Fig. 4. Sum of 16 polycyclic aromatic hydrocarbons ( 16 PAHs; µg/kg dry wt.) versus sum of six polychlorinated biphenyls ( 6 PCBs; µg/kg dry wt.) measured in the same samples of (a) organic household waste (n = 68), green waste (n = 29), and bark (n = 18), and (b) compost containing organic household waste (n = 67) and compost originating from green waste (n = 20). No concomitant PCB and PAH analysis is available for kitchen waste, foliage, shrub clippings, and grass. For illustration, the regression line (forced through zero) from all available data is added.