China's Health Ministry announced on Thursday that the iodine content in salt will be reduced next year, in response to recent public concerns about excessive iodine intake.

The iodine volume in salt, currently 30-mg iodine per kg of salt, will be lowered nationwide but provincial health authorities will have the discretionary power to adapt the level to local demand, said a statement put on the ministry Web site on Thursday.

The statement did not reveal how much would be reduced nationwide.

The ministry started the research of reducing iodine content in salt in 2007 and worked out a plan last year, the statement said.

Now the plan has been filed to the country's Committee of Food Additives and later on to the Standardization Administration for evaluation. It will be unveiled in the first half of 2010, the statement said.

In response to recent arguments from media and medical experts that some regions in the country reported excessive iodine intake, the ministry said, based on several surveys it conducted since 2007, the overall iodine intake across China was at an appropriate level. But it admitted a few areas suffered excessive intake.

The World Health Organization (WHO) recommended 150-300 mg of daily intake of iodine for an adult.

Assuming the average salt intake per capita is 5-10 g, the same assumption WHO is based on, the daily iodine intake per capita would be 150-300 micrograms with the current iodine content in salt, the ministry said in the statement.

Since 1996, iodine has been added in salt across the country as in most part of the country people could not take in enough iodine from their normal diet.

However, the one-size-fits-all program is being questioned.

Prof. Cui Gonghao, with the Medical School of Zhejiang University, told Wednesday's Chongqing Evening News that residents in coastal provinces have easier access to iodine-rich diet.

"The national standard might be too high for them," he said.

But the ministry statement said about 91.4 percent of people living in iodine sufficient areas have been cut off from the iodized salt supply.

By October 2008, iodized salt was not available in 82 counties of six provinces such as eastern Shandong and Jiangsu provinces, with a population of 28.31 million, it said.

Both iodine deficiency and excessive intake might lead to thyroid diseases.

China has devised a surveillance system over iodine deficiency since 1995.

Five nationwide IDD survey from 1995 to 2005 showed incidence of goitre among children between 8 to 10 reduced from 20.4 percent in 1995 to 5 percent in 2005.

Still, 5 to 10 percent of population have no access to standard iodized salt, the ministry said.

(Xinhua News Agency August 14, 2009)