Mercury Poisoning in Making Gold Kavachams

By Kollengode S Venkataraman (Published in April 2009)

Many religious places of worship, including Hindu temples, consider it special to adorn their icons/deities and decorate their floats with coverings made of precious metals and gemstones, and use them on special occasions. The metal covering is called Kavacham in Sanskrit, meaning “sheath.”

Hindu Temples with modest resources have relatively less expensive silver kavachams (silver price is only small fraction of gold’s). However, for temples with better resources, the preference is the gold kavacham not only on their deities, but also for floats and even dwaja-sthambham (traditional flagstaff) in front of the temple.

Resourceful temples have used solid gold sheets. The well-known example is Amritsar’s Golden Temple. A much older sheathing with solid gold plates is at the Chidambaram temple, done during the Chola’s time a millennia ago. Traditional goldsmiths in India have been preserving for centuries the intricate artwork on metal carving/engraving.

Temples want inexpensive gold coverings:  With the gold price hovering around $950/oz, making kavachams with solid gold sheets is prohibitively expensive even for rich temples. So, simulated gold kavachams have become the staple. In making these “gold” kavacham, very thin foils of gold are worked onto the surface of less expensive copper kavacham.

Traditional Gold-Plating Techniques:  Making these “gold” kavacham uses mercury at high temperatures for working gold foils onto the copper substrate through amalgamation. Handling mercury at high temperatures gives out mercury vapors, a deadly poison with high toxicity when ingested into the body. See the health deadly effects of mercury poisoning at the end.  One four-step technique of making “gold” kavacham follows:

1.  Making a rigid kavacham using 1 to 2-mm thick copper plate. Copper is malleable for artisans to engrave intricate details such as ornaments, facial expressions, and sartorial details on the kavachams. It is also less expensive. Traditional artisans do an outstanding job in engraving most intricate details on metal kavachams

The next is to giving a gold covering on the copper kavacham. Modern gold electroplating using cyanide baths, a known technology, is one option. This requires strict safety and industrial hygiene practices because of the use of deadly cyanides. But gold electroplating of the kavacham is difficult because of their unwieldy sizes and shapes. The other difficulty is the poor quality of the gold plating on uneven surfaces with intricate details.

So, temples contract the work to traditional metal smiths in India, who have preserved a centuries-old 3-step technique developed in the pre-industrial revolution era that uses mercury and high temperatures.

2.  They heat the copper kavacham pieces to around 200 deg C, and smear the copper surface with the liquid metallic mercury. At these temperatures mercury forms an amalgam with the copper surface. But it also releases deadly mercury vapors in the vicinity of the furnace.

3.   Separately, they make foils of pure gold, which is quite malleable.  The foils are only tens of microns thick (1 micron = 1/1000 millimeter).

4.  They then re-heat the amalgamated copper kavacham pieces obtained in step 2, and painstakingly work the thin gold foils on the heated mercury-rich copper surface. The gold foil forms an amalgam with mercury on the copper substrate and adheres to the copper base. During this high-temperature process, the mercury already on the surface again vaporizes.

Workers exposed to high amounts of mercury vapors:  The boiling point of mercury is relatively low, only 356 deg C. Therefore, at the working temperatures around 200 deg C , mercury vaporizes into air.

The concentration of mercury is the highest in the immediate vicinity of the heating furnace where the metal smiths work.  This cottage industry is totally unregulated in India and it is inevitable that workers ingest the mercury vapors through breathing, mouth and also through their skin.

In all likelihood, even in the finished kavacham pieces, the mercury concentration would be high on the surfaces of the kavacham

Mercury poisoning is deadly:  Mercury, once ingested, is not readily flushed out of the body. The website lists the deadly incurable and progressively degenerative diseases caused by mercury poisoning. Mercury poisoning leads to premature death of people exposed to mercury vapors. That is the reason why it is banned in tooth filling and in thermometers. 

The safe exposure limits for mercury adapted by WHO is 0.46 microgram/day/kg of body weight. (Note: 1 microgram is 0.000001 of a gram).  Obviously working near the furnace will expose people to high levels of mercury, likely to be several hundreds, possibly even thousands of times above the safe working limit.   

The reason for the silence: Traditional metal smiths have preserved the technique for generations, keeping it within their families/clan. Since the technique is preserved within their families, the incomes also stay within their families. Since they are also the sole beneficiaries of this lucrative business, they do not complain.

The temples also keep quite because it gives them inexpensive “gold” kavachams, far less expensive than solid gold coverings. And the ordinary temple-goers rarely know the details of the kavacham-making techniques to understand the associated health risks.

Indian-Americans are better educated with higher degrees in health care, chemistry and engineering. Hence the purpose of this write-up is to raise the awareness of the serious health risks for workers making these gold kavachams.

Once people recognize the dangers of mercury poisoning, one hopes it would lead to some soul-searching among the decision makers on whether we need these mercury-laced “gold” kavachams at all. After all, will we ever let our children go anywhere near the kavacham making furnace?

Partial list of diseases caused by mercury poisoning: 

Addison’s disease, gastritis, allergies, hypogonadism, Alzheimer’s’ disease, hypothyroidism, Amylotrophic lateral sclerosis, infertility, ankylosing spondylitis, insomnia, anorexia nervosa, irritable bowel syndrome, anxiety, juvenile arthritis.

Asthma, learning disabilities, attention deficit hyperactivity disorder, lupus, erythromatosus, autoimmune diseases, manic depression, bipolar disorder, multiple chemical sensitivities, borderline personality disorder, multiple sclerosis, bulimia, myasthenia gravis, candidacies, obsessive-compulsive disorder.

Chronic fatigue, panic attacks, colitis, Parkinson’s disease, Crohn’s disease, pervasive developmental disorder, depression, psychosis, endocrine disorders, schizophrenia, fibromyalgia, sciatica, food allergies. — END


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