Paragraph 10

Where contributions from industrial sources are to be assessed, at least one sampling point must be installed downwind of the source in the nearest residential area. Where the background concentration is not known, an additional sampling point must be situated within the main wind direction. In particular, where regulation 9(1)(a) applies, the sampling points should be sited such that the application of the measures referred to at regulation 7(2)(b) can be monitored.