What does the term "noxious" refer to in relation to health?

The term "noxious" is primarily used to describe substances or organisms that are harmful, poisonous, or very unpleasant. In the context of health, it specifically pertains to anything that can cause injury, damage, or adverse effects to physical or mental well-being. This can include toxic chemicals, harmful pathogens, or even detrimental thoughts and behaviors that impact mental health negatively.

The other options do not align with the definition of "noxious." For instance, describing something as beneficial contradicts the inherent meaning of being harmful, while neutrality implies no significant effect, which is also at odds with the term's implication of detrimental health consequences. Furthermore, limiting the term to only affecting physical health disregards the broader scope of how noxious influences can also impact mental well-being. Thus, the choice indicating that it is injurious to both physical and mental health captures the essence of the term accurately.