The science is clear: dozens of chemicals found in indoor and outdoor environments contribute to cancer. This evidence is based on comprehensive reviews by authoritative scientific bodies, including the World Health Organization’s International Agency for Research on Cancer (IARC) and the U.S. National Toxicology Program (NTP).
The Science
Understanding Environmental Cancer Risks in Southwestern Pennsylvania
Environmental Contributors to Cancer
The Intersection of Environment and Cancer Risk
Cancer develops from a combination of genetic and external risk factors, involving a series of interactions much like electric circuitry—where many components need to be in place to cause a light to turn on.
In the case of environmental chemicals, exposure to a single pollutant may only slightly increase risk of cancer for one individual. However, the impact changes when that exposure is widespread. When an entire community is exposed to a pollutant—or multiple pollutants—those small individual risks add up to a significant number of cancer cases in the general population. The more we reduce these collective exposures, the more cases of cancer we can prevent.
Science Companion: Regional Cancer Risks
This Science Companion and occupational reviews the state of the science related to the contribution of environmental and occupational chemicals to cancer, with a specific focus on risk factors that are elevated in Southwestern Pennsylvania. Environmental chemicals and pollutants of particular concern in our region are priority environmental risk factors.
Annual Research Briefs
CEN issues a monthy Digest, which includes a list of recently published research articles. Each year, the Science Hub reflects on the collection of articles and publishes a Year in Review.
- Two significant studies conducted in Pennsylvania add to the growing literature about impacts on cancer survival associated with air pollution exposure and increased cancer risks associated with the fracking industry.
- As CENSWPA observed in the 2023 literature, new research highlights the critical need to focus on environmental injustices related to cancer risks.
- Additionally, CENSWPA observed in the 2022 literature, research continues to demonstrate increased risk of childhood cancers associated with exposure to pesticides and air pollution.
- Lastly, CENSWPA observed in the 2021 literature, a range of cancers beyond lung cancer show increased risk associated with exposure to air pollution.
Priority Environmental Risk Factors
These environmental chemicals contribute to cancer risk in Southwestern Pennsylvania. Assessment of exposure—an important component of risk—is limited for some of these risk factors; for others, we know that exposure is higher in our region than elsewhere. Reducing exposure to chemicals or pollutants known to contribute to cancer is an important and often overlooked strategy for cancer prevention.
Air Pollution
Allegheny ranks among the worst 4% of counties nationwide with regard to estimated cancer risk from exposure to hazardous air pollutants (HAPs) and Diesel Particulate Matter (DPM). This does not include the cancer risk from fine particulate matter.
Fracking-Related Pollution
Carcinogens released and formed during the process of fracking natural gas include benzene, formaldehyde, particulate matter, and radioactive compounds threaten the wellbeing of residents in a number of counties in SWPA. Studies have shown that children living closer to oil and gas wells have higher rates of leukemia.
Pesticides
Some chemicals used in agriculture, in homes and gardens, on golf courses, playing fields, parks and in buildings are known carcinogens; others disturb biological processes that normally project against cancer. Early life exposures to pesticides used at home are tied to leukemia and brain tumors in children, as are parental exposures. A recent review of 40 studies concluded that documented use of pesticides was associated with brain cancers in farmers.
Radon
Pennsylvania ranks third among all states for levels of radon–roughly 40% of homes have radon above EPA’s action levels. Radon is the second leading cause of lung cancer in the US.
Toxic Chemicals in Consumer Products
Chemicals known to cause cancer are in a range of consumer products, including cosmetics, furniture, building materials, and home and garden pest control products, despite availability of safer alternatives.
Water Pollution
Drinking water in our region has been contaminated by radioactive and other hazardous substances, including from fracking activities.