Daily News Archive
Children's Study: Endocrine Disruption Research Needed
(Beyond Pesticides, October 29, 2003) In the October 2003
issue of Environmental Health Perspectives, the need for researching
the health effects of endocrine disrupting (ED) chemicals on children
is discussed in a series of three articles. The risk that EDs pose to
children is an important issue that needs further scientific research,
especially considering that children are at a unique risk to environmental
contamination and pesticide exposure. They take in more pesticides relative
to body weight than adults and have developing organ systems that are
more vulnerable and less able to detoxify toxic chemicals.
EDs wreak havoc by interfering with the body's hormone signaling systems.
Hormones are chemicals made by the body that help control the body's functions.
They are present in minute quantities. EDs may be mistaken for hormones
by the body, and disrupt the systems controlled by the hormones. They
may alter feedback loops in the brain, pituitary, gonads, thyroid, and
other components of the endocrine system. In particular, some EDs are
mistaken for the female hormone estrogen. These estrogen mimics interfere
with the reproductive system, causing infertility, malformed sexual organs,
and cancer of sensitive organs. Disturbingly, there are many commonly
used pesticides that are suspected endocrine disrupters, such as 2,4-D
Philip Landrigan, M.D., Anjali Garg, and Daniel B.J. Droller discuss the
need for endocrine disrupting chemicals to be studied in the U.S. federal
government's National Children's
Study (NCS), which examines "the effects of environmental influences
on the health and development of more than 100,000 children across the
United States, following them from before birth until age 21." Landrigan
et al, in the paper "Assessing
the Effects of Endocrine Disruptors in the National Children's Study"
hypothesize that "in utero and early childhood exposures to
EDs may be responsible, at least in part, for decreases in semen quality;
increasing incidence of congenital malformations of the reproductive organs,
such as hypospadias; increasing incidence of testicular cancer; and acceleration
of onset of puberty in females." They state the importance of the
opportunity that the National Children's Study gives to test these hypotheses.
In the article "Exposure
Assessment for Endocrine Disruptors: Some Considerations in the Design
of Studies," researchers Carol Rice, Linda S. Birnbaum, James
Cogliano, Kathryn Mahaffey, Larry Needham, Walter J. Rogan, and Frederick
S. vom Saal examine the various factors that must be addressed in a study
of childhood exposure to EDs in order to fully understand their effects.
These factors include "multiple routes of exposure; the timing, frequency,
and duration of exposure; need for qualitative and quantitative data;
sample collection and storage protocols; and the selection and documentation
of analytic methods."
Finally, in the article "An
Approach to Assessment of Endocrine Disruption in the National Children's
Study," researchers Matthew P. Longnecker, David C. Bellinger,
David Crews, Brenda Eskenazi, Ellen K. Silbergeld, Tracey J. Woodruff,
and Ezra S. Susser discuss why it is important for such human studies
on EDs to take place, referring to previous similar studies as points
of reference for an efficient design of the National Children's Study
to look at EDs. They state, "if properly designed, the NCS could
serve as an excellent resource for investigating future hypotheses regarding
A list of suspected endocrine disrupters from the National Institute
of Health Sciences is available at http://www.nihs.go.jp/hse/endocrine-e/paradigm/pesticide/pest-list-e.html.
For more information on pesticides and children, see Beyond Pesticides'
Schools Program Page.