Mike Robicheux, a Louisiana physician, described the situation as "the biggest public health crisis from a chemical poisoning in the history of this country."[237] In July, after testing the blood of BP cleanup workers and residents in Louisiana, Mississippi, Alabama, and Florida for volatile organic compounds, environmental scientist Wilma Subra said she was "finding amounts 5 to 10 times in excess of the 95th percentile"; she said that "the presence of these chemicals in the blood indicates exposure."[2][238][239] Riki Ott, a marine toxicologist with experience of the Exxon Valdez oil spill, advised families to evacuate the Gulf.[240] She said that workers from the Valdez spill had suffered long-term health consequences.[241]