Which of the following is NOT a means of exposure to hazardous substances?

The correct choice identifies "contamination" as something that does not directly represent a means of exposure to hazardous substances.

To understand this, it’s important to recognize that means of exposure refer to the ways in which a person can come into contact with hazardous materials that can lead to adverse health effects. Ingestion refers to the consumption of hazardous substances, injection points to direct entry into the bloodstream (usually through a needle), and absorption describes the process where substances penetrate through the skin into the body.

"Contamination," on the other hand, implies that a hazardous substance is present on a surface or within a medium (such as air, water, or soil). While contamination is a critical aspect of understanding environmental and public health risks, it is not a direct pathway through which individuals are exposed. Instead, it leads to potential exposure scenarios, but does not represent the specific methods of exposure like the options listed.

Thus, the distinction lies in the fact that the other options outline direct methods of how hazardous substances can enter the body, while contamination describes a condition that may lead to exposure rather than being a mode of exposure itself.