He is temporarily taking on this role from Sicco Louw, who is serving as Acting Director-General of RIVM since the departure of DG Hans Brug. 

Mr Tolsma has held various roles in recent years, including interim director of Finance, Compliance & Control and of Organisation, Operational Management and Personnel at RIVM, and acting coordinator of the National Functionality for Upscaling Infectious Disease Control. After that, he was acting coordinator of the temporary working organisation for Prevention Programmes and Public Health Upscaling, which has been added to RIVM as a new domain as of 1 November 2025.