The state of California, in the United States of America, has a population of nearly 40 million people and is the 5th largest economy in the world. During the coronavirus disease 2019 (COVID-19) pandemic in 2020-2021, the state experienced a medical surge that stressed its sophisticated health-care and public health system. During this period, ventilators, oxygen, and other equipment necessary for providing ventilatory support became a scarce resource in many health-care settings. When demand overwhelms supply, creative solutions are required at all levels of disaster management and health care. This study describes the disaster response by the state of California to mitigate the emergency demands for oxygen delivery resources.

This paper provides an overview of disaster public health preparedness, response, and recovery activities with particular reference to examples that have occurred in California. It discusses the public health considerations from two aspects: 1) general public health effects; and 2) public and environmental health control measures. The latter discussion is divided into: 1) drinking water; 2) human wastes; 3) food; 4) personal hygiene; 5) mass care and shelter; 6) solid waste and debris; 7) hazardous materials; 8) injury prevention programs and public health information; 9) vector control; and 10) disease control and surveillance. Two tables summarize the disaster medical and health functions as they relate to public health.