MEXICO CITY — Researchers from Mt Sinai's Icahn School of Medicine published a study indicating a link between exposure to particulate matter 2.5 (PM2.5) during the first year of life and impaired impulse control, as well as higher body fat, in children in Mexico City. The study analyzed data from a group of 434 children born largely between 2007 and 2008 who are part of a longitudinal health study in Mexico City.

The authors modeled ambient PM2.5 levels during pregnancy and the children's first year of life. The group with the highest levels of PM2.5 exposure showed a pattern of high impulsivity and deficits in inhibitory control. These behavioral changes related to impulse control were linked to higher body fat and higher BMI in children between four and eight years old.

Jamil Lane, a co-author with Mt Sinai's Icahn School of Medicine, noted that much obesity research focuses on diet and physical activity, often overlooking environmental exposures like air pollution. "A lot of the obesity research primarily focuses on – and is being shaped by – diet and physical activity, and a lot may not include environmental exposures, including air pollution," Lane said. "Our study is novel in that we are showing that high levels of air pollution early in life may cause more difficulty with self-regulation, which contributes to weight gain." The study authors stated, "Our study shows that greater early exposure to PM2.5 in the first year of life is associated with alterations in inhibitory control function in childhood." They added, "The effect is likely due to altered eating behaviors related to inhibitory control that are programmed early in life."

PM2.5 is a pollutant composed of microscopic solid or liquid particles suspended in the air. Common manmade sources include traffic emissions and the burning of fossil fuels. PM2.5 is considered a probable carcinogen and is linked to health problems including dementia and strokes. Previous research has shown that PM2.5 has properties that can disrupt metabolism and is associated with weight gain. The study acknowledges limitations including a small population size and limited covariates.