All necessary measures shall be taken that do not involve any excessive costs to reduce exposure to PM2.5, with the aim of achieving the regional target value for reducing exposure stated in Appendix 18.104.22.168, Part B, for the year indicated therein.
The necessary measures shall be taken to ensure that the regional average exposure index for 2015, established in accordance with Appendix 22.214.171.124, Part A, does not exceed the regional exposure concentration obligation laid down in Part C of that Appendix.
The regional average exposure index for PM2.5 shall be assessed by the Flanders Environment Agency in accordance with Appendix 126.96.36.199, Part A.
In accordance with Appendix 188.8.131.52, the number of sampling points on which the regional average exposure index for PM2.5 is based, and its spread, shall be such that an accurate picture is obtained of the exposure of the population in general. The number of sampling points shall not be less than the number obtained by applying Appendix 184.108.40.206, Part B.