The study, led by USC Norris Comprehensive Cancer Center, found that non-smokers under 50 diagnosed with lung cancer often had healthier diets than the average American. Lung cancer has historically been associated with older male smokers, but in this study younger, non-smoking women were diagnosed with the disease more often than men and reported consuming more fruits, veggies, and whole grains than their male peers. The researchers suspect that pesticide exposure could be a risk factor, since non-organic produce and whole grains tend to carry higher pesticide residues than foods like meat and dairy.³

In fact, a growing body of research highlights potential links between pesticide exposure and cancer diagnoses in people under 50. One study, published in Nature Medicine this year, examined the “exposome footprint”—environmental and lifestyle exposures—in colorectal cancer patients under 50.⁴ Researchers compared the exposome footprint of younger patients with that of older patients (over 50) and noted significant differences in three categories: diet, tobacco, and pesticide exposure. The herbicide picloram, commonly used in pasture, rangeland, and forestry, stood out, showing a “very clear correlation signal” with the development of early-onset colorectal cancer.⁵  The researchers also noted that, because picloram was introduced in the mid-1960s, younger patients were exposed to it earlier in life and for a longer time, compared with those born before its widespread use began.

In Iowa, the nation’s corn capital and the second-leading agricultural state in cash receipts, the conversation surrounding pesticides and cancer carries particular weight.^{6 7 8} The state has the second-highest rate of cancer incidence nationwide and a higher cancer rate for people under 50 than the national average.^{9 10} Yet, it doesn’t dramatically stand out from other states in well-known modifiable risk factors such as tobacco, obesity, and UV exposure, according to Dr. Richard Deming, medical director at MercyOne Cancer Center in Des Moines. Iowans do, however, face above-average “environmental exposure to agricultural chemicals.” The Iowa Environmental Council and the Harkin Institute published a report this year finding that pesticides, nitrates, “forever chemicals” (PFAS), and radon are “ubiquitous across the state”—and all are linked to cancer risk.  Among Iowans under 50, six of the 10 cancer types linked to these substances are on the rise.¹¹

A glaring void within chemical safety assessments is the narrow focus on evaluating single substances to determine “safe” exposure limits. In real world scenarios, however, pesticide exposure typically includes a complex mixture of multiple chemicals at one time. And the combined impact of these substances on human health is hard to measure. A study conducted in Peru and published in Nature Health in 2026, emphasizes this knowledge-gap as a factor in its concerning findings.¹² The study showed that those living in pesticide-heavy environments experienced a roughly 150 percent increase in cancer risk, with Indigenous and rural farming communities facing some of the highest exposure levels. Individuals in these communities encountered approximately 12 different pesticides at once in “elevated concentrations.”

“The impact of pesticide use on cancer incidence may rival that of smoking,” concluded a 2024 study published in Frontiers in Cancer Control and Society.¹³ Which raises the question—why do we tolerate an agricultural system so heavily dependent on deadly chemicals?

References

1. More than 4 in 10 Cancers and Cancer Deaths Linked to Modifiable Risk Factors. (2017, November 21). American Cancer Society. https://www.cancer.org/research/acs-research-news/more-than-4-in-10-can…
2. Eating more fruits and vegetables tied to unexpected lung cancer risk. (2026, April 26). ScienceDaily. https://www.sciencedaily.com/releases/2026/04/260417224454.htm
3. Eating more fruits and vegetables tied to unexpected lung cancer risk. (2026, April 26). ScienceDaily. https://www.sciencedaily.com/releases/2026/04/260417224454.htm
4. Staff, A. P. (n.d.). Can pesticide exposure increase Early-Onset colorectal cancer risk?https://ascopost.com/news/april-2026/can-pesticide-exposure-increase-ea…
5. United States Prevention, Pesticides Environmental Protection Agency. (1995). R.E.D. FACTS Picloram pesticide reregistration. https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/…
6. St James, T. (2026, March 2). California leads U.S. agriculture in total production value; Iowa ranks second as corn tops crop values - RFD. RFD-TV. https://www.rfdtv.com/california-leads-u-s-agriculture-in-total-product…
7. Farm Income and Wealth Statistics - Farm sector financial indicators, State rankings. (n.d.). https://data.ers.usda.gov/reports.aspx?ID=4048
8. Iowa Corn. (2024, May 29). Iowa Corn Facts and FAQs | Iowa Corn Growers Association. https://www.iowacorn.org/corn-facts-faq/
9. Midwest, L. C. I. (2026, April 9). - Investigate Midwest. Investigate Midwest. https://investigatemidwest.org/pesticides-cancer-and-public-health/
10. Investigate Midwest. (2026, March 31). Iowa’s high cancer rate linked to nitrate, pesticides, PFAS and radon, new report finds. https://investigatemidwest.org/2026/03/31/iowas-high-cancer-rate-linked…
11. Investigate Midwest. (2026, March 31). Iowa’s high cancer rate linked to nitrate, pesticides, PFAS and radon, new report finds. https://investigatemidwest.org/2026/03/31/iowas-high-cancer-rate-linked…
12. Pesticide exposure linked to 150% higher cancer risk in major study. (2026, April 26). ScienceDaily. https://www.sciencedaily.com/releases/2026/04/260426012314.htm
13. Midwest, L. C. I. (2026, April 9). - Investigate Midwest. Investigate Midwest. https://investigatemidwest.org/pesticides-cancer-and-public-health/