Reframing Anthropocene metal pollution: The overlooked role of colonisation in the Southern Hemisphere

Toxic metals and metalloids, including lead, cadmium, and arsenic, have been increasingly mobilised by anthropogenic disturbance. However, interpretations of metal enrichment in the Anthropocene have largely prioritised industrialisation, often overlooking the foundational role of colonisation and its associated socio-environmental transformations. This omission is particularly pronounced in the Southern Hemisphere, where research remains comparatively limited despite the profound and often more direct legacy of colonial extractive activities. As a result, global narratives of environmental change risk underrepresenting the historical drivers shaping contamination patterns outside the Global North. We analysed lake sediment records from a latitudinal transect spanning southeastern Australia, Tasmania, and sub-Antarctic Macquarie Island, regions that experienced relatively recent but intense colonial disturbance, to quantify metal enrichment, accumulation rates, and transport pathways from pre-1850 Common Era (CE) background conditions to the present. Palaeogeochemical records were integrated with an atmospheric transport and deposition model to distinguish atmospheric inputs from catchment-derived processes. Lead exhibits the most well-defined regional signal, with post-1850 CE concentrations up to 4.7 fold higher than background and 1950s enrichment factors up to 13.5 fold greater. All lakes received episodic atmospheric metal inputs, with the Tasmanian site receiving the greatest inputs, however, expression varied with background geochemistry and catchment disturbance. Remote, low-background sites exhibited the greatest relative enrichment. These findings provide robust evidence of long-range atmospheric metal transport linked to colonial-era resource extraction and highlight the need to integrate colonial histories and social context into global assessments of environmental change in the Anthropocene.