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.