I'm guessing you are using Iray. Look on the render tab in the Environment section. By default, Iray sets the Environment Mode to Dome Only or Dome and Scene with a low resolution HDRI on the Dome. The Draw Dome property also defaults to off, so you cannot see the Dome in the render (but you will see it in reflections if you have a highly reflective object). To render with only scene lights, set the Environment Mode to "Scene Only". This will turn off the dome, which I suspect is what is giving you the blue glow.

DAZ also has a Headlamp by default. It will add it to the scene at the camera location if you do not have any scene lights. To get rid of the headlamp, go to the General section of the Render Settings for Iray and find the Auto Headlamp property. It can have two values, "Never" or "When No Scene Lights". The "When No Scene Lights" is default. If you change it to "Never" you should get a dark render.