In the kitchen of her rental home in northwest Washington, D.C., Shelly, a mom of two, points to the sink. "We had a fungus, a mushroom, growing out right here. They fixed that," Shelly says.

That mushroom was just one sign of the mold that once pervaded the house. Shelly lives in the home with her 7-year-old daughter. She says the mold issues often set off the child's asthma. "She really couldn't breathe during those tough times," Shelly says.

(NPR is only using Shelly's first name to protect her from potential retaliation from her landlord.)

Her daughter frequently ended up in the emergency room. "It's devastating. It's given me anxiety. It's taken away a lot of her education," Shelly says.

This summer, doctors at Impact DC, the asthma clinic at Children's National Hospital, decided Shelly's daughter needed a different kind of specialist to address this health problem – a lawyer.

That's how attorney Lacia Japp ended up touring Shelly's home in late September to check that mold and other health hazards were being fixed. Japp works for Children's Law Center, a D.C.-based nonprofit legal service organization that fights to improve kids' health. She's part of the center's Healthy Together Program, a medical-legal partnership that works with several D.C.-area clinics.

Japp points to places throughout the house – on the basement walls, in the bedroom and bathroom – where signs of dark green mold and water leaks have now been removed. "It looks much better," Japp says, though she notes the repairs aren't finished.

Doctors call in the lawyers from the Healthy Together program when a low-income family needs help with housing conditions that are harming kids' health. Often, it's asthma.

In D.C., a child with asthma who lives in a low-income community is 20 times more likely to end up in the emergency room than a child in a more affluent neighborhood. Similar disparities in the burden of childhood asthma occur throughout the U.S. One major driving factor is poor housing conditions.

"It could be mice, infestation, rats, roach infestation – it could be a lot of water damage that creates mold and all of that. All of those are allergens and that can exacerbate the child's asthma," says Tracy Goodman, a lawyer who has directed the Healthy Together Program since its launch more than two decades ago.

When housing is a medical issue

Goodman says lawyers start off by documenting health-harming conditions in a home and sending a letter to the landlord informing them of their legal obligation to make fixes.

The lawyers try to push landlords to make repairs and address infestations voluntarily. "And the hope is the landlord will then fix everything. And occasionally that happens. But that's very rare," says Ashley Close, another lawyer with the program.

If the landlord doesn't comply, they'll take them to a special housing conditions court to force them to make repairs.

And there's research to back that up. Data collected by the Children's Law Center found that after a legal intervention, kids with asthma experienced fewer trips to the ER and fewer hospitalizations.

In fact, some insurers and hospital systems have been subsidizing these legal interventions through grants and other payment arrangements. One plan, AmeriHealth Caritas District of Columbia, a Medicaid plan, now directly reimburses Children's Law Center after successful legal interventions. Karen Dale, the plan's CEO, says connecting low-income patients with legal assistance is good medicine, because social needs like substandard housing play a critical role in influencing health.

"There's so much evidence that shows that what happens in a doctor's office, in the seven to 10 minutes that someone spends there, is not the best predictor of their overall health and wellbeing – that it is all the other things that occur that impact their health," Dale says.

The concept of medical-legal partnerships to help improve health outcomes and address persistent health disparities has been around for a few decades, but interest has exploded in recent years, says Bethany Hamilton, co-director of the National Center for Medical-Legal Partnership at George Washington University's Milken Institute School of Public Health. She says about 500 such partnerships exist across the country.

Just last month, Kaiser Permanente announced it was ramping up a program that offers grants to legal aid groups so they can assist its health plan members in fighting evictions. "Sometimes I'm like, why isn't [the model used] everywhere?" Hamilton says.

And legal interventions can also be cost-effective. Dale co-authored the research with the Children's Law Center that found that, in the 18 months after a legal intervention, her managed care organization spent an average of $10,000 less on health care for kids with asthma, mostly due to reduced hospital visits. For children with the most severe asthma, the savings were around $60,000.

Cockroaches, rodents and finally, a new apartment

Sometimes an unhealthy living situation can be a critical medical crisis. That was true for Kanna Bowen's 5-year-old daughter, Deveah, who was admitted to the hospital dozens of times while living in substandard housing.

Bowen moved to D.C. when Deveah was an infant so she could get specialized care at Children's National Hospital for her severe asthma. Bowen says her first apartment in the city had spiders and mouse infestations that triggered Deveah's asthma.

"She was sick a lot there," Bowen says. At one point, Bowen says, Deveah was being hospitalized every three to four weeks. "It was real bad."

It was a "potentially life-threatening" situation, says Dr. Dale Coddington, one of the pediatricians at Children's National who treated Deveah during this time.

Coddington referred Bowen to Children's Law Center. They helped her find a second apartment through the subsidized housing program she relies on, but it turned out to be even worse. She says the outside looked like an abandoned house. Inside, there was lots of visible mold, water stains from leaks, rodents and roaches everywhere.

"It was like a pile of roaches – and one in my refrigerator," she recalls. She says they bit her while cooking and infiltrated her bed. "It was bad."

Bowen says she tried to get the property manager to fix things but her requests were ignored. So her attorney at Children's Law Center, Ashley Close, took the landlord to court. A housing inspector found extensive problems. Close says carrying out the repairs would have required Bowen to move out of the unit.

A lawyer for Bowen's former landlord told NPR in an email that "the landlord did not know that there were repairs needed until the tenant filed a court case." The lawyer said the landlord took action to remedy the situation.

Close says the landlord offered to either put her client in a hotel or settle the case. They took the settlement because Kanna Bowen was able to move into another subsidized rental unit.

Tracy Goodman of the Children's Law Center says it's often cheaper for landlords to risk paying a fine from the city than it is to make repairs. She says some landlords create shell companies that make it harder to trace them or name them in lawsuits.

"We also see that there are instances of owners that are essentially wanting to push out the low-income residents so that they can redevelop and then rent at higher rates or sell the properties for great profit," Goodman says.

She says like many other urban areas, D.C. has a shortage of low-cost housing, which makes it all the more important to make sure that when clients do find a place they can afford, it's actually livable.

Kanna Bowen says her daughter, Deveah, is in better health since they moved into their new apartment last year. While she still has severe asthma, Bowen says her daughter hasn't been hospitalized in about a year. "She's doing way better," Bowen says.

On the day I visited Bowen's apartment, Deveah was outdoors playing ball with her dog, Teddy – just like any happy, healthy 5-year-old kid.

Editing and layout by Carmel Wroth. Radio story edited by Jane Greenhalgh.