Inequality and poverty have taken center stage in American politics in the years since the recession. Fast food workers have raised the profile of low-wage work, cities and states around the country are raising the minimum wage, and elected officials in both parties have made the struggles of poor Americans core political issues.

But David Michaels, Ph.D., M.P.H., who leads the Occupational Safety and Health Administration under the Obama administration, says that workplace inequality is more than just wages. In an interview, Michaels, who is responsible for enforcing federal laws to project workers from illness and injury, says the regulatory structures he oversees aren’t sufficient to protect vulnerable workers from harm.

NBC: The political conversation about inequality in recent years has focused on wages. You’ve made the point that when addressing inequality, we should focus more on workplace health and safety issues. Why?

Michaels: Wages are clearly a core component of the discussion of inequality and the ability to get into and stay in middle class. But workplace health and safety issues also have an enormous impact. Workplace injury and illness can push workers out of middle-class jobs and make it hard to enter into the middle class in the first place.

Studies show that workplace injury…