Higher exposure to lead among children from low- and middle-income nations accounts for more than a fifth of the gap in learning outcomes between rich and poor countries, according to an analysis.
A review of 47 studies by researchers at the Center for Global Development, a Washington think-tank, suggests that more than 20 per cent of the gap in basic reading and mathematics can be attributed to elevated levels of lead in the blood, increasing concerns over the barriers to learning in the developing world.
It highlighted that children in low- and middle-income countries have average lead exposures that are 10 times higher than US levels, with only 40 per cent of children in those countries able to read and understand a simple story, compared with more than 90 per cent in the OECD club of mostly rich nations.