Concerned by low iodine levels in desalinated water, Israel starts nationwide study
Hebrew University tests water supplies after Health Ministry finds iodine concentration among Israelis far below WHO-recommended levels, prompting childhood development worries
Nathan Jeffay is The Times of Israel's health and science correspondent

The rise of desalinated water in Israel means many citizens are lacking the important mineral iodine, and a new national study is setting out to assess the scale of the problem.
A team of Hebrew University scientists is starting to test levels of iodine in 50 local water supplies across Israel, driven by concern that a lack of the trace mineral is negatively impacting the nation’s health and especially children’s development.
The study is being launched just weeks after a Health Ministry survey found that iodine concentration among Israelis is much lower than the World Health Organization’s recommended concentration.
The WHO says that urine samples should have 100 micrograms of iodine per liter, while the average for Israeli adults surveyed was 60 and the average for children was 86. It considers iodine, needed in trace amounts, an “essential dietary element” which is required for the synthesis and function of two hormones in the thyroid, T3 and T4.
The Health Ministry raised concerns that its findings could be an indicator of harm to children’s cognitive and mental development and decided to start advocating for legislation that will require table salt to be enriched with iodine as it is in several other countries.
Prof. Yona Chen, who is leading the Hebrew University study, told The Times of Israel: “We’re worried because around 80% of drinking water in Israel is now desalinated, which we know reduces calcium levels, and this can impact humans. Also, according to our testing, mineral water has low levels.”

“But iodine is very important to humans because the metabolism is controlled to a significant extent by iodine. It’s essential for the thyroid and for other hormonal activities,” he said.

He said that iodine is one of several minerals that is low in desalinated water, but the precise levels have been studied less than others.
Chen said: “Calcium has been researched properly and is controlled by the government, with procedures for increasing calcium in desalinated water. Magnesium is also reduced by desalination and has been researched, though additions of magnesium are not yet required. Iodine levels are less understood, and there is no solution in place for increasing iodine levels.”
The new national study will make use of an electronic device for testing iodine levels developed by Chen’s lab, which he said is more accurate than most existing devices. The study will take around six months, and he hopes that it will provide statistics that advance policy discussion on iodine, and possibly encourage a solution that boosts the nation’s iodine levels.