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Storing Drinking Water in Copper Vessels- Science or Myth?

What will you learn in this article?

Traditionally, in India, it was always recommended storing drinking water in copper vessels or in silver vessels overnight. Texts from Ayurveda clearly reflect that storing drinking water in copper vessels is a good way of keeping water germ free. While silver might be a costly affair for many, copper is cheap and easily available. Numerous sellers on various online portals such as Amazon are quoting about this Ayurvedic recommendation and selling products.

India is a developing country. Providing safe water in such a huge resource constrained country harboring 2nd largest population of the world is a challenge. Consequently, water borne bacteria and viruses frequently contaminate drinking water. Due to this, diarrhoea remains a perennial issue and keeps occurring in epidemic proportions in such countries. Millions of lives are lost every year.

Can the ayurvedic recommendation of storing drinking water in copper vessels be used to tackle this menace of diarrhoea in countries like ours? Is this traditional practice and recommendation really scientific or is it just a myth?  Let’s explore the answers using science!

In Developing Countries Diarrhoea is a Killer Epidemic

Diarrhoea contributed 4.1% of the total global burden of disease. Nearly 90% of this is due to unsafe water supply, sanitation and hygiene. Children in developing countries are the most common victims of these waterborne infectious diseases causes diarrhoea.

Globally, around a billion people lack access to safe drinking-water. Safe drinking-water is not available to the majority of the world’s population, especially to those in developing countries. A germ infested water causes various diseases including diarrhoea. These germs can include various dangerous forms of viruses and/ or bacteria. Escherichia coli (ETEC), rotavirus, Vibrio cholerae (the one that causes cholera), and few species of Shigella are few of these germs infamous for spreading via contaminated water and causing killer diarrhoea.


Diarrhoea is one of the leading causes of mortality and morbidity, especially in children of developing countries. Approximately two million lives are lost each year.

Look at India, for example. Cholera still ravages many parts of this beautiful country. During 1996-2007, at least more than 222,000 individuals suffered from cholera.

Shigellosis, a disease similar to cholera, causes a severe form of diarrhoea known as acute bacillary dysentery. It can cause complications which can be rapidly fatal. Shigellosis is generally caused by a bacteria called Shigella flexneri. What’s concerning is that Shigellosis represents approximately 10% of all diarrhoeal episodes among children aged less than five years.

Escherichia coli (ETEC) is another bacteria that commonly causes diarrhoea. Infection with ETEC causes a special form of diarrhoea called traveler’s diarrhoea. This form of diarrhoea (as the name suggests) is seen frequently amongst travelers. It is estimated that around 30% to 70% of international travelers will develop diarrhoea during their travels or after returning home. Risk of developing this diarrhoea is higher while travelling to resource-poor countries in Africa, Asia, the Middle East, and South America. However, rate of infection with ETEC is higher in India compared to other developing countries.

Vibrio cholerae, Shigella, ETEC- these are all bacteria. And, in this discussion, we cannot ignore viruses. One such “not-to-be-ignored” virus is Rotavirus. Rotavirus is the most common cause of diarrhoea in infants and children. In Asia, rotaviruses are responsible for 45% of hospitalizations for severe diarrhoea in infants.

Diarrhea causing organisms

Microbial contamination of water is a major problem in developing countries. The existing interventions taken by government in these countries to provide safe drinking-water to the people have many shortcomings. In developing countries such as India less than 1/3rd of households have piped water. Also, there are additional problems due to the disruption of piped water supplies in rural and urban areas. Hence, there is a need to store water in nearly every house for drinking, food preparation and bathing purposes.

The presence of diarrhoea causing microbes in water from defective or contaminated water distribution systems can be a major health risk to those who are dependent on such supplies for drinking water. A major source of contamination of drinking water in developing nations is during household storage. Several scientific studies have shown that household level interventions at point-of-use actually have significant impact on combating this menace of contaminated drinking water. Such point-of-use (PoU) interventions at household level contribute to 30-40% reduction in diarrhoeal diseases.

In short, PoU interventions at every individual house are a sustainable way to providing safe drinking-water.

Storing Water in Copper Vessels- What do Ancient Texts Say?

Medical use of copper has been recorded in Smith Papyrus, one of the oldest books known. Written between 2600 and 2200 B.C., this ancient Egyptian text records the use of copper to sterilize chest wounds and to sterilize drinking water. Other early reports of copper’s medicinal uses are found in the Ebers Papyrus, written around 1500 B.C. The Greek physician Hippocrates (460 to 380 B.C), widely recognized a Father of Western Medicine, noted use of copper for the treatment of leg ulcers. Greeks were also prompt in recognizing anti- microbial properties of copper.  The Greeks sprinkled a dry powder composed of copper oxide and copper sulfate on the wound to prevent it from getting infected. Another popular antiseptic used by the Greeks was a boiled mixture of honey and red copper oxide. The Greeks had easy access to copper from the island of Kypros (Cyprus). In fact, the name copper is derived from the name of this island.

In 1st century AD black copper oxide was routinely given with honey to remove intestinal worms. This combination was used to treat “eye roughness,” “eye pain and mistiness,” and ulceration of the mouth. It was applied into the ears to relieve ear infections.

Similar medical usage of copper has also been recorded by Aztecs and Persians. In short, the ancient world had already recognized that copper is a classic antiseptic.

Ayurveda copper vessel drinking water

Texts from Ayurveda clearly mention storage of water in copper vessels as a way of keeping water germ free. During that era in India, drinking from copper cups was regular practice alternative to drinking from glasses. Such water is referred to as “tamra jal” in Ayurveda. According to Ayurveda, our body is composed of 3 life forces- kapha, vata and pitta. These 3 life forces are are called as “doshas” in Ayurveda. The entire science of Ayurveda is about maintaining an accurate balance between these three doshas. According to Ayurveda, water stored in a copper vessel can help maintain balance between the doshas.

If scientifically accurate, cleansing and purifying drinking water just by storing in copper vessels is remarkably simple and cost- effective for every common man to follow.

Question is- Is This Scientifically Proven?

Investigating Science Behind Storing Drinking Water in Copper Vessels

During 1800s it became popularly known that copper mine workers were immune to cholera. In 1867 Victor Burq reported that those working in copper mines had far fewer deaths due to cholera than anyone else during the cholera epidemics in Paris of 1832, 1849 and 1852. By 1893 it was scientifically proven that copper has toxic effect on harmful microbes. Between 1892–1973, more than 300 scientific experiments conclusively proved that copper, even in very minute quantities, can easily destroy viruses and bacteria that cause diarrhoea.

In 2012 an elegant study was published in the Journal of Health, Population, and Nutrition. This study was conducted by scientists from Institute of Ayurveda and Integrative Medicine- Bangalore, and National Institute of Cholera and Enteric Diseases- Kolkata. In this study the scientists aimed to evaluate the effect of copper pot on microbially-contaminated drinking-water. They used drinking water sourced from ground (which is generally used as drinking water by majority) for this study. This water was found to be contaminated (500 CFU/mL) with diarrhoea causing bacteria such as Vibrio cholerae O1, Shigella flexneri 2a, enterotoxigenic Escherichia coli, enteropathogenic E. coliSalmonella enterica Typhi, and Salmonella Paratyphi.

The study found the such contaminated water, when stored in copper vessel for 16 hours in room temperature, effectively killed all the above bacteria. The bacteria were completely non recoverable even when the scientists tried resuscitating these bacteria by introducing enrichment broth. The copper ions leaking from the vessel into water are efficient killers of all these diarrhoea causing microbes. Also, the levels of these copper ions leaking into water is just 1/20th of what is safety level prescribed by the current WHO guideline. This makes storing drinking water in copper vessels a very simple, cheap extremely effective and safe way of preventing diarrhoea.

One more fact to be noted by the scientists from this study was that copper pot is as active in regular drinking-water (pH 7.83±0.4) as that in distilled water (pH 6.7±0.05), and the level of copper released in the regular drinking water is far less (177±16 ppb) than that in distilled water (~420 ppb). What this means is, it is probably better to just store drinking water in copper vessels rather than first boil and then store.

This 2012 study confirms what was earlier described in 2009 via an experiment by scientists from Institute of Ayurveda and Integrative Medicine- Bangalore. In that study, water highly contaminated with Escherichia coli, Salmonella Typhi and Vibrio cholerae (diarrhoea causing organisms) was stored overnight in glass bottles and copper bottles. The water in copper bottles turned out to be completely purified- the diarrhoea causing bacteria were completely killed. But the same water in glass bottles continued harboring these germs. Again, the level of copper in water from copper bottles was way below the WHO defined safety levels- which makes such storage strategy very safe for mass usage.

Now let me spark some controversy by describing one study published in 2009 by the Department of Microbiology at Punjab University. This study was published in the Antonie van Leeuwenhoek Journal. The scientists conducting this study (Riti Sharan et al) aimed to understand the effects of temperature and pH on inactivation E. coli (a diarrhoea causing bacteria) in water stored in a copper vessel. Through this study, the researchers expectedly confirmed that copper vessel can inactivate this diarrhoea causing bacteria with remarkable efficiency. While this finding was not different from other what was seen in other studies, the scientists discovered that temperature and pH had a substantial effect on amount of copper released from the vessel into water stored.  At low pH (6.0) and at moderately high temperature (30°C), high amount of copper may get released and can start touching the WHO defined safety levels within 12 hours.

After going through this study, one might get concerned given the fact that India is a tropical country with high temperature and where low pH water is common.

But, here is where one must not just read the findings of the study, but should go into the details of how the study was conducted. The earlier two studies we discussed simply stored contaminated drinking water in copper vessels overnight. This methodology is simple and this is what we do in real life.

The 2009 study by Punjab University used a complex method. To investigate the effects of temperature, the scientists at Punjab University stored a bacterial suspension at pH 7.0 up to 48 hours in copper vessels at 5, 15, 25 and 35°C. For evaluating effect of pH, they stored a bacterial suspension at 30°C for up to 48 hours in copper vessels at pH 6.0, 7.0, 8.0 and 9.0. But this is not what happens in real life. We don’t store bacterial suspensions- we store water which might be contaminated with microbes. This study tested only E.Coli. However, in real life, water is not contaminated just by a single bacteria- but a set of different microbes. Next, no one stores water at a single constant temperature. Temperature keeps varying with time of the day.

If I really want to take one learning from this study by Punjab University, it would be that it might not be advisable to boil water and store this hot water in copper vessels. Combine this with what the earlier 2 studies revealed, and it becomes simple guideline:

“Just filter water and store it in copper vessels overnight. That’s it! There is no need to boil”.

Drinking Water from Copper Vessel and its impact against COVID-19

COVID-19 pandemic has altered the very fabric of our existence. Millions have died and this pandemic is still ongoing.  In India the fatality rate because of COVID-19 is 2.04% while  recovery rate in India has is 68.32% (as per report dated August 09, 2020). However, India is a huge country and there are striking differences in how COVID-19 is behaving even within India, across different regions.

One such notable difference has been noted with the Yadgir District. The Yadgir district is located in the state of Karnataka in South India.  We must also note that Yadgir district is a backward district and its backwardness has been documented in the Najundappa committee report on regional imbalance. Due to low socioeconomic status of the population in this district, it lacks proper heath education and is only equipped with remote health care facilities. In spite of such challenges, Yadgir district seems to have left other districts behind in terms of recovery rate. According to the State Covid-19 War Room report, the recovery rate of the infected COVID-19 patients in Yadgir district is 87.8% (compared to the 68.32% in India as a whole). The neighboring region- Kalaburagi- is a well-developed region compared to Yadgir, but has shown a recovery rate of only 64%.

Yadgir copper drinking water

In Yadgir District, groundwater is rich in copper and this ground water gets used as drinking water by the population living in Yadgir. Experts have hypothesized that copper supplementation can help combat COVID-19 by enhancing  immunity. It is believed that copper may provide a protective shield for Covid-19 infected individuals. This ingestion of copper through drinking water may have made the people living in Yadgir District develop a strong immunity against COVID-19, leading to such high recovery rates.

Copper Covid-19

Will drinking water stored in copper vessels help us protect against COVID-19? May be. It might be the case for the people living in Yadgir District, according to few experts!

Long term drinking of water rich in copper may have protected people in Yadgir District of Karnataka from COVID-19

Final Summary:

Based on the available data, I would recommend that every household should use copper vessels to purify drinking water. There is no need to boil water. Maybe, one can filter water using a clean cloth to remove any particulate impurities. Then water can transferred into a copper vessel at night. In the morning this waster can be transferred to an earthen pot (commonly used in villages), which keeps the water cool and fresh.

Filling up drinking water in copper vessels and leaving them overnight, if followed in every household, will clearly eliminate the epidemic of diarrhoeal diseases in developing countries like India.

The use of copper pots in Indian households is extremely common. So, such recommendation is likely to be socially accepted by the masses. This method of purifying water is super economical. It is not dependent on fuel, electricity, replaceable filters, intensity of sunlight, etc. to operate or maintain it. It is simply a passive storage of water. Considering the conditions prevailing in rural villages and the urban slums of developing countries, the health benefit that can be achieved by using copper vessel as a PoU water-purification device will far outweigh the cost of the vessel. It will be a one-time investment with no recurring costs.

There are numerous other benefits of drinking water stored in copper vessels. However these benefits are beyond the scope of the current article.

I have tried my best to use all the evidences logically in an unbiased fashion.

Please share your views in the comments section.

Dr Subir Roy

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