ENVIRONMENTAL hormones - which mimic human hormones and disrupt the endocrine system - have emerged as a worldwide threat to health and reproduction. Zhang Qian reports.

We live in a polluted world where toxic chemicals are everywhere - in the air we breathe, the food we eat and the things we use - and doctors are warning everyone, especially pregnant women, to beware of environmental hormones and keep their children safe.

These compounds block or mimic estrogens, androgens (such as testosterone) and thyroid hormones, disrupting the endocrine system and reproductive system. They are known as EDCs, endocrine-disrupting chemicals and also environmental estrogens.

Prolonged exposure to e-hormones can cause damage to the reproductive system, early puberty, birth defects, low sperm count, growth problems and brain and nervous system damage. Learning disorders can result.

These are very much the products of industrialization, such as plastic bags, and the problem is worst in developing countries where growth is rapid and environmental safeguards are poor. People living in polluted areas and near unregulated industrial operations are at highest risk, but many dangerous chemicals are common in households where they are contained in some cleansers, plastics and construction materials.

"We are living in a seemingly convenient yet actually dangerous world, as chemicals are very much a part of life; they seem to make life easier but actually hurt our health," says Fudan University Professor Zhuang Guoshun of the Center for Atmospheric Chemistry, Department of Environmental Science and Engineering.

In Taipei last week, doctors called a press conference to warn that the reproductive health of Taiwanese people was jeopardized by these e-hormones that are absorbed in many forms. Consuming hot food and drinks from plastic containers, using cosmetics with estrogen and stabilizers, using heavy detergents and strong household cleaners are just a few of the problems, they said. They warned about infants' plastic pacifiers and milk bottles.

Toxic chemicals have been around a long time and studies increasingly show they harm the reproductive system.

These compounds are found in polluted air, water, soil, industrial waste, and contained in pesticides, herbicides, fungicides, animal growth hormones - and the food that results from them. They are also found in e-waste products, many plastics and common household cleaning agents.

There are around 100,000 man-made chemicals in the world and around 1,000 new chemicals are added to the environment each year.

Hundreds are toxic, including PCBs, DDT, dioxin (from burning rubbish), Freeon (chlorofluorocarbons in refrigerants and accelerants), fentin acetate (a fungicide), PVC (polyvinal chloride in plastic bags), Styrene and Styrofoam in plastics and home construction.

Some can be passed from mother to child, such as estrogenic BPA (bisphenol A), used to make some plastics and some metal containers for food.

These disrupters pose great danger to reproduction in both humans and animals, according to Dr Tony Lu, chief medical officer of WA Optimum Health Care, which recently opened in Shanghai.

Lora Zheng, a 39-year-old mother in Shanghai, was shocked when her daughter started menstruating at the age of 10. Most women Zheng's age started at around 13. Doctors say environmental hormones may be a cause.

One study in the US showed that 48 percent of black girls and almost 15 percent of white girls begin menstruation before they are eight years old.

George Xue, 34, has been trying without success to father a child for the past three years. His doctor told him recently that his sperm count is low, making natural conception difficult.

Many Chinese men have the same problem. Doctors say many factors, including environmental hormones, may be responsible. Other factors include smoking, drinking and lack of physical activity.

"Being exposed to abundant environmental female hormones has greatly reduced sperm density in men in the past dozens of years," says Dr Lu.

Studies by University of Copenhagen shows that average sperm density of men dropped by 41.5 percent - from 113 million to 66 million from 1940 to 1992. Similar research in China found sperm density in men dropped by around 20 percent from 1983 to 1996.

Exposure to environmental hormones also increased the sterility rates in women and rates of abnormal fetuses. Congenital deformity in the reproductive and urinary systems is a common fetal abnormality linked to environmental hormones.

These endocrine disrupters also contribute to higher rates of endometriosis in women and prostate cancer and testicle cancer in men, thyroid cancer and breast cancer in both men and women.

They can also be linked to neuro-degenerative diseases like Parkinson's and Alzheimer's, as well as diseases like diabetes and attention deficit disorder when the immunity and nerves are damaged, according to Dr Lu.

Benny Shi, 8, is restless. He fidgets in class, can't focus, repeatedly kicks the chair in front of him. He has been diagnosed with attention deficit hyperactivity disorder.

"ADHD in Benny's case is one of the consequences of long-term exposure to toxic hormones," says Dr Lu. Other causes include genetics, brain injury and exposure to lead. It's treatable but not curable.

"What makes the environmental hormones so dangerous is that many people may have been exposed while they were not aware of it," says Professor Zhuang of Fudan University.

Inhalation and ingestion are the two major ways chemicals enter the system.

"Adults are exposed to endocrine disrupters through direct contact with pesticides, insecticides, herbicides, fungicides, fumigants, cosmetics, flame retardant on clothes and furniture, Teflon cookware, detergents, resins and plasticizers. The list goes on and on," says Dr Lu.

Environmental hormones travel in the food chain from soil and water to plants for animal feed, from the animals to the people who use them for food. The same is true of fish and seafood.

Various man-made hormones (oral contraceptives and growth hormones for livestock and poultry) all add environmental hormones continuously to the food chain, accelerating their movement to the top of the food chain.



Protect you and your family from e-hormones

Apart from avoiding environmental hormones as much as possible - and this means checking how food was grown or fed - consumers can take other steps to protect themselves, according to Professor Zhuang.

Plastics

? Don't heat food in plastic containers because heating releases toxins.

? Keep plastics away from infants as they can easily absorb chemicals.

? Avoid PVC (polyvinychloride used to make plastic bags); PV (polyvinyl) is safer since it doesn't release toxins as readily.

Diet

? Eat a balanced and varied diet to decrease buildup from toxins connected with a single source. Eat foods of different brands from different markets; go for seasonal foods.

? Organic, or close to organic is best.

? Avoid fatty meat and fish because some environmental hormones accumulate and persist in fatty tissues. Avoid food from large animals since they may have been given hormones. Avoid big fish from polluted coastal waters. Avoid animal organs.

? Eat toxin-expelling foods such as unpolished rice, buckwheat, millet and other grains, spinach and leafy greens, turnip, cabbage, soybeans - lots of green veggies and fruit.

? Avoid processed foods with additives, preservatives, color enhancers and sweetener. Better yet, avoid all processed food.

Expel toxins

? Sweat with physical exercise or sauna; sweat expels toxins.

? Ensure regular bowel movements.

? Protect the liver, which removes toxins from the blood. Over-drinking reduces liver function.

Pregnant women

? Pregnant women - and all women - should be especially careful every way. In addition, they should not use cosmetics containing female hormones since they can be absorbed into the bloodstream and passed to the fetus.

? Too much female hormone can disrupt hormones in both male and female fetuses and cause abnormalities in the reproductive system.

Household

? Avoid using strong chemical cleansers and household products, like polishes and window cleaners. Traditional soaps and cleaners made of natural fat and alkali are better.

? If you feel you are suffering from environmental hormones, see a doctor; cleansing and other therapies are available.