Water contamination: Can we stop the world’s biggest killer?

It may be surprising to some, but water-borne diseases are the leading cause of death in the world. There are an estimated 3.4 million deaths a year according to the World Health Organisation (99% of which occur in developing countries (Prüss-Üstün et al., 2008)), whilst four-fifths of illnesses in developing countries are caused by contaminated water (Fonyuy, 2014). Clearly the problem of water pollution and contamination is now one of the most pressing issues for developing countries.

So how does water get polluted? Surface water is more commonly contaminated, and this can pose a high risk as many public waterways are used for drinking and cooking water as well as sanitation. However, a lack of infrastructure in towns and cities can lead to sewage and garbage being dumped straight into these waterways. Groundwater is usually safer as it gets filtered as it passes through underground layers of sand, clay and rock (Kjellstrom et al., 2006). Nevertheless, industry and mining can affect the mineral and pH levels of both ground and surface water. Arsenic (especially a problem in southern Asia, including Bangladesh) and fluoride, can leech through the soil into groundwater from both natural and anthropogenic sources, and are seen as the most dangerous inorganic contaminants in the world (Farooqi, 2015). 

The overriding contamination of freshwater comes from nitrogen and phosphurus, which are carried into the water from agricultural runoff. This leads to eutrophication of water bodies, and enhanced productivity of algae to form toxic algae blooms. A consequence of the increased respiration rates is that it depletes the water of oxygen, which can create 'dead zones' with devastating effects on local fauna.

It is not just freshwater reserves which are being increasingly contaminated. Go to any beach in Britain and it’s easy to see the amount of waste and debris washed up onto our shores. There are billions of pieces of plastic floating around are oceans, right down to microscale which can have a devastating effect on wildlife. The BP oil spill in the Gulf of Mexico is a well-known example of water pollution, where 780,000 cubic metres of oil were released into the ocean, causing havoc to marine wildlife as well as the local fishing and tourism industries. Meanwhile, Diaz and Rosenburg, 2008 report more than 400 marine dead zones, caused by toxic algae blooms and oxygen depletion. 

 Why is freshwater contamination such an issue in developing countries, whilst in general richer ones are able to get around the problem? The answer, inevitably, focuses around money. Many developing countries lack the finances to build the necessary infrastructure, such as pipes, treatment plants and wells. The problem is being exacerbated in many African countries by high population growth rates, meaning increased use of unsafe water for drinking, cooking and sanitation.

However the developed world has its problems as well. Recently in the USA there have been reports of contaminated groundwater due to deposition of waste water from the hydraulic fracturing, or fracking, process of extracting natural gas. Although natural gas has been hailed as a cleaner alternative to coal, and a transition fuel whilst the world switches to a future which utilises renewable energy sources, it brings its own environmental impacts. Methane concentration has been found to rise with proximity to fracking sites (Holzman, 2011). This video shows an example of how methane levels are so high in some US drinking water supplies that they are actually flammable: 

This has led to a backlash against fracking in regions which are experiencing water pollution. Developed nations have higher expectations with regard to their water supply and are typically willing to take steps to protect the quality of that water.  

How realistic is it though, to expect to radically reduce water contamination in developing countries? Historically poorer agricultural countries are often the ones experiencing the most rapid economic growth, driven by increased globalisation and growing demand for minerals and other commodities.  This typically involves rapid expansion of cities, including the building of new factories and roads, but often without the infrastructure to support dealing with contaminated water.  

However preserving water quality and improving accessibility brings significant potential economic benefits due to a decreased spend on health and less time spent on collecting water, thereby increasing economic productivity. For a developing country to prosper, it is in their interest for economic growth and improvements to the water supply to go hand-in-hand.

In the news this week…

Just a short one. Donald Trump is the President-elect of the United States of America. This divisive result will have numerous effects worldwide, but what does it mean for the future well being of the planet?

In 2012, he wrote on his twitter account, “The concept of global warming was created by and for the Chinese in order to make US manufacturing non-competitive”. Essentially, we now have a climate change denier as the leader of the second most polluting country on Earth. More recently he claimed that he would “cancel all wasteful climate change spending”. As far as our efforts to decrease carbon dioxide emissions in order to slow global warming go, this is not good news.

Just over a week ago, National Geographic released their documentary ‘Before the Flood’. This film explores the real issues threatening the planet such as melting ice caps, massive deforestation and rising sea levels and all in all paints a rather forbidding picture, as well as stressing how the USA is one of the biggest culprits. It ends on an optimistic note, with Johan Rockström, a professor of Environmental Science at Stockholm University, saying he thinks ‘we have tipped the world towards a sustainable future, the fear is are we doing it too slowly?’. Four years of Trump in power will be a stumbling block to any progress that has been made. Not only is he proposing a move back to coal-fired power stations (although the low price and abundance of natural gas due to fracking may end up making this an empty promise), but he has vowed to renegotiate the Paris agreement (there is nothing to stop him just ignoring it anyway) and wants to eradicate the Clean Power Plan which aims to reduce emissions from existing power plants by 30% by 2030.

This will have consequences that reach far beyond the US, as it effectively rules out any remaining hope of limiting global temperature rise to 2 degrees above pre-Industrial levels. 20% of the carbon emission reduction agreed to in the Paris agreement is set to come from the US, so them dropping out may set a precedent for the other most polluting nations.

This blog is focussing on water, and it is worth pointing out that Earth is not the only planet in the solar system with water on. There might not be as much liquid water on Mars as there used to be (de Haas, 2014) but actually there is an abundance of water ice below the surface as the following video explains:

Only time will tell whether we damage our planet so irrepairably that many parts of it are uninhabitable, but with 2016 set to be the hottest year on record (breaking the previous record set in 2015) maybe we shouldn’t be too hasty in ruling out a trip over to our red neighbour! And if we’re still in need of water we could consider this:

http://www.trump.com/merchandise/trump-natural-spring-water/

An update in Central Asia

Just an update to my second blog post. I spoke about tensions in central Asia between five countries, some of which were lacking in water, others in the means to generate electricity.

Well, Tajikistan has officially begun construction on what is set to be the world’s largest dam (a whopping 335 metres tall). More information about the Rogun hydropower project can be found in this BBC article.

The proposed dam had drawn criticism from downstream neighbouring Uzbekistan. However, since the recent death of its President Islam Karimov, relations between the countries seem to be improving.

It will take over a decade to complete, but progress means an end to freezing cold winters is in sight for many Tajikistan residents.

The trucks are rolling in to begin construction on the world's tallest dam.

Desalination: How the Middle East is dealing with its water crisis

As I touched on in my second blog, the Middle East is in a water crisis. This has been brought on by severe droughts, inefficient irrigation techniques and careless water use. I believe that there is hope for the future, due to technological advances in methods to produce more freshwater which are being employed not just in this area, but in water stressed regions throughout the world. However this remaining a privilege enjoyed by wealthier countries only remains a sad likelihood.

The following diagram shows as an example, Saudi Arabia’s renewable water capacity compared the global average. You may have to look quite hard to spot the blue bar which represents Saudi Arabia! Despite this, Saudi Arabia has the third highest use of water per capita of any country worldwide behind the USA and Canada.

Source: 2015 Case Study on Saudi Arabia. Data adapted from this website.

Large scale desalination first emerged in the mid 1950’s, although techniques were developed in the 1600s for use on boats in the event of an emergency. However, technological and material improvements over the last two decades have led to huge advances in methods of fresh water production and also increased the efficiency with which water is used. There are two commonly used desalination technologies: thermal desalination and reverse osmosis. Thermal desalination produces a vapour of fresh water, whilst the reverse osmosis method uses high pressure and a membrane to separate fresh water and salt water.

Israel is a good example of where desalination has risen to prominence over the last decade. A country that in 2004 relied solely on its limited rivers, lakes and groundwater for it’s freshwater, then suffered from the severe drought which hit the Middle East around 2007. It now produces over 55% of its domestic water from desalination plants, which make water taken from the Mediterranean Sea suitable for drinking, and actually has a surplus of fresh water.

Conventional desalination is an energy intensive and costly process. It requires countries to be wealthy and also in relatively close proximity to the sea (not too far inland or at high elevation) for it to be cost effective, otherwise it is often cheaper to transport freshwater from places where it is not a scarce resource, than to desalinate and then transport sea water (Zhou & Tol, 2005). Transport of 1600km, or an elevation of 2000m roughly matches desalination costs. Desalination Countries with only a small amount of coastline relative to overall size such as Syria and Iraq may not find the costs of transportation further inland feasible.

The high energy cost of desalination is still a limiting factor for the poorer countries. It has been estimated that around 15% of domestic oil production in Saudi Arabia goes towards desalination. If increasing fresh water demand requires more and more fossil fuel burning to fuel desalination plants then there is of course a possibility of cycle in which climate change brought on by the release of greenhouse gases leads to droughts, and flash floods which can contaminate the water supply thus decreasing fresh water reserves further (DeNicola et al., 2015). 

There are other environmental impacts to be considered too. The discharge of highly saline brine solution which often has a raised temperature, has the effect of increasing salinity of nearby ocean water by 5-10ppm and increasing the temperature by 7-8°C (Dawoud & Al Mulla, 2012). This can create an adverse environment which can be fatal for marine life.

In an attempt to counter the negative environmental effects, renewable energy is being increasingly utilised to provide the power for desalination. A great, but small- scale example of this is on the Maldivian Island of Gulhi, where excess heat from the local power generator is able to produce 10,000 litres a day for the island’s 1200 inhabitants, reducing its reliance on imported water.

The following diagram, summarises the disparity of water use between the wealthy and less wealthy nations. It shows the total water used in countries which are rich due to their abundance of oil as a natural resource greatly surpasses the amount of water which is available as a renewable resource (which does not include desalinated water). In short, rich countries can afford to overcome their natural shortage of water whilst poorer countries can not.

Source: www.carboun.com

In my opinion, this demonstrates two things. Firstly, the importance of desalination and other methods of producing fresh water, but also that many residents of the countries which cannot currently afford to build these expensive plants are condemned to a life in which water shortage is a chronic problem. Water shortages spread discontent in areas and can lead to dissent against authorities. This of course was a contributing factor in the descent to civil war seen in countries such as Syria and Yemen, and has the potential to cause more conflicts in the future.