- Note that the term "spa bath" can also refer to a spa or hot tub.
A spa bath
basin of water having a temperature of up to 45 degrees Celsius (Fahrenheit), containing salts, herbal extracts
or herbal oils, in which the hands, feet or the entire body are placed.
It can also be run with electrodes
inserted into the bath, operating under DC circuit which then is called a "galvano-spa-bath". Spa baths are generally used to promote healing or feelings of relaxation. For medical applications of spa bath in physiotherapy
, see: balneotherapy
. For non-medical applications, see: body treatment
Using a DC circuit, the array of the galvano-spa-bath develops oxygen, hydrogen and metallic ions in statu nascendi. The activated ions generated react in contact with the skin of the user. According to the results from literature (ref-26), those activated ions can be taken up by the sweat glands of the skin, similar to an ordinary spa bath, and transported through the body of the user, depending on the pH of the solution. Galvano-spa-bath is used by "healing centers" and lay persons for treatment of dysfunctions of the body. It is partly advertised, misleadingly, for medical treatment of diseases, without having presented any scientific proof up to date, although the company Aqua Detox promised to present clinical studies on the effectiveness of the galvano-spa-bath to support a medical indication for the use. In order to understand the impact of the galvano-spa-bath on the human body, it is necessary to review the basic electrochemical and bio-kinetic reactions emerging from the electrodes of the array. Most of the galvano-spa-baths have employed a stainless steel array, therefore the focus is on that array.
Hydrotherapy in general dates back to ancient cultures from China, Japan (Onsen, Japanese Hot Springs), and most recently to the Thermae (Roman Hot Springs). After an oblivion during the Middle Ages, hydrotherapy was rediscovered during the 18th and 19th century by J.S.Hahn (1696–1773), MD, Vincent Priessnitz (1799–1851), Oertel (1764–1850), and Rausse (1805–1848). In Woerrishofen (south Germany) Sebastian Kneipp (1821–1897) developed the systematic and controlled application of hydrotherapy for the support of medical treatment delivered only by doctors at that time. Galvano-spa-bath was first introduced by Sere and then adopted by Heinrich Stanger and his father Johann Stanger, the latter a tanner from Ulm (south Germany), according to Lehr (ref-24). Based on the work of Franz Heinrich Martens, MD from Jena, Germany, Golding Bird, MD from London, UK, Robert Remak, MD, from Charite, Berlin, Stanger developed his own electrochemical hand bath made out of oak, equipped with electrodes and DC circuit. On electrochemical operation, the bath tube and electrodes were covered with water containing tannin (tannic acid), wherein J. Stanger put his hands suffering from gout and / or rheumatic disease in order to get relief.
Physico-chemical reactions at electrodes
Most galvano-spa-baths have used arrays composed of surgical steel (V2A, stainless steel, or CrNi177 steel). Stainless steel is a good conductor, has a low degree of electric resistance, is a chemically inert material, i.e. free of auto-oxidation due to passivation, and is a well-known material in medicine and household usage. Most sorts of V2A steel are composed of iron (up to 80 -90%w/w,) chromium (up to 20% w/w), nickel (up to 6% w/w), manganese (up to 2% w/w) and always 1% w/w of elements, not determined by chemical analysis (ref-25). The stainless steel array of the galvano-spa-bath is operated on low voltage DC circuit (12 volts, 2 ampere, conductivity up to 1.1 mS, temperature of the spa bat : 30 - 35 degrees Celsius), resulting in a process of galvanized electrolysis. In medical electrotherapy, "galvanic" means "direct current" circuit (DC). In electrochemical reactions, there is a positively charged anode and a negatively charged cathode, wherein the anode is also known as a sacrificial anode. Sacrificial anode means that during the operation of the galvano-spa-bath, the anodic loss of stainless steel material (ref-26) will account for chromium by approx. 200 mg and nickel by 60 mg (total weight of the array 100 gram, i.e. 1 - 2 m length, diameter of 3 mm, duration of operation of 30 min, 12 volt, up to 2 ampere; all information available from the vendors). Under DC circuit operation of the galvano-spa-bath, there are the following physico-chemical reactions affecting the users body (short list):
- (1) diffusion of ions of the galvano-spa-bath (e.g. sodium and chloride) to the counter charged electrode, e.g. negatively charged ions of the solution will diffuse to the positively charged anode;
- (2) liberation of positively charged metallic ions from the sacrificial anode into the solution of the galvano-spa-bath, such as chromium-III, nickel-II, manganese-II, iron-III;
- (3) reaction of ions of the solution (in general water, and sodium chloride) with the surface of the sacrificial anode and cathode; the anode is generating positively charged protons and partly negatively charged hydroxy ions, which are released into the solution; electrons left behind in the metallic structure of the stainless steel electrode are transported to the kathode via the connecting wire; negatively charged chlorine ions of the solution are migrating to the anode and are oxidized to chlorine (gas), which is evaporating, as the users of the galvano-spa-bath can smell, another part of the chlorine gas is reacting with the metallic surface of the anode of the stainless steel electrode resulting in the destruction of the metallic surface structure, i.e. precipitation of salts such as chromium-chloride, nickel-chloride, or iron-chloride. The following chemical reactions are taking place at the positively charged anode and negative cathode of the preferred array made of stainless steel; similar reactions tale place with arrays made of platinum, palladium, or titanium:
- * Cathode (negative pole, in general there is a reduction reaction, i.e. coloring the indicator paper phenolphthalein in blue):
- * i) 2 H30+ + 2 electrons ↔ H2 (hydrogen gas) + H2O (water)
- * ii) ½ O2 + H2O + 2 electrons ↔ 2 OH- (hydroxy ion)
- * iii) 2 OH- + Me2+ ↔ Me(OH)2
- Me is the abbreviation for metallic ions from the array; e.g. chromium, nickel, iron, zinc, manganese, platinum, titanium, or palladium, depending on the alloy of the electrode; Me(OH)2 is the colored metallic-hydroxy-cover on the surface of the electrode, consisting of the metallic ion and hydroxy ions, protecting the electrode against quick degradation.
- * Anode (positive pole, in general there appears an oxidation reaction, i.e. generation of oxygen, as bubbles surfacing):
- * i) 2 OH- ↔ H2O + ½ O2 + 2 electrons
- * ii) Me ↔ Me2+ + 2 electrons
- * iii) Me2+ migration to the epidermis of the skin, entry to the body through the sweat glands.
- (4) reaction of the ions of the solution with metallic ions of the stainless steel anode resulting in the precipitation of metallic oxides and hydroxides, e.g. chromium-hydroxide, nickel-hydroxide, iron-hydroxide; those ions, complexes and precipitates are colored, e.g. chromium-III-hydroxide is light green, iron-III-hydroxide is reddish-brown, manganese-IV-oxide is dark brown. This combination of colors, slowly developing, while operating the foot bath, is generated by the metallic ions from the stainless-steel electrode. If one takes an electrode made by platinum, or titanium, no change of the color will occur, since both elements are positively charged, not generating colored complexes in solution (ref-25);
- (5) reduction-oxidation-reactions among the metallic ions of the solution, released from the anode, e.g. oxidation of the positively charged chromium-III to the negatively charged chromium-VI through reaction with iron-III ions; this are highly active ions, i.e. ions in statu nascendi being capable of reacting with other structures e.g. skin of the human body;
- (6) cathodic reduction and precipitation of metallic ions, and generation of negatively charged hydroxy ions, the latter ones reacting with positively charged metallic ions such as chromium-III.
Bio-physical reactions on the human body
Both the released and activated metallic ions, and the electromagnetic field of the array, are often claimed to be acting in concert on the human body. In general three basic bio-physical effects will be recognized, i.e. as (1) electro-thermal, (2) electro-physical and (3) electrochemical. Depending on the resistance and conductivity of the array, the temperature of the galvano-spa-bath will slightly increase during current operation. Since stainless steel is a good electrical conductor, there are only small temperature increases up to 2 degrees Celsius in a volume of 5 liters of water, over a period of 30 minutes of operation, according to the manual of the manufacturers. This might have the same effect on feet as seen with an ordinary foot-bath, as known from hydrotherapy.
The electromagnetic field of the array is also claimed to contribute to the improved circulation in the periphery of the body, due to interference with paramagnetic ions of tissue and blood stream, which is known as "galvanic hyperthermia". It has to be recognized that a galvano-spa-bath operating under 12 volts / 2 ampere will produce an electrical-body-thru-current of approx. 120 micro-ampere similar to the stangerbad (ref-23), or iontophoresis. However, the electromagnetic field is only indirectly involved in this electro-physical effect, since the array is placed between feet or hands, not going directly through body parts. This can easily be shown by taking an ampere meter between both hands, while standing in an operating galvano-spa-bath. Due to the Bayliss reflex, a vasomotor reflex, blood-flow will increase by improving circulation and oxygen supply to the local tissue. Carbon dioxide and other metabolic products are taken away from local tissue by the increased blood flow. Wound healing has been reported – under DC circuit – in medical literature (ref 1, 2), however not yet under the use of the galvano-spa-bath. This might also be accompanied by forced diuresis liberating metabolic products through the kidney and skin (sweat glands), as it is well-known from thermal mineral bath or from occupational and environmental health studies in hot work places, such as at a smelter or geographical hot regions (ref 3). In addition to urinary diuresis, local blood perfusion at the lower limbs, and lymphatic drainage might also be due to the well-known cutaneous-visceral reflex of L5 / S1 (if the feet are placed in the bath). Users of the galvano-spa-bath are reporting on an increased urinary output after several applications, similarly as seen after traditional foot massage. All those effects together can be termed as "regulation" of homeostasis or "detoxification".
Bio-kinetics of ions from stainless steel
However the major difference between the array of the galvano-spa-bath and other – traditional – procedures for improving circulation and detoxification is the stainless-steel electrode used by producers around the world. Stainless steel is a robust alloy, good conductor with little resistance and capacity of chemical passivation, which makes it resistant against oxidation. However, under the influence of DC circuit, the stainless steel array will act like a sacrificial anode
, degrading and releasing ions into the galvano-spa-bath, which are regarded as highly toxic. Under electrical current, chromium-, nickel-, manganese-, and iron-ions are released from the anode, as explained. Those ions are charged positively, complexed by molecules of water, then being counter-charged (as seen for hexavalent chromium) and can migrate under the influence of the electromagnetic field of the array to the negatively charged skin (ref-18) of the feet of the user of the galvano-spa-bath. The skin of feet and hands has more than 2000 sweat glands per square centimeter, which not only are liberating metabolic products from the body, but also can pick up ions from the galvano-spa-bath. This is a well-known effect from iontophoresis
. In addition, it has been shown by Griesz-Brisson (ref-6) that chromium and nickel ions are absorbed from the bath through the skin. From 6–10 hours after having used the V2A stainless-steel electrode, one will find a tsunami
of chromium and nickel in the urine: i.e. chromium up to 16 micrograms per gram of creatinine
, and nickel up to 25 micrograms per gram of creatinine, and copper at 100 micrograms per gram creatinine. This has been published by the Swiss-based company Body Detox AG
from Winterthur, as a documentation of "detoxification" of heavy metals. Surprisingly, when the same patients were using the platinum electrode, all of a sudden, no chromium and nickel were found in the urine, but platinum, which was not present under the use of the stainless steel array (ref-26). In contrast, workers in galvanic industry having been exposed to chromium and nickel, through protective cloths, over an 8–hour work–shift did not have more than 1 – 5 micrograms per 1 gram of creatinine of each of those elements in the urine, as we know from occupational and environmental health studies (ref-16).
Again, from many studies in work medicine (ref -9 through ref-13), it is a well-known fact that chromium-ions can penetrate the skin of hands and feet, whereas hexavalent chromium is better absorbed than the trivalent chromium. The same is valid for nickel-ions. Baranowska-Dutkiewicz (ref-10) observed a chromium-hexavalent penetration rate of 10 micrograms / square centimeter skin / hour in a 0.2 molar solution of hexavalent chromium. Agren reported (ref-7) a release of zinc into the intact skin of volunteers of 5 micrograms / square centimeter skin / hour. Considering that the galvano-spa-bath is operated with an electrical-body-through-current similar to the stangerbad, i.e. approx. 120 micro ampere, it would not be surprising to find chromium in the urine after the application, as has been reported (ref-6).
Toxicity of electrodes made of stainless steel, platinum, titanium
Stainless steel releases chromium, nickel, manganese and iron ions from a stationary matrix (ref-26, ref-30, ref-31). Chromium ions, i.e. chromium-hexavalent, which is generated under the electrolytic process of the galvano-spa-bath equipped with a stainless steel electrode, is the cause of occupational cancer of the lung and nose (ref 4). The same is observed with nickel-II-ions. Every dermatologist knows the allergic reactions due to earrings
made of chromium, nickel, or cobalt. Again from occupational medicine, we know the effect on the skin of construction workers in building industry of chromium-III-salts, being present in cement or cement concrete. They are causing eczema
, are capable of penetrating the skin, and getting absorbed by the sub-epidermal tissue. Alloys made of chromium and nickel have been banned from orthopedic implants because more than 10% of the patients with hip-replacement have shown allergic reactions to the stainless steel alloy (ref-14, ref-28). In this medical field, other non-toxic alloys made of tantalum
are now used again. Those metals were first used in 1944 (ref-27), for covering defects in the skull resulting from war injuries. Arrays, covered with commercially available platinum (10 micrometer thickness, core metal is titanium), and used in the galvano-spa-bath, are also degraded in terms of the sacrificial anode
(ref-26). They release platinum ions into the galvano-spa-bath, from where they are absorbed by the body. The electrodes degrade quicker if the pH is well above 7, and chloride is present due to the electrochemical scale. The same can be observed with arrays made of titanium. Both metals are the cause of allergic skin (ref-19) and lung reactions, as we – again – know from work medicine. Dental workers, e.g. exposed to metal dust of platinum
(ref-19), or nickel (which is used in dental medicine as NiTi-alloy, ref-15) are very often suffering from generalized allergic reactions (ref-17, ref-21). In some countries of the European Union, such allergies are regarded as occupational diseases and recognised by workman's compensation system, if occurring at the work place.
Galvano-spa-bath and cancer in 2007
From the medical point of view, one cannot follow the ads of some producers, traders and “health centers” that solid tumors (i.e. cancer) can be treated, prevented, counter-acted or symptoms be alleviated by the application of electrodes of the electrochemical galvano-spa-bath, releasing carcinogenic metallic ions such as nickel-II or chromium-VI. Certainly, platinum-chloro-complexes such as carboplatin (ref-29), cisplatin or oxyplatin are used for systemic treatment of e.g. metastatic ovarian cancer, but it is highly questionable whether an array of an electrochemical galvano-spa-bath made of platinum can have the same effect. In addition, electrochemical galvano-spa-bath treatment, or alongside treatment of people suffering from cancer, might negatively interfere with the well-established pharmacological treatment due to induction on metallothionein, which is known to neutralize the platinum derivatives of cancer therapy (ref-20). Finally, due to the possible induction of metallothionein, from the authors of this article, it is not recommended to use the electrochemical galvano-spa-bath, or iontophoresis, stangerbad or any other means of electrotherapy before, or along with, cancer chemotherapy, without approval of the responsible doctor or treatment center. To date, no data are available on the positive effect of such mentioned means of electrotherapy. In order not to mislead patients suffering from e.g. cancer, such ads must be prevented by the responsible industry, manufacturer, producer, trader, or “health center”. At this site, it has to be noted that certain medical centers, approved by the National Health Centers of the European Union, are using hyperthermia, another art of electrotherapy, for treatment of cancer.
Taking all the scientific data together on the electrochemical spa bath, the user should be very careful operating on the V2A-stainless steel electrode. Due to toxic reactions on the human body, one should recommend not to use electrodes made of stainless steel, platinum, palladium or titanium, in medical electrotherapy operating on DC circuits.
Possible harmless materials for arrays of the galvano-spa-bath
New electrode materials for medical electrochemical application, i.e. galvano-spa-bath, iontophoresis or stangerbad, focusing on material free of toxic reactions to users, should have chemically stable surfaces under DC circuit similar to stainless steel, low electrochemical over potentials, i.e. highly positive electrochemical potential; in addition, the electrodes must be readily available, inexpensive, and provide a high grade of conductivity. There are different alloys employed for the use as cardiovascular implant. They are non-toxic to the human body, i.e. no allergic reaction, or the cause of cancer is known. Those alloys are excellent conductors, have low electrical resistance, enough stability to form arrays for application in a galvano-spa-bath, and are also degrading under DC circuit. Other material such as gold, silver, molybdenum, or vanadium, is highly conductive, non-toxic but not recommended for use in galvano-spa-bath, due to the stiffness of the material and its high costs and partly allergic reactions (e.g.vanadium, ref-19, ref-21). Elements being present in the human body such as sodium, potassium, magnesium or zinc are not usable as electrodes of the galvano-spa-bath due to their highly negative electrochemical potential, resulting in quick degradation of the material of the array under DC circuit. In addition, those elements are well-known for increase of the pH of the electrolytic solution: e.g. metallic sodium is reacting aggressively with water under generation of explosive concentrations of hydrogen. Magnesium and zinc are melting away under the influence of DC circuit of the electrochemical galvano-spa-bath and are also dissociating the solution.
Possible therapeutic application of the galvano-spa-bath
To date, no clinical study on the therapeutic effectiveness of galvano-spa-baths has been reported in medical literature. However taking all together the bio-physio-chemical effects of the galvano-spa-bath, one might arrive at the conclusion that the use of the galvano-spa-bath might be of advantage for the human body – in a range of other procedures known from alternative medicine, such as thermal mineral bath, oxygen-enriched thermal bath, foot massage, or just doing exercise on a regular basis. From WW-II experiments (ref-27) on Navy soldiers, it is known that salt water can dry out the human body if in contact with the skin, which is the same with the thermal bath containing high concentrations of salt and is possible with the galvano-spa-bath (because the electrolytes added to the galvano-spa-bath and the release of elements from the electrode are generating a hyperosmolar solution separated from the human body fluid by the semipermeable membrane, i.e. skin). It is part of the medical treatment of chronic rheumatic diseases, such as gout or fibromyalgia, to use alternative medicine, even if it is just Nordic walking (in order to increase the oxygen supply to the body). However unless the electrochemical spa bath has not shown that it can provide medical treatment in the same way as the stangerbad or iontophoresis it must not advertise any relief or alleviation as a medical treatment. There is a large body of old literature from the 19th century, when the procedures of galvanotherapy were born. In Europe Golding Bird from London, UK and Robert Remak, MD from Charite Hospital, Berlin (ref-22) and Duchenne from Paris (ref-23) have done a broad application and evaluation of electrotherapy on patients. Golding Bird operated the first department of physical therapy using electrotherapy at the Guy hospital in London, around 1840. In Russian medical literature, one can find reports on the application of galvanic current (DC) for the detoxification if chromium salts from the body of workers (ref 5). Therefore producers, traders, “health centers”, and supporters of the galvano-spa-bath should at first provide patients and users with documentations on the biological safety of their system on the human body. The user has a right on information about the galvano-spa-bath regarding the change of immunological parameters (MELISA or lymphocyte–transformation test (LTT), blood picture, blood pressure, and urinary excretion of heavy metals. Because the galvano-spa-bath is operating on DC circuit, the sacrificial anode vendors must prove that their arrays are not liberating toxic compounds. Further, they should provide studies on the positive effect of the galvano-spa-bath on medical indications, where they would like to support the medical state of the art. Producers and traders of the galvano-spa-bath have to recognize that they have to reinvest part of their revenue into serious studies, if they want to claim any – even hidden - medical effect from the use of their galvano-spa-bath.
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