Final answer:
Pesticides and cleaning agents are classified as chemical contaminants, which can lead to significant health and environmental concerns such as endocrine disruption and birth defects.
Step-by-step explanation:
Pesticides and cleaning agents are examples of chemical contaminants. These are substances introduced into the environment that can cause harm or discomfort to living organisms. Pesticides, such as DDT, and cleaning agents can lead to various environmental and health issues, including endocrine disruption, birth defects, and biomagnification where the concentration of toxic substances increases within the food chain. Moreover, chemical agents are known to contaminate groundwater and can be found in high concentrations due to residential, commercial, and industrial activities.