Chemistry of Freshwaters - Principles of Environmental Chemistry - page 154

ethers (PBDEs), 166 and perfluorooctane sulfonates (PFOS), 167 which have
been found in Great Lakes' water and biota.

3.3.5.2.3 Endocrine disruptors. Concern has recently been expressed
over the possible role of various synthetic organic chemicals (e.g.
organochlorine pesticides, PCBs, phthalates, alkylphenolethoxylates
(APEs), alkylphenols, etc.) as disruptors of endocrine systems of wildlife
and perhaps even of humans. 168,169 Reproductive changes in male
alligators from Lake Apopka, Florida, embryonic death, deformities,
and abnormal nesting behaviour in fish-eating birds in the Great Lakes
region and the occurrence of hermaphroditic fish near sewage outfalls on
some British rivers have been attributed to postulated oestrogenic or
anti-androgenic effects of some of these chemicals. 168,169 Most APEs,
which are used as detergents, emulsifiers, wetting agents, and dispersing
agents, enter the aquatic environment after disposal in wastewater.
During biodegradation treatment of the latter, the APEs are trans-
formed into more toxic, short-chain ethoxylates, alkylphenol carboxylic
acids, and alkylphenols. 170 The threshold concentration of nonylphenol
in water for production of the female egg yolk protein, vitellogenin, in
male rainbow trout is 10 mgL 1 . 171 It also appears that nonylphenol

concentrations in many European rivers are up to 10 times higher than
those found in USA rivers, which are typically o 1 mgL 1 , 170,172 the EU
limit. It has been suggested, however, that natural oestrogens (e.g.
oestrone and 17b-oestradiol) may be responsible for the observed effects,
perhaps after conversion of inactive excreted metabolites to active forms
by bacterial enzyme action during sewage treatment. 173 The COMPRE-
HEND (Community Programme of Research on Environmental Hor-
mones and Disruptors) 1999-2001 survey found that in some domestic
sewage euents there were oestrogenic steroids present, almost certainly
from human excretion, at concentrations sucient to account for most
of the oestrogenicity, causing widespread sexual disruption, in fish in
rivers throughout England and Wales. 174 Maximum measured concen-
trations were 14 ng L 1 for oestradiol, 51 ng L 1 for its principal
metabolite oestrone, 17 ng L 1 for another metabolite oestriol, and 2 ng
L 1 for the synthetic steroid ethinylestradiol, the active ingredient in the
birth control pill. As a result, the Environment Agency has set a
threshold exposure limit for steroid estrogens of 1 ng L 1 for oestradiol,
3ngL 1 for oestriol and 0.1 ng L 1 for ethinylestradiol in sewage
euent. 175 In industrial euents, the oestrogenic steroids were not
detected but nonylphenol (NP), NP mono- and diethoxylates, and
bisphenol-A were found at concentrations up to 3, 7, and 1 mgL 1 ,
respectively. 174 The relatively high hydrophobicity of alkylphenols has

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