Which of the following describes contaminants that can come from agricultural practices?

Pesticides are substances used to prevent, destroy, or control pests that can harm crops or livestock in agricultural settings. When applied to fields, these chemicals can run off into nearby water bodies during rain events or irrigation, leading to contamination of water supplies. This runoff can introduce harmful residues into drinking water resources, which can pose health risks to humans and animals.

In contrast, radionuclides are typically associated with natural radioactive materials or industrial processes, rather than agricultural practices. Heavy metals can originate from various sources, including industrial pollution and mining activities, but are less directly linked to standard agricultural practices. While microbes can also be associated with agriculture, particularly in the context of wastewater or manure management, pesticides more directly characterize the inputs commonly used in farming that can lead to contamination of water sources.