MIAMI — Scientists know that red tide and other harmful algae blooms can kill marine life and make pets and people sick. Certain types of algae produce toxins that can cause respiratory problems, liver failure and nervous system issues. People and animals can be exposed by simply breathing in the air around a bloom or having skin contact.

But how much toxin is too much? And who is more at risk? Florida Atlantic University is starting a new study on the effects of human exposure to algae and their toxins after persistent blooms in South Florida over the past few years have fouled rivers and canals in the west and east coasts, killing fish, terrifying residents and scaring tourists away.

“Despite the intensity and frequency of cyanobacterial blooms in South Florida, data on human exposure to these blooms and microcystin concentrations in tissues of people who have been exposed is limited,” said Shirley Gordon, lead researcher and a professor at FAU’s Christine E. Lynn College of Nursing. “Understanding thresholds for both short- and long-term health impacts is crucial to protect the health of Floridians.“