| To determine the impact that chromated copper arsenate (CCA)-contaminated mulch imposes on the environment and human health, forty commercially purchased mulch samples from Cincinnati Metropolitan area were studied. This study was conducted in three phases; (1) quantified TCLP metal concentrations leached from each mulch, (2) conducted bioavailability studies to determine potential threats to human health from mulch, and (3) analyzed rhizosphere microbial communities before and after mulch application through plate counts. It was found that the mulches leached chromium, copper, and arsenic. In the bioavailability and microbial studies, there were no significant differences observed between the composite mulch and negative control mulch treatments. In all cases, metals accumulated in the edible plant portions were at concentrations below the recommended daily doses. These results provide an indication of the potential threat to human health from CCA-contaminated mulch, and calls for public awareness/educational programs about mulch uses. |
