One-tenth of all birth defects in Jiangsu, one of the mainland’s richest provinces, are caused by environmental pollution, and half of the remaining cases are at least partly related to the environment, according to a five-year medical study in 13 cities.
From 2001 to 2006, the number of birth-defect cases on the mainland rose by 50 per cent to 1.2 million, but there has been no large-sample study to explain why it happened. The biggest data pool on the issue was amassed by the Jiangsu Birth Defects Intervention Programme, which tracked more than 26,000 pregnant women from 2001 to 2005.
The team, led by Hu Yali of Nanjing University, will receive the Chinese Medical Science and Technology Award in Beijing today for its findings, the Chinese Medical Association confirmed yesterday.
Researchers found the most prevalent defect was congenital heart disease. The disease, closely related to air pollution, is often fatal and difficult to detect. The situation is particularly severe in some hospitals lacking proper equipment and trained staff.
Cleft lip was the second-most-common condition and also related to air pollution. Unlike heart disease, the defect can be detected by ultrasound and is not fatal, but many parents chose to abort fetuses with the condition, fearing that it might lead to some other, more severe defects.
The third most frequently reported disease was congenital hydrocephalus, or excessive fluid in infants’ brains, which, according to some overseas studies, is sometimes a result of vehicle exhaust emissions.
“Birth defects have become the single biggest killer of mainland infants,” Dr Hu was quoted by the Nanjing Morning Post as saying.
Jiangsu’s defect rate, about 1 per cent, is about one-sixth of the national average. In poorer provinces, or areas with heavy industry, the figure is much higher. But mainland studies about the relationship between the environment and birth defects have been limited.
A 2007 study carried out in Taiyuan , capital of coal-rich Shanxi , showed that the abundance of small particles in the air, a major contributing factor to the mainland’s air pollution, was a significant reason for miscarriage, birth defects and neonatal deaths.
A study by the Shenzhen Maternal and Child Health Institute last year found that the city’s birth-defect rate was higher than the national average, indicating that birth defects did not necessarily go down as income increased. Urban dwellers typically make more money than people outside cities.
Health education was an effective way of countering the problem, the Jiangsu study found. The children of workers, farmers, poorly educated people and low-income groups were the most at risk of birth defects, the study said.
A programme involving more than 3,000 families in the province showed that even simple education about precautionary measures could dramatically increase would-be parents’ awareness of the dangers, helping doctors make correct diagnoses and take preventive measures.
The mainland was in desperate need of key intervention technology and standardised practice, Dr Hu said. In one district of Wuxi , only 15 couples took premarital medical tests in 2005 after the government abandoned mandatory testing – a change that raised the risk of birth defects. Medical personnel also needed better education and training, the study said.