Researchers are reporting mass die offs of wild birds and sea mammals due to bird flu. They're tracking the deaths to better understand the virus and how it might create a greater threat to humans.
NPR's Ailsa Chang talks with Nancy Krieger, a social epidemiologist at Harvard University, about her efforts to preserve federal health data that recently disappeared from government websites.
NPR's Ailsa Chang talks with Nancy Krieger, a social epidemiologist at Harvard University, about her efforts to preserve federal health data that recently disappeared from government websites.