Health Impacts of Nuclear War Act of 2023

S 2398, the Health Impacts of Nuclear War Act of 2023, directs the Department of Health and Human Services to establish a 5-year research program studying long-term health effects from nuclear war's environmental impacts - such as reduced sunlight, crop failures, and ozone damage - using $10 million annually. It requires an assessment of U.S. health system readiness for these effects and mandates a report to Congress within one year of enactment. The bill amends the Public Health Service Act to explicitly include these environmental health consequences in federal preparedness planning for nuclear threats. This affects federal health agencies, researchers, and emergency response systems by prioritizing research and planning for cascading health crises beyond immediate nuclear explosions.