Beyond hotspots: Estimating population lead exposure from battery recycling

Area of Science:

• Environmental Health
• Toxicology
• Public Health

Background:

• One in three children globally experience elevated lead exposure.
• Lead-acid batteries represent the primary use of lead, with unsafe recycling practices posing a significant environmental and health risk.
• Existing research often focuses on localized high-exposure 'hotspots' from recycling, potentially underestimating broader population impacts.

Purpose of the Study:

• To estimate the contribution of lead-acid battery recycling to global lead exposure.
• To reconcile differing approaches to exposure assessment, considering both localized and widespread low-level exposures.
• To quantify the impact of expanding the geographical scope of concern around recycling sites.

Main Methods:

• Development of a novel simulation model to estimate lead exposure.
• Integration of data on lead-acid battery recycling and population-level exposure.
• Reconciliation of traditional 'hotspot' exposure models with recent evidence on wider-area, lower-level exposures.

Main Results:

• Modelled estimates suggest lead-acid battery recycling may account for approximately 36.22% of lead exposure in low- and lower-middle-income countries.
• The majority of harm is attributed to widespread, low-level exposure rather than localized high-concentration pollution.
• Expanding the assessment area around recycling sites increased the estimated contribution of battery recycling to global lead exposure by an order of magnitude (from 0.55% to a higher estimate).

Conclusions:

• Lead-acid battery recycling is a substantial, underestimated source of global lead exposure, particularly in lower-income countries.
• Public health strategies must address widespread, low-level lead exposure from recycling, not solely localized pollution.
• Accurate assessment of recycling's impact requires considering broader geographical areas and population-level effects.