Environmental risk assessment of white phosphorus from the use of munitions — A probabilistic approach Original Research Article

White phosphorus (P4) is a highly toxic compound used in various pyrotechnic products. Ammunitions containing P4 are widely used in military training areas where the unburned products of P4 contaminate soil and local ponds. Traditional risk assessment methods presuppose a homogeneous spatial distribution of pollutants. The distribution of P4 in military training areas is heterogeneous, which reduces the probability of potential receptors being exposed to the P4 by ingestion, for example. The current approach to assess the environmental risk from the use of P4 suggests a Bayesian network (Bn) as a risk assessment tool. The probabilistic reasoning supported by a Bn allows us to take into account the heterogeneous distribution of P4. Furthermore, one can combine empirical data and expert knowledge, which allows the inclusion of all kinds of data that are relevant to the problem. The current work includes an example of the use of the Bn as a risk assessment tool where the risk for P4 poisoning in humans and grazing animals at a military shooting range in Northern Norway was calculated. P4 was detected in several craters on the range at concentrations up to 5.7 g/kg. The risk to human health was considered acceptable under the current land use. The risk for grazing animals such as sheep, however, was higher, suggesting that precautionary measures may be advisable.