Which agency focuses primarily on human and environmental health?

The Environmental Protection Agency, commonly referred to as the EPA, primarily focuses on protecting human health and the environment. This agency's mission includes regulating pollutants that can impact air and water quality, managing hazardous waste, and ensuring that chemical substances do not pose a risk to public health or the environment.

The EPA also engages in research and education to promote environmental stewardship and public awareness about environmental issues. By implementing regulations and conducting assessments, the agency plays a critical role in safeguarding the health of individuals and communities alongside maintaining the integrity of ecosystems.

In contrast, other agencies mentioned, such as the FDA, OSHA, and NIH, have different primary objectives. The FDA is mainly concerned with food and drug safety, OSHA focuses on workplace safety, and NIH primarily conducts and funds medical research. Thus, the EPA distinctly emphasizes the broader scope of both human health and the environmental health interconnectedness, making it the correct choice for the question.