fig2
From: Assessment of the impact of sampler housing on indoor passive air sampler measurements of SVOCs
Figure 2. Indoor ambient levels of target compound groups, measured by active air sampler during the calibration period. Please note the different units for OPEs and PAHs. Each compound group reflects 8 weekly sampling periods, 2 replicates (n = 16). ∑PCBs is the sum of 6 congeners, ∑OCPs is the sum of 5 compounds, ∑PBDEs is the sum of 4 congeners, ∑HBCDDs is the sum of 3 isomers, ∑NFRs is the sum of 13 compounds, ∑OPEs is the sum of 11 compounds, and ΣPAHs is the sum of 23 compounds.