The presence on nano-sized particles of air pollution (with a diameter of just 100 nanometers) has for the first time been detected in children’s urine. The finding is particularly concerning as the particulate matter, also known as black carbon, has been linked to heart diseases and other respiratory conditions. Despite the EU’s commitment to improving air quality, notably through the National Emissions Ceilings Directive (2016/2284/EU) and the reduction commitments for 2020 and 2030, the findings only reinforce the sense of urgency in finding and implementing concrete and effective solutions to prevent a major European (and global) public health risk.