Fine air pollution particles trapped by street tree barks: in situ magnetic biomonitoring

CHAPARRO, MARCOS A.E.; CHAPARRO, MAURO A.E.; CASTAÑEDA MIRANDA, ANA G.; MARIÉ, DÉBORA C.; GARGIULO, JOSÉ D.; LAVORNIA, JUAN M.; NATAL,MARCELA; BÖHNEL, HARALD N.

ENVIRONMENTAL POLLUTION

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2020

0269-7491

Particulate airpollution in cities comprises a variety of harmful compounds, including fine ironrich particles, which can persist in the air for long time, increasing theadverse exposure of humans and living things to them. We studied street tree(among other species, Cordyline australis, Fraxinus excelsior and F.pensylvanica) barks as biological collectors of these ubiquitousairborne particles in cities. Properties were determined by the environmental magnetismmethod, inductively coupled plasma optical emission spectrometry and scanning electronmicroscopy, and analyzed by geostatistical methods. Trapped particles are characterizedas low-coercivity (mean±s.d. value of remanent coercivity Hcr = 37.0 ± 2.4 mT) magnetiteminerals produced by a common pollution source identified as traffic derived emissions.Most of these Fe rich particles are inhalable (PM2.5), as determined by the anhystereticratio χARM/χ (0.1 ? 1 μm) and scanningelectron microscopy (< 1 μm), and host avariety of potentially toxic elements (Cr, Mo, Ni, and V). Contents of magneticparticles vary in the study area as observed by magnetic proxies for pollution,mass specific magnetic susceptibility χ (18.4 ? 218×10-8 m3 kg-1) and in situ magneticsusceptibility κis (0.2 ? 20.2×10-5 SI). The last parameter allows us doing in situ magneticbiomonitoring, being convenient because of species preservation, measurementtime, and fast data processing for producing prediction maps of magneticparticle pollution.