Agriculture Reference
In-Depth Information
Table 17.4.
Steroid hormones reported in US rivers (Kolpin
et al
.,
2002).
Hormone
N
RL (μg l
−1
)
Freq (%)
Max (μg l
−1
)
Med (μg l
−1
)
17
β
-estradiol
85
0.5
10.6
0.2
0.16
17
β
-estradiol
70
0.005
5.7
0.074
0.03
Oestrone
70
0.005
7.1
0.112
0.027
Oestriol
70
0.005
21.4
0.051
0.019
Testosterone
70
0.005
2.8
0.214
0.116
Progesterone
70
0.005
4.3
0.199
0.11
cis
-Androsterone
70
0.005
14.4
0.214
0.017
N, number of samples; RL, reporting level; Freq, frequency of detection; Max/Med, maximum/median detectable
concentration.
Generally, hormones are detected in 3-20% of
the river samples. Although the maximum con-
centrations are well below 1 mg l
−1
for all hor-
mones, this does not eliminate of the possible
interactions of these hormones and other con-
taminants in the environment (Kolpin
et
hormones may alter or disrupt the functions of
the endocrine system and cause adverse effects
to organisms including mimicking or blocking
receptor binding, or altering the rate of hor-
mone synthesis or metabolism through interac-
tions with the endocrine system (Meyers
et al
.,
2001). The effective levels of these hormones
are as low as ng l
−1
of water (Colborn
et al
.,
1993). For instance, a high incidence of inter-
sexuality (feminization) was observed in a wide
population of male roaches in the UK (Jobling
et al
., 1998). Also, after exposure to cattle feedlot
effluent, both testosterone synthesis and testis
size decreased in male fathead minnows
(Orlando
et al
., 2004).
Groundwater contamination with steroidal
hormones is rarely reported but can occur with
leaching and runoff from fields or leaking from
sewage systems (Jacobsen
et al
., 2005). In sam-
pling locations near a residential septic system,
Swartz
et al
. (2006) detected 0.2-45 ng l
−1
of
17b-estradiol and 0.4-120 ng l
−1
of oestrone in
the groundwater. The US Geological Survey
(2005) reported a 60% frequency of detecting
steroid hormones in groundwater from 47 sam-
pling locations susceptible to contamination from
either animal manure or human wastewaters.
The concentrations of 17b-estradiol ranged from
13 to 80 ng l
−1
in eight springs draining a karstic
aquifer (Wicks
et al
., 2004).
al
.,
2002).
Free oestrogens (total oestradiol and E1)
and testosterone were detected (0.5-5 and
1-28 ng l
−1
, respectively) in small streams drain-
ing from farm fields following application of
poultry litter (Shore
et al
., 1995). In a river adja-
cent to a feedlot, the concentration of oestrone,
17a-estradiol and 17b-estradiol was 900, 35
and 84 pg l
−1
, respectively, 80 km downstream
from the feedlot (Soto
et al
., 2004). Both E2a and
E2b were present in the streams receiving the
drainage from 800-cow dairy farm (Zhao
et al
.,
2010). The presence of E2a and E2b was con-
sistent throughout the spring months though at
low concentration (<1 ng l
−1
). Runoff due to
melting of snow and thawing of frozen ground
water during spring months might have moved
oestrogens from soil to the streams. Oestrone
(E1) and oestriol (E3) were not detected in
streams (detection limit: 0.061 and 0.036 ng l
−1
,
respectively).
Zeranol was detected in rivers in Europe,
where use of HGP is banned (Laganà
et al
.,
2004). Authors hypothesized that what they
detected were in fact metabolites of the myco-
toxin zearalenone. Following land application
of manure from cattle treated with all three
HGPs (TBA, MGA, zeranol), runoff from rainfall
simulation contained residues only sporadically
(less than 10% of the samples). When detected,
these were in ppt (ng l
−1
) concentrations in run-
off (Biswas
et al
., 2011). Exposure to steroidal
Best management practices to
minimize loading to water
Ultimately, manure is applied to cropland or pas-
tures as a fertilizer or soil amendment, with the
goal of recycling manure nutrients through
