In:
Environmental Science: Processes & Impacts, Royal Society of Chemistry (RSC), Vol. 23, No. 12 ( 2021), p. 1930-1948
Abstract:
Fish bioconcentration factors (BCFs) are commonly used in chemical hazard and risk assessment. For neutral organic chemicals BCFs are positively correlated with the octanol–water partition ratio ( K OW ), but K OW is not a reliable parameter for surfactants. Membrane lipid–water distribution ratios ( D MLW ) can be accurately measured for all kinds of surfactants, using phospholipid-based sorbents. This study first demonstrates that D MLW values for ionic surfactants are more than 100 000 times higher than the partition ratio to fish-oil, representing neutral storage lipid. A non-ionic alcohol ethoxylate surfactant showed almost equal affinity for both lipid types. Accordingly, a baseline screening BCF value for surfactants (BCF baseline ) can be approximated for ionic surfactants by multiplying D MLW by the phospholipid fraction in tissue, and for non-ionic surfactants by multiplying D MLW by the total lipid fraction. We measured D MLW values for surfactant structures, including linear and branched alkylbenzenesulfonates, an alkylsulfoacetate and an alkylethersulfate, bis(2-ethylhexyl)-surfactants ( e.g. , docusate), zwitterionic alkylbetaines and alkylamine-oxides, and a polyprotic diamine. Together with sixty previously published D MLW values for surfactants, structure–activity relationships were derived to elucidate the influence of surfactant specific molecular features on D MLW . For 23 surfactant types, we established the alkyl chain length at which BCF baseline would exceed the EU REACH bioaccumulation (B) threshold of 2000 L kg −1 , and would therefore require higher tier assessments to further refine the BCF estimate. Finally, the derived BCF baseline are compared with measured literature in vivo BCF data where available, suggesting that refinements, most notably reliable estimates of biotransformation rates, are needed for most surfactant types.
Type of Medium:
Online Resource
ISSN:
2050-7887
,
2050-7895
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2021
detail.hit.zdb_id:
2703791-5
