Cancer remains a devastating health crisis nearly fifty years after the declaration of the “War on Cancer.” Better treatments and earlier detection have dramatically improved prognosis for some types of cancer, yet significant disparities persist (National Cancer Institute 2022). Cancer survivors often confront long-term health challenges (Oeffinger et al. 2006). Nationally troublesome trends exist, including rising rates of cancer in young people (Miller et al. 2020; di Martino et al. 2022), increases in lung cancers among never-smokers (Pelosof et al. 2017), and growing rates of testicular and kidney cancer, as well as most kinds of leukemia (National Cancer Institute 2022). It appears our medical system’s dominant approach to addressing cancer through treatment and screening is not fully working, which begs the question: what stones have been left unturned in cancer prevention?

One important strategy for preventing new cases of cancer is reducing exposure to tobacco smoke (Moolgavkar et al 2012). Ongoing investment is needed to continue that progress; however, a recent study suggests that factors other than smoking are also contributing to cancer incidence. For the 12 types of cancer for which smoking is a known risk factor, the study concluded that eliminating smoking entirely would reduce the incidence of these 12 cancer types by about 40 percent on average in U.S. counties, thus leaving 60 percent of cancer cases still occurring. More important, the benefit of eliminating smoking would vary substantially from county to county across the U.S. (Myers et al 2020). While this finding affirms the importance of smoking cessation, it also underscores the need to understand what other factors could be contributing to cancer risk and what more can be done to address them.

We are exploring these questions in Southwestern Pennsylvania. In Allegheny County, home to Pittsburgh, a follow up analysis estimated that lung cancer would drop only 10.6 percent if smoking were eliminated, compared to an average reduction in lung cancer rates across all U.S. counties of 62.5 percent (Myers et al. 2021). It turns out that Allegheny County is in the top four percent of U.S. counties for estimated risk of cancer from diesel and air pollutants categorized as “air toxics,” with environmental justice areas at even higher risk, illuminating long-standing inequities in exposures. Cancer risk from large industrial pollution sources, such as iron and steel production including coking, is even more striking (Graham 2021). In addition, Pennsylvania’s average levels of radon are the third highest compared to other states (World Population Review 2022). Over the past 15 years, the region has seen intense development by the oil and gas industry with activities near homes, schools, and water supplies raising concerns about carcinogenic exposures (Environmental Health News 2021; Warner et al. 2013.) Additional environmental cancer risks in the area include asbestos, pesticides, carcinogenic by-products of water treatment, and per-and polyfluoroalkyl substances—a class of thousands of chemicals known as PFAS (Pennsylvania DEP 2021; Cadwallader et al. 2019).

Read the full article about reducing pollution by Polly Hoppin and Philip R.S. Johnson at Grantmakers In Health.