Variation in air pollution
Below is pollution data for Israel and two U.S. cities  representing the range of particulate matter as measured by the Air Quality Index (AQI). An increase of just 10 points in the AQI caused a drop in Israeli students' scores on the Bagrut exam and even had effects a decade later, lowering their monthly wages by $30.
Source: U.S. EPA air quality data and Figure A2 of Ebenstein et al (2016)