The Who, What, Where, When and Sometimes, Why.

Breast Cancer and the Environment

Factors inside and outside our bodies affect our health. Those outside our bodies are often called environmental factors.

There’s no one scientific definition for the term “environment.” In health research, scientists may use different categories to decide if a risk factor is environmental.

Environmental factors may include things found in nature that we eat, drink, touch or breathe, as well as man-made factors. They may be passive (such as sunlight or secondhand smoke) or active (such as eating fruits and vegetables or drinking alcohol).

Even medications, such as birth control pills or menopausal hormone therapy (postmenopausal hormones), are sometimes considered environmental exposures.

Factors such as age, hormones produced in our bodies (such as estrogen) and family history are considered personal or genetic factors rather than environmental factors. However, they can interact with environmental factors and affect our health.

Environmental factors and health

Some factors in our environment help keep us healthy. Others are linked to an increased risk of breast cancer or other diseases. Still others have little, if any, effect on our health.

Studies of environmental factors

Researchers use different types of studies to learn about the environment and breast cancer risk.

Learn more about different types of research studies.

To learn more about the role of the environment in breast cancer, Susan G. Komen® sponsored a study from the National Academies of Sciences, Engineering, and Medicine (formerly the Institute of Medicine), “Breast Cancer and the Environment, a Life Course Approach.”

 Updated 04/22/24