Biological contamination refers to the presence of harmful microorganisms, such as bacteria, viruses, fungi, or parasites, in food, water, or the environment. These contaminants can cause illness in humans and animals when ingested or contacted. Common sources include improperly handled food, contaminated water supplies, and unsanitary conditions. Preventing biological contamination involves proper hygiene practices, such as washing hands, cooking food to safe temperatures, and ensuring clean water sources. Regulatory agencies, like the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA), set guidelines to minimize risks and protect public health from these biological hazards.