Concrete – the extensive dangers to the planet and human health
Apart from water, concrete due to its benefits of endurance and low cost of production is the most widely used building material on the planet. It provides foundations for modern cities, homes, offices, streets, and pavements.
Cement is a basic component of concrete. The cement industry pumps out more than eight billion tonnes every year.
The sheer scale at which we produce cement means that cement alone before it’s even been made into concrete accounts for four to eight per cent of man-made carbon emissions including dust and gases.
Creating concrete requires huge amounts of non-renewable resources from raw materials, large amounts of energy mostly powered by fossil fuels to heat, mix and cool the ingredients.
Sand is an important part of cement and is being harvested from the environment-destroying beaches and riverbanks which need their sand to prevent flooding and keep ecosystems running.
Concrete uses almost a tenth of the world’s industrial water use – straining supplies for drinking and irrigation, 75 per cent of this consumption is in drought and water-stressed regions.
Concrete replaces natural structures like floodplains or forests without adequately mimicking their essential functions.
Animals, plants, fungi, and their ecosystems have been smothered under tonnes of concrete. It is estimated that about 60 per cent of the soil in the City of Melbourne is covered. This increases flooding, as water cannot sink into the ground thereby increasing run off. The floods in New Orleans after Hurricane Katrina were made more severe because urban and suburban streets could not soak up the rain like a floodplain.
Cement production emits large amounts of toxic substances and pollutants into the air such as cadmium, thallium, and mercury creating considerable environmental pollution.
These toxic elements are bad for anyone exposed to them, but they can also damage the ecosystems nearby wherever the cement is being produced.
Concrete, new or aged is subject to vapour emissions “outgassing” forever unless you make the extra effort to seal the capillary or gel pore system found in all concretes.
Concrete is well known for magnifying heat on hot days – being the significant material that contributes to the heat island effect. It also traps gases from our car exhausts and air conditioner units.
Every part of the process of making concrete has the potential to cause serious damage to the environment however it seems that humanity is far from phasing it out.
The cement industry has undergone some changes to clean up its carbon emissions with concrete being recycled and alternative energy sources being sought.
However, the politics of concrete seen in the form of stimulus spending projects by governments around the world plus cementing our riverbeds and hillsides in the name of flood and mudslide prevention – coupled with the technological advances of the cement industry – makes it difficult for another voice to be heard.
In Japan construction companies have been ordered to “hold back the sea”.
Environmentalists say that mangrove forests could provide a cheaper buffer.
What are the alternatives? While construction companies are fuelled by developers seeking to maximise profits for their shareholders and themselves versus what’s best for the planet or human health and not checked by themselves or government policies we have lots more to lose in air quality, natural resources, water, sand, soil, ecosystems and their natural functions. •