Roundup, one of the most commonly and widely used weed killer, contains Glyphosate as one of its main ingredients. Glyphosate is a systemic and broad-spectrum herbicide that was patented by a U.S. company, Monsanto, in 1970. Bayer acquired Monsanto on June 7, 2018.
After the patent for Monsanto expired in the U.S. in 2000 and outside the U.S. in 1991, many other manufacturers started marketing their glyphosate products leading to a substantial increase in sales and global usage. The chemical name of glyphosate is N-(phosphonomethyl) glycine, and it blocks an enzyme in the plant, which helps in preparing amino acids and proteins, thus, killing the plants within a few days.
Since 2013, there was an awareness created that Roundup may lead to some serious medical conditions. It did confirm in March 2015, when the World Health Organization (WHO) announced that there was a probable link between glyphosate and Non-Hodgkin's lymphoma and other forms of cancer. The speculations are that the manufacturer knew about this linkage and covered its tracks unofficially. In December 2018, the city of Sonoma banned the use of glyphosate-based herbicides on all the city properties. While, in January 2019, French authorities officially stopped the sale of Roundup Pro 360, and in March 2019, the city of Miami banned the use of glyphosate-based herbicides in the city’s properties.
IARC, considered to be the apex in the field of cancer research, classified glyphosate as a “probable human carcinogen.” According to IARC, Roundup is made up of other ingredients that are toxic in themselves, and are also known to increase the toxicity of glyphosate. Monsanto has known this for many years but still refuses to study the link between cancer and Roundup.
EPA scientists performed an independent evaluation of available data for glyphosate and found that there was no evidence that glyphosate causes cancer. According to EPA, they considered a more extensive and relevant dataset than the International Agency on the Research for Cancer (IARC). EPA’s cancer classification is consistent with other international expert panels and regulatory authorities, including the Canadian Pest Management Regulatory Agency, Australian Pesticide, and Veterinary Medicines Authority, European Food Safety Authority, European Chemicals Agency, German Federal Institute for Occupational Safety and Health, New Zealand Environmental Protection Authority, and the Food Safety Commission of Japan.
Under EPA’s Endocrine Disruptor Screening Program, Glyphosate has undergone Tier I screening. Based on the available information, EPA concluded, using a weight-of-evidence approach, that the existing data do not indicate that glyphosate has the potential to interact with the androgen, estrogen, or thyroid signaling pathways. Following the recent public comments on the risk assessments, EPA released the Glyphosate Proposed Interim Decision for public comment in April 2019. According to the decision, EPA is management measures on pesticide release height, droplet size, and wind speed to address pesticide spray drift. EPA is also proposing measures to prevent or reduce weed-resistance, which includes giving farmers better information on the mode of action, how to report potential weed resistance issues, and the need for scouting to maintain glyphosate as a tool for growers.