California Wastewater Treatment Operator Practice Exam

Which gas diminishes your sense of smell?

1. Carbon monoxide

2. Ammonia

3. Hydrogen sulfide

4. Sulfur dioxide

The correct answer is: Hydrogen sulfide

Hydrogen sulfide is a toxic gas that is commonly found in sewers, landfills, and other industrial settings. Exposure to high levels of hydrogen sulfide can lead to a numbing of the olfactory nerve, which diminishes your sense of smell. This can make it difficult to detect any other odors in the environment, making it a dangerous gas to be exposed to. Carbon monoxide, ammonia, and sulfur dioxide are also toxic gases but they do not specifically target the sense of smell in the same way as hydrogen sulfide does. They can still have negative health effects, but they do not directly diminish the sense of smell.