 beryllium was released into the air from routine operations and three accidental fires at the rocky flats plant ( rfp ) in colorado from 1958 to 1989 . 
 we evaluated environmental monitoring data and developed estimates of airborne concentrations and their uncertainties and calculated lifetime cancer risks and risks of chronic beryllium disease to hypothetical receptors . 
 this article discusses exposure - response relationships for lung cancer and chronic beryllium disease . 
 we assigned a distribution to cancer slope factor values based on the relative risk estimates from an occupational epidemiologic study used by the u.s . 
 environmental protection agency ( epa ) to determine the slope factors . 
 we used the regional atmospheric transport code for hanford emission tracking atmospheric transport model for exposure calculations because it is particularly well suited for long - term annual - average dispersion estimates and it incorporates spatially varying meteorologic and environmental parameters . 
 we accounted for model prediction uncertainty by using several multiplicative stochastic correction factors that accounted for uncertainty in the dispersion estimate , the meteorology , deposition , and plume depletion . 
 we used monte carlo techniques to propagate model prediction uncertainty through to the final risk calculations . 
 we developed nine exposure scenarios of hypothetical but typical residents of the rfp area to consider the lifestyle , time spent outdoors , location , age , and sex of people who may have been exposed . 
 we determined geometric mean incremental lifetime cancer incidence risk estimates for beryllium inhalation for each scenario . 
 the risk estimates were < 10(-6 ) . 
 predicted air concentrations were well below the current reference concentration derived by the epa for beryllium sensitization.imagesfigure 1figure 2figure 3figure 4figure 5figure 6 
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