Fig. 3: Income-based differences in estimated IQ loss attributable to PM_2.5 exposure during neurodevelopment under 2023 air quality conditions.

Data based on country-level population-weighted mean concentrations across four income categories calculated on Gross National Income per capita⁴⁴. Estimated median IQ loss is represented by horizontal lines, boxes indicate interquartile range (25–75th percentiles), whiskers show full data range between minimum and maximum; white circles indicate individual country data points; black diamonds indicate income classification means.