Forest fires are more harmful than previously imagined, causing stunted growth in children who were exposed to smoke while in the womb, according to new research from Duke University and the National University of Singapore.

The authors found pre-natal exposure to haze from forest fires led to a statistically significant 1.3-inch decrease in expected height at age 17.

“Because adult height is associated with income, this implies a loss of about 3 percent of average monthly wages for approximately one million Indonesian workers born during this period,” the authors write.

“While previous research has drawn attention to the deaths caused by the forest fires, we show that survivors also suffer large and irreversible losses,” they wrote. “Human capital is lost along with natural capital because of haze exposure.”

“This disadvantage is impossible to reverse,” said co-author Subhrendu Pattanayak of the Duke Sanford School of Public Policy.

Read more at Duke University

Image: Smoke and haze from Indonesian forest fires extended over a huge area In October 1997.  CREDIT: NASA