In vitro assessment oral and respiratory bioaccessibility of Mn in school dust: Insight of seasonality in a semiarid environment

Abstract In school environments in the Sonoran Desert, dust contains anomalously high manganese (Mn) of geogenic origin, similar to those reported at industrial sites. Non-carcinogenic risk assessment for children exposed to Mn was estimated for two sampling seasons (pre-monsoon, post-monsoon). We determined the total Mn content in school dust samples by portable X-ray fluorescence (PXRF), and we used geochemical indices for Mn-source apportionment. We identified dust mineralogy by X-ray diffraction (XRD). We obtained the oral and lung bioaccessibility by in vitro tests. The results showed a much higher total Mn content (1725.7 mg·kg-1) in the