Charlotte Auerbach (1899-1994). She was a German-Jewish geneticist and zoologist who contributed to the discovery of mutagenesis and its effects. She succeeded in identifying toxic agents capable of producing mutations, in particular she demonstrated that mustard gas was a chemical mutagen. 
His studies served as a basis for further studies on mutations and cancer.

fuente: https://www.bbc.com/mundo/noticias-47476328

a) Define "mutation" and "mutagen". Give a couple of examples of mutagenic agents.

b) Justify why children who were subjected to the Chernobyl nuclear power plant disaster have a very high incidence of cancer.