Effectiveness of Maryland’s Lead Law (MD 760)

Project Funders: U.S. Department of Housing and Urban Development (HUD) and the Abell Foundation

Project Partners: Baltimore City Health Department

Project Contact: Jonathan Wilson, jwilson@nchh.org, 443.539.4162

Project Description

In 1994, Maryland enacted a law that prescribed a lead-based paint risk reduction standard for pre-1950, privately owned rental housing. This standard applied at each tenancy change and requires sampling to verify that dust lead loadings were within acceptable limits or performing specific lead hazard reduction treatments, followed by an independent visual inspection without dust sampling. In this project, NCHH evaluated the ability of visual inspection alone to predict treatment completion and dust lead loadings.

NCHH enrolled 52 Baltimore housing units into the study and performed the law-specified treatments. Before treatment, study risk assessors conducted visual assessments and dust lead wipe sampling in each unit. After treatment, Maryland-certified visual inspectors conducted the law’s required visual inspection, followed by the study risk assessors, who performed a separate visual assessment and collected dust wipe samples. One year later, study risk assessors performed another visual assessment and dust wipe sampling (n=34).

We found that dust lead loadings declined significantly immediately after prescribed lead treatments were implemented. Fifty-three percent (53%), 20%, and 47% of units had at least one sample that exceeded 1995 EPA/HUD floor, windowsill, and window trough clearance guidance of 100, 500, and 800 μg/ft², respectively. Overall, 73% of units had one or more immediate post-intervention single-surface sample results exceeding the 1995 clearance values that were in effect at the time of the study. One-year post-intervention loadings remained significantly below pre-intervention levels for floors but not windowsills or troughs.

The conclusion of this project was that, without dust lead testing, visual assessments alone did not ensure that prescribed treatments were completed or that dust lead loadings were below clearance values.

Project Update

Since the completion of this study, Maryland’s Department of the Environment (MDE) has updated this law. According to the MDE website, effective January 1, 2015, “Maryland’s Reduction of Lead Risk in Housing law requires owners of rental properties built before 1978 to register their units with MDE, distribute specific educational materials, and meet specific lead paint risk-reduction standards at certain triggering events.” MDE has a “Standard of Care” fact sheet for owners summarizing compliance requirements, including how to meet Risk Reduction Standard requirements.


Breysse, J., Anderson, J., Dixon, S., Galke, W., & Wilson, J. (2007, October). Immediate and One-Year Post-Intervention Effectiveness of Maryland’s Lead Law Treatments. Environmental Research, 105(2), 267-275.


Latest page update: April 4, 2024.