Click here for the full version of this report on the Rethink Priorities website.
This report is a “shallow” investigation, as described here, and was commissioned by GiveWell and produced by Rethink Priorities from November 2021 to January 2022. We updated and revised this report for publication. GiveWell does not necessarily endorse our conclusions. The primary focus of the report is to provide an overview of what is currently known about the exposure to lead paints in low- and middle-income countries.
- Lead exposure is common across low- and middle-income countries (LMICs) and can lead to life-long health problems, a reduced IQ, and lower educational attainment. One important exposure pathway is lead-based paint (here defined as a paint to which lead compounds have been added), which is still unregulated in over 50% of countries globally. Yet, little is known about how much lead paint is being used in LMICs and to what extent it contributes to the health and economic burden of lead (link to section).
- Home-based assessment studies of lead paint levels provide evidence of current exposure to lead, but the evidence in LMICs is scarce and relatively low quality. Based on the few studies we found, our best guess is that the average lead concentration in paint in residential houses in LMICs is between 50 ppm and 4,500 ppm (90% confidence interval) (link to section).
- Shop-based assessment studies of lead-based paints provide evidence of future exposure to lead. Based on three review studies and expert interviews, we find that lead levels in solvent-based paints are roughly 20 times higher than in water-based paints. Our best guess is that average lead levels of paints currently sold in shops in LMICs are roughly 200-1,400 ppm (80% CI) for water-based paints and 5,000-30,000 ppm (80% CI) for solvent-based paints (link to section).
- Based on market analyses and small, informal seller surveys, we estimate that market share of solvent-based paints in LMICs is roughly 30%-65% of all residential paints sold (the rest being water-based paints), which is higher than in high-income countries (~20%-30%) (link to section).
- There is also evidence that lead-based paints are frequently being used in public spaces, such as playgrounds, (pre)schools, hospitals, and daycare centers. However, we do not know the relative importance of exposure from lead paint in homes vs. outside the home (link to section).
- As many studies on the exposure and the health effects of lead paint are based on historical US-data, we investigated whether current lead paint levels in LMICs are comparable to lead paint levels in the US before regulations were in place. We find that historical US-based lead concentrations in homes were about 6-12 times higher than those in recently studied homes in some LMICs (70% confidence) (link to section).
- We estimate that doubling the speed of the introduction of lead paint bans across LMICs could prevent 31 to 101 million (90 % CI) children from exposure to lead paint, and lead to total averted income losses of USD 68 to 585 billion (90% CI) and 150,000 to 5.9 million (90% CI) DALYs over the next 100 years. Building on previous analyses done by LEEP (Hu, 2022; LEEP, 2021) and Attina and Trasande (2013), we estimate that lead paint accounts for ~7.5% (with a 90% confidence interval of 2-15%) of the total economic burden of lead. We would like to emphasize that these estimates are highly uncertain, as our model is based on many inputs for which data availability is scarce or even non-existent. This uncertainty could be reduced with more data on the use of paints in LMICs (e.g. frequency of re-painting homes) and on the average dose-response relationship between residential lead paint levels and blood lead levels (link to section).
Jenny Kudymowa and Ruby Dickson jointly researched and wrote this report. Carmen van Schoubroeck assisted in revising the report for the public-facing version. Jason Schukfraft and Tom Hird supervised the report. Thanks to David Reinstein, William McAuliffe, Greer Gosnell, James Hu, and Bjorn Larsen for helpful comments on drafts. Further thanks to Bruce Lanphear, Lucia Coulter, Clare Donaldson, Sara Brosché, Bret Ericson, Elsbeth Geldhof, Angela Bandemehr, Ashley Fisseha, Steve Wolfson, Drew McCartor, Richard Fuller, Emily Nash, Adam Kiefer, and Perry Gottesfeld for taking the time to speak with us. GiveWell provided funding for this report, and we use their general frameworks for evaluating cause areas, but they do not necessarily endorse its conclusions.