Exchange of Pb from Indian to Atlantic Ocean is driven by Agulhas current and atmospheric Pb input from South Africa.

Using a spatiotemporal dataset of dissolved lead (dPb) from the subtropical oceans surrounding South Africa, this study quantifies the exchange of dPb between the Indian and Atlantic Oceans. Despite the absence of a major Pb source within the South Atlantic sector and the complete phase-out of leaded petroleum in Southern Africa, the ecologically important southeast Cape Basin shows an elevated surface dPb concentration (21-30 pmol kg). We estimated up to 90% of the measured dPb in surface waters of the Cape Basin was delivered from the Indian Ocean via the Agulhas Current (AC).