Posted on 20th December, 2023 at 12:13:53 AM
The proof comes from epidemiological observation. The cause and effect relation between cancer and some common substances in our environment was first noted amongst the chimney sweepers in London who used to develop cancers of the scrotum due to continuous exposure to chimney soot. Gradually many more such substances have been discovered and later verified through tests in laboratory animals and interventional studies in the community. It is true that often the proof is indirect but it is scientifically established that direct intervention or change in dietary habits and lifestyle have caused a decline in incidences of stomach cancer, liver cancer, mouth cancers, and uterine cervical cancers in some communities.
