A national network of public health laboratories prevents an estimated 270,000 cases of food poisoning and saves half a billion dollars every year, according to a study released today. By preventing foodborne illness, PulseNet not only saves lives but also saves an estimated $500 million a year in medical costs and lost productivity, according to the study published in the American Journal of Preventive Medicine. In comparison, the network costs public health agencies about $7 million a year to run. So, for every dollar spent, an estimated $70 is saved.