§ Ms Short
To ask the Secretary of State for the Environment (1) whether current monitoring has established a relationship between stratospheric ozone depletion and UV-B measurements at ground level; and what research is being undertaken to validate scientific models linking ozone depletion and ground level UV-B;
(2) what facilities exist in the United Kingdom for monitoring of UV-B radiation at ground level; to what extent results are affected by low-level ozone pollution in the areas surrounding the monitoring sites; and how successfully these results can be used to predict UV-B levels in other less polluted areas;
(3) what plans he has (a) in the short term and (b) in future years should UV-B levels rise further as a result of ozone depletion, to make UV-B monitoring data available to the public on a daily basis;
(4) what plans he has to upgrade or extend the network of UV-B monitoring stations in the United Kingdom; and if he will outline the work to be done and the timetable.
§ Mr. Yeo
The National Radiological Protection Board (NRPB), on behalf of the Department of Health, has operated since 1988 three monitoring sites for surface ultra-violet radiation at Chilton, Oxfordshire, Leeds, and Glasgow. The board plans to add three further sites by the end of the year at Camborne, Cornwall, Kinloss, and Lerwick. My Department supports research at Reading university which is playing a leading role in international programmes for determining standards for improved UV-B monitoring networks. I have asked the Department's stratospheric ozone review group (SORG) to assess possibilities for an improved network in its next report this autumn.
Air pollution, including low-level ozone, will have some influence on UV-B radiation reaching the ground, although much less than natural conditions such as cloudiness. The exisiting NRPB sites cover a range of situations from rural to outer urban and are believed to give a good indication of the maximum UV-B levels experienced throughout the United Kingdom. The additional sites planned for the end of this year will provide a further check on this.
Results from the NRPB network are published annually. I understand a scheme to release weekly bulletins is imminent. The Department's stratospheric ozone review group will review ground level UV-B irradiation in its report this autumn. So far, no increase in UV-B has been detected in the United Kingdom against the background of natural variability. The frequency of reporting will be reviewed should this position change.
Monitoring UV-B cannot of itself establish the link between ozone layer depletion and UV-B at ground level, but is essential to validating mathematical models. Current models agree well with monitoring data under the "worst-case" clear sky conditions. They are limited by the 698W availability of precise data on pollution levels, aerosols and clouds, which act to further reduce ground level UV-B.