The tsunami and nuclear disaster in Fukushima, Japan, now threatens the developing brains of children in Cambodia – but not for reasons that were ever expected.Cambodia has long struggled with iodine deficiency. The element is crucial to early brain growth: When pregnant women and their infants have low levels, the children can permanently lose 10 to 15 IQ points. Iodine deficiency is considered the world’s leading preventable cause of mental impairment.

But there is a cheap, easy remedy: iodised salt. As salt is cleaned and packaged, potassium iodate may be sprayed on it, normally at a cost of only a dollar or two per tonne.

That means, nutrition experts say, that the IQ of entire nations can be raised 10 points for just a nickel per child per year.

Cambodia was making great progress against iodine deficiency until 2011, according to a report published in 2015 by the Iodine Global Network, a public-private partnership combating the deficiency.

Like many countries with regular flooding, Cambodia’s soil has little natural iodine, so its crops also contain little. In 1997, according to Unicef, almost one-fifth of its population had goiters – swollen thyroid glands in the neck that indicate serious deficiency, which can also cause dwarfism and cretinism.

In 1999, with help from donors, Cambodia began iodising table salt. In 2003, the National Assembly and King made it mandatory. Dozens of small producers in Kampot and Kep provinces who made salt by evaporating seawater formed a cooperative that was given potassium-iodate spraying machines.

From 2000-2011, use of iodised salt rose to 70 percent from 13 percent of households, according to a 2015 study in the journal Nutrients. Market sampling in 2008 found only 1 percent of salt with no detectable iodine.

But then things began falling apart.In 2010, Unicef and other donors turned responsibility for iodination over to the government and salt producers. Enforcement grew lax, and spraying machines that broke went unrepaired, according to a recent VOA News report.

Then in 2011, after the earthquake and tsunami in Japan, the global price of iodine tripled. The price increase had multiple causes, said Roland Kupka, a Unicef micronutrients expert.

Global iodine stocks were already low because of the 2008 recession. One-third of the world’s iodine is produced by Japan’s natural gas drillers, who extract it from brine pumped from coastal wells.

The catastrophe damaged wells, set refineries ablaze and sharply cut electricity output. Adding to the problem, the release of radioactive iodine from the Fukushima nuclear reactor set off panic buying of protective potassium iodide pills, especially in the western US. Prices briefly reached 50 times their normal levels.

Raw iodine prices remained high for two years, forcing the Indian companies that make potassium iodate to plead for donor help. Iodine is also used in X-ray machines, LCD screens and pharmaceuticals. Iodised salt accounted for only a tiny market share, so producers could not match other buyers’ bids.

The whole global iodination effort “may be put in jeopardy unless action is taken”, a 2011 report prepared for Unicef said.

High prices also wreaked havoc on Cambodia’s salt industry. Noniodised salt from Vietnam was half the cost, so it was smuggled in. Salt meant for the Kampot co-op was sold without iodination.

Some wholesalers who were supposed to test salt before repackaging it for retailers stopped doing so.

In 2014, scientists from Unicef and Cambodia’s planning ministry tested 1,862 salt samples bought at dozens of markets. They found that only 1 percent of coarse salt and 23 percent of fine salt met government standards.

But monthly reports from the salt co-op said that over 90 percent of its samples did. “We can be sceptical of the legitimacy of the internal control,” the Unicef report said.

A quick test of 2,300 schoolchildren showed that iodine concentrations in urine had dropped by roughly 30 percent since 2011, and that the problem “threatens the program’s sustainability”, the authors concluded.

Unicef is urging the government to enforce its own laws and do better testing, Kupka said, and the Kampot co-op has set up a fund to buy potassium iodate in bulk.

There is still time to save children from permanent damage, said Jonathan Gorstein, executive director of the Iodine Global Network.

“The thyroid is a pretty efficient gland at storing iodine,” he said, so it can take five to 10 years of deficiency before goiters and brain damage return.

That happened in Ethiopia, he said. Until 2000, the nation bought naturally iodised salt from Eritrea, but fighting between the two countries cut off that trade and Ethiopia starting mining its salt flats, which had no iodine.

After about eight years, “a generation of newborns with no protection against mental retardation was born”, Gorstein said.

In 2011, Ethiopia tackled the problem. With donor help, it got spraying machinery and began enforcing iodination standards on industry.

Now, 80 percent of its households use iodised salt. “What we really want to avoid,” Gorstein said, “is this pattern in which success leads to backsliding.”

Donald G McNeil

The new york times