Based at UNLV’s School of Public Health, the program was first launched about two decades ago through the Southern Nevada Health District. It was the first time Nevada had a dedicated effort to track children’s blood lead levels and understand where and how exposure was happening in Clark County. For five or six years, the program quietly did its work, collecting data and raising alarms where needed — until federal funding dried up and Nevada’s effort, like many others around the country, was shuttered.Then Flint happened.