Archive for the ‘Water chemistry’ Category
Swimming Performance and Disinfection Byproducts: Biocides, Biofilm and PoolNaturally® Plus
By David Knighton MD
Co-Founder and CEO of Creative Water Solutions and PoolNaturally® Plus
Introduction
Walk into a building with a pool and you can instantly tell it’s there by the smell. No matter how big the building, small the pool, or robust the heating and ventilation system, that characteristic “chlorine” smell is there. If you are like me, a few minutes of exposure to the smell will bring tightness to my chest, itching to my eyes, and after about 20 minutes a light headed feeling. Go outside and it all goes away in about an hour. Swim and it can take days to return to normal. Competitively swim or swim daily and you probably get so used to the air you become acclimated to the irritation of disinfection byproducts (DBP). In the past few years, a lot of research has defined what causes this smell, what effect it has on swimmers, and what can change the creation of DBP’s so the pool becomes a “you don’t know there is a pool until you see it” experience.
How are DBP’s formed?
DBP’s are formed when chlorine, bromine or any halide molecule used to kill bacteria in the water, combines with biologic molecules that contain carbon and nitrogen. The most prevalent molecule in the swimming environment is urea from urine and sweat. Urea undergoes chemical changes in the pool and combines with chlorine or bromine to form over 30 different DBP’s. Some of these molecules stay in the water and others are volatile so they diffuse into the air above the water and eventually into the entire building. The act of swimming actually increases the concentration of DBP’s by churning up the water and increasing the concentration of these molecules in the air.
What Effects do DBP’s have on people?
We know a lot about the effect of one DBP – chloroform – since it was the most commonly used anesthetic for decades. The fancy name for this class of DBP is trihalo-methane (THM). There are many different THM’s with different effects on people, just like there are many different types of DBP’s that have different effects on people. We will look at chloroform and trichloronitrate.
Chloroform inhaled at a concentration of 10,000 ppm puts you to sleep. Prolonged exposure at this very high level will kill your liver, depress your heart function and kill you. In human volunteers, exposure to 4,100 ppm causes serious disorientation and 1,000 ppm causes dizziness, nausea, fatigue and headaches. Prolonged exposure to as little as 10 to 200 ppm can cause liver enlargement and effects on the central nervous system. For a reference, we have measured THM concentrations in commercial indoor pools in the 2 – 3 ppm range.
Application of chloroform to the skin causes redness of the eyes and itching of the skin. One study of people exposed to low levels of chloroform in their drinking water showed a correlation between chloroform concentration and rectal and bladder cancer. In fact, an international health agency classifies chloroform as a carcinogen for humans.
Other studies, especially from Europe, document the effect of trichloronitrate on swimmers. They conclude that this DBP is related to reactive airway disease or asthma in people who swim frequently. Another study shows that DBP’s are associated with changes in DNA in urinary bladder cells that correlate with an increased risk of cancer.
To summarize, DBP’s not only smell bad, they irritate your skin, eyes and lungs; cause central nervous system changes such as dizziness and headaches; cause fatigue; and with prolonged exposure are potential carcinogens.
How do DBP’s affect swimming performance?
Any athletic performance is determined by muscle contraction. Muscle contraction is an energy consuming activity that is related to oxygenation of the blood and blood flow to and from the contracting muscle. Oxygen is used along with blood delivered nutrients to produce energy so the muscle cells can contract and propel the swimmer through the water. Oxygen is delivered to the blood through the lungs as we breathe. Oxygen is then carried by our red blood cells to all tissues in our body including muscles, by blood flow. Blood flow depends on our heart to pump the blood and arteries to carry that blood to our exercising muscles.
At rest, our muscles require very little blood flow and oxygen. As we start to exercise and use our muscles to propel us through the water, they consume all the oxygen and nutrients in the area, then tell their arteries to dilate and send more blood. That causes our hearts to beat faster to supply more blood for the dilated arteries and that eventually causes us to breathe faster to deliver more oxygen to our lungs. A big part of athletic training, is to maximize this energy transport system from air to muscles. The more we exercise, the better the system works. The better the system works, the more we can exercise.
DBP’s affect performance in a number of ways. First, the air just above the water is what a swimmer inhales during swimming. That air has the highest concentration of DBP’s. The amount of oxygen in air follows the rules of physics. The higher the concentration of DBP’s, the fewer oxygen atoms in the same amount of air. So the swimmer in a pool with high DBP’s needs to move more air in and out of their lungs to remove the same amount of oxygen as a swimmer in a pool with lower DBP’s.
DBP’s like trichloronitrate cause lung irritation and narrowing of the tubes that bring air into our lungs. Because of the narrowing, less oxygen gets to the microscopic areas of our lungs where the delivery of oxygen to the blood occurs. Therefore, we need to move more air to extract enough oxygen for our exercising muscles. One result of this lung irritation is the use of drugs, called bronchodilators, that open up the airways and others, that control the inflammation caused by the irritating DBP’s. This asthma is a significant problem in many competitive swimmers.
Like most diseases, some people are more sensitive to DBP’s than others.
Those swimmers who are sensitive to DBP’s have to work harder to provide adequate energy for their contracting muscles than those who are less sensitive to DBP’s irritation.
Performance and conditioning is all about maximizing oxygen extraction from the air, blood flow to the muscles, and removal of waste products from the exercising muscle. DBP’s play a significant role in oxygen concentration in the air; delivery of air to the blood, and pumping of blood to the muscles. Along with the other health effects of chronic exposure to DBP’s and the uncomfortable irritation they cause, swimmers should do everything possible to minimize the concentration of DBP’s in their pools.
What can swimmers do?
Since urea is one source of nitrogen containing bio-molecules that form DBP’s, swimmers can reduce their formation by not urinating in the pool. Sweat is another source of urea that cannot be easily controlled since training causes increased sweating. I’ve talked to many competitive swimmers who tell me they don’t want to stop their training to go to the bathroom to urinate or that their coaches won’t let them take a break. Changing this would help create a more healthful environment for every swimmer, coach, lifeguard, and spectator.
What can facilities can do?
Ventilation
To understand the role of ventilation in this problem, we need to remember that DBP’s are at their highest concentration on the surface of the water. This is the boundary layer where there is little air movement. Traditional ventilation brings outside air inside, warms it up or cools it off depending on the temperature, and then moves it through the building, eventually pushing the air back outside. This is a very expensive process. Moving more air from the outside and through the entire space of the natatorium doesn’t address the area of the pool where DBP’s are in their highest concentration. Increasing the air movement at the surface of the pool does result in a decrease in the concentration of DBP’s. Paddock Evacuator Company’s Chloramine Evacuation System achieves this by a system that moves the air across the boundary layer and moves it outside.
Water treatment
Water disinfection and formation of DBP’s is a classic “rock and a hard place” situation. Chlorine and bromine are very effective and efficient killers of swimming (planktonic) bacteria and algae. They accomplish this through their chemistry. They are very reactive with other atoms and molecules. This reactivity oxidizes proteins and sugars in the cell wall of bacteria and algae, but also reacts with carbon and nitrogen containing compounds to form DBP’s in the water and air. It is the main way we control bacterial growth in most water systems. Even treatment systems, such as salt pools, control bacterial growth with chlorine. You don’t have to add the chemical, a reactor in the pool creates bio-reactive chlorine from the chloride ion in common salt.
When we started treating commercial pool water with PoolNaturally® Plus we found that the air quality in the pool area improved in a couple of days and the air in the entire facility was significantly improved after a week of treatment. Over time our customers starting saying that the only way you know there is a pool in the building is to see the water. Swimmers, coaches, lifeguards, and pool patrons all reported less eye, skin, hair, and lung irritation. After a swim meet in one of our pools, many swimming teams demanded that their facility add PoolNaturally® Plus.
To measure the effect of PoolNaturally® Plus on DBP concentration, we did a study with a fitness club to measure the THM in the air above the pool surface and the water in their two indoor pools (75,000 and 86,000 gallons). We measured levels weekly, for two weeks before PoolNaturally® Plus was introduced and then about every other week for 33 weeks. They have a high bather load and use chlorine for disinfection. We measured a steep decline of THM in the water resulting in 75% reduction in 33 weeks. In the air above the pool the chloroform concentration was decreased by 55%. The air quality improved just like in our other indoor facilities.
How does PoolNaturally® Plus affect DBP production?
The quick answer is we don’t know. We do have a hypothesis. PoolNaturally® Plus is made from Sphagnum moss leaves. In our laboratory, over the past 8 years, we have shown that PoolNaturally® Plus inhibits biofilm formation. Biofilm is a slime like substance that protects bacteria that adhere to the pool or filter surface. In fact, most bacteria prefer to adhere to a surface and cover themselves in biofilm, than to swim unprotected in the water where chlorine can kill them. We think the unique environment inside the biofilm helps convert urea and other organic compounds into DBP’s. We postulate that inhibiting biofilm reduces the production of DBP. The product could also have a direct effect on the DBP produced in the pool. We know the concentration is significantly decreased. We don’t quite yet know how.
PoolNaturally® Plus and swimming performance
We know competitive swimmers like training in water conditioned with PoolNaturally® Plus. We know that swimmers with asthma report that they don’t use their inhalers when they swim in outdoor or indoor pools where water is treated with PoolNaturally® Plus. We also know that lifeguards and aquatic professionals report fewer respiratory problems working around pools with PoolNaturally® Plus. We don’t know if their training and eventual performance is improved, and it will take time and study to know if the reactive airway disease, DNA changes and other health effects of DBP’s are improved.
Summary
- Use of chlorine and bromine as disinfectants in pools produces disinfection byproducts that have significant health and performance effects.
- DBP’s, such as chloroform, other THMs and trihalonitrates irritate people’s eyes, skin, lungs, and central nervous system.
- Pool water conditioned with PoolNaturally® Plus reduces the “chlorine smell” in treated pools and resulted in a 75% decrease in THM in commercial pool water and 55% reduction in natatorium air.
- Patrons of pools treated with PoolNaturally® Plus report significantly less eye, skin and lung irritation.
References
Articles about asthma and chlorine:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1747493/
http://www.pslgroup.com/dg/2076de.htm
http://www.erj.ersjournals.com/cgi/content/abstract/19/5/827
http://swimming.about.com/od/allergyandasthma/a/cl_pool_problem.htm
http://findarticles.com/p/articles/mi_m0CYP/is_13_111/ai_111200649/
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1626429/
Chloroform and effects on humans:
http://www.osha.gov/SLTC/healthguidelines/chloroform/recognition.html
THMs and bladder and colorectal cancer:
http://www.biomedcentral.com/content/pdf/1477-3163-3-2.pdf
More about Paddock Evacuator Company’s Chloramine Evacuation System:
http://www.paddockevacuator.com/about_evacuator.html
More about Creative Water Solutions’ PoolNaturally® Plus system:
Creative Water Solutions Involved in Energy Efficient Makeover at Debbie Meyer Swim School
Creative Water Solutions is proud to announce its involvement and support of the Debbie Meyer Swim School Makeover Project.
Check out the exciting makeover at the Debbie Meyer Swim School and all the various energy savings that can be achieved by applying current knowledge and the latest technologies to maintain superior water clarity and sanitation
Opening your pool this summer the PoolNaturally® way!
If you are a new or returning PoolNaturally® user, here are our suggestions for a more natural pool opening:
Spring Start Up/Opening
Install the PoolNaturally® system at the beginning of the pool season for best results, but better late than never! Returning PoolNaturally users report much easier pool start up the following summer. Excellent opening results are seen even if users installed PoolNaturally as late as August of the last pool season.
Start with a fresh filter
Remove filter media (sand, DE) and replace with fresh media if you are just starting the PoolNaturally system. If you have a cartridge filter, for best results replace it or please ensure the cartridge is well cleaned. Why? If you are new to PoolNaturally, your pool has years of accumulation of biofilm and the filter will contain a large amount of it. The easiest way to get rid of much of it fast is to change out the media or replace the cartridge filter.
If you used PoolNaturally last season, be sure to backwash the sand filter after filling your pool with water. Place cleaned or new cartridge filters back in the system.
Less is more!
When starting/opening your pool, know what you are putting in it! If you used PoolNaturally last summer, don’t start by adding shock, algaecides and cyanuric acid. Expect that your pool will start up with a minimum amount of additives.
-Add chlorine to get desired free chlorine.
-Adjust pH, alkalinity, hardness , and CYA to recommended levels below:
- Free chlorine 1-2 ppm
- pH 7.2-7.6
- Alkalinity 40-120
- Hardness 200-300
- CYA *less than 20 ppm
-Once water has been balanced, add PoolNaturally® PoolRefills to PoolNaturally® contact chamber according to the dosage chart below. It is important that once there is enough water in your pool to start the pumps, get it balanced and add PoolRefills as soon as possible, to begin experiencing the conditioning effects of moss.
How Your Pool Will Change With PoolNaturally
Depending on the age and how much your pool is used, there could be a lot of material (including scale) that is shed from the pipes, pumps, heater, and pool surfaces – this is evidence that the PoolNaturally system is working! Use a pool vacuum to get rid of the larger particles that settle out in the pool and clean or backwash filters to get rid of the smaller particles.
Maintain 1-2 ppm of chlorine – you won’t need anything higher. With PoolNaturally, your pool is no longer precariously on the edge of ‘going bad.’ It will take less chlorine to maintain this 1-2 ppm free available chlorine, so turn down your automatic chlorinator or salt generator to the lowest settings.
Living Green Expo at the Fairgrounds
May 7 & 8 Creative Water Solutions and Recreation Aquatic Solutions will be at the Living Green Expo
Living a healthier, safer and more sustainable life can be easy, and it can save you money.
The Living Green Expo (May 7-8 at the State Fairgrounds) is the one place in Minnesota to learn about all the latest in products, services and information to help you live greener. The annual spring tradition is one of the largest and most successful green events of its kind, and it is the largest zero-waste event in the state.
The Living Green Expo offers something for everyone, including showcasing simple ways to protect the family and home from toxins, explore energy efficient and environmentally friendly alternatives, grow and eat better foods and protect our planet for future generations.
New this year, The Expo has an expanded layout, Friends School Plant Sale partnership, the first Green Wedding, an Eco Kids Parade, a Complete Streets in Action demonstration and Electric Vehicle Experience. Free Chinook Books given to the first 200 visitors each day. Secure bike storage is available. Metro Transit provides shuttle services at the Expo and free transportation to and from the Expo with the Go Greener Pass.
No matter where you are on the “green spectrum,” the Expo has something for you.
Swimming Pools and Asthma
During our test this last summer at the St. Paul, MN outdoor aquatic park we surveyed the swimmers twice a week. One of the most striking findings was that swimmers with asthma did not need to use their inhalers when swimming in the pools that were conditioned with PoolNaturally Plus. We then treated the indoor aquatic park in St. Paul and had similar results.
Able to Swim Again
In fact one lady wrote to me about her inability to swim indoors due to her asthma. She was a competitive swimmer in her younger years and had to stop swimming because of severe breathing problems from asthma caused by the air in the pool. She heard about the sphagnum moss treated pools and how people could swim without using their inhalers so she tried swimming again. She reported that she could do a full workout without breathing problems and thanked me for “giving her back her favorite sport”.
With a little research the relationship between recreational and home water, chlorine and asthma became clear.
The Chemical Reactions
Here is what happens when we use chlorine to sanitize water in a pool or in our municipal water supply. As it turns out chlorine is not the problem. A byproduct of chlorine and biological molecules that contain nitrogen is the formation chloramines. These chloramines come in many different forms such as mono, di, and trichloramines. One of these compounds, a molecule called trinitrochlorine, has been implicated in causing airway irritation.
Trinitrochlorine is a volatile molecule that is extremely irritating to tissues such as your eyes, skin and airways. Because the molecule is volatile, it rises to the surface of water and is easily inhaled. In fact, in a pool, the levels of trichloronitrate are highest in the air right on top of the water. So every time a swimmer takes a breath, they inhale an irritant that causes airway constriction called reactive airway disease. The smell we all associate with a chlorine pool is actually the smell of the multiple species of chloamines, not chlorine. The problem is that chlorine is so reactive, it immediately finds and combines with nitrogen containing compounds to create chloramines..
Correlation between Pools and Asthma
A recent study reported in the pediatric literature, showed that children who are repeatedly exposed to swimming pools have a significantly higher incidence of reactive airway disease or asthma, than those who aren’t exposed to pools.
In our research laboratory, we are currently studying why the pools treated with PoolNaturally Plus don’t cause this reactive airway response, skin irritation, or burning eyes and don’t smell. We know that for chlorine to become trichloronitrate you need chlorine, nitrogen containing biological molecules and a low pH. It could be that the amount of biofilm in the pool correlates with the amount of trichloronitrate because biofilm contains and produces huge amounts of nitrogen containing molecules and it creates a local microenvironment that has a very low pH. It could therefore be the “engine” that drives the formation of these toxic molecules. In the laboratory we know that the moss in PoolNaturally Plus inhibits the formation of biofilm and if our hypothesis is correct it could greatly reduce the formation of chlorine to trichloronitrate by removing the primary nitrogen source, the biofilm . We will find out with further research
Cyanuric Acid and Last Summer’s Journey
This last summer we added our Sphagnum moss pool product to the Highland Park Aquatic Center in St. Paul. We treated two pools. One was a 430,000 gallon Olympic pool and the other was a 22,500 gallon children’s activity pool. You can read about the results on our website.
One lesson we learned involved cyanuric acid, outdoor pools, and chlorine. The accepted dogma is that cyanuric acid is required for outdoor pools and spas to stabilize the chlorine against UV degradation. In fact, most granular or solid chlorine sold in stores is stabilized with cyanuric acid. Dichlor and Trichlor have cyanuric acid in the formula.
When cyanuric acid interferes with chlorine
We started to try and understand the chemistry and science of cyanuric acid because of its side effects. Cyanuric acid above a certain concentration (which is dependent on pH) inhibits chlorine’s (hypochlorous acid to be precise) ability to oxidize bacteria. Failure to oxidize means no killing.
We also found that cyanuric acid is denser than water so it sinks to the bottom of a body of water. Therefore, the level of cyanuric acid on the surface of the pool or spa is the lowest level in the pool and it increases from there to the bottom. It will be the highest in the deepest part of the pool.
We tested this at the Olympic-sized pool. We sampled water at the bottom, middle and top of the pool. The cyanuric acid was set for 40 ppm. At the surface the level was 30-40 ppm, in the middle it was 60-70 ppm and at the bottom it was 100 ppm. From the middle of the pool to the bottom hypochlorous acid was essentially ineffective.
The other fact about cyanuric is that it is nonvolatile. That means as you add more and more to your pool or spa the concentration continues to increase. The only way to decrease the concentration is to empty some water and replace it with fresh water without cyanuric acid so you dilute out the chemical. In places where the spa or pool is full all year long, the concentration of cyanuric acid can increase to the point where the pool has no effective chlorine. I think this is why most pools have algae outbreaks starting in the bottom of the pool. The high cyanuric acid levels inhibit hypochlorous acid so no killing of algae occurs.
The experiment
So, after we learned this, I decided to decrease the cyanuric acid level in the pools gradually to see if it is really needed. The pool engineers told me “if you do that there will be no free chlorine in this pool in the morning.” We agreed to decrease cyanuric acid by 10 ppm each week and monitor the results. The free chlorine levels never decreased and the combined chlorine remained at 0. We decreased the cyanuric acid to zero and never added any more for the rest of the summer. The levels slowly decreased to zero as makeup water diluted out the cyanuric acid. The children’s activity pool behaved exactly the same.
In another pool we treated we were able to manage the large pool all summer without any cyanuric acid and maintained free chlorine levels from 1-3 ppm with no combined chlorine all summer.
Water treated with moss doesn’t need cyanuric acid
The bottom line is that with moss treated water, cyanuric acid is not needed. The mechanism for this probably centers around biofilm. I don’t think that cyanuric acid prevents chlorine from UV degradation or the free chlorine levels would have decreased in the outdoor pools we treated. We know the moss inhibits biofilm formation in the laboratory and know that biofilm absorbs chlorine. We know that free chlorine levels skyrocket when moss is added to the pool and to maintain a level of 1-3 ppm free chlorine, the chlorine added to the pool decreases by over half. So a pool with moss doesn’t need cyanuric acid. That allows the chlorine added to the pool to remain active providing effective microbial control.
Salt Water Pools, Chlorine and Moss: the naked and not always green truth.
In my continuing travels to dealers, shows and meetings I am frequently asked, “Does the moss work in a salt water pool? “ Or “why do I need moss since my pool doesn’t need chlorine since it is a salt pool?” So this blog is about the science and chemistry of salt-water pools.
First, definitions: I’m going to talk about pools where the sanitizer is made from salt by a generator – not about the very few pools that actually have salt water similar to that in the ocean. Second, when I talk about green pool products I’m using the word to describe a product that is sustainable, with no artificially made chemicals, that doesn’t introduce toxic chemicals to the air, water or ground.
How does a salt water pool work?
Salt is usually sodium chloride or potassium chloride. When these chemicals are in water they become positively charged sodium or potassium and negatively charged chloride ions. In a salt pool, solid or crystalline salt (like table salt) is passed through a generator that produces hypochlorous acid and delivers it to your pool.
This is the exact same chemical that results when you place chlorine in your pool. Salt generated chlorine doesn’t add cyanuric acid in addition to the chlorine, which is added when “stabilized chlorine” such as dichlor or trichlor are used.
So a salt pool is simply a different way of delivering chlorine to your pool to make hypochlorous acid. It is no greener or different than using liquid or solid chlorine. Again, the end product that works to kill bacteria in water is hypochlorous acid and whether you produce this from salt, or deliver it to the water as chlorine, it is all the same thing.
Is a salt pool greener?
The short answer is no. People who sell salt generators want customers to think it is green since it uses salt that doesn’t have a bad name vs. chlorine that had a bad reputation. The end result of each method is the same production of hypochlorous acid that causes the exact same problems with pool water regardless of how the chlorine is delivered to the water. Salt-water generation of chlorine is no greener than adding bleach or granular chlorine to the water.
Does moss work in a salt-water pool?
The short answer is yes. It works the same way whether the sanitizer is added chlorine, bromine, cooper or silver salts, or ozone. It has the same positive effects with all types of sanitizers (except biguanides).
In our customer’s experience using moss with a salt generator, the amount of salt consumed by the generator decreases by 80-90% to keep the free chlorine in the pool between 1-2 ppm. This puts much less strain on the salt generator and results in less chlorine being added to the environment. The other effects of moss, such as pH stabilization and biofilm effects are the same.
Will Getting Rid of Biofilm Get Rid of Crypto?
Biofilm
A couple of weeks ago I attended the World Aquatic Conference in Atlanta that focused on health and safety issues in aquatic recreation. There were a few sessions on Cryptosporidium and pool contamination.
A long time ago I spend three months in rural Ivory Coast in Africa and saw the effects of parasites on health. There it is a daily, widespread and often fatal problem. Trying to eradicate the parasites is impossible, so most of the medical effort centered on treatment. Luckily, we have very few parasitic diseases so general knowledge about parasite patterns of transmission and growth are widely known.
Parasites in Pools and Lakes
Cryptosporidium, or Crypto for short, can be a serious health problem from pools and lakes. Giardia in lakes is a type of Crypto. Both parasites set up home in the intestines of mammals and cause diarrhea with the accompanying dehydration.
Contrary to most people’s belief, these parasites do not proliferate or “grow” in the water – only inside mammal’s intestines. They can live in the water for long periods of time waiting for an unsuspecting mammal, maybe you, to swallow the water. Then they set up shop and start to divide causing intestinal disease. Huge numbers of Cryptosporidium parasites can reside in every stool from an infected animal or human. As few a 10 ingested organisms can cause serious disease. Read the rest of this entry »
Moss? How Did This Get Started?
Welcome to the first of hopefully many conversations about all things water. I am Dr. David Knighton one of the founders and President of Creative Water Solutions LLC. Along with Vance Fiegel (my business and research partner for 25 years) we started Creative Water Solutions to bring the miracle of Sphagnum moss to the world.
How did this all get started? That’s a question I get asked daily when people realize that my background is in Vascular Surgery, Cellular Biology and Wound Healing. The answer is a fascinating story of serendipity. I was returning from a trip to Germany. Somewhere over Nova Scotia I ran out of reading material and paper work. I got bored and asked the flight attendant for anything to read. She brought back Atlantic Monthly, People Magazine and Golf Digest. I golf poorly but enjoy the process and the outdoors. I usually don’t read People Magazine unless I’m waiting in a doctor’s office so I chose Atlantic Monthly.
Moss for Treating Wounds
In that issue there was a single page article about the use of Sphagnum moss in WWI to treat battle wounds. The Germans and the English found that if they packed their soldiers wounds in a special species of Sphagnum Moss that they survived in higher numbers than if they packed the wounds in cotton. The author postulated that the effect was due to the amazing absorbency of the moss. Being an expert in wound healing, a trauma surgeon, and knowledgeable about wounds and infection, I postulated that this moss must have an effect on bacterial growth. Read the rest of this entry »
