Which of the following is an environmental factor that may increase cancer risk?

Asbestos is recognized as a significant environmental factor that can increase the risk of several types of cancer, particularly lung cancer and mesothelioma. This naturally occurring mineral has been widely used in construction and insulation due to its flame-resistant properties. However, when asbestos fibers are inhaled, they can cause cellular damage over time, leading to the development of cancer. The carcinogenic properties of asbestos have been well-documented, with numerous studies establishing a clear link between asbestos exposure and cancer risk.

On the other hand, genetic predisposition refers to inherited factors that may increase an individual's risk for developing cancer but does not fall under environmental influences. A healthy diet and physical activity are generally associated with reducing cancer risk, by promoting better overall health and helping to maintain a healthy weight, which may contribute to lowering the likelihood of certain cancers. Therefore, asbestos stands out as the correct choice as it directly contributes to increased cancer risk through environmental exposure.