Environmental health science is concerned with agent, host, and environmental factors in disease (the epidemiologic triangle). Which statement is true about the triangle?
A. Agent factors can include particles, toxic chemicals, and pesticides.
B. The environment is the domain in which disease-causing agents may exist.
C. The host is the person who affords lodgment of an infectious agent.
D. Disease causality includes three major factors: agent, host, and environment.
E. All of these are correct.

Environmental Health Science is focused on the connection between the natural environment and human health, it refers to the area of science that studies how the environment and the environmental conditions in which we live affect human health and diseases.

A. Agent factors can include particles, toxic chemicals, and pesticides.

Agents are microbes, chemicals, or physical causes of illness or injury, such as: Viruses, Bacteria, Radiation, Chemicals, Physical hazards.

B. The environment is the domain in which disease-causing agents may exist.

Environments are the environments through which the agent must move to reach the host. For example: Air, Water, Food, Wastewater.

C. The host is the person who affords lodgment of an infectious agent.

Hosts are people and animals that contract the disease, such as: Children, Neighbors, Pets, Ourselves.

D. Disease causality includes three major factors: agent, host, and environment.

Diseases need three ingredients to spread: Agent, Host, Environment. These ingredients are the disease-causing triad. Diseases need all three to spread.