An examination at Hospital Number Six revealed the toxic fingerprint of the reactor deep within Legasov’s body: doctors found fission products, including iodine 131, cesium 134 and 137, tellurium 132, and ruthenium 103, in his hair, airways, and lungs. His health shattered, he suffered from headaches, nausea, digestive problems, and chronic insomnia. Nevertheless, Legasov threw himself into collating material for the report, which was compiled from the work of dozens of specialists and hundreds of documents.
