Hold the Salt

Hold the Salt

EUREKA!

[NEW FINDINGS AND RESEARCH]

Highway runoff threatens lakes.

Road salt helps make winter driving safer. It also threatens the health of freshwater ecosystems, reports Ph.D. student and coauthor Flora Krivak-Tetley ’02, Adv ’18, in a study published in Proceedings of the National Academy of the Sciences. By analyzing longterm salinization data from the U.S. Geological Survey and the EPA, KrivakTetley’s team estimates that nearly 8,000 bodies of water in the North American lakes region face elevated levels of chloride due to runoff from nearby roads. Though the concentration of salt in lakes has increased by as much as 300 percent within the past few decades, the contamination can be reversed. “Most lakes have water flow in and water flow out,” says Krivak-Tetley. “So, if you just stop using salt, it will wash out over the course of some years, with a decrease in the concentration in the lake water.”

Survey Says

Mentors boost college enrollment.

>» Many high school seniors who have the potential to succeed in college choose not to apply. Economics professor Bruce Sacerdote ’90 decided to find out what could be done to increase enrollment rates among this cohort. His study, published in American Economic Journal: Applied Economics, found that the best motivation for promising high schoolers—even better than financial incentives—is having a mentor to help guide the application process. Mentors are particularly effective for female students, whose college enrollment increased by 15 percent. As the United States continues to lose its lead among nations with the highest rate of college-educated individuals in the workforce, Sacerdote points to the fact that boosting college enrollment rates results in economic growth. “The best way to help Americans is to have GDP growing,” he says.