Final answer:
An example of an environmental risk factor is when a patient's drinking water contains high levels of lead, as it is a non-behavioral, external factor affecting health. Environmental risk factors, which also include radon exposure, air pollution, and UV light exposure, are external and can be modified to reduce the risk of disease.
Step-by-step explanation:
An example of an environmental risk factor is when a patient's drinking water contains high levels of lead. This is a direct environmental factor that can affect the individual's health negatively. Lead in drinking water is a well-documented hazard that can lead to a variety of health issues, including developmental problems in children, and it has been linked to a variety of diseases. It is a clear non-behavioral, external factor that can contribute to disease alongside other environmental factors such as radon exposure, air pollution, and UV light exposure.
Environmental risk factors are distinct from factors such as age, gender, and genetic predispositions, which are generally non-modifiable. They differ as well from behavioral risks like diet or alcohol consumption, even though consuming large amounts of sweetened beverages, following an unhealthy diet, or engaging in physical inactivity can also be considered environmental risk factors, as these behaviors contribute to conditions like metabolic syndrome. Metabolic syndrome in turn elevates the risk for various diseases such as cardiovascular diseases and type 2 diabetes.
In contrast, other options provided, such as a strong family history of autoimmune diseases, a lactose-free gluten-free diet, or moderate alcohol consumption, are more closely aligned with genetic and behavioral factors rather than purely environmental ones.