Sand and gravel are now the world’s most extracted materials – surpassing fossil fuels – but overexploitation and shortages are fuelling violent conflict and leading to worrisome environmental, economic and health impacts, according to researchers writing in journal Science.
The past century has seen a 23-fold increase in the volume of natural resources used for buildings and transport infrastructure, and sand and gravel has accounted for the vast majority of these materials (79 per cent in 2010). In 2010, 11 billion tonnes were mined, with the Asia-Pacific region having the highest extraction rates.
But because sand is typically treated as a common-pool resource (as it is costly to regulate access), it has led to a “tragedy of the commons”-type situation where it is being “selfishly” extracted without considering long-term consequences – leading to degradation and overexploitation.
The researchers – Aurora Torres, Jodi Brandt, Kristen Lear and Jianguo Liu – said rapid urbanisation was the main driver of increasing sand use as it is a key ingredient in building materials like concrete, asphalt and glass.
“Urban development is thus putting more and more strain on limited sand deposits, causing conflicts around the world.”
Limited sand resources were fuelling illegal trade in the commodity, with the researchers pointing to evidence of organised crime groups in Italy, India and other countries.
“The high profits generated by sand trade often lead to social and political conflicts, including violence, rampant illegal extraction and trade, and political tensions between nations.”
India’s “Sand Mafia”, for example, was noted as one of the most powerful and violent organised crime groups, responsible for the death of hundreds of people.
The environmental implications were sobering, with sand extraction from rivers, beaches and sea floors affecting ecosystem integrity, placing “enormous burdens” on habitats, migratory pathways, ecological communities and food webs.
There were cascading effects on the provision of ecosystem services, water and food security, and human wellbeing and resilience. For example, sand mining exacerbated the effects of the 2004 Indian Ocean tsunami on Sri Lanka.
And research is beginning to show health impacts.
“Health impacts associated with sand mining remain poorly characterised, but there is evidence that the conditions created by extracting sand can facilitate the spread of infectious diseases.”
With demand for sand resources only set to increase, the researchers said there was “a pressing need” for a global sand governance system.
“Based on what we have already learned, we believe it is time to develop international conventions to regulate sand mining, use and trade,” they wrote in an accompanying Conversation piece.
Low-carbon materials can help
The researchers said efforts were needed to increase efficiency of sand use and trade, which could include recycling policies and avoiding waste along the supply chain.
The Fifth Estate has featured a number of articles promoting the use of waste glass in lieu of sand for concrete and prefabricated panel applications, particularly important as stockpiles of waste glass build up.
- See Waste glass could lead to cheaper, lighter, stronger prefab concrete and Australian leadership: zero carbon cement possible in 10 years
However the researchers said “drastic innovation” would be needed because there were no alternatives to sand mining that would meet skyrocketing global demand.