Marjorie Aelion, dean of the School of Public Health and Health Sciences at the University of Massachusetts, and colleagues at the Medical University of South Carolina recently conducted a study attempting to find possible connections between exposure to heavy arsenic levels in pregnant women and developmental delays in their children.

The study, published in the Jan. 8 edition of International Journal of Hygiene and Environmental Health, suggests there is a significant relationship between soil levels of arsenic and cases of mental retardation and developmental delay.

According to the study, the cause remains unknown for 50 percent of individuals suffering from mental handicaps, and the causes that are known are not well understood. The study hypothesizes that the prevalence of heavy metals such as arsenic in soil may contribute to a greater percentage of cases than previously assumed.

The researchers used an inexpensive statistical approach to gather information. Instead of using blood and urine samples from subjects, the researchers used data from medical records to gather the study’s population, excluding children with identified genetic causes of developmental disorders.

Aelion explained some of the benefits of this type of statistical approach.

“[This type of study] allows us to narrow down the number of metals we measure by indicating which ones are important,” she said. “It allows us to focus geographically and do a follow-up study in geographic areas that had the most interesting results,” she continued.

The study, conducted in South Carolina, focused on the areas where mothers of children with developmental delays resided during pregnancy.

Aelion commented on the dangers of exposure during pregnancy.

“Heavy metals can affect the mind of a developing child because heavy metals can cross the placenta of a pregnant woman and can cross the blood-brain barrier in the fetus,” said Aelion.

According to Aelion, there are multiple sources of arsenic which could contribute to concentrations of the chemical in soil.

“Arsenic can occur naturally and can occur as a byproduct of industrial activities,” she said. “There are very few studies that measure arsenic in residential soils, and we do not know if it could be associated with negative health outcomes in children,” she added, indicating a need for more research in this area.

Although Aelion emphasized that there is much still unknown about the affects of how arsenic and other chemicals can impact the development of children both while in the womb and after birth, there are some steps parents can take to protect their children once they are born to avoid exposure.

“Arsenic can be in groundwater that is consumed by people who rely on private wells for their drinking water,” said Aelion. “Some soils have high arsenic naturally; limiting children’s play in dirt and keeping a clean house if dirt is tracked into the house is helpful,” she went on. “Some children’s playground equipment made of wood was treated with arsenic-containing compounds in the past.”

Despite these cautions, Aelion maintains that low exposures to arsenic after birth are unlikely to cause severe mental impairment or developmental delay.

 The article Aelion published was co-authored by Yuan Liu, a biostatistics doctoral student in the Epidemiology and Biostatistics Department in the School of Public Health at the University of South Carolina at the time of publication. Dr. Suzanne McDermott, a professor in the Department of Family and Preventive Medicine at the University of South Carolina School of Medicine, who is an epidemiologist, and Dr. Andrew Lawson, a professor in the Epidemiology and Biostatistics Department at the School of Public Health at the University of South Carolina, also contributed to the research.

Bobby Hitt can be reached at [email protected].