ramesh prouchotte is an official of the union that represents 5,000 security workers here, all of whom were subjected to renewed, rigorous police checks, following the paris terror attacks last year, and some of whom were found to be a security risk. after the paris attacks, they withdrew 85-- >> 85. >> reporter: 85 badges. people who can no longer work in security. >> no. >> reporter: the airport sits in paris' northern suburbs, which have a high percentage of imfrantz from muslim countries, many of whom find work here. the new security checks looked for evidence of radicalization, where the employees have traveled, what they read, who they associate with. it's known as the "insider problem," and it's acknowledged here and elsewhere in the aviation world. mike vivian is the former head of operations for britain's civil aviation authority. >> clearly, some countries are possibly more vulnerable than others to this. and it can be surreptitious, below the radar, so to speak. so it is a serious issue. it's being looked at. >> reporter: the fact that the egyptair plane had been to eritrea