Fig. 4
a–d Scatterplots of molecular weight and hydrophobicity (log KOW) showing the relative differences and trends between house dust and SPM samples (DMP, DINA and DEHAz are not pictured due to their constantly low concentrations); circular areas are normalized to 100%; log KOW values were determined with the quantitative structure–activity relationship (QSAR) model JANUS (Additional file 1: Table S1; [103])