These area-based assessments of the Mykolayiv and Kherson oblasts consider the potential release of hazardous substances from industrial facilities damaged or destroyed during hostilities in Ukraine, and provide the kind of event- and facility-specific information that is crucial in assessing the immediate and long-term environmental and health risks. The assessments reflect the situation before the collapse of the Kakhovka dam, and thus establish a baseline for an analysis of the effects of the dam disaster.