Environmental health examines how natural and built environments impact human health. It covers air pollution, water quality, and chemical exposure, emphasizing prevention and protecting vulnerable populations. This field involves multiple disciplines and considers complex interactions between environmental factors and health outcomes. Ethical frameworks guide environmental policy, including utilitarianism, deontology, and environmental justice. Major challenges include air and water pollution, climate change, and toxic chemical exposure. Policy development involves scientific evidence, stakeholder engagement, and various instruments to address these issues and promote public health.