As if the Nile River isn’t already affected by enough climate and regional geopolitical pressure, now there’s a new report on how heavy metal toxicity may be causing irreversible damage to its waters.

Scientists with the Viterbi School of Engineering at the University of Southern California found that the impacts of pollution are most pronounced in Egypt, where the Nile is a key source of drinking water and agricultural irrigation. Sediment at the bottom of the Nile holds heavy metals like cadmium, nickel, chromium, copper, lead and zinc. 

Untreated wastewater and agricultural water contribute to the problem, as does increased damming on the river. “The river flow is no longer strong enough to carry out these metals to the sea and hence, they sink to the bottom sediments causing irreversible pollution,” the authors explain.

The researchers, who published their work in the American Geophysical Union journal Earth’s Future, warn that in addition to humans, the pollution levels have the potential to affect migratory birds that travel the Nile River, part of which (the Blue Nile) runs through Sudan and Ethiopia as well as Egypt.

The authors say that despite the accelerated pollution because of these processes, especially in the Nile Delta, there are conservation measures that can help to reverse degradation.

“Yet the increasingly engineered Nile flow, the low gradient of the delta and the active silting impede heavy metal flushing,” they said.  “Our findings alarm future increase in heavy metal pollution in response to increased untreated drainage water reuse.”

The authors call for international cooperative agreements for integrated water management along the Nile River.

Image: NASA