A quantitative assessment of the BSE risk associated with fly ash and slag from the incineration of meat-and-bone meal in a gas-fired power plant in Denmark

The simulations were run on a 1-week basis. Our results suggest that if the slag is collected and re-incinerated the median BSE infectivity remaining in the fly ash per week would be 3.1E−11 cattle ID50. A cattle ID50 is the amount of infectivity that will cause infection in 50% of cattle exposed to it. During the weeks when BSE was infected in the SRM-MBM, the median infectivity in the fly ash was estimated as 8.7E−10 cattle ID50 and 2.9E−12 human ID50. The 95th percentiles were 2.1E−08 cattle ID50 and 5.8E−10 human ID50, respectively. One ton of fly ash would contain ≤1.8E−07 cattle ID50 95% of the time. These are the potential exposures of the cattle or human populations. The potential exposures of individuals are far less.