Review of health studies at Kerala

The results of five studies of the health of the population of a coastal strip of Kerala State, India are reported. The natural radioactivity of the sand subjects these people to an average irradiation of 4 mGy/year (400 mrad/year), four times the average for India. The evidence of one of these studies that irradiation causes Down's Syndrome is reviewed. It is concluded that the investigation had been insufficiently rigorous to be able to make this connection. (U.K.)