NEW ORLEANS (WGNO) -- New research from Tulane University found brown anole lizards in New Orleans carry the highest blood-lead levels ever recorded in a vertebrate.
The study found that the lizards lead levels exceeded all previously reported values for fish, amphibians, birds, reptiles and mammals.
"What's astonishing is that these lizards aren't just surviving, they're thriving with lead burden that would be catastrophic for most other animals," said study author Alex Gunderson, assistant professor of ecology and evolutionary biology in Tulane's School of Science and Engineering.
Tulane officials said this research underscores the lingering legacy of lead contamination in New Orleans and the complex ways organisms adapt, or fail to adapt, in polluted environments.
The brown anoles are an invasive species originally from the Caribbean. They've been in New Orleans since at least the 1990s. They are now more common than the green anole, which is a native species.
PhD student Annelise Blanchette and Gunderson led the study and discovered that the lizards could withstand lead levels 10 times higher than the already extreme concentrations found in the field before showing any decline in performance.
Tests measured traits such as balance, sprint speed and endurance, which are commonly impaired by lead exposure.
"These animals are performing at full capacity despite record-setting lead levels, making them one of the most, if not the most, lead-tolerant animals known to science," Blanchette said.
Analysis of the lizard's brain and liver tissue showed only minor effects from lead exposure.
"We need to reevaluate what we know about toxicity thresholds in vertebrates," Gunderson said. "If we can figure out what's protecting them, we might uncover strategies that could help mitigate heavy metal poisoning in people and other species."