$439m award brings Roundup to centre stage
Debate starts afresh over key chemical in weedkiller
Ascience California court case that linked Roundup to cancer has prompted more calls for a ban on the popular herbicide — but should it?
Like a hardy thistle that won’t die, debate surrounding cancer and the key chemical in one of the world’s favourite weedkillers continues to sprout.
Two years after argument had apparently been settled here in New Zealand, a San Francisco jury has ordered Monsanto to pay $439 million to a former school groundkeeper, on the basis its product had contributed to his cancer.
The lawsuit from Dewayne Johnson claimed Roundup caused his non-Hodgkin’s lymphoma, which Monsanto denied.
The company insisted hundreds of studies have established that the active ingredient in Roundup — glyphosate — was safe and planned to appeal.
That wasn’t enough to reassure many here — and one group, GE Free NZ, went as far as stating the ruling had “brought out the dark underbelly of Monsanto”.
New Zealand scientists have read about the case with interest — notably because it was based on some relatively new evidence.
In 2016, the International Agency for Research on Cancer (IARC) re-classified glyphosate as a “probable human carcinogen” — a decision based on an extensive review of available data, including human studies.
However, the impact of this finding was being debated widely, partly due to the involvement of large corporations, University of Otago toxicologist Dr Belinda Cridge said. But there were also questions about the IARC’s work itself — when it looked at a chemical’s carcinogenic potential, it didn’t generally conduct a full risk assessment, or judge where and how contact with the chemical might occur.
Cridge pointed out that even red meat consumption had been classified as a probable carcinogen, something which also highlighted that wider factors were critical to determining full risk.
Still, she said, the underlying finding of the IARC stood — glyphosate may cause cancer, but under the right conditions and exposures.
As for the US case, it cited that additives in the Roundup, beyond the active glyphosate compound, may have had a synergistic effect to cause the cancer.
Such effects occurred when two chemicals which are relatively benign separately, acted together to make a small effect much