What Are Sperm Telling Us?
By Nicholas Kristof, 2/20/21, NY Times

Something alarming is happening between our legs.
Sperm counts have been dropping; infant boys are developing
more genital abnormalities; more girls are experiencing
early puberty; and adult women appear to be suffering
declining egg quality and more miscarriages.
Its not just humans. Scientists report genital anomalies
in a range of species, including unusually small penises
in alligators, otters and minks. In some areas, significant
numbers of fish, frogs and turtles have exhibited both male
and female organs.

Four years ago, a leading scholar of reproductive health,
Shanna H. Swan, calculated that from 1973-2011, the sperm
count of average men in Western countries had fallen by 59%.
Inevitably, there were headlines about €œSpermageddon€� and
the risk that humans would disappear, but then we moved on
to chase other shiny objects.

Now Swan, an epidemiologist at Mt Sinai Medical Center in
New York, has written a book, €œCount Down,€� that will be
published on Tuesday and sounds a warning bell. Her subtitle
is blunt: €œHow our modern world is threatening sperm counts,
altering male and female reproductive development, and
imperiling the future of the human race.€�

Swan & other experts say the problem is a class of chemicals
called endocrine disruptors, which mimic the bodys hormones
& thus fool our cells. This is a particular problem for
fetuses as they sexually differentiate early in pregnancy.
Endocrine disruptors can wreak reproductive havoc.

These endocrine disruptors are everywhe plastics, shampoos,
cosmetics, cushions, pesticides, canned foods and A.T.M.
receipts. They often arent on labels and can be difficult
to avoid.

€œIn some ways, the sperm-count decline is akin to where global
warming was 40 years ago,€� Swan writes. €œThe climate crisis
has been accepted €” at least by most people €” as a real threat.
My hope is that the same will happen with the reproductive
turmoil thats upon us.€�

Chemical companies are as reckless as tobacco companies were
a generation ago, or as opioid manufacturers were a decade
ago. They lobby against even safety testing of endocrine
disruptors, so that we have little idea if products we use
each day are damaging our bodies or our children. Were all
guinea pigs.

Aside from the decline in sperm counts, growing numbers of
sperm appear defective €” theres a boom in two-headed sperm €”
while others loll aimlessly in circles, rather than furiously
swimming in pursuit of an egg. And infants who have had greater
exposures to a kind of endocrine disruptor called phthalates
have smaller penises, Swan found.

Uncertainty remains, research sometimes conflicts & biological
pathways arent always clear. There are competing theories
about whether the sperm count decline is real and what might
cause it and about why girls appear to be reaching puberty
earlier, and its sometimes unclear whether an increase in
male genital abnormalities reflects actual rising numbers or
just better reporting.

Still, the Endocrine Society, the Pediatric Endocrine Society,
the Presidents Cancer Panel and the World Health Org have
all warned about endocrine disruptors, and Europe and Canada
have moved to regulate them. But in the US, Congress and the
Trump admin seemed to listen more to industry lobbyists than
to independent scientists.

Patricia Ann Hunt, a reproductive geneticist at Washington
State Univ, has conducted experiments on mice showing that
the impact of endocrine disruptors is cumulative, generation
after generation. When infant mice were exposed for just a
few days to endocrine disrupting chemicals, their testes as
adults produced fewer sperm, & this incapacity was transmitted
to their offspring. While findings from animal studies cant
necessarily be extended to humans, after three generations of
these exposures, one-fifth of the male mice were infertile.

€œI find this particularly troubling,€� Professor Hunt told me.
€œFrom the standpoint of human exposures, you could argue we
are hitting the third generation just about now.€�

What if anything does all this mean for the future of humanity?

€œI do not see humans becoming extinct, but I do see family
lines ending for a subset of people who are infertile,€� Andrea
Gore, a prof of neuroendocrinology at the UT Austin, told me.
€œPeople with impaired sperm or egg quality cannot exercise
their right to choose to have a child. That may not devastate
our species, but it is certainly devastating to these infertile
couples.€�

More research is necessary, & govt regulation & corporate
responsibility are crucial to manage risks, but Swan offers
practical suggestions for daily life for those with the
resources. Store food in glass containers, not plastic. Above
all, dont microwave foods in plastic or with plastic wrap on
top. Avoid pesticides. Buy organic produce if possible. Avoid
tobacco or marijuana. Use a cotton or linen shower curtain,
not one made of vinyl. Dont use air fresheners. Prevent dust
buildup. Vet consumer products you use with an online guide
like that of the Environmental Working Group.

Many issues in headlines today wont much matter in a decade,
let alone in a century. Climate change is one exception, and
another may be the risks to our capacity to reproduce.

The epitome of a €œlow blow€� is a kick to the crotch. And that,
friends, may be what we as a species are doing to ourselves.

https://www.nytimes.com/2021/02/20/o...ors-sperm.html