A new documentary from the Humankind series, about "Health Inequality."

This documentary looks at why the wealthiest Americans live as many as 15 years longer than the poorest. It's a troubling question at a time when income inequality has reached levels not seen since the run up to the Great Depression.

Nationwide — even with more people covered through the Affordable Care Act — nearly 30 million Americans remain without health insurance. And medical problems that go undiagnosed and untreated often get worse.

For this program, we talked with patrons of a Massachusetts food pantry frequented by people of low income. We also visited Bellevue Hospital in New York City, America's oldest public hospital, where many patients live below the poverty level. Physician Dave Chokshi there describes his efforts to take care of patients who are sometimes under severe financial strain. He says taking off a morning to line up at the clinic may cost them crucial hours on the job, when they could be earning income.

We also consider the many stressors affecting the working poor. For multiple reasons — from food insecurity to struggling to pay the rent and utilities to social prejudice — living in poverty can contribute to tense, frustrating conditions.

This anxiety in turn can impact a person's health, with symptoms ranging from headaches to difficulty sleeping to depression. Public health experts have even noticed that children born into poverty may have a lower than normal birth weight, attributable to a range of stressors afflicting the mother and in some cases maternal malnourishment.

And it's little surprise that people don't always cope with these pressures healthfully, which may explain why those living in poverty have higher rates of smoking than others. In addition, it's been shown that marketers of tobacco products and of fast food tend to target the poor.

The problem of "health inequality" is a complex and morally troubling dilemma.

David Freudberg is executive producer of the Humankind series, produced in association with WGBH Boston.

For more information and to listen to this documentary and many others in the series, go to Humanmedia.org.