What in the world is a “xenobiotic,” and why is this a problem in my swimming pool water?
Xenobiotic Danger in Recreational Water
By Robert Lowry, Aqua Magazine
What in the world is a "xenobiotic," and why should I be worried about it?
No, it isn't some new kind of disease, bacteria, parasite or organism. It is a term that is used as a catch-all for a number of things. Xeno is Greek for "foreign" and "biotic" is from "bios," which means "life," but also means "biologically active."
Common xenobiotics we encounter daily include household products such as window, countertop and floor cleaners; dishwashing and laundry compounds; and heavy-duty potent chemicals such as degreasers, drain cleaners and oven cleaners. They also include pharmaceutically-active compounds and endocrine-disrupting chemicals. Drugs, both legal and illegal, are also considered to be xenobiotics also.
There are many concerns when it comes to providing high-quality drinking water: scarce water sources, droughts, expanding population and well closings. You can add xenobiotics to the list as well. As xenobiotics go down the drain and through the sewer system, septic tanks do not destroy these chemical wastes, resulting in local pollution.
While drinking water quality has gotten better over the past few decades, the lack of fresh, uncontaminated source water has caused municipalities to consider and implement water-recycling practices. It may be easier to remove the contaminants from household wastewater and recycle it rather than removing contaminants from industrial or agricultural polluted source or ground water. However, recycling water poses another question in terms of the xenobiotics present in water and how they may build over time, an idea which plays a large role in the world of recreational water.
Take perchlorate, for example. An example of both a xenobiotic and an endocrine disruptor, perchlorate is the primary ingredient of solid rocket propellant and in munitions beginning since the 1950s. Perchlorate is also used in the production of explosives and fireworks — it adds the blue color to firework displays.
For disposal, perchlorate is often dissolved in water and poured on the ground. It breaks down very slowly in the environment, but it moves quickly through underground and surface water. Wastes from the manufacture and improper disposal of chemicals that contain perchlorate are increasingly discovered in soil and water. Traces of perchlorate have been found in groundwater in virtually every state in the U.S. It has been detected in many rivers and low levels have been found in some lettuce samples and milk.
How does it affect the body? First, perchlorate interferes with iodide uptake into the thyroid gland. Because iodide is an essential component of thyroid hormones, perchlorate disrupts the function of the thyroid. The thyroid helps to regulate metabolism. In children, the thyroid also plays a major role in proper development. Impairment of thyroid function in expectant mothers may impact the fetus and newborn and result in effects including changes in behavior, delayed development and decreased learning capability. Changes in thyroid hormone levels may also result in thyroid gland tumors.
Although the range of health effects for these xenobiotics is broad, all of these compounds are foreign to the living organism in which the health effect is observed, making them xenobiotic.
Prescription medications are formulated to be highly soluble and not readily degradable in the human digestive system. These properties make them persistent in water and not readily degraded by sunlight. Pharmaceutical residuals appear in urine and sweat as a product of their use and subsequent excretion. Other prescription preparations such as topical ointments and lotions for dermal conditions are easily shed into the water upon immersion.
More importantly, these medications appear in sewage in water. When scientists recently tested sewage in Australia for the top 50 different prescription medications, all 50 drugs were present. And after testing streams in 30 states, a study published by the U.S. Geological Survey in March 2002 found trace amounts of everyday products such as soap and prescription drugs in 80 percent of the water sources sampled. Streams showed 95 different chemicals from antibiotics to fragrances.
The bottom line: If municipalities are going to recycle sewage and mix it with source water to meet demands, they have to consider the monitoring and treatment of xenobiotics as well.
The ultimate recycling of water is a commercial recreational water facility (a public swimming pool, spa or hot tub). The water is sometimes used for years before draining or significant dilution.
A study done by J. Alan Beech in 1981 found the amount of pollution per person who enters a pool is 200 mL (milliliters) of sweat and 50 mL of urine. No reliable studies have been done on which to base the amount of urine voided in the water by swimmers. Warren and Ridgeway from Water Research Laboratory, Marlow, England estimated it to be 25-50 mL per swimmer in 1978. Beech estimated it to be much higher for children under 10 years of age. He adopted a value of 50 mL per swimmer.
Kuno from C. C. Thomas in Springfield, IL, reported that an active swimmer in water at 24° C (75°F), when the air temperature was 38° C (100° F) lost approximately 1 liter (1.06 quart) of sweat per hour. For his calculation he assumed 10 percent of the volume or 100 mL/hr. The average time spent in the pool is two hours. The EPA estimates that child swimmers aged 5-9 years spend three hours in pools at a time, teenagers spend six hours and adults one hour. Beech used an average of two hours which produced 200 mL of sweat.
We know drugs appear in sewage. Therefore, it is not a quantum leap to understand that drugs, household cleaners and personal care preparations are present in recreational water.
Of primary concern is the potential for adverse health effects. Drug residual concentrations reported in sewage to date are an order of magnitude (two or more times) below those at which an effective therapeutic dose would result from ingesting the water. [That is in sewage, not in recycled, recreational water that may be years old. The concentrations will be much higher in old recreational water.]
Multiple drugs in the water raises the possibility of drug interactions that may cause health effects not otherwise observed.
Then there is the idea of continuous, multiple or repeated exposure to low levels of these drugs — swimming every day in a drug soup may have untold consequences. It could take one or many exposures over months or years for any symptoms or adverse health effects to appear. This could make finding xenobiotics in recreational water as the culprit nearly impossible. Doctors may not even be able to diagnose the problem, much less the cause.
Imagine if you will, what might be in swimming pool, spa, hot tub, whirlpool, waterslide, waterpark, lazy river or other recreational water. How much and what might be in the water of a recreational facility that has a daily bather load of 9,000 people and has used the same water for 100 days? What about the spa that has 25 people in it all day long and the water is a month old?
If you swallow some pool water, are you ingesting some or all of the commonly prescribed drugs? It is estimated that 25 to 30 percent of all people over the age of 18 years have tried illegal drugs; you may be ingesting some pot, cocaine, heroin, methadone, crack or other drugs. You could be getting extra hormones, amino acids, vitamins or minerals. You could even be getting some extra caffeine or nicotine.
Xenobiotic material has been in the water since the very first pool was ever built. We have just recently been able to analyze it, and we are just now talking about it. And unfortunately, there are no easy tests for xenobiotics or drugs, as they are insignificant on a total dissolved solids test.
We also do not know what any common water sanitizers will do to xenobiotics. They may destroy them. They may do nothing to them. They may chlorinate them, brominate them or oxidize them to unknown byproducts that may be harmful or harmless.
At present for recreational water, the only defense we have against xenobiotics is draining. One draining method used in England and Europe is to drain 30 liters (about 8 gallons) of water per bather per day. This may also reduce the need to superchlorinate.
One recommendation is to use water from an approved potable municipal water treatment facility. This water must meet the requirements of the Safe Drinking Water Act. Some 100+ known contaminants are below the level determined safe and it has been tested. Do not use ground water, well water or surface water in a recreational water facility unless the water has been tested by the local health authority and approved for drinking. There is no way of knowing what is in that water without extensive and expensive testing.
As I mentioned earlier, xenobiotics is a hot topic in drinking water right now, meaning it'll naturally trickle down to the pool industry. It won't be long before recreational water comes under scrutiny — will you be ready when your customers start asking about it?
A good basic primer on swimming pool water balance and chemistry
Understanding Water Balance
from Poolgear.com
H2Oh! - Understanding the chemical composition of a healthy swimming pool
Just imagine – your drinking water may not be good enough to swim in. After all, tap water often has high levels of minerals and low pH – two factors that can harm your pool and prevent chemical treatments from doing their job. The two most important things to remember about the health of your pool are that it must be sanitized and it must be balanced. The best way to sanitize your pool is with chlorine. Keeping your pool balanced, means keeping the five basic pool water components (pH, total alkalinity, calcium hardness, total dissolved solids and stabilizer) within their proper ranges, helps your sanitizer work more effectively. That's why we say to achieve a healthy pool, sanitizing and balancing are equally important.
Total Alkalinity
In simple terms, total alkalinity refers to how much alkaline is in the water. But you can't fully know the importance of total alkalinity without referring to pH, because the two go hand-in-hand. High alkaline water leads to high pH. Low alkaline water leads to low pH. For now, just remember that the average swimming pool should have an alkalinity reading of 100 ppm.
Swimming Pool Water pH Levels
Keeping your pH levels within the proper range is not only important for swimmer comfort, it's also important for keeping your equipment and pool finish in good condition. pH refers to the acidity or baseness of your pool water. All you need to remember is that a proper pH level is around 7.4 to 7.6 on a pH test kit's numeric scale. 0 to 7 reflects a low or acidic pH. 8 to 14 means the pool has a base pH level. Low pH readings mean your chlorine will dissipate a lot quicker. High pH levels make chlorine inactive. And that means the money you're spending on chlorine is a waste.
Calcium Hardness
Anyone who's ever washed their hair in hard water knows that hard water doesn't do much for getting up a good lather. But in your pool, just the right amount of calcium is essential. Too little and your plaster can erode. Too much and your water could become cloudy, scale could form and stains might start. 200 to 400 ppm is the general range for calcium hardness, while 300 ppm is ideal for the average pool.
Stabilizer
Stabilizer is to chlorine like your home's insulation is to keeping in hot or cold air – it helps retain your chlorine longer just as insulation helps retain heat or air conditioning. Stabilizer is even added to some chlorine compounds to protect them from the breakdown effects of sunlight. When your stabilizer level is low, you'll use a lot more chlorine. When it's high, you may need to dilute your pool water to bring it back into the 40 to 100 ppm ideal range.
Total Dissolved Solids (TDS)
Like calcium, there are many other dissolved elements in pool water. Unless it's distilled, all water contains dissolved minerals. As pool water evaporates, minerals remain behind and become concentrated. The more concentrated these minerals become, the harder it is for chemical additives to work and stains can form. If you have 3000 ppm or more of total dissolved solids or TDS, you may need to drain some water and add fresh water.
View the full size Understanding Water Balance portion of our "Pool Care Tips" manual.
Does Sphagnum moss help control Bio Film in swimming pools and spas?
Biofilm, a new perspective on the behavior of bacteria
Thoughts on the Moon Landing and Biofilm
July 17th, 2009, by cwsnaturally.com
Where were you when the first human foot made an imprint on the moon 40 years ago?
I was in Ferkessedougou, Ivory Coast working at a mission station for the summer between my sophomore and junior year of college. I spent part of my time doing maintenance and the other helping with surgery. I remember listening to the short wave radio as we heard Voice of America describe the landing. It was night and there was a bright African full moon. After they landed I went outside and looked at the moon marveling at the advances in technology that allowed that human footprint on the lunar surface.
The next morning I excitedly told my co-worker, in my broken French, what happened the night before. He asked me "How long did it take them to get there?" "Three days was my answer." He thought a while and then said, "The moon is as far away as Buoake." Buoake is a three-day walk from the mission station.
His frame of reference was completely different than mine and in a way both were accurate.
A Different Understanding
That experience is very similar to what is happening in the understanding of how bacteria live in pools and spas. The old, accepted model says that bacteria like to swim and remain suspended in the water. We now know that 99% of bacteria in water swim to the nearest surface, attach themselves, and set up a microscopic colony that is protected by a layer of sticky protein and sugar molecules we call biofilm.
The biofilm protects the bacteria from chlorine or other chemicals put into the pool to control bacteria. In fact it absorbs chlorine, bromine or ozone so a lot has to be added to the pool to maintain proper levels. As we study biofilm in our laboratory and more fully understand how it affects pools, spas and any other system where water, bacteria and a surface are present, we are convinced that most of the water problems plaguing the recreational water experience are due to biofilm.
The bad news is that bacteria protect themselves with biofilm and that all the chlorine, bromine, ozone, cooper, silver, UV light or other systems that only affect bacteria suspended in water are totally ineffective against bacteria protected with biofilm. The good news is that we are discovering that the sphagnum moss in SpaNaturally and PoolNaturally may be nature's answer to controlling biofilm.
While this research may not compare with the accomplishment of Apollo 11, in the future we'll know that cleaner, safer water with fewer chemicals was a dream fulfilled through the scientific effort of hundreds of scientists who transformed our understanding of how bacteria live and protect themselves.
This pool smells like it has too much Chlorine. WRONG!!!
The Chlorine Myth / What creates that chlorine smell
To some people chlorine is the devil, its the worst. Maybe they saw an episode of 20/20 that said "Chlorine, The Silent Cleanser." Well it's not as bad as you may think, in fact its the best thing for you and we are here to clear all charges against chlorine.
Myth: Chlorine Burns Your Eyes When You Open them Underwater
Fact: Low pH burns your eyes when you open them underwater. A pool that has low pH means that the water is acidic. When water is acidic, its like putting your tongue on a battery (though not as harsh) but if you expose your eyes to it then yes, it's gonna burn. You could have a chlorine reading of 10 ppm (Parts Per Million) and as long as your pH is ok, then your eyes will be ok.
Myth: Chlorine can do long term damage on my filter system
Fact: No it can't, but low pH can corrode metal and high pH can leave a hard deposit. We can simply say that most problems that are associated with chlorine are really the fault of chlorine. The only thing bad about chlorine is that you can't eat it, or can you?
Great packet of information about pool water treatment
Pool Treatment 101: Introduction To Chlorine Sanitizing
Mastering the knack of maintaining a healthy pool is not difficult with the right information and a little diligence. The proper use of chlorine is a key step to keep your pool healthy.
For general pool treatment, chlorine has three essential characteristics:
1. It acts as a rapid and persistent sanitizer,
2. It is an effective algaecide, and
3. It is a strong oxidizer of undesired contaminants.
Everything you wanted to know about algae – especially how to destroy them!
You may recall from science class that algae are one-celled plants. There are more than 20,000 species. Yuck!
Algae that grows in swimming pools and spas, can be green, brown, yellow, black or pinkish. Most often they're a slimy substances that resembles fur and typically grow on the steps and in corners – places where circulation may not be optimum. Most swimming pools are in the sun several hours per day, and it's sunlight that speeds algae growth. Terrific right!
How to diagnose and treat calcium deposits in your swimming pool
Scale Tales
Calcium deposits can creep into a pool from various sources — but a few simple steps will prevent them from taking hold.
Even a well-scrubbed pool can fall victim to metal or mineral deposits every so often.
These blemishes might form around the waterline, or harden along the steps. And because their sources can range from underground mineral layers to popular chlorine compounds, the process of tracing scale to its source — and preventing its return — can seem like a daunting task.
Would your swimming pool benefit from a liquid chemical feeder?
Feed Needs
Liquid chemical feeders can simplify pool maintenance — but an awareness of their workings is crucial for effective use.
For much of the pool industry's history, chemicals have been added to the water in two basic ways: By pouring solutions into the pool, or by placing tablets in a feeder of some sort. These techniques are both simple and time-tested, but they're not always ideal — especially for pools with high bather loads, or those that require rapid chemical adjustments.
Healthy Swimming Pool FAQs
Healthy Swimming Pools – Frequently Asked Questions
1. Does swimming cause asthma?
2. What about research from Belgium that found swimming in chlorinated pools can cause asthma in children?
3. Can I get sick from using a swimming pool?
4. How can I recognize a healthy pool?
5. How can I protect myself and other swimmers?
6. How do pool operators keep a swimming pool healthy?
7. Does chlorine prevent all recreational water illnesses?
8. Is chlorine safe for swimming pools?
9. What causes "chlorine" odor, red eyes and itchy skin?
10. What should I be asking my pool operator?
11. How can I learn more about swimming pool health and safety?
Common Salt system problems and how to prevent them
Preventing Saltwater Problems
Many salt-related issues can be avoided through proper knowledge of the causes and an effective maintenance regimen.
Scale, stains and cloudy water are the most common challenges with saltwater pools — but only if they are not maintained correctly.
Proper maintenance goes a long way toward avoiding common problems in these pools. Watching for early signs can also help you prevent potential issues from escalating into obvious problems.

