Environ Monit Assess. 2026 Mar 30;198(4):386. doi: 10.1007/s10661-026-15225-0.
ABSTRACT
Urban air pollution is a major challenge for environmental health, especially in tropical cities where complex topography and fossil fuel dependence exacerbate poor air quality. Epiphytes, which rely on atmospheric water and nutrients, are particularly sensitive to airborne contaminants and represent promising biomonitors. This study compares the potential of vascular and non-vascular epiphytes to accumulate airborne pollutants, providing a direct assessment of their biomonitoring performance. We evaluated these epiphytes as biomonitors of urban air pollution in Medellín, Colombia. Six species were studied: three vascular epiphytes (Tillandsia recurvata, Pleopeltis macrocarpa, Rhipsalis baccifera), two bryophytes (Fabronia ciliaris, Kymatocalyx dominicensis), and one lichen (Flavoparmelia caperata). Host tree leaves were included for comparison. The samples were collected from 49 trees across sites representing contrasting pollution levels. We quantified magnetic susceptibility (χ) as a measure of particle accumulation, complemented by scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectroscopy (ICP‒OES). The results revealed marked interspecific differences: vascular epiphytes presented significantly higher χ values than bryophytes, lichens, and host tree leaves did. T. recurvata presented the strongest response, with median χ values up to an order of magnitude greater. Non-vascular species reflected pollution differences only weakly, indicating limited suitability for active monitoring. SEM revealed abundant metal particles and microplastic debris on vascular epiphytes, whereas ICP‒OES confirmed elevated Ba, Cu, and Cr at polluted sites. These results provide the first integrated assessment of epiphyte functional groups for biomonitoring in a tropical city, demonstrating that vascular epiphytes, particularly T. recurvata, are robust, accessible and low-cost biomonitors.
PMID:41912976 | DOI:10.1007/s10661-026-15225-0
