DIN CEN/TR 16998:2017-06

The Technical Report CEN/TR 16998 presents the current state of knowledge on the sources of nitro- and oxy-PAHs in ambient air (combustion processes, atmospheric reactions). Furthermore, it provides information on the toxicity of these substances and on measured concentrations at differently polluted locations (traffic-related, industrial, urban background, clean air areas). It also presents a tried-and-tested measurement method for determining these substances, which could be the subject of future standardization. The authors of the report, the members of WG 21 of CEN/TC 264 "Air quality", come to the conclusion that the concentrations of nitro- and oxy-PAHs in ambient air are of concern with regard to their toxicity and suggest further studies on the formation, degradation and rearrangement of these substances as well as an update or addition of emission factors. Furthermore, they recommend the long-term measurement of selected characteristic compounds (for example, 1-nitropyrene, 2-nitrofluoranthene, 9,10-anthraquinone) at representative locations in order to obtain information on their origin (traffic or secondary formation of aerosols) and to identify geographical deviations and long-term trends.