**7. Conclusions**

While the use of irradiation to control microbial populations in foodstuffs, on medical devices, and on the environment is relatively old, the use of electron beam irradiation to eliminate potential human and animal pathogen from sewage sludge is relatively new. At the present times electron beam irradiation is a mature technology and is capable to provide the required power to irradiate sludge at the flow rates used in a sewage sludge decontamination municipal plant. The quality control techniques are readily available to provide measurements of the dose needed to decontaminate the sludge and the technology has proved its capability to eliminate bacterial populations and ascaris ova to levels that are considered safe for humans and animals in landscape, agricultural, and landfill applications. Analysis of the costs involved in using electron beam technology to decontaminate sewage sludge showed that they are competitive with usual costs involving mechanical and chemical means to treat the sewage sludge. Application of this technology opens new possibilities for major agglomerations worldwide to safely repurpose municipal sewage sludges.
