Beyond hotspots: Estimating population lead exposure from battery recycling

One in three children worldwide have elevated lead exposure. Lead-acid batteries are the main use of lead by weight, and many are recycled unsafely, but it is uncertain how much of human exposure can be traced to this recycling. In this paper we provide new modelled estimates suggesting that around 36% of lead exposure in low- and lower-middle-income countries may come from battery recycling, although there remains significant uncertainty. The vast majority of harm comes from mass population low-level exposure, rather than localised hotspots. Previous studies have typically focused on small populations with high exposure living within hundreds of metres of polluted sites, but recent reduced-form quasi-experimental evidence demonstrates smaller negative effects for people living within much wider areas, affecting many more people. Our simulation model reconciles these approaches, and shows that expanding the area of concern around each recycling site increases the estimated share of global lead exposure attributable to battery recycling by an order of magnitude, from just 0.55% when considering only the high exposures within a few hundred metres of a site.