2 research outputs found
Additional Treatment of Wastewater Reduces Endocrine Disruption in Wild Fishî—¸A Comparative Study of Tertiary and Advanced Treatments
Steroid estrogens are thought to be the major cause of
feminization
(intersex) in wild fish. Widely used wastewater treatment technologies
are not effective at removing these contaminants to concentrations
thought to be required to protect aquatic wildlife. A number of advanced
treatment processes have been proposed to reduce the concentrations
of estrogens entering the environment. Before investment is made in
such processes, it is imperative that we compare their efficacy in
terms of removal of steroid estrogens and their feminizing effects
with other treatment options. This study assessed both steroid removal
and intersex induction in adult and early life stage fish (roach, <i>Rutilus rutilus</i>). Roach were exposed directly to either
secondary (activated sludge process (ASP)), tertiary (sand filtrated
(SF)), or advanced (chlorine dioxide (ClO<sub>2</sub>), granular activated
charcoal (GAC)) treated effluents for six months. Surprisingly, both
the advanced GAC and tertiary SF treatments (but not the ClO<sub>2</sub> treatment) significantly removed the intersex induction associated
with the ASP effluent; this was not predicted by the steroid estrogen
measurements, which were higher in the tertiary SF than either the
GAC or the ClO<sub>2</sub>. Therefore our study highlights the importance
of using both biological and chemical analysis when assessing new
treatment technologies
Effects of Exposure to WwTW Effluents over Two Generations on Sexual Development and Breeding in Roach <i>Rutilus rutilus</i>
Exposure
to environmental estrogens in wastewater treatment works
(WwTW) effluents induces feminized responses in male fish, including
the development of eggs in male testes. However, the impacts on the
offspring of exposed fish are not well understood. In this study,
we examined whether roach (Rutilus rutilus) from mothers that had been exposed to an undiluted WwTW effluent
from early life to sexual maturity had altered susceptibility to gonadal
feminization and an impaired capacity to reproduce. For males from
both WwTW effluent exposed mothers and dilution water exposed mothers,
effluent exposure for up to 3 years and 9 months induced feminized
male gonads, although the intersex condition was relatively mild.
There was no difference in the severity of gonadal feminization in
roach derived from either WwTW effluent exposed or dilution water
exposed mothers. Furthermore, a breeding study revealed that roach
with effluent-exposed mothers reproduced with an equal success as
roach with mothers exposed to clean water. Roach exposed to the effluent
for 3 years in this study were able to reproduce successfully. Our
findings provide no evidence for impacts of WwTW effluent exposure
on reproduction or gonadal disruption in roach down the female germ
line and add to existing evidence that male roach with a mild intersex
condition are able to breed competitively