20 August 2019: A World Bank report on global water quality finds that poor water quality is costing nations more than previously thought. It highlights that in middle-income countries, GDP growth falls by half in areas downstream of highly-polluted water bodies. The report also disputes 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 knock-on effects are limiting economic growth and causing serious health impacts on children. Improvements or change to water quality are not part of a “natural” economic cycle, but rather an outcome of citizen action.

The report, titled ‘Quality Unknown: The Invisible Water Crisis,’ relates to SDG target 6.3 on wastewater treatment, which is associated with three indicators: nitrogen, which relates to use of agricultural fertilizers; electrical conductivity, which is a measure of salinity in water; and biological oxygen demand (BOD), a proxy marker for 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, with microplastics and pharmaceuticals noted as pollutants of emerging concern.

The authors have applied a methodology for determining the downstream impacts of water pollution and the implications for child health and economic growth. They draw on the UN Environment Programme (UNEP) GEMState water quality database, which contains more than 3.3 million observations of water quality from 72 countries, for 224 different parameters. These observations are combined with other available data, and machine learning has been applied to understand trends.

The authors note that the range of pollutants tends to expand with prosperity, with more than 1,000 chemicals being newly released into the environment each year in the US alone, equivalent to around three new chemicals each day, posing a monitoring challenge even for well-resourced governments. The report highlights “great uncertainty” in defining safe levels of concentration of pollutants, and suggests that these may be lower than previously believed.

The report highlights “great uncertainty” in defining safe levels of concentration of pollutants.

Nitrogen, applied as fertilizer, turns into nitrates in the water, which in turn is linked with ‘blue baby syndrome’ due to a lack of oxygen at birth. Other impacts are childhood stunting and loss of earning opportunities in life. Whereas each additional kilogram of nitrogen produces 5% more crop, it also results in 19% more childhood 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 patterns, reduces the world’s ability to grow food. Furthermore, pregnant women exposed to high levels of salt are more likely to develop hypertension and experience miscarriage.

The authors recommend: measuring water quality and making the information publicly available; preventing pollution where possible through improving regulation and ensuring transparency; and treating water pollution where necessary. They highlight the possibilities of new technology such as; satellite data that can now provide information at finer scales than before; ‘smart contracts’ that would have rules embedded in a blockchain that automatically require payments from polluters; and machine learning to detect patterns and trends in water quality that may otherwise go unnoticed.

The report warns that investing in infrastructure for wastewater treatment alone will not be sufficient to improve water quality. Good governance, lack of corruption, accurate monitoring, effective enforcement, incentives for private investment, good land use policies and civic engagement are also important. It concludes that, while water quantity problems generally receive more attention from the development community, the impacts of poor water quality may be more severe, constituting an ‘invisible crisis.’ [Publication: Quality Unknown: The Invisible Water Crisis]