Endocrine disruption is a relatively
new concept in environmental health. There has been an explosion of research
and understanding, but it remains an area of enormous scientific uncertainty. The story of lead suggests that uncertainty
should not supersede a precautionary approach when the stakes are so high
(i.e. widespread exposure combined with profound health effects).
We are all exposed to many thousands of endocrine disruptors and researchers
speculate that they are capable of exerting population-wide effects
levels of exposure
. They are measurable at very low levels in the body
fluids and tissues of all our children.
Some of them (persistent organochlorines) are stored in the body for
long periods of time.
of this is unclear. Wildlife, exposed to higher levels of persistent
organochlorines, has been found to suffer reproductive dysfunction and sexual
At present we live with
uncertainty as to whether endocrine disruptors might be affecting cancer
rates, reproductive function and development, neuro-development, the immune
systems and thyroid function of children.
Of immediate concern are the
levels of two persistent organochlorines with endocrine disruption action,
dioxin and PCBs, in the breast milk of mothers in the Great Lakes Region.
(Recent Health Canada estimates indicate
that exclusively breastfed infants under 6 months of age in the Great Lakes
region are likely exposed to almost six
times the Tolerable Daily
Intake of 10 pg TEQ/kg bw/day for dioxin.) Although breast milk is clearly
considered best for the baby, this is an area that warrants continued
scientific and immediate policy attention.
We need to focus on reducing the chances that these substances continue
to end up in the environment and ultimately, in human tissues, being passed on
from generation to generation.
Colborn, T, D.
Dumanoski, and J. Peterson Myers, Our Stolen Future (Dutton, New York, 1996), see in particular, Chapter
11 (Beyond Cancer) and Chapter 11 (Flying
Blind). Haines M., et.al.,. Dioxins & Furans. Chapter 6.0 and
Polychlorinated Biphenyls. Chapter 11.0In: Persistent Environmental Contaminants and the Great Lakes Basin
Population: An Exposure
Assessment. Health Canada. Minister of Public Works and Government Services, Canada. Catalogue No. H46-2/98-218E. (1998).