GUADALAJARA, 19 June 2021:
Finely ground eggshells are to be used in tandem with chemicals as part of an environmental group’s effort to reduce the high level of heavy metals in Mexico’s Santiago River.
The H2O organisation is carrying out a campaign throughout the western state of Jalisco to collect at least four tonnes of eggshells for use in removing lead, mercury and other contaminants from the river, said Bernardo Galan, the group’s representative in that state.
Eggshells, magnesium oxide and calcium oxide are used to form a mixture that is inserted into the soil near the river and helps eliminate both faecal material and heavy metals.
“We pour our physical-chemical mixture into a trench that’s 1m-wide and 10m-deep, and that’s where the process takes place,” he said yesterday, explaining that metal absorption and mineral recovery occur during the rainy season.
The activist said as much as 70% of organic matter and up to 20% of heavy metals and their contaminants can be absorbed.
A clean-up day is scheduled for August, when the environmental activists will “plant” 12 tonnes of the mixture near the Santiago River with the goal of achieving initial results within a year.
This technique was used last year to clean up several wells in Lerma, a town in Mexico state that is the source of the Lerma River.
Partial evaluations carried out to date by environmental activists and academics have confirmed a 60% reduction in organic material and a 25% drop in the amount of heavy-metal pollution in that portion of the Lerma River, although they will conduct a more thorough assessment in July.
Eggshells donated by ordinary citizens, beekeeping companies and Jalisco’s hotel sector are being taken to a processing centre where they are dried naturally, ground into powder and subsequently stored.
According to H2O, the effort to clean up the Santiago River is important because of the large number of communities that are forced to use its polluted water – noting the kidney diseases and different types of cancer its residents have contracted over the past two decades.
One of those places is El Salto, a municipality where hundreds of people have died of kidney diseases caused by drinking the river’s polluted water and breathing in its toxic fumes.
A study carried out in 2010 by the Autonomous University of San Luis Potosi (funded by the Jalisco state government but kept secret for a decade) found lead, arsenic, benzene, cadmium and other poisonous heavy metals in the water and detected mercury in the bloodstreams of 98% of children in six communities located near the river.
Last year, Washington DC-based Inter-American Commission on Human Rights (IACHR) granted precautionary protection measures in favour of the inhabitants of areas near the banks of the Santiago River.
In a press release on 7 Feb 2020, the IACHR said it deemed them “to be at serious, urgent risk of suffering irreparable harm to their human rights as a result of the alleged environmental pollution of the Santiago River and Lake Chapala in the state of Jalisco.”