illegal, and secondly, a poor grasp by our authorities of the risks of using these unacceptable methods of weed control in areas of high sensitivity such as in the Fish Hoek valley.”
Andre du Plessis, an Edgemead resident, has been very vocal in trying to stop the City’s practice of using products which contain glyphosate.
He said the City had told him it followed the guidelines set by national legislation and he would have to lobby national government to change the law.
“Because something is law, does not mean it is safe or correct. Apartheid was also once law , but remained immoral and incorrect, so are fracking, nuclear plants, taking away of property rights without compensation and tolling of our N1/N2 without proper public participation,” he said.
He said the thousands of babies who died or were born horribly deformed in the 1960s because their mothers took thalidomide for morning sickness was a chilling example of the sort of devastating repercussions that could result from exposure to harmful chemcials.
He said the Agri Law, Act 36/1947 that protects the use of glyphosate was hopelessly outdated because studies all over the world had show how destructive glyphosate was.
Ms Cox said: “Given the marketing of glyphosate herbicides as benign, it is striking that laboratory studies have found adverse effects in all standard categories of laboratory toxicology testing. These include medium-term toxicity (salivary gland lesions), long-term toxicity (inflamed stomach linings), genetic damage (in human blood cells), effects on reproduction (reduced sperm counts in rats; increased frequency of abnormal sperm in rabbits), and carcinogenicity (increased frequency of liver tumors in male rats and thyroid cancer in female rats).
In studies of people (mostly farmers) exposed to glyphosate herbicides, exposure was associated with an increased risk of miscarriages, premature birth, and the cancer non-Hodgkin’s lymphoma, she said.
Glyphosate has been called “extremely persistent” by the US Environmental Protection Agency, and half lives of more than 100 days have been measured in field tests in Iowa and New York. Glyphosate have been found in streams following agricultural, urban, and forestry applications.
Ms Cox said glyphosate reduced populations of beneficial insects, birds, and small mammals by destroying vegetation on which they depend for food and shelter, and, in laboratory tests, it had increased plants’ susceptibility to disease and reduced the growth of nitrogen-fixing bacteria.