Yes, that's a good question, especially when you start to use automation in construction. A 3-D printer is an automation system. It's a system that can deploy concrete or other material, but most of the time we are working with concrete. It can deploy concrete based on your 3-D model and, of course, the closed operation doesn't require too much human interaction when you're doing the printing itself, meaning that your workers are going to be far away from the concrete deployment itself when you're printing the deployment of the concrete.
I don't have any official research data to show here, but it is expected to improve the safety of the workers by using automation, as you're keeping them a little more busy with the automation side of things, the programming of the machines and operating the machines far away from the deployment of the material itself.