UV Radiation Found Higher in Many Areas

Ultraviolet radiation, which causes skin cancer and cataracts in humans, has increased over large regions of the Earth in the last 15 years as ozone in the atmosphere has decreased, new research shows.

The annual average amount of UV-B, the portion of the ultraviolet spectrum that causes the most damage, has increased 9.9% per decade at the southernmost portions of Argentina and Chile.

The changes in North America are smaller, about a 4% increase for areas near the U.S.-Canadian border, said the study published in Geophysical Research Letters.

In countries such as England, Germany and Russia and in Scandinavia, annual exposure rose by 6.8% in 10 years.

“The increases are largest in the middle and high latitudes, where most people live,” said Dr. Jay R. Herman, an atmospheric scientist at NASA’s Goddard Space Flight Center in Maryland.

The finding is based on analysis of data from an instrument called Total Ozone Mapping Spectrometer flown aboard NASA’s Nimbus-7 satellite.

Scientists consider the risks of further increases in ultraviolet radiation to be serious.

Long-term exposure to UV-B from the sun is associated with basal cell and squamous cell carcinomas, and is responsible for other harmful effects to the skin, eyes and immune system.

Ozone is depleted through complex chemical reactions, some of it from man-made chlorofluorocarbons.

The depletion has been sharply reduced in recent years through international agreements curbing emissions.