Which of the following is an example of a chemical health hazard?

Exposure to asbestos or lead is a clear example of a chemical health hazard because both substances are toxic materials that can cause serious health issues when inhaled or ingested. Asbestos fibers can lead to lung diseases such as asbestosis and mesothelioma, while lead exposure can result in neurological issues, developmental disorders, and other systemic health problems. These hazards are classified as chemical because they involve harmful chemical agents that can affect human health either through direct contact or environmental exposure.

In contrast, the other examples listed pertain to physical hazards rather than chemical ones. Working with heavy machinery primarily presents mechanical or physical risks, while climbing heights without safety equipment poses fall hazards. Similarly, working in extreme temperatures is categorized as a physical hazard due to risks associated with heat stress or frostbite, rather than exposure to harmful chemicals. Thus, the focus of the correct answer is specifically on the health risks associated with exposure to chemical substances.