Long-Term Effects of Heavy Metals on Children’s Health
Industrial growth has created the potential for environmental problems in Mexico because attention to environmental controls and urban planning has lagged behind the pace of industrialization. Many communities are impacted by the increased industrialization with many of the environmental pollutant effects observed in children. The long term effects of chronic exposure of lead and other elements present in the environment surrounding smelters and mines are not well known. Follow up studies are the ideal design to evaluate the effects of multielement exposure and their repercussion on health later in life. Health parameters to be tested include: morphometrics, immunological, neurodevelopment, endocrine disruption, geneotoxicity and cardiovascular.

Mexican collaborative researcher Dr. Mercedes Meza in the Yaqui Valley of Sonora, Mexico. Photo provide by Mercedes Meza.

Arsenic and Health: Diabetes and Breast Cancer in the U.S.-Mexico Border

Diabetes
The association between arsenic exposure and diabetes mellitus has been inferred for a number of years and has received more attention due to recent epidemiologic reports, which have linked the two through environmental and occupational sources. The high incidence of diabetes in Hispanic and Native Indian populations in both the Southwestern U.S. and Northern Mexico could, in part, be explained by their exposure to arsenic via their drinking water. Since diabetes is essentially a vascular disease and arsenic has been associated with producing many vascular effects, investigators propose to collaborate to profile if populations exposed to arsenic have changes in gene regulation and proper maintenance in clotting factors.

Breast Cancer
Breast cancer is the leading cause of cancer death in the world and reproductive, dietary, environmental and genetic characteristics have been linked to this type of cancer. Accumulating evidence from epidemiologic studies suggest that risk of breast cancer is reduced in relation to increased consumption of folate and related B vitamins. Arsenic is a known human carcinogen present in drinking water supplies around the world, which induces chromosomal and DNA damage. Simultaneous effects of environmental, dietary, and genetic traits may be playing a role in the high incidence of breast cancer in the Border region.

Mine Tailings: Phytostabilization and Phytoremediation

Mine tailing pile in Nacozari, Sonora, Mexico.  Photo provided by Diana Meza.

Extensive mining activity has occurred in the arid and semi-arid ecosystems of the northern and central Mexico and the southwestern United States. As a result, there are large numbers of tailings sites with elevated metal concentrations, including arsenic, lead, and cadmium, which are #1, #2, and #7 respectively, on the U.S. Environmental Protections Agency’s Agency for Toxic Substances and Disease Registry for Hazardous Substances list. Phytostabilization has been proposed as an economical remediation strategy to stabilize the metal contaminants and prevent human and animal exposure through dust particles or dissolution of metals into ground and surface waters. Phytoextraction is a second technology that has been proposed in which plants are established and used to extract and remove the contaminant metals from the tailings. Plant tissue which has accumulated metals are harvested and disposed.  Click here to view the Sonoran Remedial Project Website.

 

Landfill Leachate Plumes: Characterization, Natural Attenuation and Bioremediation
Mass urbanization in the Border Region has resulted in a large number of uncontrolled or illegal landfills of both municipal and solid waste as well as hazardous waste. Plumes generated from these landfills are threatening already scarce water supplies in the arid and semi-arid Border Region. The objectives of this project are to identify xenobiotic hazardous contaminants in landfill leachates from Mexican and Arizonan Border communities, and to characterize processes contributing to their natural attenuation. The extent of landfill leachate contamination in the Border Region is expected to be extensive, therefore, there is a great need to develop low-cost bioremediation strategies to eliminate hazardous contaminant from such plumes. For this purpose, the project will be used to develop a permeable reactive barrier system for passive treatment of landfill leachate plumes.