HOW MUCH CLEANING IS ENOUGH? AN EVALUATION OF ALTERNATIVE POST-LEAD HAZARD INTERVENTION CLEANING PROCEDURES By:

This study evaluated and compared two procedures to clean lead dust and debris after lead hazard control activities were completed in housing with lead-based paint hazards. 1995 Federal guidelines prepared by the U.S. Department of Housing and Urban Development for the control of lead-based paint hazards in housing strongly recommend that after lead hazard control interventions all walls, ceilings, floors and other horizontal surfaces be cleaned using a three step process – an initial HEPA vacuum, wet wash with a lead cleaner, and a final HEPA vacuum. This study evaluated the effectiveness of the recommended three step procedure and compared this process to a two step procedure that omits the final HEPA vacuum. Cleaning procedures were evaluated in twenty-seven dwelling units that had undergone significant lead hazard control interventions likely to produce lead dust. Dust lead samples were collected on floors and in window sills and troughs prior to the lead hazard intervention, after the wet wash step of the cleaning procedure, and after completion of the second HEPA vacuuming. The results of the study demonstrate that dust lead surface loading on smooth and cleanable surfaces following both the three step and two step cleaning procedures can achieve 1995 Federal guidance dust clearance levels and levels substantially lower. Dust lead levels measured after the two step cleaning procedure are similar to levels measured after a three step cleaning procedure. While the benefits from a second HEPA vacuum are difficult to measure, the results suggest that the time saved by omitting the second HEPA is small relative to the other elements of the cleaning process.