Review of Fate, Exposure, and Effects of Sunscreens in Aquatic Environments and Implications for Sunscreen Usage and Human Health (2022) / Chapter Skim
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5 Bioaccumulation and Measured Concentrations of UV Filters in Biota
5 Bioaccumulation and Measured Concentrations of UV Filters in Biota
Pages 103-120
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From page 103... ...
filters in biota, including estimates for bioaccumulation, bioconcentration, and biomagnification factors. HOW BIOACCUMULATION INFORMATION IS USED IN ECOLOGICAL RISK ASSESSMENT Understanding bioaccumulative potential of chemicals is an essential element of both classification and labeling of chemicals (e.g., Safety Data Sheets, U.S.
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From page 104... ...
From a regulatory perspective, bioaccumulation, bioconcentration, and trophic magnification are expressed as ratios of tissue concentrations to exposure medium concentrations (Table 5.1)
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From page 105... ...
CB-LW/CD-LW TMF TMF (unitless) em or 10m BAF = bioaccumulation factor; BCF=bioconcentration factor; BMF = biomagnification factor; BSAF = biota-sediment accumulation factor; BSSAF = biota-suspended sediment accumulation factor; TMF=trophic magnification factor.
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From page 106... ...
The BCF-BAF modeling program within the EPA EPI SuiteTM was used to perform estimations of BCF. Measured log Kow values were used when available; otherwise, log Kow values were first estimated using EPA ECOSAR (V 2.11)
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From page 107... ...
and can be considered as likely to bioaccumulate above threshold values for regulation in the absence of definitive bioaccumulation data from well conducted laboratory studies or evidence of high rates of metabolism. It is therefore unsurprising that these compounds are also studied in laboratory environments to provide experimental log Kow and bioconcentration data (see section on Laboratory-based Tissue Concentration Studies)
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From page 108... ...
during studies of tissue concentrations from natural seawater environments. While oxybenzone metabolism has been demonstrated, it does not always yield detectable levels of metabolites when studied.
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BIOACCUMULATION AND MEASURED CONCENTRATIONS OF UV FILTERS IN BIOTA 109 FIGURE 5.2 Various degradation products of oxybenzone detected in gilt fish bream (Sparus aurata) bile, plasma, liver, muscle, and gill.
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From page 110... ...
Because lipophilicity is an important factor in interpreting bioaccumulation, the preferred expression of experimental tissue concentrations is lipid normalized wet weight. Studies can either be performed to empirical steady state followed by depuration to understand the toxicokinetics of the compound, or first order uptake and depuration rate constants can be experimentally determined with the ratio deriving the BCF estimate.
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From page 111... ...
(2021) on the mussel Mytilus edulis indicate bioaccumulation of this UV filter is low and, in many instances, tissue concentrations were nondetectable.
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From page 112... ...
uptake for low and high exposures Oxybenzonea Procambarus clarkii 42 d uptake Water BCF: 54 ± 23 L/kg, DW, lipid normalized He et al., 2021b (red swamp crayfish) 42 d depuration Homosalatea Procambarus clarkii 42 d uptake Water BCF: 991 ± 569 L/kg, DW, lipid normalized He et al., 2021b (red swamp crayfish)
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From page 113... ...
was too short to achieve steady state; too few organisms were used to assess variability; the study lacked time course data to determine kinetic rates; exposures were excessively variable; and exposures were in the range of acute and chronic toxicity. Laboratory studies, in general, were substantially less abundant in literature than field studies of tissue concentrations (see Appendix D)
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From page 114... ...
. While documentation of tissue concentrations is an important and relevant endeavor, no study available from the literature adequately quantifies tissue burdens alongside exposure concentrations in aquatic food, water, or sediment in a manner conducive to calculating BAFs, BCFs, BMFs, or TMFs (trophic magnification factor)
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From page 115... ...
Octocrylene The laboratory-based BCFs of 830–880 L/kg (lipid normalized wet weight) were associated with tissue concentrations of ~900–8,600 ng/g (Pawlowski et al., 2019)
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Oxybenzone Oxybenzone had a laboratory-based BCF of 33–160 L/kg (lipid normalized wet weight) with 3.3–16 ng/g as the tissue concentration at steady state.
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From page 117... ...
. The highest measured tissue concentration in the study yielded 32.7 µg/g, which corresponds to 0.10 mmol/kg, which is below the known nonpolar and polar critical body burdens for acute and chronic toxicity (McCarty and Mackay, 1993; McCarty et al., 2013)
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From page 118... ...
Knowledge Gap: Currently available field studies of tissue concentrations lack comprehensive characterizations of UV filter exposure in water and sediment, leaving interpretation solely as presence and concentration of UV filters in tissues. While important and relevant, these findings would benefit from additional research by considering both tissue burdens with UV filters and spatial and temporal UV filter exposure concentrations in aquatic food, water, or sediment.
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From page 119... ...
Knowledge Gap: Future research needs include development of standard guidelines on bioconcentration under laboratory conditions for saltwater fish and invertebrates and improved studies of critical body residues in acute and chronic exposures to simultaneously understand both bioaccumulation and toxicity and to address mixture toxicity of UV filters simultaneously.
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