By Nic Fleming and Ian Cobain

The world's largest mobile telephone manufacturers have been patenting devices to reduce the risk of brain tumors among users while rejecting claims of any health hazards.

Engineers for the "Big Three" - Nokia, Ericsson and Motorola - have all invented new components to shield users from radiation emissions from the handsets.

One application that Nokia has lodged with the United States Patent Office in Washington, and which has been seen by The Times, notes that "it has been suggested that" continuous exposure to radio frequency irradiation could lead "to a development of malignant tumor".

The patents show that the manufacturers have been working on radiation-reducing components for at least eight years. The companies maintain that there is no contradiction between their public stance and the existence of the patents.

Scientific opinion is divided. The most recent large-scale study found no links between such phones and cancers, although other studies suggest that there may be health risks.

However, the discovery that manufacturers have apparently "hedged their bets" by applying for patents on irradiation-reducing components has alarmed consumers' groups and some scientists.

The patents are now to be used in evidence in a series of US lawsuits launched this year against businesses including the British market leader Vodafone. Some 25 US patents were unearthed by Carl Hilliard, of the Wireless Consumer Alliance, last month.

Alasdair Philips, of the British consumer watchdog Powerwatch, said: "This is confirmation that the phone companies take the possibility of health problems far more seriously than they say in public."

The patents also alarmed Dr Alan Preece, a medical physicist at Bristol University, who demonstrated in a government-funded study two years ago that mobile-phone radiation affected brain activity in ways unconnected with its heating properties.

He said: "I think they are hedging their bets by doing this so that if the evidence does emerge, they have products up their sleeves."

Christopher Newman, a 42-year-old neurologist, is bringing a £500 million lawsuit against companies including Motorola and Verizon Communications at the US federal court in Baltimore, claiming they are responsible for his malignant brain tumour. Verizon is a joint venture between America's Bell Atlantic and Vodafone, the UK's most popular network with over 12 million of the 40 million mobile users.

Mr Newman's lawyer has also recently filed class actions in five states, again naming Verizon and Motorola and others such as Nokia and Ericsson. These seek unspecified punitive damages, money to reimburse people who bought mobile headsets to reduce exposure and free protective headsets for all mobile users.

Cases have been filed on behalf of four more tumour victims. One, Michael Murray, used to test mobiles for Motorola and claims his work caused his two brain tumors.

Thompsons, Britain's biggest personal-injury law firm, has on its books 30 phone users who claim to be suffering a range of health problems.Tom Jones, a partner, said: "Any judgment showing liability in the States would strongly affect the likelihood of successful claims here."

Manufacturers denied that the patents meant that they accepted the existence of hazards. Michael Westmark, Ericsson spokesman on health, said: "Given the available scientific evidence, there is no link between mobile use and negative health effects" - a view also expressed by Norman Sandler of Motorola.

William Plummer, Nokia vice president said: "There is no contradiction here. The patents talk of 'suggestions' of health risks. A third of our employees are engaged in research and development and it is a natural course of business that they then file for patents."

The Times (London) June 11, 2001