Gender Bending Perfumes, Pesticides and Case Of The Disappearing Male.

We all begin female

Sex differentiation, or the process by which a fetus becomes male or female depends on gonadal steroid hormones.  These hormones when present determine certain organizing functions which permanently differentiate sex organs into male or female genitalia. The process begins before 8 weeks gestation.  Before this time however, the playing field is level. Both embryos destined to be male or female begin with the same equipment. At 6 weeks all embryos have Wolffian and Mullarian ducts, and at this stage internal organs are said to be bipotential- meaning, yep, you guessed it, have the potential to become male OR female.  

The differentiation process begins for males by a gene on the Y chromosome called, the SRY gene.  When this gene is expressed it initiates biochemical pathways by which androgen hormones are produced so that the fetus becomes male.  Under this influence the Wolffian ducts become the vas deferens and seminal vesicle and the Mullarian ducts degenerate.  The undifferentiated gonads then become the future testes, prostate and scrotum.

In females there is no Y chromosome or SRY gene to initiate sexual differentiation so development progresses without the biochemical cues that turn the embryo into a male. The Mullarian ducts remain and the undifferentiated gonads now become ovaries and other structures of the female genitalia.

A Delicate Process

The endocrine system is the body’s communication network and the hypothalamus and pituitary can be likened to the command center. Along with the ovaries, testes, adrenals, thyroid and pancreas, the endocrine system regulates the functions of the body by secreting chemical messengers called hormones.

These hormones determine the development and the regulation of the reproductive system from before birth and throughout life.  As mentioned above, the processes of sexual differentiation in the fetus is tightly controlled by the hormones  produced at different gestational periods.  For males and females alike the process is exquisitely sensitive to minute changes in hormonal concentrations, especially during critical windows of development.

In 1989 papers published in The Journal of Animal Science authors clearly demonstrated the sensitivity of the process.  They were able to show that in mice ( a species with multiple births), adjacently positioned male and female fetuses could transmit minute amounts of hormones to one another which resulted in profound changes in phenotype (visual or behavioural differences) in the baby mice.  The study concluded that at a difference of only 1 part per billion of testosterone and 20 parts per trillion estradiol (a potent form of estrogen) they could  predict entirely different brain structures, behavior, enzyme, receptor and hormone levels in the blood, in the young mice, before they were born.

Enter EDC’s

Endocrine disrupting chemicals (EDC’s)  are chemicals that mimic hormones in a variety of different ways. They have the potential to block or stimulate hormone receptors thus exaggerating or dulling physiological responses.  EDCs represent a class of substances that can be grouped based on their activity on receptor sites. The most well studied are the xenoestrogens, which mimic estrogen through binding to  estrogen receptors.  These include the pesticide methoxychlor as well as other organochloride agricultural products, PCB’s, Bisphenol A and C from plastic manufacturing and pharmaceutical estrogens (birth control pills and DES).  There are also chemicals which block androgen (male hormone) receptors or antiandorgens; most notably the fungicide vinclozolin, certain metabolites of the once popular DDT (which most of our body’s still contain), phthalates, found in all perfumes and scented products, and other PCBs (1).

When it comes to such a delicate process as sexual differentiation, the presence of these environmental and household chemicals poses a significant problem. The developing fetus is exposed to much of what is present in the maternal bloodstream, lacks the metabolic pathways to detoxify exogenous chemicals and is composed of rapidly differentiating tissue highly vulnerable to disruption.  Also because of a fetus’s small body size, as compared to an adult exposure to EDC’s is amplified in terms of relative dose reaching target tissues.

The Evidence

Reproductive and developmental abnormalities linked to EDC’s have been clearly documented across all animal groups including in birds, reptiles, mammals, amphibians, mollusks and fish, yet we like to pretend we are not animals and are exempt from their influence.

Male alligators in Lake Apopka- one of the most polluted lakes in florida, have been found to be feminized (short penises and low testosterone), due to the high levels of DDT metabolites from farming activities nearby.  Researchers also commonly find female alligators with excessive estrogen levels, and sex reversal (the animal of one sex matures and behaves like the opposite sex), and skewed sex ratios. Other reports have documented reproductive effects and skewed sex ratios on wildlife and (more females than in fish and wildlife populations exposed to EDC’s excreted into the water from women taking birth control pills (2).

This is occurring in humans as well.  While it would be unethical to test a potentially harmful EDC on pregnant women, we inadvertently performed this experiment on 6 million people between 1940-1970, when doctors routinely prescribed the drug Diethylstilbestrol

to pregnant women with disastrous consequences.  The drug is now known to cause a rare type of vaginal cancer and increase risk of breast cancer in daughters of women who took DES, as well as a wide variety of genital defects in sons of these women (3).

Studies have also shown a huge increase in male genital birth defects in recent years (4).  EDCs in men have been linked to lower semen quality, likely due to reproductive tract  defects and lower levels of testosterone.  Low levels of phthalates, present in most commercial personal care products (perfumes, lotions etc),  have been linked to shorter anogenital index  (the measurement from rectum to base of penis).  A shorter AGI increases risk of fertility problems later in life as described by Shanna Swan, director of obstetrics and gynecology at the University of Rochester.  Swan found that women whose urine had elevated levels (common in about 25% of the population) of four phthalates had sons with shorter than expected AGI (5).  

Other studies have linked phthalates to testicular atrophy and fertility problems likely relating to low testosterone levels later in life.   The more phthalates a pregnant woman is exposed to, the greater the risk of incomplete testicular descent, and demasculinization (boys whose brain structures are more similar to female brains).

Sex Ratios

Sex ratios, or the proportion of male to female live births, are historically consistent with about 102-108 male to every 100 female births. Distinct skewing of sex ratios are seen in communities close to industrial plants which produce and spew EDC’s into the environment. In Sarnia, Ontario, government officials have reported a significant decline in the number of male babies born in the last 10 years. Many large petrochemical and polymer plants operate in close proximity to residential areas in Sarnia (6). While this is by no means definitive evidence, a similar situation was seen in 1976 in Seveso Italy, when following an industrial accident that contaminated groundwater with EDC’s sex ratios became skewed (7).

Ladies - We’re Not Off The Hook!

We already mentioned the potential impact of EDC’s on men, but how about women?  In women EDC’s have been linked to precocious puberty, estrogen dominant conditions (PMS, fibroids, and MORE on Estrogen Dominance ) and development of breast and other hormonally influenced cancers. Blog on the impact of EDC’s on women coming soon.

The Government is NOT Protecting Your Interests

Every second another 20 chemicals are approved for commercial use.  With the sheer volume of new chemicals coming onto the market is is absolutely impossible to say which ones are truly safe, and which are problematic. Unfortunately the onus of safety is not placed on manufactures, with government agencies only requiring basic animal toxicology studies (where one chemical in isolation is given to animals under controlled conditions).  This method of testing is absolutely irrelevant for demonstrating safety in humans, who are exposed to thousands of these substances daily in small amounts. What testing fails to acknowledge are the long term simultaneous effects of these chemicals as well as their synergistic toxicity.  Even more disturbing is that most of them have never been tested for safety on adults at all, let alone their impacts on pregnant women or children, yet they are present in our shampoo, our air fresheners, laundry detergents and lotions.  We see things on the market, and assume they must be safe. We need to change our thinking and adopt a buyer beware manifesto to protect our health and that of future generations.

What Else Can We Do?

While some EDC’s are eliminated from the body quickly others tend to be extremely persistent so avoidance is our best bet. Detoxification tends to be difficult and depends on optimal bowel, liver and kidney function.  While we cannot completely avoid exposure (there will always be the lady in the elevator with perfume on, or the office building using harsh chemicals) the following recommendations can minimize your personal exposure.

Home and Beauty Products

  • Minimize exposure to nail polish and polish removers. 
  • Perfume is the new asbestos. Throw it away. Period. No exceptions. Use essential oils. You are not only putting your own health at risk, but the health of everyone who smells you. 
  • Avoid EDC’s in personal care products. Especially avoid anything listing phthalates, parabens and/or synthetic fragrances.
  • Check out SKIN DEEP DATABASE before you buy makeup and personal care products. This database allows you to search for potentially toxic ingredients before you buy.


  • Try to choose organic, locally produced and in season foods. Many pesticides and herbicides have some hormonal effect.
  • Peel and soak non organic fruit and vegetables in salted water. 
  • If you consume meat, choose hormone free organic and pasture raised varieties
  • If you are male concerned with fertility, avoid dairy. Remeber mamma cow produced LOTS of bovine estrogen and progesterone for her calf.  Bovine hormones act as endocrine disruptors. 
  • Avoid all North American dairy as it may be contaminated with bovine growth hormone (banned in the EU). 
  • Eat a least 40g of fiber and include a source of fermented foods daily (coconut yogurt, sauerkraut, kimchi, natto) to help bind excessive hormones and shuttle them out through the gut.
  • Rather than eating conventional or farm-raised fish, which are often heavily contaminated with PCBs and mercury, supplement with a high-quality purified krill oil, or eat seafood that is wild-caught and eat smaller fish with shorter life spans (mussels, sardines, herring, mackerel). 


  • Avoid plastics whenever possible
  • NEVER microwave or heat food in plastic
  • NEVER reuse single use plastic (water bottles etc). Plastics break down at room temp and you will consume various plastic residues in drinks/food store in single use containers. 
  • Never leave plastic water bottles in the sun or freeze them.
  • Avoid plastic wrap touching food.
  • Use glass or stainless steel cooking or food storage containers wheneevr possible. 
  • Replace your non-stick pots and pans with ceramic or glass cookware.

Household Products

  • Try to switch to chemical free, biodegradable household cleaning products.  NZ- try ECO Clean Brand.  There are so many on the market in every grocery store, there really is NO reason to use harsh chemicals that poison your family and the environment. 
  • Use chlorine free products and unbleached paper whenever possible (dioxins from bleaching are also implemented in cancers, endometriosis and fertility problems). This is especially important for sanitary products (tampons and pads), as these will be in direct contact with the vasculature rich mucous membranes of the vagina. 
  • Use a chlorine filter for your shower and drinking water. Have your tap water tested if in doubt. 
  • Avoid using artificial air fresheners, dryer sheets, fabric softeners or other synthetic fragrances.