Large-scale heavy metal pollution, coastal erosion, and seawater intrusion pose an existential threat to the Nile Delta and endanger the 60 million people (about twice the population of Texas) in Egypt who depend on its resources for every aspect of life, according to a new report. Research from USC Viterbi School of Engineering. Moreover, the Nile Delta is an important stopover for migratory birds during their journey along the East African Flyway.
The study, led by Issam Heggy of the USC Viterbi Innovation Fund, Arid Climates and Water Research Center, was published Tuesday, March 7, in the Journal of the American Geophysical Union (AGU). Earth’s future.
The impact of pollution is particularly evident in Egypt, the most populous and driest country downstream of the Nile, which relies entirely on the river as its sole source of drinking water and crop irrigation. The country is currently facing one of the highest water budget deficits in Africa after decades of compensating for dwindling water supplies through extensive and extensive reuse of wastewater, the consequences of which have yet to be studied.
“You have roughly the entire population of California and Florida living in an area the size of New Jersey, which is increasingly polluted by toxic heavy metals,” Heggie said. “Today, a civilization that has thrived in a picturesque aquatic landscape for more than 7,000 years must face the reality of this large-scale and irreversible environmental degradation.”
For the study, researchers from the United States and Egypt analyzed grain size and contamination levels of eight heavy metals in bottom sediment samples collected from two branches of the Nile River Delta. The main findings included:
Sediments at the bottom of the Nile River are heavily contaminated with heavy metals such as cadmium, nickel, chromium, copper, lead, and zinc.
The pollutants mainly come from untreated agricultural drainage and municipal and industrial wastewater. Without proper treatment of recycled water, concentrations of heavy metals increase and become permanently incorporated into the river bed unlike organic pollutants that naturally degrade over time.
Concentrations of heavy metals could be exacerbated by increased damming of the Nile River. The huge dams built upstream disrupt the river’s natural flow and sediment flow, thus negatively affecting its ability to flush pollutants into the Mediterranean Sea, leaving toxins to build up in bottom sediments over time.
Much of the heavy metal pollution is irreversible, the researchers said, but the science-based conservation measures proposed by the study could slow environmental decline and hopefully restore the Nile Delta ecosystem.
“The worsening water stress and rapid population growth in Egypt, which has reached more than 100 million people, has put local authorities in a dilemma whether to provide enough fresh water to the agricultural sector starved to secure food supplies by reusing or conserving untreated agricultural drainage water,” he said. Abu Talib Z. Abu Talib, postdoctoral researcher at the University of Southern California Viterbi and co-author of the study, “Health of the Nile River.” “The balance is tricky, and the outcomes of both options are measurable.”
“Our study confirms the need for more research on the environmental impacts of recycling untreated water and the change in river turbidity in light of the increased dam construction on the Nile,” Hajji said.
“Ongoing research with more sampling campaigns in this region could inform future conversations and collaborations between the Nile Basin countries, who have a common interest in maintaining a healthy Nile system.”