Scientists reveal public health risks with desalination

Scientists in Israel have, in separate studies, unveiled two potential public health hazards associated with consumption of treated reclaimed or desalinated water according to a report in the Times of Israel.

Researchers at the Hebrew University of Jerusalem and Hadassah Medical Centre found that that vegetables and fruits grown in soils irrigated with reclaimed wastewater contained minute quantities of pharmaceuticals. And they revealed a link between raised death rates in cardiac disease patients who have been exposed to desalinated water supplies.

One study, found traces of anti-epileptic drug, carbamazepine, in the urine of a test group of 34 men and women who, for one week, had eaten crops that had been irrigated with reclaimed water the newspaper reported. The test group had shown negligible levels of carbamazepine in their systems prior to the week of the test.

The second and ongoing study at Bar-Ilan University and Tel Hashomer Hospital has linked the lack of magnesium in desalinated water and raised death rates in cardiac patients reported the Times of Israel. The finding was based on 4,700 cases in a long- term study run between 2002 and 2013.

Desalinated water now accounts for three quarters of the nation’s drinking water.

Leader of the first study, Professor Ora Paltiel said: “Though the levels [of carbamazine] detected were much lower than in patients who consume the drug, it is important to assess the exposure in commercially available produce,” The researchers recommended further investigation work into the treatment technology. They said it was possible that other pharmaceuticals could be present in recycled water that could be more hazardous than carbamazepine.

The researchers in the second study looked at the death rates among cardiac patients between 2002 to when desalinated water first entered Israeli water supplies in 2006. And it continued the study from 2006 to 2013.

The results showed that there was a “strong correlation” between higher death rates and desalinated water. Scrutiny of the 211 patients in areas supplied with desalinated drinking water showed that they had much lower levels of magnesium than patients ares where supplies were not desalinated.

The Times of Israel said Israel’s health ministry was aware of the magnesium issue having predicted in 2010 that the annual death toll among cardiac patients supplied with desalinated drinking water would be about 250 and recommended the addition of magnesium to desalinated water. But the finance ministry block the proposal on the grounds of its projected NIS 350 million-a-year (US$93 million) cost.

The researchers were reported to be hoping that their findings would generate d public pressure on officials to add magnesium and other essential minerals to desalinated water.