Insidious Chemistry-Environmental Hormones

To the great consternation of men around the world, in January of 2011 the World Health Organization adjusted its healthy sperm index, reducing the figure from 20 million per cubic centimeter of seminal fluid in 1990 to 15 million.

The WHO's healthy sperm index refers to the minimum concentration of sperm in an individual capable of achieving in utero conception. Essentially, what was considered an unhealthily low sperm count 20 years ago passes muster today. Whereas 20 million was the mark of health before, an individual would now have to have a count of less than 15 million to be considered deficient.

Although Taiwanese people's frequent use of plastic food wrap and containers does increase the risk of ingesting plasticizers, so long as they are used cautiously and properly, there is no cause for alarm.

Actually, long before the WHO's official adjustment, large-scale studies conducted in regions across the globe had already borne out this insalubrious trajectory in male reproductive capabilities.

Lee Ching-chang, professor at National Cheng Kung University's Department of Environmental and Occupational Health, refers to a study by a Danish scholar that examined 61 scholarly articles published between 1938 and 1990 by academics around the world. The results showed that the average individual's sperm count in 1940 was 120 million per cc. By 1990, that number was down to 60 million.

Of course, conception is possible so long as one sperm manages to breach the egg's defenses, but the inevitable fact remains that a larger army of healthy sperm stands a much better chance of achieving pregnancy.

The research paints a clear picture of declining sperm levels in men, and whereas in the past women were most often blamed for a couple's fertility problems, in the foreseeable future men will no doubt be increasingly held responsible.

Fragrant lipsticks, nail polishes, and other cosmetics all may contain dangerous fixatives. In the name of safety, it is best that women purchase cosmetics either with a minimum amount of attached fragrance, or better still, no fragrance at all.

What are the reasons for the decline in the quantity of male sperm? Besides drugs and alcohol, smoking, stress and other factors related to individual lifestyle, another cause that has been confirmed by the scientific community is the environmental hormones which insidiously permeate our lives, inflicting harm on the reproductive health of both sexes.

What exactly are environmental hormones? Usually the term "hormones" refers to the small group of chemical transmitters dispatched by endocrine glands to the various organs of the body via the circulation of blood or other bodily fluids. Human growth and also the development of secondary sex characteristics are all the handiwork of native bodily hormones.

Over the last 50 years, scientists have seen mounting evidence that some of the chemicals prevalent in industrial societies are acting as surrogate, artificial hormones. When these chemicals enter a human or animal body, the body misidentifies them as actual hormones secreted by internal glands, thus inducing a raft of unintended reactions. A normally functioning endocrine system can be disrupted or suppressed by these chemical interlopers, leading to serious imbalances throughout all the body's systems.

Because of the way these outside chemical agents imitate natural hormones, they have been termed "endocrine disrupters" or "environmental hormones."

Scientists have already identified as many as 70 environmental hormones. Many are used as pesticides, such as the chemical responsible for eradicating malaria in Taiwan in the 1950s and 60s, DDT. There are also industrial chemical compounds that include heavy metals like lead, cadmium, and mercury, as well as the polychlorinated biphenyls (PCB) behind the toxic rice-bran oil contamination that afflicted more than 2000 people in the Chang-hua region in 1979. Additives in products intended for daily use are another source: plasticizers in plastic products, surfactants in cleaning products, and brominated flame retardant in electric appliances are three common examples. Then there are dioxins, byproducts of burning chlorine-based chemical compounds, which have earned the dubious moniker "poisons of the century."

There are many types of environmental hormones, but they operate along the same lines.

According to Ling Yang-chien, professor in the chemistry department at National Tsinghua University, examining the chemical structure of dioxins reveals strong similarities to the hormone estrogen. BPAs of the variety used in plasticizers, imaging agents, and anti-oxidants as well as phthalates (PAE) and the surfactant nonylphenol (NP) show the same resemblance. Therefore, absorbing large amounts of any of these compounds is likely to have the same "feminizing"- chemically speaking-effect on an individual, by tampering with their reproductive system.

For his 1996 work Our Stolen Future, scientist Theo Colborn conducted a study of Lake Apopka in Florida, whose waters are thoroughly contaminated with PCB and dioxins. He discovered several important aberrations in its resident alligator population: the male alligators' penises were much smaller than normal, and the females' ovarian follicles, while plentiful, had trouble developing to maturity in a way similar to women with polycystic ovary syndrome. This group of alligators in which the males are not fully male nor the females fully female has virtually been robbed of its ability to reproduce. Unsurprisingly, analysis of their blood samples revealed abnormally high levels of estrogen.

In any of the regions around the world plagued by environmental hormones, one may discover seagulls engaged in homosexual nesting and male birds exhibiting no interest in mating. These phenomena suggest that toxins are infiltrating the animal kingdom, upsetting the balance between the sexes and even possibly pointing the way to genetic mutation or species extinction.

Human beings are equally susceptible to the threat. In addition to decreasing sperm levels, related research suggests that environmental hormones may cause infertility and increase the risk for testicular and prostate cancer. It may delay the emergence of secondary sex characteristics in boys, as well. Women with inflated estrogen levels are at risk of developing endometriosis, polycystic ovary syndrome (which can make conceiving difficult), and breast cancer. Girls are more prone to experience puberty early. Even more frightening is that environmental hormones can be passed from one generation to the next via the placenta; if the level of invading chemicals is high during the early stages of pregnancy, a male fetus then runs a risk of developing defective sex characteristics.

When picking out toys for children, look for a seal indicating that they have met safety standards. This will protect little ones from haphazardly constructed toys with excessive plasticizer levels.

As evidence has accrued of the pernicious nature of these chemicals, many pesticides and other products that were once de rigueur have either been banned or tightly controlled: DDT, chlordane, PCB, and dioxins, to name a few. This constitutes a major step in reducing the degree of human exposure.

At present, scientists are most concerned about chemicals whose danger derives not from high levels of toxicity, but rather from their vast and unshakeable presence in everyday consumer products. Plastics with their inevitable load of phthalates (PAE) offer the greatest threat.

Phthalates derive from the combination of phthalic acid and alcohols. There are six types in common use today, of which the plasticizer dioctyl phthalate (DEHP), as well as dibutyl phthalate (DBP) and diethyl phthalate (DEP), both used as fixatives in perfumes and cosmetic products, enjoy the broadest application.

Lee Ching-chang explains that DEHP is found most often as a plasticizing agent in polyvinyl chloride (PVC) products. In its pure form it resembles soybean oil in consistency, but when combined with PVC powder and put under high pressure, it makes the PVC pliable enough to mold into all manner of different shapes.

PVC is the most common plastic in an extensive list of everyday household products that includes food wrap and food containers, rain slickers, shoes, floor coverings, building materials, toys, synthetic leathers, and medical implements.

Women's perfume, makeup, skincare products, nail polish, hair gels and hair sprays all make use of DBP and DEP to prevent fragrance decay; the more central fragrance is to the product, the higher the percentage of these fixatives it will employ. In other words, phthalates are so embedded in our daily lives that it is impossible to avoid contact with them.

(right) Unless scrap materials are incinerated at temperatures above 1000°C, they will release the dangerous environmental hormone dioxin into the atmosphere. The picture shows materials confiscated from several illegal trash processing plants awaiting incineration at the Ta Fa Industrial District in Kaohsiung.

Taiwan has been called the "plastics kingdom" principally for its role as a manufacturer, though the same epithet describes equally well the Taiwanese people's fondness for plastic products. Every year the country goes through 250,000 metric tons of DEHP and 20,000 tons of DBP. Most alarming of all is that plasticizer is introduced into products not through chemical bonding but merely as a physical admixture, which means that dispersal or leaching is a continual danger; if the plastic is old or scratched, is heated up, or comes into contact with oily food, the chances of contamination are greatly increased.

According to Chen Mei-lien, professor at National Yang Ming University Institute of Environmental and Occupational Health Sciences, in Taiwan 80% of the phthalates that accrue in the human body can be traced back to eating. This is due largely to Taiwanese people's reliance on plastic bags, freshness wraps, and storage containers. Moreover, food inevitably comes into contact with plastic products at any of several stages: storage, freezing, processing, and sales.

Chen's research group conducted a study in which they used a microwave oven to heat up convenience-store lunchboxes that were covered in PVC wrap. To their astonishment, they discovered that a single 400-gram lunchbox was capable of yielding 90% of the recommended DEHP daily limit (defined by the European Union as 0.05 mg per day per kilogram of body weight).

It's best to use plastic wrap made from PE or a biodegradable material instead of PVC, which has a greater tendency to leach, and avoid allowing it to come in direct contact with oily foods.

Compared to other environmental hormones, phthalates are fairly innocuous. The human body metabolizes them quickly: the half-life of DEP is approximately one hour, and even DEHP, which is the hardest to metabolize, has a half-life of 15-20 hours. But since Taiwanese come into contact with these chemicals so frequently, the danger is the cumulative harm arising from constant exposure.

The research of both Lee and Chen showed that Taiwanese often carry an excessive amount of plasticizing chemicals within their bodies. Chen studied the urine samples of 100 individuals and found that 90% of them showed signs of metabolized DEHP. 37% exceeded the daily limit prescribed by the EU. Furthermore, the median concentration within the samples was five times -greater than the results of similar studies conducted in the US and 1.6 times -greater than results obtained in Germany.

In 2007, at the behest of the National Science Council, Lee undertook a cooperative study with National Cheng Kung University Hospital of 76 pregnant women. The amount of metabolized DEHP that turned up in the participants' urine was 13 times that of a group of American women; there was also 4.5 times more DBP. Moreover, approximately half of these women with high concentrations of plasticizers in their systems evidenced low levels of the hormone thyroxine over the course of their pregnancies.

Lee explains that thyroxine plays an essential role in a fetus' neurological development, and there appears to be an inverse relationship between plasticizer levels and thyroxine levels. When a woman's hormones change during pregnancy, the amount of thyroxine undergoes a natural decline; under the influence of meddling plasticizers, manufacture of thyroxine is suppressed even further, with potentially disastrous results for the developing fetus.

In addition to sabotaging thyroxine production, phthalates can cause male fetuses to develop female characteristics (such as a shortening of the distance between the penis and the anus), and can induce premature onset of puberty in girls.

Since the thermal paper commonly used in ATM and credit-card receipts and lotto tickets is coated with BPA, it is advisable to wash one's hands after handling them in order to avoid ingesting toxins.

The growing risk posed by phthalates and other environmental hormones has become an issue of international concern. In 2009, the Environmental Protection Administration (EPA) initiated a series of short, medium, and long-term projects involving collaboration amongst government agencies for combatting the threat.

In terms of the everyday products that are of greatest concern to the average citizen, phthalates and BPAs have been classified as "Class 4" toxic chemical substances, defined as being capable of harming the environment and/or human health. All manufacturers that use them are required to report the use and the percentage of possible leakage.

Products that intimately affect children, objects such as milk bottles, toys, play mats, plastic shoes, and erasers, will be held to precise standards. For instance, the amount of phthalate in any product intended for children is not to exceed 0.1%.

There has been a gradual increase in the monitoring of other common products. For example, at the end of 2008 the EPA decreed that nonylphenol could not be added to household cleaning solutions. The Department of Health announced at the end of last year that they were tightening the acceptable leach standards for plasticizers (0.3% for DBP and 1.5% for DEHP). In addition, following the Consumers Foundation and other groups' disclosure that the thermal paper commonly used for ATM and credit-card receipts and lotto tickets was being coated with copious amounts of BPA on its surface, BPA has been banned for use as a chromogenic reagent, thanks to a decree from the Bureau of Standards, Metrology and Inspection (BSMI) under the Ministry of Economic Affairs.

PVC and polyvinylidene chloride (PVDC) plastic food wraps, long the scourge of environmental groups, are dangerous not only for the plasticizers they contain and the attendant dangers described earlier, but also for the fact that when burned, they release dioxins. The EPA has therefore decided to control their use, importation, and domestic manufacture beginning in 2013. Plastic wrap makers will be forced to turn to polyethylene (PE) as an alternative.

Even with tighter regulation there's still no surefire way to stamp out the presence of environmental hormones completely. BSMI second division director Chang Wei-pin admits that even though they screen dozens of shipments of toys every month and identify thousands of substandard toys, since most of these items originate in mainland China, it's almost a given that the great majority of them manage to circumvent customs entirely along the quick route to Taiwanese night markets.

Numerous experts have exhorted the EPA to remove the relatively tame Class 4 toxin designation currently assigned to the oft-encountered PAEs, BPA, and NP and replace it with a stiffer Class 1 label, designating toxic chemicals with a tendency toward bioaccumulation. This would allow the authorities to control their handling through "total release quantity control methods." At the same time, they would be able to legislate very narrow parameters for their use by requiring special permits for them to be either manufactured or imported. This type of legal approach would greatly improve the current situation.

Addressing the proponents of such legislation, however, the head of the EPA's Department of Environmental Sanitation and Toxic Substance Management, Lin Chien-hui, responds that at present the international community has yet to determine whether or not these substances bioaccumulate. Looking at things from another perspective, if these chemicals became verboten all of a sudden, it would deliver quite a shock to the domestic economy. For these reasons, the laws will remain untouched for the time being.

He does nevertheless maintain that environmental hormones are a crucial international issue, and that if scientific investigation sheds new light on their level of toxicity, or if perhaps any three out of the nine most advanced nations-the US, Canada, Japan and various European countries-were to adopt stricter controls, the EPA would certainly follow suit.

In the interim, before any more comprehensive methods are undertaken, the best way for everyday folk to lower their risk is simply to steer clear of plastic products, especially when it comes to storing hot food or using the microwave. When in contact with questionable products, take the precaution of washing your hands before eating.

With a little more effort and discipline, we can reduce our obsession with convenience-that's one step we all can take right now to protect ourselves from environmental hormones.

Keeping environmental hormones at bay

sources: Prof. Ling Yang-chien, Chemistry Department, National Tsinghua University; Prof. Lee Ching-chang, Department of Environmental and Occupational Health, National Cheng Kung University; Prof. Chen Mei-lien, Institute of Environmental and Occupational Health Sciences, National Yang Ming University