Worried parents

In Jiangkou township, Hunan, where the study took place in 2008, parents of the children involved have expressed their concern.

"I learned about the US research paper on the Internet," said Xie Xiaohua. "I’m really scared. My daughter took part in the study and now she looks smaller than other children of the same age. I don’t know if that is related to the study."

Her daughter, Liao Ke, aged 11, was one of the more than 60 children at Jiangkou Primary School who participated in the nutrition study on the transformation of carotene in vegetables to vitamin A in children’s bodies.

According to Liao, she ate three meals for free each day at school under the program when she was 7.

"I had the meals for 15 days," she said. "But I had a fever three times at the time. My parents then asked me to quit the program."

She recalled that the program’s rice looked no different from normal rice. Golden rice is yellow.

"We also had milk and vegetables with each meal," she said, adding that the children got a blood test each week.

"We don’t know why they needed to have blood tests. But we were told by teachers that the blood would be sent to the US for testing," said Liao’s mother Xie.

The program lasted only two years.

"More children were involved in the program in 2009," Xie said.

Before the program, Xie was asked to sign an agreement with the school but she said that it did not mention GM rice.

Andrea Grossman, a public relations officer for Tufts University’s human nutrition research center on aging, was quoted by the Beijing Youth Daily as saying that the study on golden rice was approved by authorities in both countries after an examination by ethics committees.

According to Xie, some teachers at the school also took part in the program. They were given school bags, pencil boxes and free tours in the provincial capital of Changsha as a reward afterward, she said.

A teacher at the primary school, surnamed Chen, whose child was also involved in the program, said that disease control and prevention experts have started investigating the case.

"Teachers were told that the rice that children had in their meals was not genetically modified. The rice and vegetables were purchased locally," said Chen, who asked to not be fully identified.

According to Chen, the school principal was replaced after the end of the program.

"As my son participated in the program, I am expecting a thorough investigation. We should know the truth," he said.

Xie agreed and urged authorities to perform medical checks on the children involved in the study, who were then aged 6 to 8.