Credits: NASA/Pablo Méndez Lázaro "Being able to see this dust before it arrives is a critical tool for public health," said Méndez-Lázaro, an associate professor at the University of Puerto Rico Medical Sciences Campus in San Juan. “We alerted federal and state agencies as well as medical doctors, which gave them time to alert the public and vulnerable populations like people with asthma. Before, decision-makers lacked the specific information to help the public protect themselves in advance."