Environmental Engineering Reference
In-Depth Information
2010
; Derbalah et al.
2003
; Scully et al.
1988
; Jensen and Helz
1998
; Jameel and
Helz
1999
; Mitch et al.
2003
; Pomati et al.
2006
; Farré et al.
2008
; Fairchild et al.
1999
; Boxall et al.
2004
; Jahan et al.
2008
; McLeese et al.
1981
; Ahel et al.
1987
;
Tyler et al.
1998
; Scott and Jones
2000
; Oberdorster and Cheek
2001
; Cleuvers
2004
; Ferrari et al.
2004
; Bedner and MacCrehan
2006
; Owen et al.
2007
). It has
been shown that low part per trillion (10-100 ng L
−
1
) concentrations of steroidal
estrogen hormones can adversely affect the reproductive biology of aquatic wild-
life such as fish, turtles and frogs, by disrupting the normal function of their endo-
crine systems (Tyler et al.
1998
; Oberdorster and Cheek
2001
). The sex hormones
(mainly estrogens and androgens) are of very high potential concern, followed by
cardiovascular drugs, antibiotics and antineoplastics, the latter being used to cure
abnormal tissue growth (neoplasms) (Sanderson et al.
2004
).
Ethylene dibromide (EDB) is among the most commonly detected contami-
nants in groundwater. It is classified as a probable human carcinogen and is highly
persistent in water (Richardson
2007
). 1,4-Dioxane is also a widespread contami-
nant in groundwater and is a probable human carcinogen (Richardson
2007
). The
transformation intermediates of nonylphenol ethoxylates (NPEOs) and alcohol
ethoxylates (AEOs), in addition to the endocrine disrupting properties, are highly
toxic and refractory and can cause hazards to aquatic ecosystems (Derbalah et al.
2003
; Fairchild et al.
1999
; McLeese et al.
1981
; Ahel et al.
1987
; Scott and Jones
2000
). DDT and its metabolites can damage the nervous system, reproductive sys-
tem, and liver. It is also a potential human carcinogen that can cause liver cancer
(Guo et al.
2009
). Ionic liquids are toxic, and their toxicity can widely vary among
organisms and trophic levels (Pham et al.
2010
).
EDCs have potential effects on organisms (microorganisms, wildlife, animals,
and humans) including: androgenic, estrogenic, anti-estrogenic and anti-andro-
genic properties; disruption of the development of vital systems such as the endro-
crine, reproductive, immune, and thyroid functions; sexual differentiation of the
brain during fetal development; cognitive and motor function. Many of them are
also suspected carcinogens (Richardson and Ternes
2011
; Colborn
1993
; Rhind
2002
; Jansen et al.
1993
; Nimrod and Benson
1996
; Hansen
1998
; Langer et al.
1998
; Helleday et al.
1999
; Vine et al.
2000
; Moore et al.
2001
; Fenton
2006
).
EDCs can have transient and persistent effects on mammary gland development
depending on dose, exposure parameters and on whether exposure occurs during
critical periods of gland growth or differentiation (Fenton
2006
). Adverse effects
from these abnormal developmental patterns include the presence of carcin-
ogen-sensitive structures in the gland, in greater numbers or for longer periods.
Inhibited functional differentiation can also be observed, leading to malnutrition or
increased mortality of the offspring (Fenton
2006
). Individually, adverse effects of
EDCs exposure are detected on sperm production in rats and humans and reduc-
tions in Sertoli cell number in sheep (Carlsen et al.
1995
; Toppari et al.
1996
; Lee
et al.
1999
; Sweeney et al.
2000
). Reductions in embryo survival and consequent
effects on the reproductive rate in females are observed for many mammalian and
bird species (IEH) (IEH
1999
). Finally, human health is adversely affected by con-
sumption of food contaminated by EDCs.
