Israel's Desalinated Seawater Could Be Contributing to Thyroid Disorders, Study Says

Study finds correlation between iodine deficiency and thyroid disorders among residents who have been drinking iodine-free desalinated water since 2011.

This is the sort of water technology most often associated with Israel: At the IDE and Veolia Sea Water Reverse Osmosis Desalination Plant in Ashkelon.
Eitan Simanor / Alamy Stock Photo

A new study has found a correlation between a rise in thyroid disease and iodine deficiency in the Ashkelon region, where desalinated seawater became the source of drinking water in 2011.

The Hebrew University researchers who conducted the study in cooperation with the Barzilai Medical Center believe there is insufficient consumption of iodine in Israel, particularly in areas where desalinated water, which lacks iodine, is used.

Study participants underwent clinical testing and answered questions about their diets. The study did not compare the incidence of thyroid disorders in the Ashkelon area with areas where the drinking water is not desalinated and iodine consumption is higher.

According to lead researcher Dr. Aron Troen, Principal Investigator of the Hebrew University Nutrition and Brain Health Laboratory at the Institute of Biochemistry, Food Science and Nutrition, nutritional habits in Israel, where iodine is not added to salt, contribute to the iodine deficiency.

“In Israel today there are areas that get up to 100 percent of their drinking water from desalinization and at the national level we are talking about 60 percent of domestic water consumption,” says Troen.

“The use of more and more desalinated water could decrease the amount of iodine consumed over time.” Iodine deficiency he adds, is not only a result of drinking desalinated water: “Desalinated water is also used in agriculture for watering plants and animals and for industrial processing of food products.”

Inadequate iodine intake can lead to thyroid diseases, including nontoxic goiters and even developmental disorders. Even less severe deficiencies are associated with hyperthyroidism, hypothyroidism and thyroid cancer. However, excess consumption of iodine can also be detrimental to health.

Desalinated water accounts for about two-thirds of domestic water consumption in Israel today. The five desalinization plants along the country’s Mediterranean coast are based on the operation of membranes that get rid of the salt, which is then sent back into the sea. The plant in Ashkelon was the first to have become operative, at the beginning of the last decade. The use of the desalinization plants enables Israel to cope with the sequences of drought years characteristic of the Middle East and to decrease its dependence on fresh water from the Sea of Galilee and underground aquifers.

The current study was undertaken at the initiative of doctoral candidate and nutritionist Yaniv Ovadia of Barzilai Medical Center, and was limited in scope. It was carried out on a sample of about 70 subjects aged 21 to 80 recruited at Barzilai, half of whom have thyroid disorders. The findings showed a correlation between iodine consumption and thyroid gland functioning.

Troen notes that if more extensive studies confirm that there is indeed a correlation between under-consumption of iodine and its low concentration in desalinated water, this will have extensive implications for increased reliance on desalinized water worldwide.

“The significant iodine deficiency that has been observed underlines the essential need to carry out a national iodine survey in a representative sample of Israel’s population and formulate a public health policy with regard to this important issue,” Troen said.

Such surveys have been conducted in 97 percent of the countries of the world.