Gender bender chemicals threaten reproduction

When most people consider the dangers of environmental pollution, a few things come quickly to mind. Injured wildlife. Contaminated air and water. Cancer from exposure to high levels of dangerous chemicals on the job. These are all serious problems, but unfortunately they are only the tip of the iceberg. New research suggests that minute levels of environmental pollutants are causing devastating, widespread, cross-generational, damage.

Scientists have found sometimes bizarre, health impacts in wildlife, including:

• shrunken penises and testicle deformities in alligators
• feminization of male fish, birds, and mammals
• decreased fertility in birds, alligators, fish, shellfish, and mammals
• gross birth deformities in birds, fish, and turtles
• premature or delayed sexual maturation in birds and fish
• weakened immune systems in birds and mammals.

Scientists have also documented several disturbing human health trends including:

• A huge decline in sperm quantity and quality in men over the past 20 years.
• A continued increase in cancer. The number of women who get breast cancer has greatly increased for example. In 1960 the risk of getting breast cancer was 1 in 20, now it is approaching 1 in 8.
• Testicular cancer rates have also increased 3-fold to 4-fold in the last 40 years.
• An increase in birth defects. Although some of the increases might be attributable to better detection, many are not. Cryptorchidism (undescended testicles), for example, has increased 2-fold to 4-fold over the last 40 years.
• The incidence of endometriosis (a painful disease of the tissues lining the uterus, which often results in sterility) is steadily increasing and now afflicts several million women in Canada and the US.

Why similar effects in humans and wildlife are occurring is still unclear, but new information based on studies of wildlife (in the wild and the laboratory) and humans now suggest that hormones may be an important part of the picture.

Hormones are complex chemicals which the body uses to send messages. Hormones stimulate or inhibit various functions in cells which, in turn, produces specific cell actions. Estrogen and testosterone are two hormones necessary for sexual development in fish, birds, and mammals for example.

Scientists now know that many environmental pollutants act as hormones, capable of disrupting normal hormone levels in the body.

These changes in the hormonal system disrupt or modify development and consequently can permanently alter reproductive, immunological, and neurological capabilities. Hormone disruption may play a role in the human and wildlife effects listed above.

In 1991, 21 respected scientists from around the world signed a joint statement noting that, "A large number of man-made chemicals which have been released into the environment, as well as a few natural ones, have the potential to disrupt the endocrine (hormonal) system of animals, including humans." Some of the chemicals which disrupt the hormone system are industrial pollution, pesticides and pharmaceutical drugs including DDT, lindane, carbaryl, dioxins, furans, PCBs, noylphenol, and DES.

Although these pollutants act like hormones, unlike natural hormones, many are difficult for the body to break down and are instead stored in fatty tissues. Thus a situation exists where a developing egg or embryo is exposed to chemicals stored over a mother's lifetime. If these bioaccumulated compounds act as hormonal mimics, then embryonic development can be modified. Although these changes may be unobserved at hatching or birth, they can lead to significant health effects later in life.

DIOXIN -- AN EXAMPLE

Dioxins are some of the most studied hormone disrupting chemicals. The Dioxin Reassessment report, released in December 1994 by the US Environmental Protection Agency (EPA), delivered sobering information about the potential health impacts of dioxins. Dioxins have been linked to a number of health effects in humans and wildlife including cancer, endometriosis, miscarriages, impairment of the immune system, decreased testis size and delays in sexual maturation, sperm count reductions, learning impairments, physical deformities and other birth defects, and other reproductive problems.

Because dioxins persist in the environment, build up in fatty tissues, and increase in concentration as they move up the food chain, they now contaminate the entire planet. Based on studies of human tissues, EPA estimated that average Americans have dioxin body burden levels well within the range known to cause the array of non-cancer injuries identified above. The major pathway in which dioxins get into our bodies is the ingestion of contaminated food.

The EPA found some groups were exposed to dioxins at levels far greater than average exposures and were, therefore, far more likely to suffer from dioxin's impacts. These groups include: nursing infants who receive dioxins through breast milk, people consuming unusually high levels of meat or dairy products containing elevated levels of dioxins, people exposed occupationally to dioxins, and people suffering direct or indirect exposures from discrete local sources such as a pulp and paper mill or incinerator.

CAUSE AND EFFECT

To protect public health and the environment, we must understand that environmental pollution causes more than cancer. Scientific limitations and the fact that it is immoral and unethical to experiment on humans mean we will never have absolute proof of the relationship between most environmental pollution and specific health effects. This is why it is critical to use and wildlife studies as a guide to assess our own public health. As in the smoking and lung cancer debate, only industry critics expect absolute proof before action is justified.

It is time for a fundamentally new approach to toxics regulation. The burden of proof must be on those who wish to create and release pollution to show that pollution will not cause health problems or the disruption of hormone levels. Clearly the weight of all the evidence urges us to phaseout uncontrollable bioaccumulative, persistent toxics.

TAKE ACTION

• Protect yourself by eating only organically grown fruit and vegetables. Ask your supermarket manager to stock more organic produce. Avoid toxic pesticides and weed killers in your own garden.
• Protect the planet by demanding a ban on the use of chlorinated pesticides.
• Walk, cycle or take public transport whenever possible. Polycyclic aromatic hydrocarbons (PAHs) from car exhaust are a direct human health threat and an indirect threat to marine ecosystems.
• Replace the toxic cleaning products under your kitchen sink with baking soda, borax, soap flakes or powder, washing soda and white vinegar.
• Avoid buying any unnecessary plastic, especially PVC (#3). Most deaths resulting from residential and commercial fires are caused by inhaling PVC fumes, not the fire itself. Combustion of PVC is a major source of dioxin.
• Buy only unbleached, recycled paper products. Ask your local stationer's to stock these products.
• Reduce meat and dairy consumption.
• Buy clothes which do not require dry cleaning. Treat clothing stains at home with natural products. Find a dry cleaner who does non-solvent cleaning.
• Oppose incineration. Promote industrial reuse and recycling.
• Become a member of Georgia Strait Alliance.

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