LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
LAS-seawater treatment LAS-distilled water treatment
35
S LAS uptake µg/mg dw
Epicuticular waxes 9.96 ± 3.10 4.90 ± 1.10
Dewaxed needles 0.007 ± 0.001 ~ 0
Remaining plant material
% of total radioactivity
0.006 ± 0.001 ~ 0
Epicuticular waxes 89.70 ± 6.02 96.90 ± 2.34
Dewaxed needles 9.90 ± 5.95 ~ 0
Remaining plant material 0.37 ± 0.23 3.10 ± 0.02
After LAS exposure in seawater or distilled water, alterations of the
epicuticular wax fine structure were observed by SEM.
Remarks: Forty-eight hours after exposure, half of the radioactivity detected was in the
epicuticular waxes, with nearly all the rest in the washing solution. LAS was
absorbed to a much greater extent in the seawater treatment (surface tension
= 29 mN/m) than in the distilled water treatment (surface tension = 45
mN/m). LAS accumulated mainly in the epicuticular wax of the needles.
Very little accumulated in the dewaxed needles or remaining plant material.
More dramatic changes in epicuticular wax fine structure were observed
following LAS treatment in seawater than in distilled water. These
observations are in agreement with the studies reported by Hamwijk (2002)
and Grieve and Pitman (1978), who demonstrated that low surface tension
(