Dear Editor: 

The November cover story, "A History of Heavy Metals," reported on the role that heavy metals play in modern life. The use of heavy metals in Chinese medicine should not be overlooked.

According to studies by major hospitals, a number of cases of heavy metal poisoning have occurred over the years because older people have insisted that newborn infants be given pa-pao-san, or "Eight Treasures Powder" (a Chinese medicine believed to relieve tai-tu, or fetal toxicosis), leading to damage of their nervous systems or even death.

A joint study conducted in August 1991 by the Consumer Foundation and the Medical Inspection Bureau in the Department of Health found that one fourth of the pa-pao-san used in Taiwan contains an excess quantity of lead.

In August 1992, The Pediatric Care Center of Tri-Service General Hospital took in a seven-month male infant suffering from protracted hyperspasmia. It turned out that he had been given a certain Chinese medicine that contained 430 ppm of lead for as long as a month. Four months after medication ceased he still had a high concentration of lead in his blood, enough to be diagnosed as lead poisoning under the standards set by the U.S. Disease Control Central.

The concept of "fetal toxicosis" first became prevalent during the Sung Dynasty. Medical experts at the time believed that it could be cured by hsiunghuang (realgar) and niu-huang (cow-bezoare), and large quantities of both were used in medicine for infants. Cinnabar (mercuric sulphide), believed to remove excess sputum and relieve ching-feng (infant convulsions), was widely used in various kinds of medicine, as well. There are even records that shui-yin (mercury) was taken directly during the Sung, Yuan, Ming and Ching dynasties. Cinnabar, realgar, cow-bezoare and other minerals were subsequently used in large quantities in pa-pao-san.

Originally, no lead-containing ingredients were used in the preparation of pa-pao-san. Large amounts of cinnabar were, however, and because cinnabar was expensive and in short supply, some Chinese pharmacists substituted other mineral in-gredients, such as huang-tan (yellow lead) or chientan (red lead or minimum--the scientific name is lead tetraoxide), which are similar to cinnabar in color. The result of this misuse was numerous cases of lead poisoning in newborn infants.

Toxological studies have shown that heavy metal poisoning damages every system of the body. Inacute poisoning, ingested heavy metals cause clear damage to the digestive system, producing nausea, vomiting, diarrhea, colic or melanosis. Inhaled in the lungs, they can cause necrotic bronchitis, tuberculosis or pneumoatothorax. In chronic poisoning, the central nervous system and the hematopoietic system are especially sensitive.

Once they enter the body, heavy metals are difficult to expel. The half life of lead in the bones, for instance, is estimated to be more than 20 years. Long-term accumulation must not be ignored. U.S. federal law maintains strict safety standards limiting the amount of heavy metals contained in foods.

The concept of fetal toxicosis originated in the ancients' misunderstanding of rashes and communicable diseases. Red lead and cinnabar are still sometimes misused in Chinese medicine today, in spite of scientific evidence, resulting in heavy metal poisoning. I hope that agencies in charge of public health will extend regulation to Chinese medicine. Until its safety can be assured, the wide-spread use of Chinese medicine among the public is not appropriate.