Evaluation of landscape coverings to reduce soil lead hazards in urban residential yards: The Safer Yards Project.
This study was designed primarily to evaluate the effectiveness of landscape coverings to reduce the potential for exposure to lead-contaminated soil in an urban neighborhood. Residential properties were randomized in to three groups: application of ground coverings/barriers plus placement of a raised garden bed (RB), application of ground coverings/barriers only (no raised bed, NRB), and control. Outcomes evaluated soil lead concentration (employing a weighting method to assess acute hazard soil lead [areas not fully covered] and potential hazard soil lead [all soil surfaces regardless of covering status]), density of landscape coverings (6 = heavy, > 90% covered; 1 = bare, < 10% covered), lead tracked onto carpeted entryway floor mats, and entryway floor dust lead loadings. Over 1 year, the intervention groups had significantly reduced acute hazard soil lead concentration (median change: RB, -478 ppm; NRB, -698 ppm; control, +52 ppm; Kruskal-Wallis, P = 0.02), enhanced landscape coverings (mean change in score: RB, +0.6; NRB, +1.5; control, -0.6; ANOVA, P < 0.001), and a 50% decrease in lead tracked onto the floor mats. The potential hazard soil lead concentration and the entryway floor dust lead loading did not change significantly. Techniques evaluated by this study are feasible for use by property owners but will require continued maintenance. The long-term sustainability of the method needs further examination.
Binns
Helen J
HJ
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. hbinns@northwestern.edu
Gray
Kimberly A
KA
Chen
Tianyue
T
Finster
Mary E
ME
Peneff
Nicholas
N
Schaefer
Peter
P
Ovsey
Victor
V
Fernandes
Joyce
J
Brown
Mavis
M
Dunlap
Barbara
B
D002641:Chicago; D004781:Environmental Exposure / Q000517:prevention & control*; D004787:Environmental Pollution / Q000517:prevention & control*; D006801:Humans; D007854:Lead; D007855:Lead Poisoning / Q000517:prevention & control*; D011897:Random Allocation; D012989:Soil Pollutants; D014505:Urban Population
D012989:Soil Pollutants; D007854:Lead