The Nile is one of the most iconic rivers in the world and in ancient times it gave rise to a unique civilization that lasted several millennia. However, its delta, once the heart of Lower Egypt, could soon lose any recognizable shape, scientists warn.
“Large-scale heavy metal pollution, coastal erosion and seawater intrusion pose an existential threat to the Nile River Delta and endanger Egypt’s 60 million people, who depend on its resources for all facets of life.”, say Egyptian and American experts from USC Viterbi. University of Southern California School of Engineering, who published their findings in a new study .
“The impact of pollution is especially pronounced in Egypt, the most populous and arid nation downstream of the Nile, which depends entirely on the river as its sole source of water for drinking and irrigating crops. The country is currently facing one of the largest water budget deficits in Africa, after decades of compensating for dwindling water supplies with large-scale and intensive reuse of wastewater, the consequences of which have so far been little studied.”, explain the scientists.
The Nile’s biodiversity in danger
The delta’s biodiversity is also at risk, they say, and among the species facing serious threats are the migratory birds that use the area as a stopover on their journey along the East African Airway.
The researchers came to this conclusion after analyzing the levels of contamination with eight heavy metals in sediment samples collected from the bottom of two branches of the Nile River delta and found that the samples were highly contaminated by toxic heavy metals, especially cadmium, nickel. , chromium, copper, lead and zinc.
These pollutants, they say, derive mainly from untreated agricultural sewage, municipal waste and industrial wastewater. “Without proper treatment of recycled water, heavy metal concentrations increase and become permanently encrusted in the riverbed, unlike organic contaminants that naturally degrade over time.”, they explain in a statement about their findings.
“Heavy metal concentrations can be exacerbated by rising dams on the Nile. Mega-dams built upstream disrupt the river’s natural flow and sediment flow and therefore negatively affect its ability to expel pollutants into the Mediterranean Sea, allowing toxins to build up in the bottom sediments over time.“, they keep going.
Heavy metal contamination is irreversible
Alarmingly, much of this heavy metal contamination is irreversible. However, science-based conservation measures could alleviate environmental degradation and restore the Nile Delta ecosystem to relatively healthy levels.
“Worsening water stress and rapid population growth in Egypt, which exceeds 100 million, has placed local authorities in the dilemma of providing enough fresh water for the thirsty agricultural sector to secure food supplies through agricultural water reuse drainage without treat or preserve the health of the Nile River,” says Abotalib Z. Abotalib, postdoctoral researcher at USC Viterbi and co-author of the study. “The balance is challenging and the consequences of both options are measurable”.
Unless decisive action is taken, the implications of heavy metal pollution will be dire for all people who depend on the delta’s water and biodiversity, emphasizes Essam Heggy, an Egyptian rocket scientist who was another of the study’s authors. .
“You have roughly the combined populations of California and Florida living in a space the size of the state of New Jersey that is increasingly contaminated with toxic heavy metals. Today, the civilization that thrived on a scenic waterscape for over 7,000 years must face the reality of this large-scale, irreversible environmental degradation.says Heggy.
More research on Nile water recycling
“Our study underscores the need for more research on the environmental impacts of recycling untreated water and the change in river turbidity due to increased damming upstream of the Nile.” “Continued research with more sampling campaigns in this area may inform future conversations and collaborations among the nations of the Nile River basin, who have a common interest in maintaining a healthy Nile River system.“.