An estimated 1.8 million people in the U.S. will be diagnosed with cancer in 2020, according to the American Cancer Society. While treatments and survival rates continue to improve, the incidence of some cancers are on the rise — including childhood cancers, leukemia and testicular cancer.
More than 600,000 men, women and children in this country are expected to die from cancer in 2020, up from 500,000 just five years ago. While it’s unclear exactly how much of this country’s cancer results from exposure to cancer-causing chemicals (carcinogens), according to the 2009 report from the prestigious President’s Cancer Panel, the linkage has been significantly underestimated — and decisive action is long overdue.
The Panel urged then-President Obama to “use the power of your office to remove the carcinogens and other toxins from our food, water, and air that needlessly increase health care costs, cripple our Nation’s productivity, and devastate American lives.”
Pesticides & cancer
Chemicals can trigger cancer in a variety of ways, including disrupting hormones, damaging DNA, inflaming tissues and turning genes on or off. Many pesticides are “known or probable” carcinogens and, as the President’s Panel notes, exposure to these chemicals is widespread.
Children are especially at risk of developing cancer from pesticide exposure, and childhood cancer rates continue to rise. Studies show that pesticide exposure during pregnancy and throughout childhood increases the risk of cancer among children.
Girls who were exposed to DDT before they reach puberty were found to be five times more likely to develop breast cancer in middle age, according to the President’s Cancer Panel. When either parent is exposed to pesticides before a child is even conceived, that child’s risk of cancer goes up as well.
Farmers, farmworkers, and their families tend to be exposed to more pesticides than the general population. They also experience higher rates of cancer. For example:
- Farmers and pesticide applicators have higher rates of prostate cancer.
- Women who work with pesticides suffer more often from ovarian cancer.
- Cropduster pilots and women who live or work on farms have higher rates of skin cancer.
As a global network, PAN supports efforts to reduce the use of cancer-causing pesticides in agriculture by investing in agroecological farming and reducing reliance on chemical inputs.
PI carcinogen data
There are several organizations that evaluate and rank chemicals for their carcinogenicity. Because carcinogenicity designations from different sources sometimes conflict with each other, PAN created a summary carcinogen designation that reflects the most toxic ranking assigned by any organization.
In addition, the different terms used by different organizations to describe carcinogen status were translated into a consistent set of terms. The equivalences between the different ranking systems are shown in the table below.
For a chemical to be classified as a PAN Bad Actor, it must be in either the Known or Probable PAN summary category.
| PAN Bad Actor category | Equivalence in other ranking systems |
| Known | IARC: Known U.S. EPA: Known, Known/Likely, Carcinogenic to humans U.S. NTP: Known |
| Known, P65 or TRI only | CA Proposition 65: Known to the State of California to be a carcinogen. California’s ranking does not distinguish between different carcinogenic potencies, using a Yes/No format. U.S. EPA TRI: Listed as a carcinogen on the Toxics Release Inventory list. This ranking does not distinguish between different carcinogenic potencies, using a Yes/No format.Any pesticide listed as a Prop 65 or TRI carcinogen but NOT as a Known carcinogen by IARC, EPA or U.S. NIH is listed separately as Known, P65 or TRI only. |
| Probable | IARC: Probable U.S. EPA: Probable (B1 and B2), Likely to be carcinogenic to humans, Likely (high doses)/not likely (low doses) U.S. NTP: Reasonably anticipated to be a human carcinogen CA Proposition 65: No parallel category |
| Possible | IARC: Possible U.S. EPA: Possible, Suggestive evidence of carcinogenicity CA Proposition 65: No parallel ranking U.S. NTP: No parallel category |
| Unclassifiable | IARC: Unclassifiable U.S. EPA: Not classifiable as to human carcinogenicity, Unclassifiable, Not classifiable, Not amenable to classification, Can not be determined, Data are inadequate for an assessment of human carcinogenic potential. This ranking also includes chemicals ranked as “Not Classified” and “Deferred.” CA Proposition 65: No parallel category U.S. NTP: No parallel category |
| Not Likely | IARC: Probably not a carcinogen U.S. EPA: Evidence of noncarcinogenicity, Unlikely, Not likely, Not likely to be carcinogenic to humans CA Proposition 65: No parallel category U.S. NTP: No parallel category |
See the following websites for details on how each agency determines carcinogenicity:
- California Proposition 65
- National Toxicology Program
- Toxics Release Inventory Program
- International Agency for Research on Cancer
For information on the PAN International designations of carcinogenicity, see the Highly Hazardous Pesticides resource page and the associated reference source on carcinogenicity, the EU Global Harmonized System.