Resumen

Assessment of the potential toxicity of metals in soil near the Tungurahua volcano, Ecuador. RCTU [online]. 2024, vol.11, n.2, pp.46-56. ISSN 1390-7697.  https://doi.org/10.26423/rctu.v11i2.821.

In 2016, the activity of the Tungurahua volcano caused ash fall and lava episodes, which were mainly concentrated in Quero. Total metal content and bioavailability were evaluated in an agricultural soil near this volcano. Total metal content was estimated by microwave-assisted acid digestion and bioavailable metals by EDTA extraction. Major metals were measured by flame atomic absorption and minor metals by graphite furnace. The total content of Cd (0.13-0.22 mg/kg), Pb (1.3-2.5 mg/kg), Co (2.1-5 mg/kg), Ni (9.4-15.4 mg/kg), Cu (15.5-20.5 mg/kg) and Zn (27-36 mg/kg) was below the values established in Ecuadorian regulations. In contrast, the contents of Sr (5.1-11.3 mg/kg), Mn (138-216 mg/kg), Fe (5537-9426 mg/kg), Mg (1065-3128 mg/kg) and K (79-147 mg/kg) were comparable to those of other volcanic soils. In conclusion, the soils studied are not potentially toxic for agricultural practices in relation to metal content.

Palabras clave : Flame atomic absorption; microwave-assisted acid digestion; EDTA extraction; graphite furnace..