The International Agency for Research on Cancer has stirred up controversy with its evaluation of two pesticides as probable carcinogens. The compounds are malathion, commonly used in mosquito control, and glyphosate, also known as Roundup. This herbicide is very widely used in agriculture to control weeds in cultivated fields.
What Is the Evidence?
To reach these conclusions, the agency examined data based on cell culture studies showing that the compound can damage DNA. In addition, it considered animal studies that show unusual tumors in rodents exposed to glyphosate.
According to the scientists who did the assessment, this evidence shows that Roundup could cause cancer in humans, too. Non-Hodgkin’s lymphoma and lung cancer are of greatest concern.
Adding Fuel to the GMO Fire
This announcement is likely to add further fuel to the debate over genetically modified organisms, or GMOs. In the United States, popular crops such as corn and soybeans have been genetically engineered so that they can resist the effects of glyphosate, while native weeds are presumably susceptible. This means that the entire field can be sprayed with glyphosate rather than making the considerable effort to target the weeds alone.
The Environmental Protection Agency is due to review Roundup safety later this year. In 2013, the EPA stated that glyphosate does not pose a cancer risk to humans.
The Company Does Not Agree
Monsanto, the maker of Roundup, has objected strenuously to the international announcement. According to Philip Miller, Monsanto’s global regulatory affairs vice president, the International Agency is “starkly at odds with every scientific agency that has studied glyphosate safety.”
Monsanto has called on the IARC to renounce its decision on the grounds that it may unnecessarily confuse and frighten farmers and consumers. The company maintains, however, that it does not expect use of Roundup to drop.