Which of the following is NOT considered an inorganic contaminant?

Pesticides are classified as organic contaminants because they are typically chemical compounds derived from natural sources or synthesized to affect living organisms, primarily to manage pests in agriculture and other applications. Pesticides may include a wide range of substances, including herbicides, insecticides, and fungicides, and they often contain carbon in their molecular structure, which is a defining characteristic of organic compounds.

In contrast, selenium, lead, and mercury are all inorganic contaminants. These substances do not contain carbon-hydrogen bonds and are primarily derived from mineral sources or human activities such as industrial processes or mining. Inorganic contaminants can have significant environmental and health impacts, particularly when they accumulate in water supplies or ecosystems. Understanding the distinction between organic and inorganic contaminants is crucial for effective water quality management and regulatory compliance.