Minerals in Water A Rocky Subject
Lead, fluoride and arsenic concern many people. Happily, experts say Guadalajara-area tap water is in good shape. Maria de la Lourdes Chavez of Larem
laboratories says levels of dangerous minerals are not high here. SIAPA Chief of Production Jose Luis Gutierrez says public water meets national standards
for microbes, toxic wastes and minerals (fluoride, calcium, magnesium, lead, arsenic and others).
Ecologist Etienne von Bertrab agrees this is probably true, although he cautions that after water leaves treatment plants, it may be biologically contaminated
before it emerges from the tap. But Gutierrez said tap water can be briefly boiled to kill any post-treatment microbes.
So is boiled Guadalajara-area tap water safe to drink?
Fluoride, which reduces tooth decay, concerns some people. It is not added to SIAPA water. "In Tepatitlan, the water is naturally fluoridated and people drink from the tap," water bottler Fernando Roque says. But a World Health Organization report says excessive fluoride stains teeth and causes a
skeletal disease.
"Dentists say you need to check the fluoride level here because it's too high," said Kimberly Fernandez, a Zapopan medical doctor with four children. So she
has her tap water analyzed in a laboratory and says it is not expensive (about $85 pesos from the lab mentioned below).
As a result, Fernandez said, "I'd drink tap water even without filtering or boiling." Even so, she had a treatment system designed for her house and removes
remaining minerals with "an activated charcoal filter (like a Brita) because it improves the taste ... I use the Brita to remove the calcium so the coffee pot
doesn't get as much buildup."
Calcium and magnesium are considered "bad" when they leave deposits in pipes and appliances, but "good" and important for human health when they are at correct
levels. Despite the effort sometimes put into removing them from water, some say that a disadvantage of treated water -- especially bottled water that undergoes even more treatment than tap water – is that it has had these minerals removed. And liquid minerals are generally considered more absorbable than pill forms.
People looking for minerals removed in water treatment, sometimes drink one of Mexico's mineral waters. Peñafiel, the best known, comes from a high-altitude spring in Tehuacan, Puebla.
"I think Peñafiel is good because of the minerals," says a Guadalajara organic chemist. Peñafiel's Web site says it contains calcium, magnesium, potassium
and low amounts of sodium, although levels are not clearly specified, a common problem in labeling bottled waters. One source says Peñafiel contains lithium, a mineral used to treat mental disorders.
Fernandez says her children's nutritionist "recommends drinking distilled water [with no minerals], and then just add what you need." She buys a liquid zinc supplement and magnesium capsules, which she empties into food. "Everything else we need occurs naturally in food."
But another Guadalajara resident said she cannot drink milk, a source of calcium, and discovered a benefit of tap water. "I can tell if I'm not getting enough calcium because my teeth get sensitive. I noticed deposits from my tap water, so I tried drinking boiled tap water. It provided me enough calcium to stop taking supplements."
Nutritionists say humans need calcium and magnesium in a balanced ratio of two to one. The Healthy Water Association says "magnesium deficiency appears to have
caused 8 million sudden coronary deaths in America during ... 1940-1994." It promotes adding 100 mg. of magnesium to each liter of all beverages.
Similarly, the World Health Organization cites epidemiological studies showing lower heart disease rates where people drink "hard" water: "The strongest ... evidence for beneficial effects was for drinking water magnesium concentrations; there was also evidence ... for drinking water calcium concentrations." WHO urges governments and water bottlers to add calcium and magnesium to "demineralized" water.
SIAPA reports varying but high levels of calcium and magnesium before water is treated. Mexican norms permit calcium carbonate, a balanced compound of calcium and magnesium, at 500 mg. per liter. SIAPA reports 35 mg. of calcium and 26 mg. of magnesium per liter (close to levels WHO advocates) in its untreated water. During treatment, SIAPA reduces the minerals but observation indicates some remain after treatment.
Thus, even people who can afford bottled water but who accept SIAPA's assurances may want to drink boiled tap water as a source of calcium and magnesium. For those reluctant to take a leap of faith, a lab test for
calcium/magnesium costs $120 pesos at Larem. (33)3810-5437.