Air quality for neodymium (Nd) was biomonitored in the English county of Leicestershire after low levels of the element were detected in topsoils from various urban parks in the city of Leicester. Thin layers of bark were collected from 55 and 41 trees growing in the city of Leicester and surrounding rural areas, respectively. Nd was monitored by ICP-MS in clean/ground/homogenised samples [LoD=0.504 ng/g dry weight (dw)]. The levels of Nd were higher in bark samples collected in Leicester city (median and ranges, in ng/g dw): 8.382 (2.021-198.91) and 7.778 (1.577-59.123). The higher concentrations of Nd in bark collected from trees growing in Leicester could be attributed to its technological uses. The Nd content varied between bark samples collected in the four cardinal sub-areas into which the city was divided (medians, ng/g dw): 45.132 (SE) > 14.397 (SW) > 7.709 (NE) > 5.950 (NW). This trend differed from the concentrations found in trees growing in the three Leicestershire cardinal points (medians, ng/g dw): 28.175 (NW) > 7.215 (NE) > 1.772 (SE). Finding a hypothesis that could explain the differences found in airborne Nd content across the monitored region is challenging as the atmospheric transport of Nd is poorly understood. Our results show a high dispersion of Nd across Leicestershire, which would be little influenced by its distribution in the topsoil, as the enrichment factors obtained as a function of the average Nd and scandium content in the upper continental crust were lower than unity in both areas (0.383 and 0.423). However, further studies are needed to identify the potential sources of Nd that could have contributed to the observed trends, because the levels found were higher than those described in bark from trees growing in uncontaminated areas. The development of a ¹⁴³Nd/144Nd isotope map could help to distinguish sources of pollution.