New detailed studies for Swiss public health authorities revealed that excess mortality rose seven percent above the usual average summer death rate, and many of the deaths were caused by air pollution, the Swiss news agency ATS reported.

"The situation took us by surprise and we were not conscious of the problem," Thomas Zeltner, director of the Federal Health Department said.

"We did not have the means to detect the problem," he added, announcing new measures to cope with future heatwaves.

Urban areas such as the northern city of Basel and the western cities of Geneva and Lausanne were the hardest hit, with the elderly suffering most though not exclusively, according to the surveys.

Dehydration and cardiovascular problems were the main causes of death.

However, 15 to 30 percent of percent of deaths were attributed to a buildup of low level ozone, which is mainly caused by pollution from road traffic. Ozone can cause breathing problems.

Authorities had estimated in November 2003 that the heatwave that ended about three months earlier had led to the deaths of 235 people in Switzerland.

Some 22,000 to 35,000 people are thought to have died around Europe as temperatures stayed in the upper 30 degree centigrade mark for several weeks. August 2003 was the hottest month on record in Switzerland.

New measures include weekly reporting of overall deaths to enable health authorities to detect variations with normal levels swiftly, Zeltner said.

Hot weather alerts and information targeting the elderly, their families and carers are also being lined up.

All rights reserved. © 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.