Risk assessment: good for health?

Risk assessment is a scientific endeavour on which risk management can be based and policy priorities can be set. Of prime importance is the choice of risk attributes and the health indicators to focus upon. Problem ranking and priority setting depend strongly on that choice. In the current risk policy of The Netherlands' Ministry of the Environment 'individual risk' is defined as the probability of dying due to one year's exposure to a certain agent or activity. If this approach is applied to the indoor environment, strong mitigation measures should be taken concerning NO2, radon and particulate matter to improve the percentage of 'healthy homes'. However, risk is more than the chance to die. Therefore some more parameters should be used to characterize the indoor environment, like chemical and biological mixtures from outside and inside and activities of inhabitants. Important health indicators like irreversible/reversible physiological effects and nuisance should be taken into account. Risk has to tell us about the possibility of health damage, about the nature of health damage and about the uncertainty in both.