THREATENING emails sent by bosses to their workers can cause health risks, according to studies by Buckinghamshire Chilterns University College (BCUC).

In the tests, 48 undergraduates from the university in Queen Alexandra Road, High Wycombe, were given blood pressure monitors before they opened their in-boxes.

Researchers found their blood pressure shot up if the messages were written in an aggressive manner.

Dr George Fieldman, the principal investigator and senior lecturer in psychology at BCUC, said it was important for managers to know the risks.

He said: "We tested it throughout and found that there was a clinically significant increase in blood pressure. It was something that should encourage managers not to send these emails to people as it could be a health risk if it were perpetuated for weeks, months and years.

"We are trying to convey there is a biological consequence of being unpleasant to people. I think it is more convenient for bosses (to send emails and) not to have to confront people,particularly if they are being reprimanded."

The volunteers, aged between 18 and 25, thought they would be taking part in filling out questionnaires but would also log into their email accounts.

They were sent emails from colleagues of equal status and those from a higher status, and they were written in a neutral or aggressive tone.

Dr Fieldman's findings were presented at a British Psychological Society Conference in Stratford-upon-Avon last week.

It was concluded that it would be counterproductive for managers to write the aggressive emails to their staff, and they should never be used to discipline staff.

Dr Fieldman said he believes emails are just one element of the problem. He said they could also have carried out the studies using letters but added that using emails ensured it was a neater experiment.