Half the Man His Father Was?

Studies are showing dramatic drops in sperm counts and rising rates of male reproductive health problems for men throughout industrialized countries. Are environmental contaminants partially to blame?

To answer that question, we have to start with another: what actually makes a man a man? We all learn in science class that a person’s biological sex starts with genes. The mother’s egg carries an X chromosome. If the father’s sperm carries a Y chromosome, the resulting embryo will be a boy. If the sperm carries an X, it will be a girl. Together, mother and father sex chromosomes form an embryo, either XY (boy) or XX (girl).

But gender is more complicated than genes. After sperm and egg become acquainted, the embryo’s reproductive tissues begin to develop. For about five weeks this process is identical in both males and females. Then, if the embryo is male, certain cells begin to grow and release testosterone, initiating development of the entire male reproductive system – including the prostate gland, penis, urethra and scrotum. At this time the brain is wired to set the stage for further maturation during puberty, and in the last two months of fetal development, testosterone signals the testes to descend into the scrotum.

Testosterone-induced development continues in boys throughout the first few years of life. Then things get quiet for a while until puberty, when the hormone raging begins again. It’s hard to imagine how just a handful of hormones — testosterone, estrogen, thyroid and a few other natural chemicals produced inside the body — orchestrate, through a complex and delicate balance of hormone signaling, the growth and development of all tissues and organs, including the reproductive system. It is even harder to grasp how significant changes in development and health can come from absolutely infinitesimal amounts of these natural chemicals.

So when tiny amounts of hormonally active synthetic chemicals get into our bodies from the food we eat, the air we breathe, the water we drink and the products we use every day, they too can cause major health impacts, even at very low doses. They can disrupt the sensitive hormone balance by blocking natural messages or sending their own misleading signals that fool the body into doing the wrong thing at the wrong time.

Thousands of peer-reviewed, published studies (mostly animal studies) suggest that certain human reproductive health problems are tied to synthetic or industrial chemical exposures. In males, these problems include two common birth defects: cryptochordism (undescended testicles) and hypospadias (a deformity of the penis), both of which have also been linked to low sperm counts and testicular cancer later in life. All four of these conditions, collectively called testicular dysgenesis syndrome (TDS), can arise from the same origin – disrupted hormone signaling in the womb during critical stages of male reproductive system development.

Animal studies have demonstrated time and time again that prenatal exposures to chemicals – including vinclozolin (a widely used fungicide), phthalates (found in PVC plastic and personal care products), bisphenol A (found in polycarbonate bottles and the linings of canned foods and beverages), and the banned but still present industrial chemicals DDT and PCBs – can cause TDS.

Statistical analysis shows that TDS conditions are on the rise in humans, particularly the incidence of low sperm counts in most highly developed countries. In several industrial regions, sperm counts have dropped fifty percent over the last 50 years, and several new studies suggest that testosterone levels may have declined 1% per year for the past 40-50 years. In the United States alone, testicular cancer has dramatically increased since the 1970s, with a reported 60% increase among whites and Asians, and 40% increase in blacks.

So what can men and their families do, to protect their ability to become fathers, and increase their chances of living a long and healthy life? Green purchasing helps. Buying products that are free of phthalates, pesticides, bisphenol A and other chemicals gives us a way to protect ourselves and contributes to the broader effort to shift markets and move the economy in a healthy direction. Many resources exist that can help guide families, communities, and institutions to greener products.

Green policies help even more. A few cities, several states and the federal government are all currently considering bills that would restrict the use of phthalates, bisphenol A and other environmental contaminants; put research dollars into green solutions; and require companies to prove that chemicals are safe before they are put into products and released on the market. Those bills and the elected officials that support them deserve our support. Chemical and product manufacturers continue to argue that animal studies should not be used to determine human health policies, but the U.S. Food and Drug Administration (FDA), tasked with protecting public health by regulating food and drugs, routinely relies on animal studies to decide which chemicals are too dangerous to be used as pharmaceuticals. Why shouldn’t they do the same for the wide variety of other chemicals that impact our health?

Most importantly, we need to give our fathers, our sons and ourselves a greener future. That can happen once we come to collectively understand how our families’ health is connected to the health of everything and everyone else. Anything we can do to reduce harm and prevent unnecessary chemical exposures will protect the health of all men and future generations to come. What better gift could a father ask for?

Learn More!

A new report, “Shaping Our Legacy: Reproductive Health and the Environment,” will be available in the coming weeks at here. The report comprehensively outlines the science behind environmental influences to male reproductive health, and points the reader to many available resources for what you can do.

Check out the Collaborative on Health and the Environment website, and the Commonweal website.

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  • http://www.stats.org invalid-0

    The only way BPA is estrogenic is if it is injected into the blood stream. Don’t just take my word for it, the European Union’s risk assessment explicitly states that oral exposure to BPA removes all estrogenic power. The reason is that

    BPA is rapidly broken down first in the gastrointestinal tract (GI) and then in the liver by enzymes which add a sugar molecule to BPA, transforming it into a water soluble BPA-glucuronide. Being water soluble, BPA-glucuronide is easily excreted in urine. This happens very quickly. The half life of BPA-glucuronide is six hours. There is a minor metabolic pathway in which some BPA is converted to a sulfate, but this is also water soluble and quickly excreted as a metabolite.

    In adult human volunteer studies, no free or parent BPA is found in blood. There is 100 percent conversion to a metabolite.

    Now, if you inject BPA into an animal’s bloodstream you can demonstrate that BPA is estrogenic. Rats and mice process BPA in significantly different ways to humans too.

    This is why independent risk assessments in Europe, Japan and the U.S. reject the animal studies showing estrogenic effects. Humans are only exposed to BPA through oral routes.

    Moreover, recent research by EPA scientists published online in December 2007 in the pre-eminent toxicological journal Toxicological Sciences found that gestational and lactational exposure to ethinyl estradiol, a sex hormone used in the contraceptive pill did produce low dose effects in rats, such as decreased sperm counts, while similar low-dose exposures to BPA had no effects whatsoever.

    So even the hypothesis that BPA has an impact in animal studies is now under question.

    Finally, given your interest in what the research says, you should note that the studies showing dramatic drops in sperm counts are nothing if not highly controversial.



    And then there are some interesting counter explanations for sperm count decline, such as salt:

    and for fertility declines, one also has to factor in smoking, the most efficient way to ingest thousands of chemicals ever designed


    While your thesis may be broadly correct,and there is some disturbing new research:


    it’s important, if we are to deal with the problem, to get the specifics right. Otherwise, we may end up solving nothing.


    Trevor Butterworth

  • http://www.bcaction.org invalid-0

    Thank you Charlotte. I look forward to reading your report. FYI readers, I looked at Mr Butterworth’s web page. Please see Source Watch’s website for info about his organization.


    “The Statistical Assessment Service (STATS) touts itself as a “non-profit, non-partisan organization” but is a stealth PR operation of the Center for Media and Public Affairs (CMPA)…

    From its inception, …STATS has repeatedly attacked environmentalists, civil libertarians, feminists and other “liberals.”

    …Media Transparency lists startup funding for STATS as having come from conservative funders.”

    Also see related links for Center for Media and Public Affairs.


    The Center for Media and Public Affairs was founded in the mid 1980s by S. Robert Lichter and Linda Lichter. According to Salon.com, “the seed money for [the] center was solicited by the likes of Pat Buchanan and Pat Robertson”.

    Media Transparency… data reveals that the overwhelming proportion of CMPA’s funding comes from conservative foundations.”

    Lastly, see related page for S. Robert Lichter, who is president of STATS as well as Center for Media and Public Affairs and is a paid consultant to the Fox News Channel.

    • invalid-0

      So, why does it matter what organization he works for? Does this make the published reports referenced any less relevant? Come on, this is the standard attack method environmentalists are using. Let’s put out a lot of fear mongering, and if anyone decides to refute the fear mongering, they get labeled as “industry or chemical sponsored” or “what about the children”. I’m getting sick with all of this. Environmentalists and special interest groups have been railroading consumers for some time on this to push an anti-plastic agenda. His statements on BPA are 100% correct. The report being touted by environmental and “public interest” groups are simply irrelevant. People are not injecting BPA. A study where it was injected to get effects (which is the only way to get effects) is completely and utterly irrelevant.

      And before you attack me next, I am simply a consumer and engineer who has worked in the filed of child safety for 10 years as a consultant studying actual hazards with consumer products (above and beyond standards).

  • invalid-0

    Actually, free, unconjugated BPA is detectable in human blood and urine. Earlier reports of no free BPA relied on less sensitive analytic methods. See, for example,

    1: J Perinatol. 2008 Apr;28(4):258-63. Epub 2008 Feb 14. Links
    Maternal bisphenol-A levels at delivery: a looming problem?Padmanabhan V, Siefert K, Ransom S, Johnson T, Pinkerton J, Anderson L, Tao L, Kannan K.
    Department of Pediatrics, University of Michigan, Ann Arbor, MI 48109-0404, USA. vasantha@umich.edu

    OBJECTIVE: The objective was to determine whether bisphenol-A (BPA) is found in maternal circulation of pregnant women in the US population and is related to gestational length and birth weight. METHOD: Circulating levels of BPA were quantified by high performance liquid chromatography-tandem mass spectrometry at delivery in 40 southeastern Michigan mothers and correlated with gestational length and birth weight of offspring. RESULT: Maternal levels of unconjugated BPA ranged between 0.5 and 22.3 ng ml(-1) in southeastern Michigan mothers. There was no correlation between BPA concentrations and gestational length or birth weight of offspring. CONCLUSION: This is the first study to document measurable levels of BPA in maternal blood of the US population. Long-term follow-up studies of offspring are needed to validate or refute concerns over human fetal exposure to synthetic exogenous steroids.

    1: Reprod Toxicol. 2007 Aug-Sep;24(2):139-77. Epub 2007 Jul 31. Links
    Human exposure to bisphenol A (BPA).Vandenberg LN, Hauser R, Marcus M, Olea N, Welshons WV.
    Tufts University School of Medicine, Sackler School of Graduate Biomedical Sciences, 136 Harrison Avenue, Boston, MA 02111, USA. laura.vandenberg@tufts.edu

    The plastic monomer and plasticizer bisphenol A (BPA) is one of the highest volume chemicals produced worldwide. BPA is used in the production of polycarbonate plastics and epoxy resins used in many consumer products. Here, we have outlined studies that address the levels of BPA in human tissues and fluids. We have reviewed the few epidemiological studies available that explore biological markers of BPA exposure and human health outcomes. We have examined several studies of levels of BPA released from consumer products as well as the levels measured in wastewater, drinking water, air and dust. Lastly, we have reviewed acute metabolic studies and the information available about BPA metabolism in animal models. The reported levels of BPA in human fluids are higher than the BPA concentrations reported to stimulate molecular endpoints in vitro and appear to be within an order of magnitude of the levels needed to induce effects in animal models.

    1: Environ Health Perspect. 2002 Nov;110(11):A703-7. Links

    Comment in:
    Environ Health Perspect. 2003 Jun;111(7):A382-3; author reply A383.
    Parent bisphenol A accumulation in the human maternal-fetal-placental unit.Schönfelder G, Wittfoht W, Hopp H, Talsness CE, Paul M, Chahoud I.
    Institute of Clinical Pharmacology and Toxicology, Department of Toxicology, Benjamin Franklin Medical Center, Freie Universität, Berlin, Berlin, Germany.

    Bisphenol A (BPA), an endocrine disruptor, is employed in the manufacture of a wide range of consumer products. The suggestion that BPA, at amounts to which we are exposed, alters the reproductive organs of developing rodents has caused concern. At present, no information exists concerning the exposure of human pregnant women and their fetuses to BPA. We therefore investigated blood samples from mothers (n = 37) between weeks 32 and 41 of gestation. Afer the births, we also analyzed placental tissue and umbilical cord blood from the same subjects. We developed a novel chemical derivatization-gas chromatography/mass spectrometry method to analyze parent BPA at concentrations < 1 micro g/mL in plasma and tissues. Concentrations of BPA ranged from 0.3 to 18.9 ng/mL (median = 3.1 ng/mL) in maternal plasma, from 0.2 to 9.2 ng/mL (median = 2.3 ng/mL) in fetal plasma, and from 1.0 to 104.9 ng/g (median = 12.7 ng/g) in placental tissue. BPA blood concentrations were higher in male than in female fetuses. Here we demonstrate parent BPA in pregnant women and their fetuses. Exposure levels of parent BPA were found within a range typical of those used in recent animal studies and were shown to be toxic to reproductive organs of male and female offspring. We suggest that the range of BPA concentrations we measured may be related to sex differences in metabolization of parent BPA or variable maternal use of consumer products leaching BPA. PMID: 12417499 [PubMed – indexed for MEDLINE] PMCID: PMC1241091 Ted Schettler