A new international study says increases in pollution and chemicals in the environment may be behind a silent epidemic of dementia cases.

Dementia

Published in the Surgical Neurology International journal, the study says that although dementia cases were generally seen in people in their late 60s two decades ago, now the disease is occurring in people in their late 40s, possibly as a result of more insecticides, pollution and other factors.

The study looked at medical statistics from 21 Western countries between the years 1989 and 2010.

The “problem was particularly acute in the United States, where neurological deaths in men aged over 75 have nearly tripled and in women risen more than fivefold,” The Washington Post reported.

“The rate of increase in such a short time suggested a silent or even a hidden epidemic, in which environmental factors must play a major part, not just aging,” Colin Pritchard, the study’s leader from Bournemouth University, told The Times of London.

Pritchard also noted environmental changes in the last 20 years that “have seen increases in the human environment of petro-chemicals — air transport, quadrupling of motor vehicles, insecticides and rises in background electro-magnetic field, and so on.”