August 20, 2019: World Bank report on global water quality reveals poor water quality costs nations more than previously thought. He points out that in middle-income countries, GDP growth halves in areas downstream of heavily polluted water bodies. The report also challenges the Kuznets curve theory that environmental conditions will improve as wealth increases. It shows that while the type of water pollution changes with economic development, the spillover effects limit economic growth and have serious repercussions on children’s health. Improving or changing water quality is not part of a “natural” economic cycle, but rather the result of citizen action.
The report, titled ‘Unknown quality: the invisible water crisis, “Concerns SDG target 6.3 on wastewater treatment, which is associated with three indicators: nitrogen, which relates to the use of agricultural fertilizers; electrical conductivity, which is a measure of the salinity in water; and biological oxygen demand (BOD), a proxy marker of general water quality. Globally, more than 80% of wastewater is discharged without treatment, while in developing countries this figure is closer to 95%. Common water pollutants studied in the report are fecal contaminants, chemicals and plastics, microplastics and pharmaceuticals being considered emerging pollutants.
The authors applied a methodology to determine the downstream impacts of water pollution and the implications for children’s health and economic growth. They are based on the United Nations Environment Program (UNEP) GEMState water quality database, which contains over 3.3 million water quality observations from 72 country, for 224 different settings. These observations are combined with other available data, and machine learning has been applied to understand the trends.
The authors note that the range of pollutants tends to widen with prosperity, with more than 1,000 new chemicals released into the environment each year in the United States alone, which equates to about three new chemicals each day, which poses a monitoring challenge, even for those with sufficient resources. Governments. The report highlights a “great uncertainty” in the definition of safe levels of pollutant concentration, and suggests that these may be lower than previously believed.
The report highlights “great uncertainty” in the definition of safe levels of pollutant concentration.
Nitrogen, applied as a fertilizer, turns into nitrates in the water, which in turn is linked to “blue baby syndrome” due to a lack of oxygen at birth. Other impacts are childhood stunting and loss of income opportunities in life. While each kilogram of additional nitrogen produces 5% more harvest, it also results in 19% more child stunting and up to 2% less adult income. In the air, nitrogen can become nitrous oxide, a greenhouse gas. Meanwhile, increased salinity, caused by excessive water extraction, sea level rise and changes in weather conditions, is reducing the world’s ability to produce food. In addition, pregnant women exposed to high levels of salt are more likely to develop high blood pressure and miscarry.
The authors recommend: measuring water quality and making information accessible to the public; prevent pollution where possible by improving regulation and ensuring transparency; and treatment of water pollution if necessary. They highlight the possibilities of new technologies such as; satellite data which can now provide information at finer scales than before; “smart contracts” that have rules embedded in a blockchain that automatically require payments from polluters; and machine learning to detect patterns and trends in water quality that might otherwise go unnoticed.
The report warns that investing in wastewater treatment infrastructure alone will not be enough to improve water quality. Good governance, absence of corruption, accurate monitoring, effective enforcement, incentives for private investment, good land use policies and civic engagement are also important. He concludes that, while water quantity issues generally receive more attention from the development community, the impacts of poor water quality can be more severe, constituting ainvisible crisis“. [Publication: Quality Unknown: The Invisible Water Crisis]