Could wastewater carry coronavirus? Expert says research needed urgently
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Could wastewater carry coronavirus? Expert says research needed urgently

Dror Avisar, head of Tel Aviv University’s Water Research Center, says that nobody knows what dangers COVID-19 might pose in streams, groundwater, beaches

Sue Surkes is The Times of Israel's environment reporter.

Untreated sewage flowing in the Kidron Stream in the Judean Desert following several days of heavy rain, November 27, 2014. (Yossi Zamir/Flash90)
Untreated sewage flowing in the Kidron Stream in the Judean Desert following several days of heavy rain, November 27, 2014. (Yossi Zamir/Flash90)

A leading Israeli expert on contaminants in water called Sunday for urgent research to be carried out into the ability of the novel coronavirus in human feces to survive in streams, groundwater, seawater and wastewater treatment facilities and on beaches.

Prof. Dror Avisar, head of Tel Aviv University’s Water Research Center, said that while there was no cause for immediate alarm, traces of the virus had been found in wastewater over the past couple of weeks in countries as far afield as Holland, China, Australia, Sweden and the US, and, more recently in Israel.

On April 17, Eau de Paris released research results confirming the correlation between the concentration of the virus in wastewater and the rate of infection among Parisians. It suggested that wastewater surveys could help predict a second
wave of outbreak.

Avisar is interested in knowing how the virus behaves in water. “I took part in a webinar two weeks ago with 1,000 water experts from 120 countries on this very subject,” he told The Times of Israel. “As of today, nobody knows what the answers are.”

Prof. Dror Avisar. (YouTube screenshot)

A team at Ben-Gurion University of the Negev reported Sunday that a new methodology of theirs had already pinpointed the virus in wastewater during the first round of sampling. They said they had found no evidence of any danger.

Avisar thinks it is essential to investigate further. “How much of the virus is whole and active and how much has been fragmented?” he asked. “Say that 15 to 30 percent of the virus that entered the water is active, then two issues arise.

“It becomes a problem in places where raw sewage flows close to human environments, or to streams, or gets into groundwater. It can form aerosols (droplets in the air).

“And in a worst-case scenario, if it lives for a few days, wildlife, such as birds and rodents, could come into contact with it. Remember that the coronavirus is zoonotic — it passed to humans from animals. Could the movement of the virus from wastewater to animals spark a second wave of COVID-19 in people? We just don’t know.”

The Dan Region Wastewater Treatment Plant (SHAFDAN) in Rishon Lezion, November 22, 2018. (Isaac Harari/Flash90)

A second area that needed research was wastewater treatment plants, Avisar continued. “We need to know whether the treatment of sewage is destroying the whole virus.”

Wastewater is treated in several stages. The first is mechanical — solids are separated and sink to the bottom by gravity. The second is biological breakdown, which relies mostly on the services of bacteria. After this, the water may be filtered and then go through disinfection; practice varies.

“Does the virus survive in water, for how long, is it active, does it survive after bacterial breakdown, and if disinfection is carried out, is it efficient? We must have the answers,” he said.

Treated wastewater irrigates crops at the Bror Hayil Kibbutz in southern Israel. (YouTube screenshot)

Israel is the world leader in wastewater recycling, processing 87% of it and using it to grow half of the country’s crops.

Effluent which has gone through the second stage of treatment can be used for fruit trees, but disinfectant is mandatory for treated wastewater used for vegetables.

Asked whether the coronavirus could enter Israel’s fruit and vegetables, Avisar, who has applied for a Health Ministry grant to carry out research, said, “It’s hard for me to believe that it’s getting into our food, but I want to know, because I can’t be certain.”

It remains unclear why Israel was not the first country to test wastewater for the coronavirus, given that it is no stranger to the practice.

View of the Bedouin city of Rahat in southern Israel, on April 8, 2019. (Moshe Shai/Flash90)

In 2013, testing around the Bedouin city of Rahat turned up traces of polio before anyone had displayed any symptoms. An immediate vaccination campaign ensured that nobody contracted the poliovirus that causes the disease.

Sunday also saw the publication of a report on the subject issued by EcoPeace Middle East (formerly Friends of the Earth Middle East), a not-for-profit organization that has been bringing Israelis, Jordanians and Palestinians together for 25 years to cooperate on projects of common environmental concern.

Its new report, on coronavirus and wastewater cooperation, notes that much sewage goes untreated or poorly treated in Jordan and in the West Bank, where it may flow down streets, enter streams — 16 of which cross into Israel — and seep into groundwater.

Streams running through Jordan, the West Bank, Israel and Gaza. (EcoPeace)

In the Jordan Valley — the agricultural heartland of Jordan, where 70% of the kingdom’s fruits and vegetables are grown — only 6% of the more than 600,000 residents are connected to a sewage system, with the rest using cesspits and with their sewage remaining untreated, the report says.

“High pollution levels have been found in the springs in the Jordan River, from the east and west banks of the river, where over a million pilgrims from around the world come to be baptized annually.”

The report calls for increased cooperation between Israelis, Palestinians and Jordanians, and for the revamping of the Middle East Consortium of Pandemic Diseases.

It urges a review of all wastewater treatment plants in Israel to ensure that efficient disinfection is being used, and says that wastewater treatment plant workers and farmers using effluent that is known not to have gone through disinfection should undergo coronavirus testing.

It says that the Jordanians and Palestinian authorities should take similar steps and should also advise owners of all homes that are not connected to sewage systems to add disinfectant to their cesspits.

And it advocates testing all cross-border streams, as well as southern Israeli beaches, particularly from Zikim to Ashdod, for any contamination by untreated or poorly treated sewage arriving in coastal seawater currents from Gaza.

A Palestinian man stands watching sewage pour out onto the beach in the central Gaza Strip on March 22, 2010. (Wissam Nassar/Flash90)

Three years ago, EcoPeace revealed that sewage from Gaza was floating northwards and forcing the desalination plant in Ashkelon, on Israel’s southern coast, to close intermittently.

“Israel changed its policy as a result and started to allow cement into Gaza to be used for the building of a modern sewage treatment plant there, ” the organization’s Israeli director, Gidon Bromberg, told The Times of Israel. Today, the enclave has three such plants, which, together, have reduced sewage flow into the sea by an estimated 40%.

Today, said Bromberg, the desalination plant operators could stop pumping seawater whenever they saw sewage build up on satellite images.

“The coronavirus pandemic is another wake-up call as to why cooperation on cross-border environment and health issues are urgent,” Bromberg said. “All of the recommendations in the EcoPeace report require decision makers to show political leadership for the sake of public welfare across the region.”

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