Synthetic
hormonal use in humans and emerging risks to the environment
Neil Noesen,
PharmD
Thesis:
We are just beginning to realize the
long-term adverse physiological and psychological effects for human users of
synthetic hormones, their welfare, and the ecological safety of our environment
and drinking water due to the survival of their metabolites through our bodies
and through our waste water treatment facilities. Emerging risks are being discovered and evaluated.
The US Environmental Protection Agency (EPA) has identified
research needs to determine future risks of synthetic estrogen metabolites in
our environment, such as those from ethinyl estradiol, and other endocrine-disrupting chemicals (EDCs). The EPA would
like studies to determine the effects of EDCs on
reproductive, neurological, and immunological function, as well as
carcinogenesis. The White House’s
Committee on the Environment and Natural Resources increased their budget to
include studies in these areas on EDCs. The US Congress added provisions to the Food
Quality Protection Act (FQPA) and the Safe Drinking Water Act of 1996 to
require testing for estrogenicity and other hormonal
activity. The Endocrine Disruptor
Screening and Testing Advisory Committee (EDSTAC) was
established in 1998 as part of the Toxic Substances Control Act. The study of EDCs
has become one of the biggest testing programs ever in the history of
toxicology.[1]
The persistence of pharmaceutical contaminants in our aquatic
environment may be partially attributed to human consumption of drugs and
subsequent discharges from sewage treatment plants. The contamination of our water resources by
pharmaceuticals and their metabolites, particularly the EDCs,
is emerging as an international environmental concern. The long-term effects of human exposure to
continuous low-level EDCs are not yet well
understood.[2]
The
Many researches have been able to correlate endocrine system
anomalies due to contaminants of EDCs. There are a few researchers who have
documented examples of aberrant animal behavior and disruptions of their reproductive
patterns due to EDCs in their habitat: gulls from
David Quanrud et al have done some
very interesting theoretical work by isolating one of the human estrogen
receptors to determine how significant our exposure is to these detectable
estrogenic contaminants. The
contaminants of ethinyl estradiol
metabolites that are passed through human urine and through waste water
treatment plants are showing to be of high enough concentrations to remove
natural human estrogen from their receptors due to a displacement by the
estrogenic contaminants found in the Constructed Ecosystems Research Facility. These studies are called competitive binding
assays and involve only isolated human receptors. Therefore no hard evidence can yet be drawn
from these studies in their relation to whole organism toxicity. Work is underway at establishing correlations
between these binding assays and more physiological relevant bioassays to
determine whole organism toxicity.[8]
[1] Daston, George P. Toxicological Sciences. 74(2):245-252, August 2003.
[2] Boyd, Glen R., Grimm, Deborah A. Occurrence of Pharmaceutical
Contaminants and Screening of Treatment Alternatives for Shoutheastern
[3] Sedlak, David L., Pinkston, Karen E Factors Affecting the Concentration of
Pharmaceuticals Released to the Aquatic Environment. Department of Civil and
Environmental Engineering,
[4] Colbourn, T. Dumanoski, D., and Myers, J.P. (1996) Our Stolen Future.
Penguin Books,
[5] Roefer, P., Snyder, S., Zegers,
R.E., Rexing, D.J., and Fronk,
J.L. 2000 Endocrine disrupting chemicals in a source water. Journal of the American Water Works
Association, 92(8):52-58.
[6]Tyler,C.R., Jobling,S., and Sumpter,J.P. 1998. Endocrine disruption in wildlife: a critical review of the evidence. Critical Reviews in Toxicology, 28(4):319-361.
[7] Ibid.