<p>Atmospheric deposition and bioaccumulation of potentially toxic elements (PTEs) threaten ecosystems and human health in regions downwind of urban and industrial emissions. This study investigates PTEs deposition at four sites in Bangladesh by analyzing 362 event-based rainwater samples using inductively coupled plasma-mass spectrometry. Spatial variability in elemental concentrations was significant across the sites (Kruskal–Wallis, <i>p</i> &lt; 0.01). Spatiotemporal patterns were governed by atmospheric circulation, and no significant correlation was found between deposition flux and rainfall amount. Annual deposition fluxes ranged from 16.8 to 5224.6&#xa0;μg&#xa0;m⁻² y⁻¹, with the highest values recorded at Sylhet. Ecological risk indices remained well below the low-risk threshold (RI &lt; 150), indicating minimal environmental risk. In terms of human health, the cumulative non‑carcinogenic hazard index remained below the safety threshold of 1.0 for all demographic groups, indicating no significant non-carcinogenic risk. However, lifetime carcinogenic risks from oral exposure exceeded the acceptable limit of 1 × 10⁻⁴. Source identification analysis revealed coal combustion, industrial activities, and fossil fuel burning as the dominant anthropogenic sources. A strong, statistically significant correlation was observed between Arsenic and Selenium (ρ = 0.89, p &lt; 0.001), confirming their common origin in coal combustion. HYSPLIT back-trajectory analysis indicated long-range transport of PTEs from the Indian subcontinent and West Asia, modulated by atmospheric circulation patterns. These findings demonstrate that while non-carcinogenic risks are minimal, cumulative carcinogenic risks from multiple elements remain a concern across the region, underscoring the need for rainwater quality assessment before potable use, emission control measures, and transboundary cooperation for air pollution management and water security.</p> Graphical Abstract <p></p> <p>This visual summary depicts atmospheric deposition of potentially toxic elements (PTEs) in Bangladesh, based on 362 rainwater samples collected from coastal and inland sites. Analysis of key 21 PTEs, including As, Se, Cs, and Tl, combined with statistical source identification (PCA, CA, NA, EF) and air mass back-trajectory modeling, identified coal combustion, non-ferrous metal smelting, and fossil fuel burning as dominant anthropogenic sources. Seasonal monsoon dynamics govern transboundary transport, delivering pollutants to Bangladesh and the Himalayan–Tibetan Plateau. Health risk assessment demonstrates that atmospheric deposition poses minimal non-carcinogenic risk (HI &lt; 1) but unacceptable carcinogenic risk (CR &gt; 1 × 10⁻⁴) from combined exposure to multiple elements, with adults showing higher risk than children. These findings necessitate transboundary pollution management that integrates atmospheric deposition into regional governance of air quality and water security.</p>