Boletín de la Sociedad Geológica Mexicana Volumen 73, núm. 1, A210920, 2021 http://dx.doi.org/10.18268/BSGM2021v73n1a210920

El color como indicador de contaminación por metales pesados en suelos de la Ciudad de México

Color as a proxy for heavy metal pollution in soils of Mexico City

Francisco Bautista^1,*, Avto Goguitchaichvili², Carmen Delgado², Patricia Quintana³, Daniel Aguilar³, Rubén Cejudo², José Luis Cortés¹

¹Laboratorio Universitario de Geofísica Ambiental, Centro de Investigaciones en Geografía Ambiental, Universidad Nacional Autónoma de México.

²Laboratorio Universitario de Geofísica Ambiental, Instituto de Geofísica, Universidad Nacional Autónoma de México.

³Laboratorio Nacional de Nano y Biomateriales, Centro de Investigaciones y Estudios Avanzados.

* Autor para correspondencia: (F. Bautista) This email address is being protected from spambots. You need JavaScript enabled to view it.

How to cite this article:

Bautista, F., Goguitchaichvili, A., Delgado, C., Quintana, P., Aguilar, D., Cejudo, R., Cortés, J., 2021, El color como indicador de contaminación por metales pesados en suelos de la Ciudad de México: Boletín de la Sociedad Geológica Mexicana, 73 (1), A210920. http://dx.doi.org/10.18268/BSGM2021v73n1a210920

ABSTRACT

The objective was the evaluation of color as a proxy for soil contamination by heavy metals in Mexico City. The concentrations of heavy metals were measured by X-ray fluorescence, and the color was determined with the Munsell Tables and colorimeter using Red Green Blue (RGB) system. From the Hue, Value and Croma values, five soil groups were formed by color: I, Dark reddish brown, 5YR 4/2; II, Dark gray, 7.5YR 4/1; III, Olive gray, 5Y 5/2; IV, Gray, 5YR 5/1; V, Pinkish gray, 7.5YR 6/2. With the Red Green Blue colorimetric values, three color indexes were calculated: Hue index, Redness index and saturation index. Validation of soil groups was greater with color indexes than with heavy metals. Groups I and II of dark color had the highest concentrations of Cr, Cu, Pb and Zn; they also had the highest percentages of Fe₂O₃, MnO, and TiO₂. Light colored groups IV and V had the highest percentages of Al₂O₃, MgO and SiO₂. Group III had intermediate values of Cr, Cu, Pb, Zn, Fe₂O₃, MnO, and TiO₂. For the first time, it is reported that the color of the urban soil of Mexico City can be used as a rapid analysis technique to identify sites contaminated with heavy metals.

Keywords: color Munsell, RGB system, color indexes, proxy techniques, heavy metals.