NYC Public Housing Mold Program Linked to Fewer Asthma ED Visits

A large-scale mold remediation initiative implemented across New York City public housing developments was associated with substantial reductions in asthma-related emergency department (ED) visits, according to findings presented at the American Thoracic Society (ATS) 2026 International Conference in Orlando, Florida.1

Investigators reported that the New York City Housing Authority’s (NYCHA) Mold Busters program was associated with an average annual reduction of 9 asthma-related ED visits per 1000 residents (95% confidence interval [CI], -11.2 to -6.6), translating to an estimated 2798 fewer ED visits annually from 2021 to 2023.1

“These results suggest that housing interventions on asthma triggers could play a critical role in reducing long-standing asthma disparities,” lead author Nina Flores, PhD, said in a statement.2 Flores conducted the work as a doctoral student at Columbia University and is now a postdoctoral fellow at The University of Texas at Austin School of Social Work and Dell Medical School.

Asthma burden remains disproportionately high among residents of public housing, particularly in low-income Black and Hispanic communities.2 NYCHA houses more than 400,000 residents, and mold complaints have been a longstanding concern. The Mold Busters program was launched in 2019 following a 2013 class-action lawsuit filed by residents who alleged mold exposure contributed to asthma morbidity.

The intervention included evidence-based mold remediation practices, improved response timelines for mold complaints, staff training, and ventilation improvements throughout NYCHA buildings.1 Prior randomized studies involving fewer than 100 participants suggested mold remediation could improve asthma symptoms, but evidence evaluating citywide implementation has been limited.

To assess the impact of the program, investigators analyzed building-level asthma ED visit data from 2016 through 2023 among NYCHA residents and compared outcomes with residents living in nearby lower-income, non-NYCHA census tracts.1 Using doubly robust differences-in-differences analyses, investigators compared pre-intervention outcomes from 2016 to 2018 with post-intervention outcomes from 2021 to 2023.

The findings suggested that, without the Mold Busters intervention, NYCHA residents would have experienced approximately 25% more asthma-related ED visits during the post-intervention period.1

The team also evaluated resident-reported mold work orders across buildings using latent class growth analysis to identify trends in mold complaint trajectories after the intervention.1 Five trajectory groups emerged, with all groups experiencing declines in mold reporting rates after program implementation. However, the magnitude of improvement varied considerably across buildings.

Buildings with slower declines in mold complaints were generally older, larger, less likely to have mechanical ventilation, and more frequently located in flood zones and neighborhoods with greater poverty. In contrast, buildings with steeper reductions in mold complaints also experienced the greatest decreases in asthma-related ED visits.1

According to Flores, the relationship between declining mold complaints and reduced ED utilization further supports the effectiveness of the intervention.2

Investigators noted the study likely underestimates the broader health benefits of mold remediation because analyses focused specifically on ED visits rather than milder asthma exacerbations, missed school or workdays, or other respiratory and allergic conditions linked to mold exposure.2

“The health benefits reported here likely underestimate the full scope of health-related benefits from the intervention,” Flores said.2

The research team plans to continue evaluating outcomes as additional data become available to determine whether benefits persist or increase over time. Ongoing work is also examining fungal exposure, allergic sensitization, and asthma-related illnesses among children living in NYCHA housing before and after mold remediation efforts.1

References

1. Flores N, Casey J, Lovinsky-Desir S, et al. Large-Scale Mold Intervention Reduced Asthma Emergency Department Visits in New York City Public Housing Differentially Across Building and Neighborhood Characteristics. Poster presented at ATS 2026 in Orlando, Florida on May 17, 2026.

2. Public housing mold intervention program reduces asthma-related ED visits. EurekAlert! Published on May 17, 2026. Accessed May 16, 2026. https://www.eurekalert.org/news-releases/1127655