Prenatal air pollution linked to lower infant cognitive performance
A Barcelona cohort study found higher prenatal exposure to NO2, black carbon, PM2.5 and PM2.5 metal content was associated with reduced novelty preference on an eye-tracking memory test at 6 and 18 months.
- Study used 168 mother-child pairs from the Barcelona Life Study Cohort with exposure estimated by land-use regression combined with time-activity data.
- Cognitive performance was measured objectively using an eye-tracking Visual Paired-Comparison task at 6 months (n = 156) and 18 months (n = 62).
- Each interquartile range increase in prenatal pollution was linked to lower novelty preference: NO2 -2.0 percentage points (95% CI -4.7 to -0.6), black carbon -2.5 (-4.6 to -0.5), PM2.5 -3.9 (-7.0 to -0.9), PM2.5 copper -2.1 (-4.0 to -0.3), and PM2.5 iron -1.4 (-3.2 to 0.3).
- The study noted suggestions of stronger associations in boys.
- This is an observational study with a modest sample size, so results do not prove causation but point to pregnancy as a vulnerable window and to eye-tracking as a useful objective early marker.