The study, which was published May 14, 2021, in Environmental Health Perspectives, analyzed data from a group of more than 1,000 pregnant women in Bangladesh who had been exposed to metals from multiple sources. The researchers looked the birth weight, birth length, and head circumference of the women’s newborns, and also measured the amounts of several metals—arsenic, cadmium, manganese, and lead—in umbilical cords. They found that higher levels of metal mixtures in the umbilical cords were significantly linked with smaller birth size.
Previous studies have shown that prenatal exposure to environmental chemicals can disrupt fetal growth, development, and organ function, thereby increasing the risk of diseases later in life. Most previous studies have looked only at how exposures to individual metals may affect birth size; the new study is one of a few to examine the impact of metal mixtures.