Evaluation of environmental pollution from the magnetic increase in urban dusts. A case study for the city of Mexicali, Mexico

  • Alexander Sánchez-Duque Laboratorio Universitario de Geofísica Ambiental LUGA, Centro de Investigaciones en Geografía Ambiental CIGA, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Col. Ex-Hacienda de San José de la Huerta, C.P. 58190, Morelia, Michoacán, México.
  • Francisco Bautista Laboratorio Universitario de Geofísica Ambiental LUGA, Centro de Investigaciones en Geografía Ambiental CIGA, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Col. Ex-Hacienda de San José de la Huerta, C.P. 58190, Morelia, Michoacán, México. Centro de Edafología y Biología Aplicada del Segura, CEBAS-CSIC (Consejo Superior de Investigaciones Científicas), Campus Universitario de Espinardo, C.P 164, 30100 Murcia, España.
  • Avto Goguitchaichvili Laboratorio Universitario de Geofísica Ambiental LUGA, Instituto de Geofísica Unidad Michoacán IGUM, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Col. Ex-Hacienda de San José de la Huerta, C.P. 58190, Morelia, Michoacán, México
  • Rubén Cejudo-Ruiz Laboratorio Universitario de Geofísica Ambiental LUGA, Instituto de Geofísica Unidad Michoacán IGUM, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Col. Ex-Hacienda de San José de la Huerta, C.P. 58190, Morelia, Michoacán, México
  • Jaime Alonso Reyes-López Laboratorio de Ciencia y Tecnología del Agua, Suelo y Medio Ambiente, Instituto de Ingeniería, Universidad Autónoma de Baja California, Blvd. Benito Juárez y Calle de la Normal s/n, Col. Insurgentes Este, C.P. 21280, Mexicali, Baja California, México.
  • Fernando Amílcar Solís-Domínguez Facultad de Ingeniería, Universidad Autónoma de Baja California Campus Mexicali, Blvd. Benito Juárez s/n, C.P. 21900, Mexicali, Baja California, México.
  • Juan Julio Morales-Contreras Laboratorio Universitario de Geofísica Ambiental LUGA, Instituto de Geofísica Unidad Michoacán IGUM, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Col. Ex-Hacienda de San José de la Huerta, C.P. 58190, Morelia, Michoacán, México
Keywords: environmental magnetism, geostatistics, urban contamination, land use, road hierarchies.

Abstract

Assessments of magnetic enhancement on urban dust samples collected on different surfaces, mostly paved and unpaved roads, were performed in order to evaluate the environmental contamination in Mexicali (medium-sized city on the Mexico-USA border). Rock and mineral magnetic techniques consisted of systematic measurements   of mass-specific magnetic susceptibility and isothermal remanent magnetization at 0.7 T. Magnetic enhancement was estimated by comparing magnetic concentration for each sample relative to reference value obtained from the site with almost no human activity also known as conservation area in the suburb of town. Additional magnetic parameters as the S-200 ratio and Curie temperatures were used to identify predominant magnetic carriers. These experiments indicate that impure magnetic is the main mineral in most studied samples. Geostatistical analysis and interpolation techniques (experimental variogram and ordinary Kriging, respectively) were carried out in order to determine the spatial distribution of magnetic enhancement and relative levels  of environmental contamination. High traffic roads with industrial areas as well as some land categories yielded unusually high level of contamination.

Published
2018-01-03
Section
Articles