What is an example of an aesthetic effect in drinking water?

An aesthetic effect in drinking water refers to characteristics that affect the visual, taste, and smell qualities of the water, but do not pose any direct health risks. Offensive taste or odor is a prime example of such an effect, as it can significantly influence consumer acceptance and satisfaction with the water. Water that tastes unpleasant or has a strong odor may lead individuals to avoid drinking it, even if it is safe from a health standpoint.

In this context, other options represent more serious health-related effects. Stomach illness and respiratory issues are connected to contaminants that can cause disease, thus impacting health directly. Skin discoloration, while it can be aesthetically unpleasing, is often associated with specific contaminants that can indicate a health concern. Hence, these options do not fall under the category of aesthetic effects, which are exclusively related to the sensory experience of water consumption.