Researcher Ortega. Researcher Ortega.

Warning issued over contaminated aquifer

UNAM researcher warns of high levels of radioactivity

The National Autonomous University of Mexico (UNAM) has issued an aquifer contamination warning for the Guanajuato municipality of San José Iturbide given high levels of radioactivity detected in at least 2,500 wells.


UNAM researcher Marcos Adrían Ortega told the newspaper Milenio that at least half of those wells supply water for farming, and that five people have died of related health complications.

Tens of stomach cancer cases are also being studied for links with the contamination, said the researcher based at the Juriquilla UNAM campus, located in Querétaro.

One well that supplies water to three San José communities showed elevated levels of alpha radiation, which could be related to the fatal cases of lymphoblastic leukemia in girls younger than 12 years old reported in the area.

Around 1,500 people from San José show some degree of radioactive contamination, said the specialist, but relocating them is not the solution, as the source of the pollution is an over-exploited aquifer that extends over a broader region.

Studies have determined that the concentrations of arsenic and fluoride in the Lerma-Chapala aquifer have doubled in the last 14 years, and that similar levels of contamination could be present in the underground reservoirs of six states: Querétaro, San Luis Potosí, Aguascalientes, Zacatecas, Durango and Sinaloa.

Ortega said the damage caused by over-exploitation of the interconnected aquifers extends 800 kilometers from San José Iturbide, and that in some areas arsenic levels are 20 to 30 times over the acceptable limits.


“Arsenic is a cause of cancer, and fluoride not only affects teeth but also the skeleton,” said the researcher.

“The age of water in these underground reservoirs is between 10,000 and 35,000 years, and the ‘younger’ waters have already been extracted,” explained Ortega.

He explained that naturally occurring pollutants such as arsenic, fluoride and sodium in deep, underground waters are now flowing to the surface, affecting human health.

Ortega said that high concentrations of naturally occurring radon, a radioactive, colorless, odorless, tasteless gas has also been detected, not only in groundwater used for human consumption, but also in the soil and air, in a radius of three kilometers surrounding San José.

Ortega claims that municipal and state authorities have blocked access to the main source of pollution detected, and that they have been remiss in not heeding the recommendations made by experts.

The National Water Commission (Conagua) has rejected the conclusion that radioactivity levels in the water supply were higher than acceptable, and has assured that the water is safe for human consumption.

Source: Milenio (sp)

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  • alance

    What a terrible embarrassment for Conagua that they are totally incompetent in testing the water quality of the aquifers. Bottled water is not a luxury, it is a necessity in Mexico. Use bottled water when cooking and brushing your teeth. The National Autonomous University of Mexico (UNAM) deserves praise for their research.

    Shower filters are also a necessity. According to the CDC, dermal exposure to hazardous agents can result in a variety of occupational diseases and disorders, including occupational skin diseases (OSD) and systemic toxicity. Historically, efforts to control workplace exposures to hazardous agents have focused on inhalation rather than skin exposures. As a result, assessment strategies and methods are well developed for evaluating inhalation exposures in the workplace; standardized methods are currently lacking for measuring and assessing skin exposures.

    Some chemicals can be absorbed in enough quantity to cause detrimental systemic effects. Skin disease (dermatitis) is considered one of the most common occupational diseases. In order to assess if a chemical can be a risk of either causing dermatitis or other more systemic effects and how that risk may be reduced one must know the extent to which it is absorbed, thus dermal exposure is a key aspect of human health risk assessment.

    • DavidF

      Where does my local home delivery bottled water company (San Miguel de Allende) get the water that is in the bottles? How do I know that it is better than the water that is coming out of my water faucet?

  • kallen

    I’ll bet that if they look closely they’ll find water issues all over Mexico. I know around our little town in Baja the locals are always dumping their used motor oil and other chemicals on the ground. It’s amazing! Any attempt at educational conversation is met with blank stares.

  • alance

    The largest bottled water supplier in my city is Santorini which is owned by Pepsi which is delivered to my kitchen for which I pay 26 pesos for 20 liters.

    Former President Vicente Fox, a longtime Coca-Cola executive, looked positively on rising soft drink and bottled water sales, seeing them as a driver of economic growth. Mexicans drink an average of 42.3 gallons of soft drinks per capita annually, surpassed only by U.S. consumers.

    The growth of soft drink consumption is slowing in comparison with water, however.

    “The sale of water has risen on the order of 8 percent, while soft drinks rose 2 percent,” Pepsi Mexico President Juan Gallardo Thurlow announced in early April.

    The Beverage Marketing Corp. in New York City says Mexico’s bottled water market composes 13 percent of the world’s total, and has grown at 8 percent for each of the past five years.

    Consumer advocates say Mexicans’ thirst could be quenched more easily and inexpensively if municipalities provided reliable drinking water.

    • alance

      I trust Pepsi to deliver certifiable pure water. The downside is that Pepsi employees hustle their water customers to buy their junk food snacks loaded with High Fructose Corn Syrup and GMO grains loaded with Monsanto glyphosate, both of which are toxic poisons responsible for diabetes, obesity and heart disease plus a damaged immune system.

      • Fortunato Arriza

        Tell fox that I found inland sea deposit of phytoplankton . Mined ,before our written history.just ask The Richard Fisher.photojournalist.para hacercasodeunpendejo esaengranderlo.

        • Fortunato Arriza


    • Fortunato Arriza

      I read that not to drink pure water causes,to degree,collapse of glandular,cardiovascular,vascular systems.causing the most common diseases that doctors (matasanos) make their money by ineffectively treating.treat the cause,not symptom.ask any curandero (brujo).

  • Fortunato Arriza

    That is region I study.below my town is inlandsea.water has nafl,selenium,absent is nacl,as indicator (taste).school children who don’t bring money for bottled water,don’t go . embarrassed . Given cristal,and sold to gringos.i go to homelandsecurity in eureka.the run me off.i hate ice.

  • Fortunato Arriza

    It is reverse osmosis in my test for salt evaporate in black plate.process is not perfect.cost is about 50 cents 5 gallons.