Using wastewater for urban agriculture in Africa poses high risk of spreading bacteria
A new study revealed urban farmers growing vegetables to feed million in African cities could be accidentally helping spread disease by irrigating crops with wastewater.
According to EurekAlert, experts discovered wastewater collected from canals used for urban agriculture in Burkina Faso was rich in virulent human pathogens. This causes gastroenteritis and diarrhea, a major cause of death in low and middle-income countries.
University of Birmingham researchers led an international team from Burkina Faso, Cameroon and Germany in studying wastewater samples from canals in the capital Ouagadougou.
The study concluded that using wastewater for urban agriculture in the city posed a high risk of spreading bacteria and antimicrobial resistance among humans and animals.
“Using wastewater for agricultural irrigation represents a very serious health risk, not least as it increases exposure to faecal pathogens,” said Laura Piddock, a professor from the University of Birmingham’s Institute of Microbiology and Infection to EurekAlert. “Wastewater appears to be a 'hot spot' for antibiotic resistant bacteria in Burkina Faso."
According to EurekAlert, Piddock said we need further investigation to determine the extent in which the exposed populations are affected by the health issue. She believes there is an urgent need to improve global access to clean water, sanitation, and hygiene in low and middle-income countries to help prevent bacterial resistance spreading from the environment to people.
"Some 200 million urban dwellers are reported to be engaged in urban agriculture worldwide and, in some cases, produce up to 90% of cities' demand for perishable vegetables,” said Dr. Blaise Bougnon, from the University of Yaounde, according to UN research. “Over 80% of domestic and industrial wastewater generated in low and middle-income countries is discharged untreated into the environment. Because of its low cost, availability and nutrient content, urban agriculture relies on wastewater for irrigation."
An increasing number of bacteria are multi-resistant against the common antibiotics and cannot be treated by current therapies, according to EurekAlert. This antibiotic resistance led to a need for more expensive drugs resulting in increased morbidity and mortality.
Between 50% and 90% of antibiotics administered to humans and animals are passed as a mixture of parent drug and metabolite forms, according to EurekAlert. The forms come with significant levels of active drug ending up in the environment.
The study also found evidence in the samples of pathogens commonly responsible for waterborne diseases. Leading people exposed, directly or indirectly, to wastewater suffering from acute diarrhea, chronic gastritis, and gastroenteritis. 842,000 people die from diarrhea annual in low and middle-income countries, according to the World Health Organisation. This is stemming from inadequate water, sanitation, and hygiene.