Effective UV radiation in the Netherlands, 1996-2001

UV radiation at ground level depends to a significant extent on the distance to the sun, the thickness of the ozone layer and on cloud cover. Aerosols also play a role, albeit to a lesser degree. The higher position of the sun in the summer months means that this period accounts for most annual radiation. There can be considerable fluctuations from year to year and from month to month in the effects associated with cloud cover.

Effective UV radiation

In De Bilt, cloud cover blocked 34% of the UV radiation on average in the period 1979-2001. In 2001, the reduction caused by cloud cover was 31%. This figure was 35% in 2000, and 31% in 1999. The total amount of UV irradiation at ground level relevant for skin cancer was approximately 2.4% higher in De Bilt in 2001 than in 2000 and almost the same as the level in 1999.

Relevance

An increase in UV radiation at ground level can result in an increase in numerous harmful effects on the environment and health, including extra cases of skin cancer. In addition to changes in the ozone layer, changes in cloud cover patterns, for example as a result of climate change, can lead to changes in UV radiation levels.

Technical note

The figure shows the total monthly amount of UV radiation and the amount of UV radiation blocked by cloud (effect of cloud cover). The UV radiation measured on the surface of the earth is the difference between these two figures (in blue).
The monthly totals state the UV radiation relevant for skin cancer (skin cancer action spectrum, De Gruijl and Van der Leun, 1994).

References

De Gruijl, F.R. and J.C. van der Leun (1994). Estimate of the wavelength dependency of ultraviolet carcinogenesis in humans and its relevance to the risk assessment of a stratospheric ozone depletion. Health Physics 67, 319-325.

Den Outer, P.N., H. Slaper, J. Matthijsen, H.A.J.M. Reinen and R. Tax (2000). Variability of ground-level ultraviolet: model and measurement. Radiat. Prot. Dosim. 91, 105.

Slaper, H., G.J.M. Velders, J.S. Daniel, F.R. de Gruijl and J.C. van der Leun (1996). Estimates of ozone depletion and skin cancer incidence to examine the Vienna Convention achievements. Nature 384, 256-258.

Relevant information outside of the Environmental Data Compendium

Information about ozone measurements in the Netherlands and Belgium can be found at KNMI and KMI.

RIVM (2000). National Environmental Outlook 5. Samsom bv, Alphen aan den Rijn. For more information about the policy with respect to depletion of the ozone layer.

RIVM (2002). Environmental balance 2002. Kluwer, Alphen aan den Rijn, for more information about future developments relating to UV radiation.

Kelfkens, G., A. Bregman, F.R. de Gruijl, J.C. van der Leun, A. Piquet, T. van Oijen, W.W.C. Gieskes, H. van Loveren, G.J.M. Velders, P. Martens and H. Slaper, H., Ozone layer - climate change interactions: Influence on UV levels and UV related effects. ISBN 90 5851 079 4. Dutch National Research Programme on Global Air Pollution and climate change, Report 410 200 112.

UNEP, Frequently Asked Questions About the Ozone Layer and Related Environmental Effects.

EPA (Environmental Protection Agency), with information about: science of ozone depletion, the regulatory approach to protecting the ozone layer, and on alternatives to ozone-depletion substances.

TEAP Technology and Economic Assessment Panel (TEAP) of the Montreal Protocol.

NASA/TOMS, most recent ozone maps and data.

NOAA, Scientific Assessment of Ozone Depletion: 1998.

ETC/ACC (European Topic Center on Air and Climate Change).