What are secondary contaminants known to affect in water?

Secondary contaminants in water primarily influence aesthetic qualities, including taste, odor, and color. These contaminants are typically not harmful at the levels present and do not pose direct health risks to consumers. However, they can significantly affect the public's perception and acceptance of drinking water. For instance, elevated levels of certain minerals or compounds can lead to unpleasant tastes or discoloration, which could discourage people from consuming the water.

In contrast, the other options focus on aspects that are not the primary concern of secondary contaminants. While some of these contaminants might indirectly relate to health and safety, they are not categorized as primary health risks like those identified with primary contaminants. Options that mention taste and color only overlook the wider range of aesthetic qualities affected by secondary contaminants, such as odor. The option regarding pH levels does not align with the classification of secondary contaminants as they are primarily about aesthetic factors rather than chemical balance.