Modelled PM<sub>2.5</sub> isoconcentration contours (μg/m<sup>3</sup>), mean annual exposure without background concentration.

<p><b>Map reprinted from Kadaster in the Netherlands</b> [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0196783#pone.0196783.ref025" target="_blank">25</a>] <b>under a CC-BY-4.0 license, 2017</b>.</p>