Ozone Depletion and Skin Cancer Incidence: An Integrated Modeling Approach and Scenario Study
A decrease in stratospheric ozone, probably caused by chlorofluorocarbon (CFC) emissions, has been observed over large parts of the globe. Further depletion, leading to an increase in biologically-effective solar UV at ground level, is expected. An integrated source-risk model has been developed and used to evaluate the increased skin cancer incidence and mortality related to various CFC emission scenarios. The model provides estimates tropospheric concentrations of CFCs, chlorine levels in the stratosphere, ozone depletion, UV irradiance, and effects on the incidence of skin cancer incidence and mortality rates.
The results obtained show that even if full worldwide compliance with the Copenhagen Amendments to the Montreal Protocol is realized, full recovery of the stratospheric ozone balance is not expected prior to 2080. At 40–50° N, full compliance with the Copenhagen Amendments is expected to lead to a maximal depletion of approximately 10 percent by the year 2000 followed by a slow recovery thereafter. In this case, skin cancer risks associated with ozone depletion, expressed in terms of incidence rates and excess mortality, are expected to increase to a maximum around the years 2040–2050. Excess skin cancer risks in the Netherlands are expected to result in an excess mortality rate of three million per year and an excess incidence of 200 per million per year. The calculated mortality risk level is above the Maximum Tolerable Risk Limit adopted in the risk-oriented policy approach for chemical substances and ionizing radiation sources in the Netherlands. Implications of risk modeling for environmental monitoring strategies and sustainable development are discussed.