Should I Filter My Water? Avoiding Disinfection Byproduct Mixtures.

Drinking Water
Drinking Water (Photo credit: SEDACMaps)

A blog called socially acceptable has written to me about reverse osmotic filtration for her water.  Do we all need this level of protection?

First, should we filter at all?  It is, after all, good clean water we get from that tap.  Well. Sort of.  Well water can be full of arsenic or coliform.  Municipal water may have lots of issues, including lead leaching into the water from older solder.

Let’s wave our magic water wands.  None of the municipal issues exist.  There are no  medications in your water.  The new municipal plant takes out that and everything else with its fantastic cleaning and filtration process.

Unfortunately, cleaning can be an issue.  Cleaning our water leaves behind disinfection byproduct (DBP) mixtures.  These are exactly as yummy as they sound.

We don’t really have a handle on what these mixtures do in the human body when they are consumed.  We do know the DBPs caused changes in migration of human cell DNA within an hour of exposure.  Not cancerous, just a change in the level of DNA movement.  But that’s within an hour.

So it makes sense to throw up an extra layer of filtration if you plan on drinking a lot of water.  Out of over six hundred DBP mixtures, chances are good that one or more does bad things to some people.

I say some people because it is likely that some of the population is resistant to any toxicity produced by DBPs.  Others aren’t as fortunate.  But those who are less fortunate will likely not make up a significant portion of the population.  At least not significant enough to “prove” that the DBPs are an issue.  Instead, any population studies would likely show a non-significant increase in cancers from DBPs.

We do know that very low levels of arsenic or lead in the water will cause problems in rats.  The DBPs might well fall into the same level of toxicity.  A number of them are substances already linked to cancer in other contexts.

What level of protection is enough?  Well, it depends on what you need.  Different people need different levels of protection.  As you age and your gut gets thinner, you will gradually need more protection.

For most people, solid carbon filtration is enough to bring down the DBP count into an acceptable range.  Whether you invest in something like reverse osmosis is more a matter of preference.  But since most people have zero filtration, carbon is a good starting place.

Beyond blocking out the bad things, take a moment to think about what you might need extra of in your diet.  Magnesium deficient individuals might need more magnesium.  A range of water soluble vitamins might be on the list of things to think about.  Adding things to your water, particularly when you drink a great deal of water, can be a good way to get them into you.

Even when you drink water can affect how much good the water does you.  People drinking more all at once had a greater effect on them than if they drank that water over a longer period.

So take a minute to consider your daily hydration.  And think about getting a filter of some kind.

Environ Sci Technol. 2010 Oct 1;44(19):7184-92.

Concentration, chlorination, and chemical analysis of drinking water for disinfection byproduct mixtures health effects research: U.S. EPA’s Four Lab Study.

Pressman JG, Richardson SD, Speth TF, Miltner RJ, Narotsky MG, Hunter ES 3rd, Rice GE, Teuschler LK, McDonald A, Parvez S, Krasner SW, Weinberg HS, McKague AB, Parrett CJ, Bodin N, Chinn R, Lee CF, Simmons JE.


National Risk Management Research Laboratory, US EPA, Cincinnati, Ohio 45268, USA.


The U.S. Environmental Protection Agency‘s “Four Lab Study” involved participation of researchers from four national Laboratories and Centers of the Office of Research and Development along with collaborators from the water industry and academia. The study evaluated toxicological effects of complex disinfection byproduct (DBP) mixtures, with an emphasis on reproductive and developmental effects that have been associated with DBP exposures in some human epidemiologic studies. This paper describes a new procedure for producing chlorinated drinking water concentrate for animal toxicology experiments, comprehensive identification of >100 DBPs, and quantification of 75 priority and regulated DBPs. In the research reported herein, complex mixtures of DBPs were produced by concentrating a natural source water with reverse osmosis membranes, followed by addition of bromide and treatment with chlorine. By concentrating natural organic matter in the source water first and disinfecting with chlorine afterward, DBPs (including volatiles and semivolatiles) were formed and maintained in a water matrix suitable for animal studies. DBP levels in the chlorinated concentrate compared well to those from EPA’s Information Collection Rule (ICR) and a nationwide study of priority unregulated DBPs when normalized by total organic carbon (TOC). DBPs were relatively stable over the course of the animal studies (125 days) with multiple chlorination events (every 5-14 days), and a significant portion of total organic halogen was accounted for through a comprehensive identification approach. DBPs quantified included regulated DBPs, priority unregulated DBPs, and additional DBPs targeted by the ICR. Many DBPs are reported for the first time, including previously undetected and unreported haloacids and haloamides. The new concentration procedure not only produced a concentrated drinking water suitable for animal experiments, but also provided a greater TOC concentration factor (136×), enhancing the detection of trace DBPs that are often below detection using conventional approaches.

PMID: 20496936

Mutat Res. 2007 Nov-Dec;636(1-3):178-242. Epub 2007 Sep 12.

Occurrence, genotoxicity, and carcinogenicity of regulated and emerging disinfection by-products in drinking water: a review and roadmap for research.

Richardson SD, Plewa MJ, Wagner ED, Schoeny R, Demarini DM.


National Exposure Research Laboratory, US Environmental Protection Agency, Athens, GA 30605, USA.


Disinfection by-products (DBPs) are formed when disinfectants (chlorine, ozone, chlorine dioxide, or chloramines) react with naturally occurring organic matter, anthropogenic contaminants, bromide, and iodide during the production of drinking water. Here we review 30 years of research on the occurrence, genotoxicity, and carcinogenicity of 85 DBPs, 11 of which are currently regulated by the U.S., and 74 of which are considered emerging DBPs due to their moderate occurrence levels and/or toxicological properties. These 74 include halonitromethanes, iodo-acids and other unregulated halo-acids, iodo-trihalomethanes (THMs), and other unregulated halomethanes, halofuranones (MX [3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone] and brominated MX DBPs), haloamides, haloacetonitriles, tribromopyrrole, aldehydes, and N-nitrosodimethylamine (NDMA) and other nitrosamines. Alternative disinfection practices result in drinking water from which extracted organic material is less mutagenic than extracts of chlorinated water. However, the levels of many emerging DBPs are increased by alternative disinfectants (primarily ozone or chloramines) compared to chlorination, and many emerging DBPs are more genotoxic than some of the regulated DBPs. Our analysis identified three categories of DBPs of particular interest. Category 1 contains eight DBPs with some or all of the toxicologic characteristics of human carcinogens: four regulated (bromodichloromethane, dichloroacetic acid, dibromoacetic acid, and bromate) and four unregulated DBPs (formaldehyde, acetaldehyde, MX, and NDMA). Categories 2 and 3 contain 43 emerging DBPs that are present at moderate levels (sub- to low-mug/L): category 2 contains 29 of these that are genotoxic (including chloral hydrate and chloroacetaldehyde, which are also a rodent carcinogens); category 3 contains the remaining 14 for which little or no toxicological data are available. In general, the brominated DBPs are both more genotoxic and carcinogenic than are chlorinated compounds, and iodinated DBPs were the most genotoxic of all but have not been tested for carcinogenicity. There were toxicological data gaps for even some of the 11 regulated DBPs, as well as for most of the 74 emerging DBPs. A systematic assessment of DBPs for genotoxicity has been performed for approximately 60 DBPs for DNA damage in mammalian cells and 16 for mutagenicity in Salmonella. A recent epidemiologic study found that much of the risk for bladder cancer associated with drinking water was associated with three factors: THM levels, showering/bathing/swimming (i.e., dermal/inhalation exposure), and genotype (having the GSTT1-1 gene). This finding, along with mechanistic studies, highlights the emerging importance of dermal/inhalation exposure to the THMs, or possibly other DBPs, and the role of genotype for risk for drinking-water-associated bladder cancer. More than 50% of the total organic halogen (TOX) formed by chlorination and more than 50% of the assimilable organic carbon (AOC) formed by ozonation has not been identified chemically. The potential interactions among the 600 identified DBPs in the complex mixture of drinking water to which we are exposed by various routes is not reflected in any of the toxicology studies of individual DBPs. The categories of DBPs described here, the identified data gaps, and the emerging role of dermal/inhalation exposure provide guidance for drinking water and public health research.

PMID: 17980649

Mutagenesis. 2004 Sep;19(5):341-7.

Genotoxicity and cytotoxicity assessment in lake drinking water produced in a treatment plant.

Buschini A, Carboni P, Frigerio S, Furlini M, Marabini L, Monarca S, Poli P, Radice S, Rossi C.


Dipartimento di Genetica Antropologia Evoluzione, Università di Parma, Parco Area delle Scienze 11A, 43100 Parma, Italy.


Chemical analyses and short-term mutagenicity bioassays have revealed the presence of genotoxic disinfection by-products in drinking water. In this study, the influence of the different steps of surface water treatment on drinking water mutagen content was evaluated. Four different samples were collected at a full-scale treatment plant: raw lake water (A), water after pre-disinfection with chlorine dioxide and coagulation (B), water after pre-disinfection, coagulation and granular activated carbon filtration (C) and tap water after post-disinfection with chlorine dioxide just before its distribution (D). Water samples, concentrated by solid phase adsorption on silica C18 columns, were tested in human leukocytes and HepG2 hepatoma cells using the comet assay and in HepG2 cells in the micronuclei test. A significant increase in DNA migration was observed in both cell types after 1 h treatment with filtered and tap water, and, to a lesser extent, chlorine dioxide pre-disinfected water. Similar findings were observed for the induction of “ghost” cells. Overloading of the carbon filter, with a consequent peak release, might explain the high genotoxicity found in water samples C and D. Cell toxicity and DNA damage increases were also detected in metabolically competent HepG2 cells treated with a lower concentration of tap water extract for a longer exposure time (24 h). None of the water extracts significantly increased micronuclei frequencies. Our monitoring approach appears to be able to detect contamination related to the different treatment stages before drinking water consumption and the results suggest the importance of improving the technologies for drinking water treatment to prevent human exposure to potential genotoxic compounds.

PMID: 15388805

Int J Artif Organs. 2007 Dec;30(12):1109-15.

High doses of water increase the purifying capacity of the kidneys.

Di Paolo N, Nicolai GA, Lombardi M, Maccari F, Garosi G.


Nephrology, Dialysis and Transplantation Department, University Hospital of Siena, Siena, Italy.



In previous studies we were successful in demonstrating that the administration of water over a short period of time increases the transport capacity in the excretory tract of rabbit ureters by increasing urinary volume in the ureter from 0.3 ml/min to 10 ml/min. This phenomenon may explain the effect of water therapy performed in thermal spas, where the administration of 1-2 liters of mineral water is performed in 30-60 minutes.


The aim of the present study is to investigate if this increased transport capacity can act also in the renal tubular apparatus to modify the excretion of some endogenous substances.


We evaluated daily renal clearances in ten subjects under basal conditions during supplemental administration of 25 ml/kg of mineral water over a 24-hour period and during the administration of the same amount of water over a 30-minute period.


Subjects who drank a water load of 25 ml/Kg over 30 minutes showed a higher diuresis than that observed in those who drank the same amount over a 24-hour period. Creatinine and urea clearance at 24 hours were significantly higher in subjects who drank the water load over 30 minutes. Serum magnesium levels and folic acid levels were also significantly higher in subjects who drank the water load over 30 minutes.


Water administration over a short period of time seems to modify the daily excretion of some endogenous metabolites.

PMID: 18203073

J Am Coll Nutr. 2004 Dec;23(6):758S-62S.

Absorption and effect of the magnesium content of a mineral water in the human body.

Kiss SA, Forster T, Dongó A.


Hungarian Magnesium Society, Szeged, Hungary.



The kinetics of magnesium (Mg) absorption, after drinking Magnesia mineral water (204 mg Mg/L), was investigated in healthy humans aged (23-60 yrs).


Serum Mg, calcium (Ca), potassium (K) and sodium (Na) content, blood hemoglobin, erythrocyte and white blood cell counts as well as urinary volume and urine Mg content were evaluated. Subjects drank 1.5 liters of Magnesia in 30 minutes; blood and the other tests were taken at 0, 2, 6, 24 and 48 hours, and after 1, 2, 3 and 4 weeks. Serum ion quotient was calculated. Serum Mg levels increased in all cases, and returned to individual normal values after 48 hrs. Subjects drank copious amounts of the mineral water only on the first two days, later they consumed one glass of mineral water at a time, totalling 1-1.5 liters daily.


Urinary volume and its Mg content significantly increased, with individual differences in urine Mg content depending on degrees of tissue Mg deficiency. For example, two subjects, who had the same initial serum Mg levels (79 m/M/L), responded to consumption of Magnesia mineral water similarly, with comparable rise of serum Mg but with different urinary Mg excretion, one rapidly excreting Mg, while the other lost less Mg over a longer period of time. The retention of more Mg in one than the other suggests that she had a “hidden” tissue Mg deficiency, despite a serum Mg level within normal limits. No subject experienced ECG or rhythm disturbance, and blood pressure remained unchanged during the study. One patient developed diarrhea.


Magnesia’s high Mg (204 mg/M) and low Na (5.4 mg/L) content makes it an excellent source of Mg for patients suffering from heart problems and/or high blood pressure.

PMID: 15637230

Eur J Nutr. 2003 Oct;42(5):279-86.

Effects of sulphate- and bicarbonate-rich mineral waters on net and fractional intestinal absorption and urinary excretion of magnesium in rats.

Feillet-Coudray C, Lafay S, Tressol JC, Gueux E, Mazur A, Coudray C.


Centre de Recherche en Nutrition Humaine d’Auvergne, Unité Maladies Métaboliques & Micronutriments INRA, Theix, 63122, St Genès Champanelle, France.


Magnesium (Mg) intake is below the recommended daily allowances in many developed countries. Mg-rich mineral waters can provide significant amounts of energy-free Mg and thus help to meet Mg requirements. We assessed the effects of different Mg-rich mineral waters on overall intestinal Mg absorption and urinary Mg excretion in 40 rats split into four groups: one received distilled water, another a solution of MgCl(2) and the others two different mineral waters, sulphated water (Hépar) and carbonated water (Badoit) mixed with the diet and as drinking water, for four weeks. The rats were given 3 mg of (26)Mg orally and 0.5 mg of (25)Mg intravenously. They were placed in metabolic cages, and diet consumption, and faeces and urine excretion were monitored during the last four days of the experiment. The rats were then sacrificed and blood was sampled. Mg levels in the diet, faeces, urine and biological samples were measured by atomic absorption spectrometry. Mg stable isotope measurements were performed by ICP/MS. Mg-rich mineral waters significantly increased net intestinal absorption of Mg by more than 30%, but the proportions of both apparent and true intestinal absorption of Mg were similar in all four groups. Thus, net and fractional retention of Mg were similar in the three Mg-supplemented groups. In conclusion, both types of Mg-rich mineral waters studied similarly increased both absorption and urinary excretion of Mg with no positive effect on the overall retention of Mg, probably because the Mg status of the rats was already satisfactory.

PMID: 14564461

J Trace Elem Med Biol. 2006;20(2):73-81. Epub 2005 Dec 20.

The effect of aging on intestinal absorption and status of calcium, magnesium, zinc, and copper in rats: a stable isotope study.

Coudray C, Feillet-Coudray C, Rambeau M, Tressol JC, Gueux E, Mazur A, Rayssiguier Y.


Centre de Recherche en Nutrition Humaine d’Auvergne, Unité Maladies Métaboliques et Micro-nutriments, INRA, Theix, 63122 St Genès Champanelle, France.


Many investigators have reported changes in mineral status with age but conflicting observations were done concerning mineral absorption. This study was conducted to clarify the effect of aging on intestinal absorption and status of minerals, using a stable isotope approach. To do so, 40 rats of different ages: 9, 22, 44, and 88 weeks were fed with a semi-purified diet for a total of 30 days. At the beginning of the 4th week, the rats received a stable isotope solution containing (44)Ca, (25)Mg, (67)Zn, and (65)Cu. Individual feces and urine were then collected during 4 consecutive days in order to measure stable isotopes by inductively coupled plasma/mass spectrometry (ICP/MS) and blood and tissues were sampled for mineral status determination. Intestinal absorption of (44)Ca and (67)Zn considerably decreased with age, whereas intestinal (25)Mg absorption decreased only moderately and intestinal (65)Cu absorption was unaffected. Plasma and bone calcium (Ca) were not modified with age whereas urinary Ca excretion considerably increased. Plasma and erythrocyte magnesium (Mg) levels were unaffected with age whereas urinary Mg excretion and Mg bone level decreased. Plasma zinc (Zn) level decreased and bone Zn level increased with age whereas red blood cell and liver Zn level and urinary Zn excretion remained unchanged. Plasma Cu level increased with age whereas liver and bone Cu levels and urinary Cu excretion remained unchanged. These results show that the effect of aging on the intestinal mineral absorption and status differ largely according to the mineral considered. Further studies are required under different nutritional conditions to explore the underlying mechanisms during aging and to adjust a better nutrition of the elderly.

PMID: 16785046

Biol Trace Elem Res. 2012 Feb 22. [Epub ahead of print]

Exposure to Low Level of Arsenic and Lead in Drinking Water from Antofagasta City Induces Gender Differences in Glucose Homeostasis in Rats.

Palacios J, Roman D, Cifuentes F.


Departamento de Química, Universidad Católica del Norte, Angamos 0610, Antofagasta, Chile,


Populations chronically exposed to arsenic in drinking water often have increased prevalence of diabetes mellitus. The purpose of this study was to compare the glucose homeostasis of male and female rats exposed to low levels of heavy metals in drinking water. Treated groups were Sprague-Dawley male and female rats exposed to drinking water from Antofagasta city, with total arsenic of 30 ppb and lead of 53 ppb for 3 months; control groups were exposed to purified water by reverse osmosis. The two treated groups in both males and females showed arsenic and lead in the hair of rats. The δ-aminolevulinic acid dehydratase was used as a sensitive biomarker of arsenic toxicity and lead. The activity of δ-aminolevulinic acid dehydratase was reduced only in treated male rats, compared to the control group. Treated males showed a significantly sustained increase in blood glucose and plasma insulin levels during oral glucose tolerance test compared to control group. The oral glucose tolerance test and the homeostasis model assessment of insulin resistance demonstrated that male rats were insulin resistant, and females remained sensitive to insulin after treatment. The total cholesterol and LDL cholesterol increased in treated male rats vs. the control, and triglyceride increased in treated female rats vs. the control. The activity of intestinal Na+/glucose cotransporter in male rats increased compared to female rats, suggesting a significant increase in intestinal glucose absorption. The findings indicate that exposure to low levels of arsenic and lead in drinking water could cause gender differences in insulin resistance.

PMID: 22354675

Water Res. 2012 Mar 15;46(4):1005-14. Epub 2011 Dec 6.

Ozone and biofiltration as an alternative to reverse osmosis for removing PPCPs and micropollutants from treated wastewater.

Lee CO, Howe KJ, Thomson BM.


Department of Civil Engineering, MSC01 1070, University of New Mexico, Albuquerque, NM 87131, USA.


This pilot-scale research project investigated and compared the removal of pharmaceuticals and personal care products (PPCPs) and other micropollutants from treated wastewater by ozone/biofiltration and reverse osmosis (RO). The reduction in UV254 absorbance as a function of ozone dose correlated well with the reduction in nonbiodegradable dissolved organic carbon and simultaneous production of biodegradable dissolved organic carbon (BDOC). BDOC analyses demonstrated that ozone does not mineralize organics in treated wastewater and that biofiltration can remove the organic oxidation products of ozonation. Biofiltration is recommended for treatment of ozone contactor effluent to minimize the presence of unknown micropollutant oxidation products in the treated water. Ozone/biofiltration and RO were compared on the basis of micropollutant removal efficiency, energy consumption, and waste production. Ozone doses of 4-8 mg/L were nearly as effective as RO for removing micropollutants. When wider environmental impacts such as energy consumption, water recovery, and waste production are considered, ozone/biofiltration may be a more desirable process than RO for removing PPCPs and other trace organics from treated wastewater.

Copyright © 2011 Elsevier Ltd. All rights reserved.

PMID: 22202904


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