In August 2014, an incident in Lake Erie, Ohio left almost half a million people without drinking water when the Mayor of Toledo was forced to ban city drinking water due to above-average levels of toxins found in the water supply.
These toxins, called microcystins, were produced by a type of blue-green algae which occurs naturally in Lake Erie and is mostly harmless. But when toxins are released, they can exist for weeks or even months, according to the U.S. Environmental Protection Agency (EPA).
UNEP, through the Global Partnership on Nutrient Management (GPNM), is identifying ways to reduce the amount of excess nutrients in the environment without hindering global development. It reflects a need for strategic, global advocacy to trigger governments and stakeholders to move towards more efficient use of nitrogen and phosphorous. It provides a platform for governments, UN agencies, scientists and the private sector to forge a common agenda, mainstreaming best practices and integrated assessments, so as to effectively 'nutrient proof' policy making and investments.
Consuming microcystis can be deadly ? it has been known to kill dogs and livestock, and can cause abnormal liver function, diarrhea, vomiting, and other symptoms in humans.
The harmful algal blooms were common in Lake Erie between the 1960s and 1980s, but after a 20-year hiatus, the blooms have been increasing over the past decade, according to National Oceanic and Atmospheric Administration (NOAA).
In the case of Lake Erie, the algae thrives on an overabundance of phosphorous due to run-off fertilizer, failing septic tanks and power plant emissions contaminating the water system, according to the Ohio Environmental Protection Agency.
The problem is by no means unique to Lake Erie. The EPA defines these blooms as a 'major environmental problem' in all 50 states. The last EPA National Lakes Assessment noted that out of more than 123,000 lakes greater than 10 acres in size spread across the U.S., at least one-third may contain the toxic algae.
The scale of the problem is compounded by the fact that modern day societies rely heavily on the use of considerable amounts of phosphorous, with half the world's food security depending on nitrogen and phosphorous and their use in fertiliser to grow crops.