A seminar will be attended by some of the world's experts on health and electromagnetic radiation. It aims to focus attention on the possible risks of such masts and force a rethink on policy.
Among those attending Tuesday's seminar are two residents from the Milford Haven action group who have been fighting for the removal of a base station near their homes for over a year.
The group was set up last year after the base station was put up on top of the fire station roof as part of a four-station£250,000 deal between the fire service and the phone company, Orange. Since masts under 40ft do not need planning permission, the first the residents knew about the mast was when it appeared.
The group is now claiming that Pembrokeshire CC was guilty of maladministration in the way it handled the planning application of the station. The claim has been denied by the council.