Title: CO2 release to the atmosphere from thermal springs of Sperchios Basin and northern Euboea (Greece): The contribution of “hidden” degassing

Authors: D'Alessandro W, Li Vigni L, Gagliano Antonina L, Calabrese S, Kyriakopoulos K, Daskalopoulou K.

Journal: Applied Geochemistry, Volume 119, 2020, 104660, ISSN 0883-2927, https://doi.org/10.1016/j.apgeochem.2020.104660.

Link to ScienceDirect: CO2 release to the atmosphere from thermal springs of Sperchios Basin and northern Euboea (Greece): The contribution of “hidden” degassing

Abstract: Greece is a region characterised by intense geodynamic activity that favours the circulation of hydrothermal fluids in the crust transporting volatiles from either the deep crust or the mantle to the surface. Elevated heat flow values are detectable at Sperchios Basin and North Euboea (central Greece), two areas defined by a system of deeply rooted extensional faults and Quaternary volcanic activity. This setting contributed to the formation of numerous hydrothermal systems, which are mostly expressed as CO2-rich thermal springs with intense bubbling. The CO2 output from six bubbling pools has been determined by flux measurements with the use of the floating chamber method. The highest bubbling CO2 output has been found at Thermopyles and Psoroneria (0.6 and 0.84 t/d, respectively), where the outgoing channels have an elevated flow (>250 l/s) of gas-charged water (>15 mmol/l of CO2). Although no bubbling is noticed along the stream, the CO2 content decreases by an order of magnitude after few hundreds of metres, indicating an intense degassing from the water. Taking into account the water flow and the amount of CO2 lost to the atmosphere, the CO2 output of the outgoing channels is quantified in 12.5 t/d for Thermopyles and 9.23 t/d for Psoroneria. Output estimation has also been made for the other springs of the area. The diffuse CO2 release from the outgoing channels has always been higher respect to that of the visible bubbling, suggesting that most of the degassing is “hidden”. Furthermore, the loss of CO2 from the water has determined a shift in dissolved carbonate species as demonstrated by the pH increase along the channel that led eventually to an oversaturation in carbonate minerals and therefore travertine deposition. The total CO2 output to the atmosphere of the study area is estimated at ~27 t/d, with the major contribution deriving from the degassing along the outflow channels of the thermal springs. Such output is comparable to that of the single active volcanic systems along the South Aegean Active Volcanic Arc and highlights the importance of “hidden” degassing along CO2-oversaturated streams.

Title: Effect of leg immersion in mild warm carbonated water on skin and muscle blood flow

Authors: Ogoh S, Washio T, Suzuki K, Ikeda K, Hori T, Olesen ND, Muraoka Y.

Journal: Physiol Rep. 2018 Sep;6(18):e13859. doi: 10.14814/phy2.13859. PMID: 30221833; PMCID: PMC6139710.

Link to full text: Effect of leg immersion in mild warm carbonated water on skin and muscle blood flow

Abstract: Leg immersion in carbonated water improves endothelial-mediated vasodilator function and decreases arterial stiffness but the mechanism underlying this effect remains poorly defined. We hypothesized that carbonated water immersion increases muscle blood flow. To test this hypothesis, 10 men (age 21 ± 0 years; mean ± SD) underwent lower leg immersion in tap or carbonated water at 38°C. We evaluated gastrocnemius muscle oxyhemoglobin concentration and tissue oxygenation index using near-infrared spectroscopy, skin blood flow by laser Doppler flowmetry, and popliteal artery (PA) blood flow by duplex ultrasound. Immersion in carbonated, but not tap water elevated PA (from 38 ± 14 to 83 ± 31 mL/min; P < 0.001) and skin blood flow (by 779 ± 312%, P < 0.001). In contrast, lower leg immersion elevated oxyhemoglobin concentration and tissue oxygenation index with no effect of carbonation (P = 0.529 and P = 0.495). In addition, the change in PA blood flow in response to immersion in carbonated water correlated with those of skin blood flow (P = 0.005) but not oxyhemoglobin concentration (P = 0.765) and tissue oxygenation index (P = 0.136) while no relations was found for tap water immersion. These findings indicate that water carbonation has minimal effect on muscle blood flow. Furthermore, PA blood flow increases in response to lower leg immersion in carbonated water likely due to a large increase in skin blood flow.

Keywords: Carbonated water; Doppler ultrasound; near-infrared spectroscopy; popliteal artery.

Title: Natural skin surface pH is on average below 5, which is beneficial for its resident flora

Authors: Lambers H, Piessens S, Bloem A, Pronk H, Finkel P.

Journal: Int J Cosmet Sci. 2006 Oct;28(5):359-70. doi: 10.1111/j.1467-2494.2006.00344.x. PMID: 18489300.

Link to full text: Natural skin surface pH is on average below 5, which is beneficial for its resident flora

Abstract: Variable skin pH values are being reported in literature, all in the acidic range but with a broad range from pH 4.0 to 7.0. In a multicentre study (N = 330), we have assessed the skin surface pH of the volar forearm before and after refraining from showering and cosmetic product application for 24 h. The average pH dropped from 5.12 +/- 0.56 to 4.93 +/- 0.45. On the basis of this pH drop, it is estimated that the 'natural' skin surface pH is on average 4.7, i.e. below 5. This is in line with existing literature, where a relatively large number of reports (c. 50%) actually describes pH values below 5.0; this is in contrast to the general assumption, that skin surface pH is on average between 5.0 and 6.0. Not only prior use of cosmetic products, especially soaps, have profound influence on skin surface pH, but the use of plain tap water, in Europe with a pH value generally around 8.0, will increase skin pH up to 6 h after application before returning to its 'natural' value of on average below 5.0. It is demonstrated that skin with pH values below 5.0 is in a better condition than skin with pH values above 5.0, as shown by measuring the biophysical parameters of barrier function, moisturization and scaling. The effect of pH on adhesion of resident skin microflora was also assessed; an acid skin pH (4-4.5) keeps the resident bacterial flora attached to the skin, whereas an alkaline pH (8-9) promotes the dispersal from the skin.

Title: The Shampoo pH can Affect the Hair: Myth or Reality?

Authors: Gavazzoni Dias MF, de Almeida AM, Cecato PM, Adriano AR, Pichler J.

Journal: Int J Trichology. 2014 Jul;6(3):95-9. doi: 10.4103/0974-7753.139078. PMID: 25210332; PMCID: PMC4158629.

Link to full text: The Shampoo pH can Affect the Hair: Myth or Reality?

Abstract:
Aim: Dermatologists most frequently prescribe shampoos for the treatment of hair shed and scalp disorders. Prescription of hair care products is often focused on improving scalp hair density, whereas the over-the-counter products focus on hair damage prevention. Little is taught in medical schools about the hair cosmetics, so that the prescriptions are based only on the treatment of the scalp and usually disregards the hair fiber health.

Materials and methods: In this work, we review the current literature about the mode of action of a low-pH shampoo regarding the hair shaft's health and analyze the pH of 123 shampoos of international brands.

Results: All shampoo pH values ranged from 3.5 to 9.0. 38.21% of all 123 shampoos presented a pH ≤ 5.5 (IC: 29.9-47%) and 61.78% presented a pH > 5.5. 26 anti-dandruff shampoos were analyzed. About 19.23% presented pH ≤ 5.5.(IC: 7.4-37.6%). 80.77% of all anti-dandruffs shampoos presented a pH > 5.5. The dermatological shampoo group (n = 19) presented 42.10% with pH ≤ 5.5 (IC: 21.8-64.6%), and 57.90% with pH > 5.5. Among the commercial (popular) products (n = 96), 34.37% presented pH ≤ 5.5 (IC: 25.4-44.3%) and 65.62% presented pH > 5.5. 15 professional products (used in hair salons) were analyzed, of which 75% had a pH ≤ 5.5 (IC: 18-65, 4%), and 25% had a pH > 5.5. 100% of the children's shampoos presented a pH > 5.5.

Conclusions: Alkaline pH may increase the negative electrical charge of the hair fiber surface and, therefore, increase friction between the fibers. This may lead to cuticle damage and fiber breakage. It is a reality and not a myth that lower pH of shampoos may cause less frizzing for generating less negative static electricity on the fiber surface. Interestingly, only 38% of the popular brand shampoos against 75% of the salons shampoos presented a pH ≤ 5.0. Pediatric shampoos had the pH of 7.0 because of the "no-tear" concept. There is no standardized value for the final pH. The authors believe that it is important to reveal the pH value on the shampoo label, but studies are needed to establish the best pH range for both the scalp and the hair fiber's health.

Title: Evaluation of pH of Bathing Soaps and Shampoos for Skin and Hair Care

Authors: Tarun J, Susan J, Suria J, Susan VJ, Criton S.

Journal: Indian J Dermatol. 2014 Sep;59(5):442-4. doi: 10.4103/0019-5154.139861. PMID: 25284846; PMCID: PMC4171909.

Link to full text: Evaluation of pH of Bathing Soaps and Shampoos for Skin and Hair Care

Abstract:
Background: Normal healthy skin has potential of hydrogen (pH) range of 5.4-5.9 and a normal bacterial flora. Use of soap with high pH causes an increase in skin pH, which in turn causes an increase in dehydrative effect, irritability and alteration in bacterial flora. The majority of soaps and shampoos available in the market do not disclose their pH.

Aims and objectives: The aim of this study was to assess the pH of different brands of bathing soaps and shampoos available in the market.

Materials and methods: The samples of soaps and shampoos were collected from shops in the locality. The samples of different brands are coded before the analysis of the pH. Solution of each sample was made and pH was measured using pH meter.

Results: Majority of the soaps have a pH within the range of 9-10. Majority of the shampoos have a pH within the range of 6-7.

Conclusions: The soaps and shampoos commonly used by the population at large have a pH outside the range of normal skin and hair pH values. Therefore, it is hoped that before recommending soap to patient especially those who have sensitive and acne prone skin, due consideration is given to the pH factor and also that manufacturers will give a thought to pH of soaps and shampoos manufactured by them, so that their products will be more skin and hair friendly.

Title: Transdermal CO2 application in chronic wounds

Authors: Wollina U, Heinig B, Uhlemann C.

Journal: Int J Low Extrem Wounds. 2004 Jun;3(2):103-6. doi: 10.1177/1534734604265142. PMID: 15866797.

Link to PubMed: Transdermal CO2 application in chronic wounds

Abstract: Chronic wounds are a challenge to treatment. In this retrospective study, the effect of transdermal CO2 application on wound healing in chronic ulcers was investigated and compared to the effect of CO2 on acute surgical wounds. Eighty-six patients (52 females and 34 males) with chronic wounds of different origin except arterial occlusive disease were included. In addition, 17 patients (5 females, 12 males) with wide excision wounds after surgical therapy of acne inversa were considered. The indication for CO2 application was a wound at risk for infection. Treatment was performed with a Carboflow device once daily for 30 to 60 minutes. There was clinical evidence of improvement of granulation and reduction of discharge and malodor within 1 week of treatment in both chronic and acute wounds. Only 9 patients, all diabetics, needed an additional systemic antibiosis. The treatment was well tolerated. No adverse effects have been noted. Transdermal CO2 application is a useful method to reduce the risk of infection and improve wound healing in both chronic and certain acute wounds. Systematic prospective trials are needed.

Title: Effects of carboxytherapy on skin laxity

Authors: Oliveira SMD, Rocha LB, da Cunha MTR, Cintra MMM, Pinheiro NM, Mendonça AC.

Journal: J Cosmet Dermatol. 2020 Nov;19(11):3007-3013. doi: 10.1111/jocd.13337. Epub 2020 Feb 24. PMID: 32091181.

Link to PubMed: Effects of carboxytherapy on skin laxity

Abstract:
Background: Carboxytherapy is capable of inducing tissue repair which results in an increase in elastic and collagen fibers.

Objectives: To evaluate the effects of carboxytherapy upon human skin collagen and elastic fiber synthesis.

Methods: Case study of nine volunteers who received a single application of carboxytherapy in the left infraumbilical region, with infusion rate of 100 mL/min and 0.6 mL/kg weight over an area of 25 cm2 . After 60 days on average, the skin was collected for histological analysis and stained with picrosirius red for collagen and Verhoeff for elastic fibers. The percentage of fibers found was marked by the Image J® program and recorded in a Microsoft Excel spreadsheet. Statistical analysis was performed using SPSS (version 20), with a significance level of 95%.

Results: An increase in the collagen and elastic fibers sample was observed in the treated group. Morphometrically, a significant increase in the percentage of collagen in the Carboxytherapy group (41.44 ± 4.50%) was observed compared with the control group (37.44 ± 3.87%) with P = .04; for elastic fibers, the percentage showed no significant difference between the control group (10.55 ± 4.33%) and the carboxytherapy group (10.44 ± 3.71%).

Conclusions: Carboxytherapy with the parameters used in this study was able to stimulate collagen and elastic fiber synthesis, with significant differences in the morphometry for collagen fibers.