Opinion, by Alfonso Stefanini
RIO DE JANEIRO, BRAZIL – I’ve heard that man’s best friend in not the dog, but reinforced concrete. The material allows for the building structures that define modern urban living, from skyscrapers to hydroelectric dams. This essential inanimate compound is composed mainly of sand, gravel, cement and water.
That being said, it is fair to say sand is the second most widely used material in sheer volume in the world, losing only to water. You cannot hold a handful of sand without it trickling through your fingers any more than you can hold a pint of water, and our modern society is watching both resources disappear before our eyes.
After watching the documentary “Sand Wars” during the third edition of environmental film festival Ambiente 2013 in Rio de Janeiro, I realized the full extent of our gargantuan appetite for sand. Sand and reinforced concrete started being used in construction a little over 150 years ago, and today fifteen billion tons of it are consumed globally every year.
Silicon Valley in California was built on sand in the form of microchips, and so are our cell phones, cars, airplanes, glass, and the list goes on. Who would have thought sand would become such a desired commodity?
Though Brazil is not on the top ten list of sand consumers, the World Bank and Brazilian Minister of Mines and Energy (MME) estimate that the country consumes 250 million metric tons per year, seventy percent of it coming from riverbanks. This is a sensitive environmental issue when talking about erosion control in a country with no specific environmental legislation protecting topsoil.
Land erosion is exacerbated by sand extraction from riverbanks adding to the existing environmental issues found in tropical countries, that lose hundreds of tons of soil per hectare in areas where the vegetation has been removed. The persistent hard rains and strong winds, in addition to agriculture and deforestation, add to the sedimentation problem that is clogging and polluting ecosystems. The dredging industry is making a killing from the environmental degradation, and so are bioengineering companies and producers of superficial erosion control materials such as biomats and geomats.
Beach sand is not an alternative construction material due to the salt content. Close to fifteen years ago a building called The Palace II was raised in Barra de Tijuca using salty sand, causing its collapse and the death of eight people, and the displacement of hundreds of residents.
The former dwellers are still waiting to be compensated and many residents still live in hotels years after the accident. Whole families had to deal with growing up without a kitchen to call their own, and those displaced children are now moving out from their parents hotel rooms without seeing their housing situation resolved. Like people displaced by the ruthless movement of sand dunes in coastal areas throughout the world, the victims of this unnecessary sand tragedy are yet to be compensated by the responsible parties.
Construction residues are responsible for taking up a vast amount of landfill space. The recovery of recycled materials is an excellent opportunity in Brazil, but very few entrepreneurs seem to be investing in technologies and machinery to take advantage of this wasted resource.
Sand made from recycled glass is becoming a viable alternative for replacing river sand. In Rio de Janeiro a ton of mixed glass sells for R$80, or approximately US$35, and a ton of sand costs in average R$150, plus delivery. Considering that there is little material loss in the glass to sand recycling, it can be an innovative alternative even when taking into consideration the required sterilization and quality control process.
While river sand is brought to Rio from distant municipalities like Seropédica and Itaguaí, glass is thrown away by restaurants and residences everywhere you look. Sand traffic from illegal operations is on the rise, and so are the prices of sand, having direct impact on construction costs.
It seems like we are digging ourselves in a hole by over utilizing a material that has tremendous ecological value in situ. It is time we leave behind the ostrich complex and take our head out of the sand.
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Alfonso Stefanini has an MA in International Environmental Policy from the Monterey Institute of International Studies in California and a BA from Hampshire College. Alfonso lives in Rio de Janeiro, and he can be reached at: [email protected].
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