swing sets, and sliding boards); toys; or other children s possessions; observations of play pat¬ 
terns; or information provided by parents, residents, care givers, or property owners. 
Post-intervention sample (also referred to as “post-mitigation” sample: A sample taken after 
residents have completed the three-step cleaning/HEPA vacuum procedure. 
Reference level(s): Levels set by the Department of Housing and Urban Development (HUD) 
and EPA to indicate surface dust that contains an amount of lead that may pose a threat of 
adverse health effects in pregnant women or children less than age 6. 
Residential building: A building containing one or more residential dwellings. 
Risk assessor: An EPA-certified professional who determines the existence, nature, severity, and 
location of lead-based paint hazards in a residential dwelling. 
Wet cleaning: A method for cleaning lead dust in the home; involves washing surfaces with a 
suitable cleaning agent to dislodge any ground-in contamination; then rinsing with clean water. 
Window trough: For a typical double-hung window, the portion of the exterior window sill 
between the interior window sill and the frame of the storm window. If there is no storm win¬ 
dow, the window trough is the area that receives both the upper and lower window sashes when 
they are both lowered. The window trough is sometimes called the window well. 
X-ray fluorescence (XRF) instrument: A handheld, battery-powered device used to analyze 
dust wipe samples. The device provides timely and accurate data, allowing inspectors to meas¬ 
ure parts per million (ppm) lead levels for individual dust wipes within seconds. 
Glossary 
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