TY - JOUR
T1 - Characterization and potential environmental risks of leachate from shredded rubber mulches
AU - Kanematsu, Masakazu
AU - Hayashi, Ai
AU - Denison, Michael S.
AU - Young, Thomas M.
PY - 2009/8
Y1 - 2009/8
N2 - In order to determine whether shredded rubber mulches (RM) pose water quality risks when used in stormwater best management practices (BMPs) such as bioretention basins, batch leaching tests were conducted to identify and quantify constituents in leachates from RM such as metal ions, nutrients, total organic carbon (TOC), and aryl hydrocarbon receptor (AhR) activity (determined by the chemically activated luciferase gene expression (CALUX) bioassay) at varied temperature and initial pH values. The results indicate that aqueous extracts of RM contain high concentrations of zinc (Zn) compared with wood mulches (WM), and its concentration increased at lower pH and higher temperature. Although methanol extracts of RM displayed high AhR activity, none of the aqueous extracts of RM had significant activity. Hence, while unknown constituents that have significant AhR activity are present in RM, they appear to be not measurably extracted by water under environmental conditions relevant for stormwater (5 < pH < 9, 10 < T < 40 °C). Our results suggest that organic constituents in water extracts of RM which have AhR activity may not be of significant concern while leaching of Zn from RM appears to be a potentially larger water quality issue for RM.
AB - In order to determine whether shredded rubber mulches (RM) pose water quality risks when used in stormwater best management practices (BMPs) such as bioretention basins, batch leaching tests were conducted to identify and quantify constituents in leachates from RM such as metal ions, nutrients, total organic carbon (TOC), and aryl hydrocarbon receptor (AhR) activity (determined by the chemically activated luciferase gene expression (CALUX) bioassay) at varied temperature and initial pH values. The results indicate that aqueous extracts of RM contain high concentrations of zinc (Zn) compared with wood mulches (WM), and its concentration increased at lower pH and higher temperature. Although methanol extracts of RM displayed high AhR activity, none of the aqueous extracts of RM had significant activity. Hence, while unknown constituents that have significant AhR activity are present in RM, they appear to be not measurably extracted by water under environmental conditions relevant for stormwater (5 < pH < 9, 10 < T < 40 °C). Our results suggest that organic constituents in water extracts of RM which have AhR activity may not be of significant concern while leaching of Zn from RM appears to be a potentially larger water quality issue for RM.
KW - Ah receptor activity
KW - Shredded rubber mulch
KW - Wood mulches
KW - Zinc
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UR - http://www.scopus.com/inward/citedby.url?scp=67651091550&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2009.04.026
DO - 10.1016/j.chemosphere.2009.04.026
M3 - Article
C2 - 19450864
AN - SCOPUS:67651091550
VL - 76
SP - 952
EP - 958
JO - Chemosphere
JF - Chemosphere
SN - 0045-6535
IS - 7
ER -