Did You Know?

During its 58^th annual session, the United Nations General Assembly proclaimed the period from 2005 to 2015 the International Decade for Action on water-related issues. Currently about 748 million people around the world do not have a simple way to access potable water. The number of people whose "right to water" is not satisfied is even greater, estimated to be around 3.5 billion.

United Nations Secretary General Ban Ki-moon summarizes the dilemma with water. He says, "Our indispensable water resources have proven themselves to be greatly resilient, but they are increasingly vulnerable and threatened. Our growing population's need for water for food, raw materials and energy is increasingly competing with nature's own demands for water to sustain already imperiled ecosystems and the services on which we depend. Day after day, we pour millions of tons of untreated sewage and industrial and agricultural wastes into the world's water systems. Clean water has become scarce and will become even scarcer with the onset of climate change. And the poor continue to suffer first and most from pollution, water shortages and the lack of adequate sanitation."

A delicate balance
The quality of any body of surface water or ground water is a function of both natural influences and human influences. Without human influences, water quality would be determined by the weathering of bedrock minerals, the atmospheric processes of evapotranspiration and the deposition of dust and salt by wind. In addition, there is the natural leaching of organic matter and nutrients from soil, hydrological factors that lead to runoff, and biological processes within the aquatic environment that can alter the physical and chemical composition of water.

Typically, water quality is determined by comparing the physical and chemical characteristics of a water sample with water quality guidelines or standards. Drinking water quality guidelines and standards are designed to enable the provision of clean and safe water for human consumption, thereby protecting human health. These are usually based on scientifically assessed acceptable levels of toxicity to either humans or aquatic organisms. Declining water quality has become a global issue of concern as human populations grow, industrial and agricultural activities expand, and climate change threatens to cause major alterations to the hydrological cycle.

The quality of water necessary for each human use varies, as do the criteria used to assess water quality. For example, the highest standards of purity are required for drinking water, whereas it is acceptable for water used in some industrial processes to be of less quality.

The problem of "eutrophication"
According to World Water Development Report 3 entitled "Water in a Changing World," eutrophication is the main problem with water systems everywhere. Eutrophication is defined as the increase in the rate of organic matter in an ecosystem. It is the ecosystem's response to the addition of artificial or natural substances, mainly phosphates, through detergents, fertilizer or sewage, to an aquatic system. Globally, eutrophication is the most prevalent water quality problem, as it impairs the beneficial usage of water. Domestic sewage is also a source of microbial pollution.

Pollution typically refers to "chemicals or other substances in concentrations greater than would occur under natural conditions." Major water pollutants include microbes, nutrients, heavy metals, organic chemicals, oil and sediments. Heat, which raises the temperature of the receiving water, can also be a pollutant. Pollutants are typically the cause of major water quality degradation around the world.

Lakes and reservoirs are particularly susceptible to the negative impacts of eutrophication because of their complex dynamics, relatively longer water residence times and their role as an integrating sink for pollutants from their drainage basins. Nitrogen concentrations exceeding five milligrams per liter of water often indicate pollution from human and animal waste or fertilizer runoff from agricultural areas. Every day, two million tons of sewage and other waste drain into the world’s waters. As a result, more people die from unsafe water than from all forms of violence, including war.

An emerging water quality concern is the impact of personal care products and pharmaceuticals, such as birth control pills, painkillers and antibiotics, on aquatic ecosystems. Little is known about their long-term human or ecosystem impacts, although some are believed to mimic natural hormones in humans and other species.

Global water outlook
The 2014 World Water Development Report presents a grim outlook for the future, unless people from both developed, developing and underdeveloped countries work together as citizens of the same planet.

• The growth rate of our urban areas creates more water and energy problems. More than half of the world’s population currently lives in cities. Between 2010 and 2015, almost 200,000 people will move to the world's cities daily, with 91 percent of this growth expected in cities of developing countries. Cities not only consume large amounts of water: their high concentration of industry, transport systems and buildings also demands large amounts of energy (cities consume 60-80 percent of the commercial energy). As many of the rapidly growing cities in developing countries -particularly in Africa, South Asia and China- already face problems related to water and energy, they will be major hotspots for water and energy crises in the future.
• Irrigation in agriculture accounts for 70 percent of global water withdrawals. The industrial and domestic sectors account for the remaining 20 percent and 10 percent, respectively, although these figures vary considerably across countries. In most of the world's least developed countries, agriculture accounts for more than 90 percent of water withdrawals. Without improved efficiencies, agricultural water consumption is expected to increase globally by about 20 percent by 2050.
• Regions already experiencing water stress are the same areas where population will grow even more. In 2030, 47 percent of world population will be living in areas of high water stress. Most population growth will occur in developing countries, mainly in regions that are already experiencing water stress and in areas with limited access to safe drinking water and adequate sanitation facilities.
• Water scarcity already affects more than 40 percent of people globally. By 2025 according to the Food and Agriculture Organization, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world’s population could be living under water stressed conditions.
• Humans are using up natural resources at an unsustainable rate. Around 3.5 planets Earth would be needed to sustain a global population achieving the current lifestyle of the average European or North American.

Each individual can help make a difference by practicing water conservation. And since contamination is prevalent globally, it would be wise to take preventative measures in health maintenance: eat well, exercise and keep your immune system in the best possible working order to deal with contaminants from an increasingly polluted environment.