Deadly Diarrhea Caused By Wastewater Irrigation Of Crops

The use of wastewater to irrigate crops is exposing children in Asia to a high risk of rotavirus infection and other deadly disease, scientists say.

AsianScientist (Mar. 13, 2014) – Researchers have identified that the use of wastewater to irrigate vegetable crops, which is common across developing countries, may significantly contribute to deadly health risks such as rotavirus, a major cause of diarrheal diseases.

Diarrheal disease is the second leading cause of death globally. More than 99 percent of deaths of diarrheal disease occur in developing countries and 90 percent of these are in children under five.

The research focused on the Beijing region and found that the risk posed to children eating vegetables grown with wastewater far exceeded the World Health Organization (WHO) acceptable level.

According to the study, carried out by University of Melbourne researcher Dr Andrew Hamilton and colleagues, the use of wastewater in irrigation is a critical health issue because microorganisms in the wastewater can be transferred from infected people, travel through the sewerage system, and then be eaten from the vegetables.

The study, published in the journal Risk Analysis, also found that some vegetables posed greater risk than others.

“This was due to leaf shape, which affects the amount of wastewater and contaminants that are retained. Choy sum poses the greatest risk, while bok choy poses the least risk,” said Dr Hamilton. “There is more wastewater irrigation in China than in the rest of the world combined. Much of this is used growing vegetables.”

Dr Hamilton explained that similar situations exist across Asia and other developing countries, and this is where the risk posed by diarrheal diseases is highest.

“Vaccination programs for rotavirus are being rolled out globally, but at this stage, they are far from reaching all children in developing countries. When vaccinations cannot be relied upon to stop the spread of rotavirus and other diarreal diseases, research like this is very important to identify other contributing causes.”

The article can be found at: Mok and Hamilton. (2014) Exposure Factors for Wastewater-Irrigated Asian Vegetables and a Probabilistic Rotavirus Disease Burden Model for Their Consumption.

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Source: University of Melbourne; Photo: AnthonyGurr/Flickr/CC.

Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

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