When you’re pregnant, or trying to survive the toddler years, making tough decisions can feel endless. When is peanut butter okay? What’s better, ‘cry it out’ or share a family bed?
But there’s one everyday factor that often flies under the radar – indoor air pollution.
“People think a lot about what they’re eating during pregnancy, but much less about what they’re breathing, which can have an impact on the baby before they’re even born,” says Sonali Bose, MD, MPH, a pulmonary and critical care physician at Mount Sinai.
That insight is at the heart of Dr. Bose’s research, supported by a pilot award from the Center on Health and Environment Across the LifeSpan (HEALS). Her work focuses on pregnant people with asthma across New York City, using low-touch air-monitoring technology to measure indoor pollution in real time.
What her team has found surprises many families.
“Indoor air can be more polluted than outdoor air, even on days when the air outside looks fine,” Dr. Bose explains.
Why does this matter so much early in life? Her research suggests that indoor air pollution can trigger inflammation in pregnant people with asthma, with downstream effects on the fetus. “We’re seeing evidence that pollutants can alter placental biology in real time,” says Dr. Bose, who advises patients on home and work environments, and sometimes even writes letters to employers on behalf of patients. “That’s one reason this window is so important.”
For families already navigating childhood asthma, these concerns show up every day in the clinic. Lauren Zajac, MD, MPH, leads Mount Sinai’s Pediatric Environmental Health Clinic and works closely with children whose asthma is worsened by home environments.
“Medication alone won’t fix asthma if a child is living with mold, roaches, or constant smoke exposure,” Dr. Zajac says. “We focus on helping families identify triggers and reduce the ones they can.”
One of the clinic’s most practical tools is the Healthy Home Kit, which gives families mattress and pillow covers to reduce dust mites, safer cleaning supplies, food storage containers to stop pests, spacers for inhalers, and portable air purifiers. “These are things families can use right away,” Dr. Zajac says. “They help restore a sense of control.”
That sense of empowerment is key, especially because not all solutions rest with individual families. Many patients live in rental housing where leaks, mold, or poor ventilation require landlord intervention. Through Mount Sinai’s pediatric environmental health programs and the federally funded PEHSU hotline, families are connected to community partners, including city home-repair programs, healthy housing initiatives, and legal aid organizations, which can help address unsafe conditions.
“It’s never just one issue,” Dr. Zajac notes. “Often it’s a poorly maintained building with multiple environmental problems. Our role is to walk families through next steps and connect them to the right resources.”
Both doctors stress that small changes matter. Families can reduce indoor air pollution by avoiding candles and air fresheners, choosing fragrance-free cleaning products, ventilating during cooking when possible, wet-dusting instead of dry sweeping, and keeping smoke completely out of the home. Using HEPA air purifiers in bedrooms and following daily air quality forecasts can also help. Prescriptions For Prevention, run by New York State Children’s Environmental Health Centers, is an excellent online resource that offers practical tips to reduce pollutantsin the home and lists key local resources to help address the problem, says Dr. Zajac. To learn about tenant rights in New York City when it comes to mold and pests, and more useful facts, you can visit the NYC Health Department’s Asthma page.
Clinicians play a critical role by asking about home environments, testing for allergies, tailoring asthma action plans, and advocating for healthier housing and school spaces. Community programs extend that care beyond the clinic walls.
Maria, who asked that her last name not be used for privacy, is 35, pregnant and has asthma. She says Dr. Bose has armed her with knowledge that she is using to take care of herself and her unborn baby. In 2021, the manager for an education nonprofit developed a “horrible cough” after moving into a new apartment in Brooklyn.
“We went to every single doctor under the sun,” says Maria. Months later, still with the cough, she met Dr. Bose. After asking questions such as what her asthma triggers were and when her asthma got better and worse, Dr. Bose suggested things Maria found surprising: She should consider moving out of her apartment and working in a different building.
“I didn’t know what a problem it was until I met Dr. Bose,” she says. Even pulmonologists didn’t connect the dots. “No one pointed to indoor air pollution.” Maria eventually decided to move apartments, and her nonprofit opened a new office in a building that harbored fewer asthma triggers for the former violin teacher.
Now, she feels confident that she knows how to protect herself and her baby from the harmful effects of indoor air pollution. She follows Dr. Bose’s suggestions: She masks up on the subway and avoids big, old buildings, which are often full of asthma triggers, including dust. She bought a HEPA air purifier filter, which turns on automatically when indoor air pollution reaches a minimum threshold.
“I feel very passionately that Dr. Bose has made navigating something that felt scary much easier,” says Maria. “She’s an angel among us.”
Moving isn’t realistic for everyone. Maria’s apartment posed especially high risks because it was inside a large, old building, and a cat had lived in the apartment previously, says Dr. Bose.
Fortunately, there are many ways to reduce indoor air pollution wherever you are living right now, Dr. Zajac and Dr. Bose say. And specially designed policies and programs exist to help.
“The most important thing people should know is that indoor air is a modifiable risk,” says Dr. Bose. “You don’t need perfection. Even small, realistic changes, combined with clinical and community support, can help protect children’s lungs and give them a healthier start in life.”
Practical Tips for Cleaner Indoor Air
Improve Ventilation
- Open windows on good air quality days to create cross-ventilation.
- When cooking, use kitchen exhaust fans that vent to the outdoors, or open windows (especially with gas stoves).
- Follow outdoor air quality alerts, and take action to reduce indoor air quality when outdoor air reaches unsafe levels.
Reduce Smoke and Gas
- Avoid using candles, incense, and scented air fresheners.
- Minimize use of gas stoves when possible; consider switching to electric or induction.
- Never smoke indoors (including cigarettes, vaping, or marijuana).
- Keep smoking completely away from doors and windows if it occurs outside.
Choose Safer Cleaning Products
- Choose safer cleaning products if possible (check this NY state resource for safety seals you can look out for), or use a vinegar/water mix.
- Open windows and turn on a fan when cleaning.
- Wear a mask while cleaning.
- Avoid aerosolized sprays; use wipes or liquids instead.
- Wet dust and mop regularly (dust becomes airborne when dry-swept).
- Avoid bleach if possible.
- Avoid plug-in air fresheners and essential oil diffusers, especially if a child has asthma.
Filter Indoor Air
- Use a portable HEPA air purifier in bedrooms or main living areas, and change filters as indicated by the manufacturer.
Control Allergens & Asthma Triggers
- Use zippered allergen-proof covers on pillows and mattresses.
- Store food in sealed containers to prevent cockroaches and mice.
- Fix leaks promptly to prevent mold.
Ask For Help
- Request mold remediation or pest control from landlords if needed.
- Seek help from community programs if housing conditions are unsafe.
- Call your regional Pediatric Environmental Health Specialty Unit (PEHSU) for free advice.
- Ask pediatricians about environmental asthma programs such as NYSCHECK (look for the section “My child has asthma. What programs can help fix things in my home that make asthma worse?”)
- Seek referrals to legal aid groups if landlords fail to fix mold, leaks, or smoke infiltration.
Online Resources
New York State Children’s Environmental Health Centers
Mount Sinai Institute for Exposomic Research Learning Hub
Indoor Air Quality – NYC Health
Children’s Environmental Health Network