This Radiation Exposure Compensation Act (Reca) provided one-time payouts to people who may have developed cancer or other diseases while living in areas where activities such as atomic weapons testing took place. It paid out $2.6bn (£2bn) to more than 41,000 claimants before coming to an end in 2024.

Benefits were paid to such neighbours, frequently called “downwinders”, in Arizona, Utah and Nevada, but not New Mexico, where the world’s first test of a nuclear weapon took place in 1945. Research published in 2020 by the National Cancer Institute suggested that hundreds of cancers in the area would not have occurred without radiation exposure.

St Louis, meanwhile, was where uranium was refined and used to help create the atomic bomb as part of the Manhattan Project. After World War Two ended, the chemical was dumped near the creek and left uncovered, allowing waste to seep into the area.

Decades later, federal investigators acknowledged an increased cancer risk for some people who played in the creek as children, but added in their report: “The predicted increases in the number of cancer cases from exposures are small, and no method exists to link a particular cancer with this exposure.”