Ultraviolet absorbents
(UVAs) and industrial antioxidants (IAs)
are contaminants of emerging concern. In this study, we investigated
the distribution and partitioning of these contaminants in surface
water, suspended particulate matter (SPM), sediment, and various tissues
of lake sturgeon (
Acipenser fulvescens
) and northern pike (
Esox lucius
)
from the St. Lawrence River (SLR), Quebec, Canada. Results indicated
that 2,6-di-
tert
-butyl-1,4-benzoquinone (BHTQ) was
the dominant contaminant in the dissolved phase of the surface water,
with median concentrations of 43, 15, and 123 ng/L for three sampling
sites, respectively. Surface water collected downstream of a major
city showed higher levels of various UVAs, BHTQ, and diphenylamine
compared to the upstream, suggesting the influence of the urban activities
on the contamination of these emerging contaminants in the SLR. SPM
showed greater sorption capacities of most target contaminants compared
to those of the sediment. Different contamination profiles were found
in lake sturgeon and northern pike, implying that the accumulation
of UVAs and IAs in fish depends on their feeding behavior. The field-based
tissue-specific bioaccumulation factors (BAFs) for frequently detected
contaminants (log BAF 1.5–4.2) were generally comparable to
or lower than the Estimation Program Interface modeling results (1.4–5.0),
indicating that some of these contaminants may be less bioaccumulative
than previously expected.