A modeling procedure to predict cancer risks associated with inhalable oil dust from Kuwait oil lakes

A model was constructed to estimate cancer risks associated with PM₁₀-bound polycyclic aromatic hydrocarbons (PAHs) from Kuwait oil lakes. The design of the risk model was based on a conceptual "chain of events" leading from levels of PAH compounds in oil lakes, erosion of oil dust and input into the atmosphere, to contaminant concentration in air, to actual human exposure in residential areas. Uncertainties in the "chain of events" model were addressed using Monte Carlo techniques. To identify the exposure duration of concern [duration beyond which risk becomes unacceptable (i.e. Risk > 10^-6)], four exposure durations were tested 10, 20, 40, 70 years. 40 years was identified to be the exposure duration of concern based on the 95th percentile of the risk distribution. As a result, die acceptability of risk was specified in terms of a single constraint on the 95^th percentile of the risk distribution evaluated after 40 years of exposure: 0 < Risk(40 y)_0.95 ≤ 10^-6. Based on this constraint, it was estimated that a removal rate of 217,793.27 m³/year to be an adequate action for risk management. The northern oil lakes were identified as the lakes of most concern when inhalation exposures are considered.