1 Department of Mechanical Engineering, University of Alberta, Alberta, Canada.
2 Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
3 Occupational Health & Safety and Environmental Protection Unit, European Organization for Nuclear Research (CERN), Geneva, Switzerland.
4 Beams Department, European Organization for Nuclear Research (CERN), Geneva, Switzerland.
5 Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom; Department of Clinical Microbiology, University Hospitals of Leicester NHS Trust, Leicester, United Kingdom. Electronic address: [email protected].