Two villagers stand in front of a cement plant in Hengdong county in 2014.[YANG YI/CHINA DAILY]

According to the national health authority, excessive levels of lead in the blood can cause long-term damage to a child's intellectual development, and nervous and digestive systems, and can lead to anemia and cardiovascular disease.

"In China, courts have no standard way of qualifying how much damage has been caused to a child's development (by pollution), so it's difficult for them to come up with a compensation figure," Dai said.

He said the independent teams that courts use to provide research or context on an issue (these can be university institutes or companies) are not allowed to advise on the link between pollution and health damage. This would need to be approved by the Supreme People's Court.

In the United States, courts take into consideration the short - and long-term effects on a plaintiff's studies, employment and relationships when deciding compensation, Dai added, "but in our country there is no such practice."

Wang Canfa, a law professor at the China University of Political Sciences and Law who works with the Center for Legal Assistance to Pollution Victims, said the lack of guidelines to determine what affect pollution has had on a person's health has led not only to low compensation payouts, but also some cases have been lost while others have not even made it to court.

Many professionals are unwilling to even do research on the link because such studies are lengthy and expensive, he added.

Wang Zhenyu, an attorney specializing in environmental disputes, represented a similar case to Dai's in the northwestern province of Gansu. He is not confident the compensation issue can be fixed soon and suggested local governments set up special funds to help people affected by pollution.

"We have many ways to solve disputes, not only lawsuits," he said. "We can take advantage of administrative measures to initially provide aid to victims."