Presence of Chromium, Copper, and Arsenic in Schoolyard Soils

Historically, wood products were treated with chemicals to prevent rot and decay. Many chemicals contained high levels of Cr, Cu, and As. In addition to residential uses (e.g., decks), many such products were utilized for playground equipment on public school grounds. High rainfall in southern Louisiana poses a risk for metallic elements to leach into soils adjacent to playground structures. In this study, wood products at 11 public schools in Louisiana were evaluated to determine (i) residual presence of Cr, Cu, and As in schoolyard lumber and (ii) if those metallic elements leached into soils adjacent to playground equipment. Wood products and soils were evaluated on‐site using a portable X‐ray fluorescence spectrometer. Results readily identified two different types of wood products used in schoolyard playgrounds: (i) chromated copper arsenate (CCA) treated lumber, typical of older wood products and (ii) newer wood products preserved with high levels of Cu, virtually devoid of Cr and As (non‐CCA). Many CCA lumber products had Cr levels of 2500 mg kg −1 or higher. In areas featuring CCA lumber, levels of As and Cu in adjacent soils were two to three times higher than levels of comparable control soils at the same schools; Cr levels were also higher than control soils. At 7 of the 11 schools evaluated, As levels in soils exceeded state screening limits. Schools can help to limit exposure to such elements by replacing CCA treated wood, and for contaminated soils, deep tilling, excavation/replacement, or covering soils with wood mulch or gravel.