A senior family planning official in China has noted an alarming rise in the number of babies with birth defects.
Jiang Fan, from the National Population and Family Planning Commission, said environmental pollution was the cause of the problem.
A Chinese newspaper reports that she said a child was born with physical defects every 30 seconds because of the degrading environment.
The commission has introduced a screening programme in the eight worst-affected provinces.
The report in the China Daily newspaper said Shanxi province, which is rich in coal, had the highest rate.
The commission blamed emissions from the region's large chemical industry for the problems there.
The BBC reports researchers also blamed exposure to nitrogen dioxide, carbon monoxide and particulates for the increase.