Atmospheric dustfall is a major contributor to particulate matter in semi-arid cities, yet the specific drivers of associated health risks remain obscured by high background dust levels. Previous studies treated source apportionment and risk assessment separately. This fragmentation fails to reveal whether the dominant mass contributors coincide with the primary health risk drivers. To address this gap, a total of 129 atmospheric dustfall samples were collected from 10 urban sites and one suburban background site in Hohhot, a representative semiarid city. This study investigated the spatiotemporal distribution, sources, and source-specific health risks of 16 potentially toxic elements (PTEs). The results indicated that PTEs derived from natural sources (e.g., Fe, Ti, Mn, and Ba) were the dominant components, with deposition fluxes reaching 8388, 438.8, 91.1, and 62.6 kg/(km2 & sdot;a), respectively. In contrast, concentrations and deposition fluxes of anthropogenic PTEs (As, Ni, Cr, Cd) were comparatively low. The crustal source was the predominant contributor to the total element concentration in dustfall (83.8%), whereas industrial sources (7.9%), coal combustion (5.8%), and a mixed source of vehicle emissions and dust (2.4%) made relatively minor contributions. The non-carcinogenic risk was primarily attributed to coal combustion, whereas the carcinogenic risk was mainly linked to coal combustion, industrial sources, and mixed sources of vehicle emissions and dust. Furthermore, given Hohhot's high natural background deposition, the contribution of natural sources to the health risks is non-negligible. These findings challenge the assumption that reducing total dust effectively mitigates risks. We propose a paradigm shift from general dust suppression to precise control of toxic anthropogenic emissions in semi-arid environmental management.