La Vuelta air not always healthy

The Netherlands is preparing for La Vuelta Holanda which starts on Friday 19 August. How clean is the air in the places that the peloton is visiting? Researchers from Utrecht University have mapped the annual average air quality of each stage of La Vuelta and demonstrate that the air is most polluted at the start (Utrecht) and finish (Madrid). They also conclude that for many stretches the air quality does not meet World Health Organization (WHO) guidelines. Nevertheless, the health benefits of cycling generally outweigh the risks. It's often said that "cycling is healthy" when we set off in all kinds of weather. But how clean is the air you breathe if you cycle the same route as the La Vuelta peloton on a normal day? This was the question researchers Roel Vermeulen  and  Jules Kerckhoffs asked themselves. Using satellite images, traffic information and air quality data about nitrogen dioxide, particulate matter and ozone, they made a stage map booklet showing the air quality for each stage of La Vuelta.