PAH Accessibility in Particulate Matter from Road-Impacted Environments.
Snowmelt, surface runoff, or stormwater releases in urban environments can result in significant discharges of particulate matter-bound polycyclic aromatic hydrocarbons (PAHs) into aquatic environments. Recently, more-specific activities such as road-tunnel washing have been identified as contributing to contaminant load to surface waters. However, knowledge of PAH accessibility in particulate matter (PM) of urban origin that may ultimately be released into urban surface waters is limited. In the present study, we evaluated the accessibility of PAHs associated with seven distinct (suspended) particulate matter samples collected from different urban sources. Laboratory-based infinite sink extractions with silicone rubber (SR) as the extractor phase demonstrated a similar pattern of PAH accessibility for most PM samples. Substantially higher accessible fractions were observed for the less-hydrophobic PAHs (between 40 and 80% of total concentrations) compared with those measured for the most-hydrophobic PAHs (<5% of total concentrations). When we focused on PAHs bound to PM from tunnel-wash waters, first-order desorption rates for PAHs with log Kow > 5.5 were found in line with those commonly found for slowly or very slowly desorbing sediment-associated contaminants. PAHs with log Kow < 5.5 were found at higher desorbing rates. The addition of detergents did not influence the extractability of lighter PAHs but increased desorption rates for the heavier PAHs, potentially contributing to increases in the toxicity of tunnel-wash waters when surfactants are used. The implications of total and accessible PAH concentrations measured in our urban PM samples are discussed in a context of management of PAH and PM emission to the surrounding aquatic environment. Although we only fully assessed PAHs in this work, further study should consider other contaminants such as OPAHs, which were also detected in all PM samples.
Norwegian Institute for Water Research, Oslo Centre for Interdisciplinary Environmental and Social Research , Gaustadalléen 21, NO-0349 Oslo, Norway.
Ian J
IJ
Allan
Environmental and Molecular Toxicology Department, Oregon State University , ALS 1007, 2750 SW Campus Way, Corvallis, Oregon 97331, United States.
Steven G
SG
O'Connell
Environmental Assessment Section, Norwegian Public Roads Administration , PO Box 8142 Dep, 0033 Oslo, Norway.|Department of Environmental Sciences, Norwegian University of Life Sciences , PO Box 5003, N-1432 Aas, Norway.
Sondre
S
Meland
Norwegian Institute for Water Research, Oslo Centre for Interdisciplinary Environmental and Social Research , Gaustadalléen 21, NO-0349 Oslo, Norway.
Kine
K
Bæk
Norwegian Institute for Water Research, Oslo Centre for Interdisciplinary Environmental and Social Research , Gaustadalléen 21, NO-0349 Oslo, Norway.
Merete
M
Grung
Environmental and Molecular Toxicology Department, Oregon State University , ALS 1007, 2750 SW Campus Way, Corvallis, Oregon 97331, United States.
Kim A
KA
Anderson
Norwegian Institute for Water Research, Oslo Centre for Interdisciplinary Environmental and Social Research , Gaustadalléen 21, NO-0349 Oslo, Norway.
Sissel B
SB
Ranneklev
D004784:Environmental Monitoring; D052638:Particulate Matter / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons
D052638:Particulate Matter; D011084:Polycyclic Aromatic Hydrocarbons