**3. Human exposure to PBDE contaminations and uptake**

As a result of the presence of gaseous and particulate PBDEs in air, the human PBDE uptake is dominated by inhalation, but the relevance of this pathway is strongly affected by atmospheric PBDE levels. Hites and Sjödin et al. reported concentrations of 5.27–301 pg. m−3 in ambient air and 0.06–67 ng m−3 at indoor air, but increased levels up to 312.1 ng BDE-209 m−3 at a Swedish e-waste recycling site [38, 39]. Average BDE-209 levels of 0.13 ng m−3 (gaseous) and 140 ng m−3 (particulate) were reported by Li et al. in 14 Chinese air samples and total BDE-209 uptake by inhalation was quantified as 3000 ng d−1 (respiration) and 69 ng d−1 (dust uptake), equivalent to 84% of the total daily uptake [40]. This finding was validated by multiple studies. As a consequence, 16% of daily PBDE uptake, and even higher ratios in case of lower ambient PBDE levels, are assigned to dietary uptake underlining the relevance as second dominant pathway.
