Fate and Exposure Assessment of Pb Leachate from Hypothetical Breakage Events of Perovskite Photovoltaic Modules

Emerging lead halide perovskite (LHP) photovoltaics are undergoing intense research and development due to their outstanding efficiency and potential for low manufacturing costs that render them competitive with existing photovoltaic (PV) technologies. While today's efforts are focused on stability and scalability of LHPs, the toxicity of lead (Pb) remains a major challenge to their large-scale commercialization. Here, we present a screening-level, EPA-compliant model of fate and transport of Pb leachate in groundwater, soil, and air, following hypothetical catastrophic breakage of LHP PV modules in conceptual utility-scale sites. We estimated exposure point concentrations of Pb in each medium and found that most of the Pb is sequestered in soil. Exposure point concentrations of Pb from the perovskite film fell well below EPA maximum permissible limits in groundwater and air even upon catastrophic release from PV modules at large scales. Background Pb levels in soil can influence soil regulatory compliance, but the highest observed concentrations of perovskite-derived Pb would not exceed EPA limits under our assumptions. Nonetheless, regulatory limits are not definitive thresholds of safety, and the potential for increased bioavailability of perovskite-derived Pb may warrant additional toxicity assessment to further characterize public health risks.