New Delhi, Jan. 19: Iodised salt has led to dramatic improvements in the intelligent quotients of an entire generation of children living near the foothills of the Himalayas but the anti-iodisation lobby is still active, a senior doctor has said.

The IQ levels of school children in Gonda district in the Terai region of the Himalayas are far higher today than what they were in the 1980s, an era before edible salt was iodised, Dr N. Kochupillai, the former head of endocrinology at AIIMS, said.

The government had banned the sale of non-iodised salt in 1986 and universal iodisation had been achieved by 1990.

Iodine deficiency leads to goitre, mental retardation and cretinism. “It’s important to recognise the dramatic impact that iodised salt has had as the anti-iodisation lobby is at work again,” Kochupillai said.

“It’s worrying. These groups are pressuring state salt commissioners to allow priority rail transport of non-iodised salt.” Under existing rules, only iodised salt gets priority.

Lack of iodine at birth and in childhood leads to hypothyroidism, a condition that can impair the growth of the brain and body. Salt iodisation is expected to compensate for the lack of iodine through diet.

Medical teams visiting Gonda in the mid-1980s had detected high levels of mental retardation among children. Doctors revisited the schools in 2001.

Among 60 children studied in 1986, doctors found 23 per cent with IQ lower than 70, a value that classified them as mentally retarded. In 2001, not a single child in a group of 60 was mentally retarded. The incidence of children with low and below average IQ had dropped from 33 per cent in 1986 to 8 per cent in 2001. The proportion of children with above average IQ rose from 1 per cent in 1986 to 16 per cent in 2001.

“We can see the transformation in their faces,” said Manju Mehta, a psychiatry professor at AIIMS. “There have been changes in reasoning and arithmetic abilities, too.”

In 2000, the then government had revoked the ban on the sale of non-iodised salt. But, after persuasion by the medical community, the present government has again banned the sale of non-iodised salt.