Things in our daily lives that expose us to TOXIC HEAVY METALS

Heavy metal is a serious threat to the health of your body and brain. I’m not referring to Ozzy Osbourne or Metallica here, although too much head-banging has probably damaged more than a few brain cells.  I’m referring to the metals found in food, water, air and many commercially-available products. Products you or your family or pets may interact with every day.

1) 
Where Does Heavy Metal Exposure Come From?

Air  

As a result of industrial activities, especially the burning of fossil fuels and metal production, cadmium, lead, and mercury have become common air pollutants. Inhalation of the toxic vapours opens the door to the neurotoxic and carcinogenic effects that can develop with long-term exposure, making individuals working in or living close to fuel or metal production plants more susceptible to increased exposure. The metals dispersed in the air can also contaminate waterways and soil as the vapours fall to the ground.

2) Water  

It’s no surprise that with all the industrial activity, our drinking water has become contaminated with the waste and by-products of civilization, and that includes heavy metals like cadmium, arsenic, chromium 6, lead, copper, and mercury. And don’t count on your local water district to remove these contaminants before it comes out of your tap. The contamination can be introduced after the water leaves the treatment plant. Cadmium can come from corrosion of galvanized pipes, as can lead from old plumbing systems. Drinking and bathing in the contaminated slurry can contribute to kidney and liver damage, intestinal problems, delayed physical and mental development in children, and cancer.

3) Vaccines 

The topic of vaccines remains a hot issue among those strongly for them and those strongly against them. If you’re OK with vaccinating yourself or your children, be aware of what’s in the concoction. Sometimes they contain heavy metals. Mercury is used as a preservative called thimerosal, which is nearly 50% mercury! You might also find aluminium used to boost the immune response to the vaccine. Did you know there can also be some other weird ingredients in vaccines like chick embryo cells, monkey kidney tissue, and mouse serum protein?

4) Amalgam Dental Fillings 

If you have silver dental fillings, which is the standard, you’re being exposed to mercury every day they’re in your mouth! That’s like sucking on a mercury popsicle that never melts, increasing your risk of Candida overgrowth, ALS, Alzheimer’s, and cancer. The American Dental Association claims amalgam is completely safe even though mercury makes up half of their composition. Amalgam fillings tend to be the greatest source of mercury exposure in adults who have them.

5) Fluorescent Lightbulbs 

If you’re using compact fluorescent light bulbs at home, be wary of about 5 milligrams of mercury inside each bulb. Mercury gives them the cool burning property that makes them more efficient, but that’s also why you can’t just put a broken or spent one in the garbage. Mercury is an environmental toxin and aneurotoxin in humans. Apply caution when changing and disposing of CFLs, particularly if the bulb is broken because you can be exposed via direct skin contact and mercury vapour.

6) Antiperspirants 

It’s simple biology at work. The natural release of sweat from your armpits combined with the bacteria on the skin equals body odour. To prevent that, antiperspirants use agents that clog the pores of the skin to prevent sweating. And one commonly used ingredient to stop the sweating is aluminium. But the skin is like a sponge and absorbs whatever’s on it, including metals from your skincare products. Aluminium has been linked to liver disorders and degenerative brain diseases such as Alzheimer’s, ALS, and Parkinson’s.

7) Cigarette Smoke 

For us non-smokers, the horrid smell alone is enough to keep us away. We certainly don’t deserve being ambushed by the heavy metal cocktail that can include vaporized aluminium, arsenic, cadmium, mercury, and lead. If you’re a smoker, you’re breathing in significantly more of the metals than non-smokers in your presence. When inhaled through smoking, heavy metals have a long biological half-life, giving the toxins ample time to accumulate in bones and organs where they can have harmful effects.

8) Fish 

This in no secret. It’s been known for years that fish swimming in contaminated water accumulates toxins in their bodies. Mercury from the burning of fossil fuels finds its way to the ocean where bacteria in the water convert it to a more toxic form, methylmercury. Plankton eats the bacteria, small fish eat the plankton, big fish eat the small fish, and humans eat the big fish. And it’s not just mercury you need to worry about. Cadmium and lead are problematic too depending on where the fish was caught. Warnings about excessive fish consumption shouldn’t pertain only to pregnant women and young children. You can’t simply cook out the heavy metals!

9) Agricultural Chemicals  

Another reason to eat organic! Man-made pesticides can contain arsenic, lead, and mercury among other human and environmental poisons. Some inorganic fertilizers are no better, as liming materials can contain elevated levels of arsenic, cadmium, and lead. And what goes in the soil can be absorbed by the food grown in it. Remember, heavy metals can’t be cooked out during the food prep stage.

10) Medications 

The use of metals in the manufacture of pharmaceuticals is commonplace. While some metals are harmless, there’s still a presence of mercury being used in the preparation of some medicines. Manufacturers won’t be bold and put mercury in the list of ingredients, so look out for any of the following: thimerosal (TM) , phenylmercuric acetate (PMA), phenylmercuric nitrate (PMN), mercuric acetate (MA), mercuric nitrate (MN), merbromin (MB), or mercuric oxide yellow (MOY). Mercury can be hiding in ointments, contact lens solutions, and nasal sprays.

Don’t panic—power is knowledge. Use this list of toxins, and the surprising places they might be lurking, to inform your buying decisions.

Aluminium

Although not technically a heavy metal, aluminium is a metal that can pose a serious threat to health, particularly with excessive exposure. It has been linked to Alzheimer’s disease and Parkinson’s disease. Aluminium is found in:

-Baby formula

-Baked goods and processed foods

-Deodorants

-Over-the-counter and prescription antacids

-Other pharmaceutical drugs as a binding agent

-Aluminium pots and pans

-Shampoo

-Skin cream

CADMIUM

Cadmium has serious repercussions for the brain and inhibits the body’s ability to use nutrients like iron, zinc and calcium, leaving people more vulnerable to the bone and immune system disorders.  Cadmium is found in:

-Automobile seat covers

-Black rubber

-Burned motor oil

-Ceramics

-Cigarettes

-Evaporated milk

-Fertilizers

-Floor coverings

-Fungicides

-Furniture

-Refined wheat flour (white flour)

-Silver polish

-Soft drinks from vending machines with cadmium in the pipes

LEAD

Linked to dementia, Alzheimer’s disease, learning disabilities, seizure disorders, aggression, hyperactivity and many other health issues.  It is found in:

-Canned food

-Cigarette smoke (firsthand or secondhand)

-Coloured, glossy newsprint

-Some ceramic dishes

-Lead paint in older homes

-Lead water pipes in older buildings

-Refined chocolate

-Vehicle emissions (yes, even though lead gasoline was banned two decades ago in some countries)

MERCURY

Known for its speedy ability to cross the blood-brain barrier to affect the brain, mercury is linked to neurological, psychological and immunological disorders in people, including diseases like Alzheimer’s.  It has also been linked to heart arrhythmias, headaches, blurred vision and weakness. It is found in:

-Dental fillings: Many dentists cite studies that show no mercury particles were released from fillings but numerous studies show that mercury is primarily released as a vapour to gain access to the brain and blood.

-Fish: Not all fish, but many farmed varieties tend to be contaminated with mercury.

-Immunizations: Many vaccines, even those used for children contain the mercury-based preservative thimerosal in excessive amounts, for both children and adults.

Three scientists have won the Nobel prize in chemistry for their work in harnessing evolution to produce new enzymes and antibodies.

Frances H Arnold, George P Smith and Gregory P Winter win Nobel prize in chemistry

Three scientists have won the Nobel prize in chemistry for their work in harnessing evolution to produce new enzymes and antibodies.

British scientist Sir Gregory P Winter and Americans Frances H Arnold and George P Smith will share the 9m Swedish kronor (£770,000) prize, awarded by the Royal Swedish Academy of Sciences.

Half of the prize goes to Arnold, from the California Institute of Technology, for her work on directing the evolution of enzymes – proteins that speed up chemical reactions. In a nutshell, Arnold introduced genetic mutations into enzymes and then looked to see what effect the mutations had. She then selected the cases where a particular mutation proved useful – for example, allowing the enzyme to work in a solvent it would otherwise not work in.

Her work has made it possible to cut out the use of many toxic catalysts and has led to the development of enzymes for all manner of fields, including the development of biofuels and the production of pharmaceuticals.

The other half of the award goes to Winter and Smith, for their work on “phage display of peptides and antibodies.” A phage is a virus that can infect bacteria, “tricking” bacteria to reproduce it. Smith genetically engineered phages so that they would include a certain protein on their outer capsule. He was the ability to separate out these modified phages from those without the protein. The technique means that scientists are able to explore how the protein might interact with. Winter used this technology to develop new drugs that have transformed medicine, offering therapies for diseases ranging from cancer to autoimmune conditions.

Arnold is only the fifth woman to be awarded the prize for Chemistry – the last female scientist to scoop the award was Ada E. Yonath in 2009 who shared the prize for her work on understanding the structure of ribosomes: the protein-manufacturing structures inside cells.

Prof Carol Robinson, president of the Royal Society of Chemistry welcomed the announcement. “Today’s Nobel Prize in chemistry highlights the tremendous role of chemistry in contributing to many areas of our lives including pharmaceuticals, detergents, green catalysis and biofuels,” she said. “Directed evolution of enzymes and antibody technology are subjects that I have followed with keen interest; both are now transforming medicine.”

Corona Discharge vs. UV Ozone Generation

Ultraviolet (UV) ozone generation Ultraviolet lamps have been used for decades to generate ozone.  This lamp emits UV light at 185 nanometers (nm). Light is measured on a scale called an electromagnetic spectrum and its increments are referred to as nanometers. Figure 1 represents an electromagnetic scale; note the location of higher-frequency ultraviolet light relative to visible light (the range of light perceptible by the human eye). Figure 1 Wavelengths in nm Air (usually ambient) is passed over an ultraviolet lamp, which splits oxygen (O2) molecules in the gas. The resulting oxygen atoms (O-), seeking stability, attach to other oxygen molecules (O2), forming ozone (O3). The ozone is injected into the water, or air stream, where it inactivates contaminants by actually rupturing the organisms’ cell wall.  Corona Discharge (CD) ozone generation The technologies involved in corona discharge ozone generation are varied, but all operate fundamentally by passing dried, oxygen-containing gas through an electrical field. The electrical current causes the “split” in the oxygen molecules as described in the section on ultraviolet ozone generation. Past this common feature the variations are many, but the generally accepted technologies can be divided into three types - low frequency (50 to 100 Hz), medium frequency (100 to 1,000 Hz), and high frequency (1,000 + Hz). Since 85% to 95% of the electrical energy supplied to a corona discharge ozone generator produces heat, some method for heat removal is required. Also, proper cooling significantly affects the energy efficiency of the ozone generator, so most corona discharge systems utilize one or more of the following cooling methods: Air or water. Ozone Being created via Corona Discharge. At the heart of a corona discharge ozone system is the dielectric. The electrical charge is diffused over this dielectric surface, creating an electrical field, or “corona”. Critical to CD ozone systems is proper air preparation. The gas feeding the ozone generator must be very dry (minimum -80 degrees F), because the presence of moisture affects ozone production and leads to the formation of nitric acid. Nitric acid is very corrosive to critical internal parts of a CD ozone generator, which can cause premature failure and will significantly increase the frequency of maintenance.  The chart below shows that relative ozone output decreases as moisture content increases. Of the ozone technologies mentioned above, none has a clear advantage. However, to help narrow the field for a particular application, consider the amount of ozone required. You may find that low and medium frequency ozone systems will have prohibitively high initial costs for applications requiring less than ten lbs./day. However, they have a proven history of durability and reliability. High frequency ozone generators seem to have the best combination of cost efficiency and reliability for applications requiring less than ten lbs/day of ozone output. Advantages of Corona Discharge ozone generation Corona discharge ozone generators can use oxygen preparation thereby doubling the ozone output per given volume vs. dry air Small construction allowing generator to be installed in virtually any area Can create a more pure form of ozone without creating other harmful or irritating gases if using dry air or oxygen as a feed gas Corona cell life can exceed ten years Can create high quantities of ozone (up to 100-lbs/day) Can be more cost-effective than UV-ozone generation   Disadvantages of UV ozone generation Maximum ozone production rate is two grams/hr per UV bulb - depending on size Highest concentration of ozone that can be produced by 185-nm UV lamp is 0.2 percent by weight, approximately 10% of the average concentration available by corona discharge Considerable more electrical energy is required to produce a given quantity of ozone by UV radiation than by corona discharge Lower gas phase concentrations of ozone generated by UV radiation translate into the handling of much higher gas volumes than with CD-generated ozone UV lamps solarize over time, requiring periodic replacement

http://www.ozoneapplications.com/info/cd_vs_uv.htm

The History of Atomic - Model

Aristotle (350 B.C.) disagreed with Democritus's model of the atom in Aristotle was a Greek philosopher. Many of his ideas were more thought based than scientifcially based. For this reason, Aristotle strongly disagreed with Democritus. He felt that there was no smallest part of matter and that different substances were made of earth, fire, air, and water. Aristotle did not have an atomic model due to the fact that he thought atoms did not exist.

Democritus was the first scientist to create a model of the atom. He was the first one to discover that all matter is made up of invisible particles called atoms. He created the name "atom" from the Greek word "atomos", which means uncuttable. He also discovered that atoms are solid, insdestructable, and unique. HIs model was just a round solid ball. Democritus didn't know about a nucleus or electrons, all he knew was that everything is made of atoms.

Lavoisier was a French nobleman that founded several elements and put the first table of elements together. He used Aristotle's ideas of fire, earth, air, and water to create experiments invesigating combustion and oxidation. By using previous knowledge of atomic bonding, he discovered important elements like oxygen, hydrogen, and sulfur. He discovered that water was made of oxygen and hydrogen, and air included nitrogen. Lavoisier also created the first chemistry textbooks and tables.

Dalton's atomic theory

John Dalton (1766-1844)

John Dalton developed an atomic theory in the 1800s. He did experiments, worked out some atomic weights and invented symbols for atoms and molecules. His most important conclusions are summarised below:

• All matter is made of atoms
• Atoms cannot be broken down into anything simpler
• All the atoms of a particular element are identical to each other and different from the atoms of other elements
• Atoms are rearranged in a chemical reaction
• Compounds are formed when two or more different kinds of atoms join together

Dalton's theory was developed and changed as new evidence was discovered.

JJ Thomson's discovery of the electron

JJ Thompson discovered the electron in 1897. This showed that the atom contained smaller pieces, whereas Dalton had thought that atoms could not be broken down into anything simpler.

Rutherford's nuclear atom

In 1911 Ernest Rutherford used experimental evidence to show that an atom must contain a central nucleus. This was further evidence that an atom contained smaller pieces.

Bohr's electron orbits

Niels Bohr further developed Rutherford's nuclear atom model. He used experimental evidence to support the idea that electrons occupy particular orbits or shells around the nucleus of an atom.

The development of the theory of atomic structure is an example of:

• How a theory may change as new evidence is found
• How a scientific explanation is provisional but may become more convincing when predictions based on it are confirmed later on.

Marie and Pierre Curie were a European couple that contributed to atomic chemistry by exploring the mysteries of radioactivity. After radiation was discovered by Henri Baquerel, Marie decided to look further into this discovery. Through this she and her husband discovered the elements radium and polonium and won the Nobel Peace Prize for their works in radioactivity. Her discovery later added to the atomic model.

http://www.bbc.co.uk/schools/gcsebitesize/science/add_ocr_gateway/periodic_table/atomstrucrev5.shtml

Disinfection By-Products

Chlorine was discovered in 1774 by the chemist Karl Scheele . One of the first known uses of chlorine for disinfection was not until 1850, when Snow used it to attempt to disinfect London’s water supply during that now-famous cholera epidemic. It was not until the early 1900’s, however, that chlorine was widely used as a disinfectant . Chlorine revolutionized water purification, reduced the incidence of waterborne diseases across the western world, and “chlorination and/or filtration of drinking water has been hailed as the major public health achievement of the 20th century” . Chlorine remains the most widely used chemical for water disinfection in the United States . However, close to 1 billion people in the world still lack access to safe drinking water, and new questions about health effects from chlorine by-products formed during disinfection have led to questions about the advisability of using chlorine to provide safe water for this population. This page summarizes information about the production, and health effects, of disinfection by-products (DBPs).

These guidelines must be evaluated in context of the WHO Guidelines which state: "Infectious diseases caused by pathogenic bacteria, viruses, protozoa, and helminths are the most common and widespread health risk associated with drinking-water"  (Chapter 7, Microbiological Aspects; Section 7.1, pg 118). Additionally, a previous version of these guidelines states: "Where local circumstances require that a choice must be made between meeting either microbiological guidelines or guidelines for disinfectants or disinfectant by-products, the microbiological quality must always take precedence, and where necessary, a chemical guideline value can be adopted corresponding to a higher level of risk. Efficient disinfection must never be compromised" (Chemical Aspects; Section 3.6.4, pg 49/65).

In disinfection, gaseous chlorine (Cl₂) or liquid sodium hypochlorite (bleach, NaOCl) is added to, and reacts with, water to form hypochlorous acid. In the presence of bromine, hypobromous acid is also formed. Both chlorine and bromine are in the “halogen” group of elements, and have similar chemical characteristics. Hypochlorous and hypobromous acid form strong oxidizing agents in water and react with a wide variety of compounds, which is why they are such effective disinfectants.

In 1974, Rook  discovered that hypochlorous acid and hypobromous acid also react with naturally occurring organic matter to create many water disinfection by-products, including the four primary trihalomethanes:

• Chloroform – CHCl₃
• Bromodichloromethane (BDCM) – CHCl₂Br
• Dibromochloromethane (DBCM) – CHClBr₂
• Bromoform – CHBr₃

At the center of each of the four trihalomethanes is a carbon atom, and it is surrounded by and bound to four atoms: one hydrogen and three halogens. These four compounds are collectively termed trihalomethanes and are abbreviated as either THM or TTHM (for total trihalomethanes).

Rook’s discovery of THMs in drinking water led to research on other chemicals formed when chlorine is added to water, and to the health effects of these chemicals. Richardson  identified greater than 600 water disinfection by-products in chlorinated tap water, including haloacetic acids (HAAs). THMs, and to a lesser extent HAAs, are currently used as indicator chemicals for all potentially harmful compounds formed by the addition of chlorine to water. In many countries the levels of THMs and HAAs in chlorinated water supplies are regulated based on this assumption.

Humans are exposed to DBPs through drinking-water and oral, dermal, and inhalational contact with chlorinated water ⁶. In populations who take hot showers or baths, inhalation and dermal absorption in the shower accounts for more exposure to THMs than drinking water .

World Health Organization (WHO) Research and Guideline Values for DBPs

The World Health Organization (WHO) International Agency for Research on Cancer (IARC) reviews research conducted on potential carcinogens and develops monographs that summarize the research and classify the compound. Links to the monographs for BDCM, DBCM, bromoform, and chloroform are available below (see Additional Resources(https://www.cdc.gov/safewater/chlorination-byproducts.html#resources) ). As can be seen in Table 1 (below), chloroform and BDCM are classified as possible human carcinogens. The classifications of possible human carcinogens come from data that is extrapolated from research on animals that may or may not be relevant to human cancer. DBCM and bromoform are not classifiable, indicating there is no evidence supporting these two compounds as carcinogens, but there is not enough research to classify them as non-carcinogenic. There is inadequate epidemiological evidence of carcinogenicity in humans for all four compounds.

Table 1: IARC Classification of THMs
	Humans	Classification
Chloroform	Inadequate evidence for human carcinogenicity.	Possible human carcinogen (Group 2B)
Bromodichloromethane	Inadequate evidence for human carcinogenicity.	Possible human carcinogen (Group 2B)
Dibromochloromethane	Inadequate evidence for human carcinogenicity.	Not classifiable as to its carcinogenicity in humans (Group 3)
Bromoform	Inadequate evidence for human carcinogenicity.	Not classifiable as to its carcinogenicity in humans (Group 3)

WHO states that “all people, whatever their stage of development and their social and economic conditions, have the right to have access to an adequate supply of safe drinking water” . To this end, WHO has developed guideline values for many contaminants in drinking water. It is important to note that these guideline values are not standards. “It must be emphasized that the guideline values recommended are not mandatory limits. In order to define such limits, it is necessary to consider the guideline values in the context of local or national environmental, social, economic, and cultural conditions and waterborne disease occurrence” .

To develop the guideline values for drinking-water, WHO reviewed the literature for well-designed and documented studies showing health effects from exposure to each of the THMs . A safety factor of 1,000, an average adult human weight of 60 kilograms, and an average drinking water consumption of 2 liters per day were incorporated into the development of each guideline value. The chloroform, bromoform, and dibromochloromethane guideline values were all obtained using a total daily intake calculation. It was assumed that 50 percent of total daily intake of chloroform came from drinking water, and 20 percent of total daily intake of bromoform and dibromochloromethane came from drinking water (in areas with no showers, this assumption leads to a conservative estimate of risk). The models developed for bromodichloromethane and chloroform were based on an excess cancer risk of 10^-5, or one extra cancer per 100,000 people at the guideline value for 70 years .

• The chloroform guideline value was developed from a study showing hepatotoxicity in beagle dogs ingesting chloroform-laced toothpaste for 7.5 years. (A linearized multi-stage model based on observed increases in kidney tumors in male rats supports this total daily intake calculation).
• The bromoform guideline value was developed from a study showing lesions on the livers of rats exposed to bromoform for 90 days.
• The dibromochloromethane guideline value was developed based on the absence of histopathological effects in rats exposed for 90 days.
• The bromodichloromethane guideline value was developed using a linearized multi-stage model based on observed increases in kidney tumors in male mice.

The WHO Guideline Values  for the THMs are shown in Table 2. WHO also considers potential health effects caused by exposure to the four compounds simultaneously. In addition to the individual guidelines, there is an additional guideline that states the following: the sum of each individual THM concentration divided by its guideline value cannot be greater than one. This is depicted in the following equation:

Table 2: WHO Guideline Values for Trihalomethanes in Drinking Water (WHO, 1996)
	WHO Guideline Value
Chloroform	200 μg/L
Bromodichloromethane	60 μg/L
Dibromochloromethane	100 μg/L
Bromoform	100 μg/L

These guidelines must be evaluated in context of the WHO Guidelines which state: "Infectious diseases caused by pathogenic bacteria, viruses, protozoa, and helminths are the most common and widespread health risk associated with drinking-water"  (Chapter 7, Microbiological Aspects; Section 7.1, pg 118).
Most importantly, the WHO specifically states in the 2nd edition of the Guidelines that: "Where local circumstances require that a choice must be made between meeting either microbiological guidelines or guidelines for disinfectants or disinfectant by-products, the microbiological quality must always take precedence, and where necessary, a chemical guideline value can be adopted corresponding to a higher level of risk. Efficient disinfection must never be compromised" (Chemical Aspects; Section 3.6.4, pg 49/65). In the 4th edition of the Guidelines, the WHO states: "In all circumstances, disinfection efficiency should not be compromised in trying to meet guidelines for DBPs, including chlorination by-products, or in trying to reduce concentrations of these substances"  (Chapter 8 Chemical Aspects, Section 8.5.4, pg 188).
Thus, waterborne pathogens pose a real and more immediate threat to health; water disinfection by-products are certainly the lesser of these two evils.

USEPA Standards for DBPs

The disinfectant/disinfection by-products (D/DBP) rule that regulates DBPs in the United States was designed to be implemented in three stages (Table 3) ^, . The US Environmental Protection Agency (USEPA) does not regulate THMs or HAAs individually – there is only a standard for total THMs and total HAAs.

Table 3: D/DBP Rule Implementation, USEPA
Stage	TTHM Standard	HAA Standard
Initial	100 μg/L
Stage 1	80 μg/L	60 μg/L
Stage 2	80 μg/L	60 μg/L

The USEPA has calculated cancer potency factors for the four THMs, which can be used to calculate the probability of cancer for varying exposure levels (Table 4). As can be seen, DBCM has the highest factor, and bromoform is an order of magnitude lower.

Table 4: USEPA Cancer Potency Factors
Compound	Cancer Potency Factor
Chloroform	insufficient data
Bromodichloromethane	0.062 mg/kg/day
Dibromochloromethane	0.084 mg/kg/day
Bromoform	0.0079 mg/kg/day

Thus, the extra cancer from chloroform was calculated to be negligible.

Other countries in the developed world, particularly in Europe, have established much stricter standards for DBPs in drinking water. These countries have the resources to follow the precautionary principle, which advocates the avoidance of chemicals until they are proven safe. These low standards are met, in part, by researching and implementing alternative disinfection methods (such as the use of ozone, UV light, and chloramines) and water treatment strategies (such as filtration before disinfection).

DBPs and the Safe Water System

Addition of chlorine to untreated water will lead to the formation of DBPs. A significant amount of energy and time has been invested in the United States and Europe to determine the human health effects of these DBPs and how to restructure water treatment processes to prevent DBP formation in order to minimize the slight risk of cancer from long-term exposure to DBPs. However, diarrheal disease in the developing world is still a leading cause of infant and under-5 mortality and morbidity. In these populations, the risk of death or delayed development in early childhood from diarrheal disease transmitted by contaminated water is far greater than the relatively small risk of cancer in old age.

CDC has tested Safe Water System water to measure the concentration of THMs in the finished water. In that study, household chlorination of turbid and non-turbid waters did not create THM concentrations that exceeded health risk guidelines ^, . In addition, ceramic filtration, sand filtration, cloth filtration, and settling and decanting were not effective mitigation strategies to reduce THM formation. Since this finding may not hold for all source waters worldwide, reducing organic matter in turbid source water may reduce the potential for DBP formation . To do this:

• Let the water settle for 12-24 hours and then decant water into a second bucket. Chlorinate this decanted water, and/or
• Filter the water through a cloth or filter before chlorination.

The Safe Water System is a proven intervention that consistently reduces diarrheal disease(https://www.cdc.gov/safewater/data/publications-by-topic.html#diarrheal) incidence among users in the developing world. This disease reduction leads to healthier children and adults. There is a slight risk to the ingestion of THMs at the WHO guideline value level. Although the risk from THMs is important to address, until centrally treated, piped water can be delivered to every family, the initial critical need is the provision of microbiologically safe drinking water to reduce the incidence of diarrhea and other waterborne disease.

If you have any questions or comments on this page or the Safe Water System, please email 

References

1. White, G. The Handbook of Chlorination, 2nd Edition. Van Nostrand Reinhold Company, New York. 1986.
2. Gordon G, Cooper WJ, Rice RG, Pacey GE. Disinfectant residual measurement methods. AWWA Research Foundation, American Water Works Association. 1987.
3. Calderon RL. The epidemiology of chemical contaminants of drinking water. Food Chemical Toxicology. 2000;38:S13-S20.
4. Rook JJ. Formation of haloforms during chlorination of natural waters. Water Treatment Examination. 1974;23:234-243.
5. Richardson SD. The role of GC-MS and LC-MS in the discovery of drinking water disinfection by-products. Environmental Monitoring. 2002;4(1):1-9.
6. Lin, Tsair-Fuh, Shih-Wen Hoang. Inhalation exposure to THMs from drinking water in south Taiwan. Science Total Environment. 2000;246:41-49.
7. Backer, LC, Ashley DL, Bonin MA, Cardinali FL, Kieszak SM, and Wooten JV. Household exposures to drinking water disinfection by-products: whole blood trihalomethanes levels. J Expo Anal Environ Epidemiology. 2000;July-August 10(4); 321-6.
8. WHO. Guidelines for drinking-water quality, 2nd edition, Volume 2: Health Criteria and other supporting information[PDF – 94 pages]. World Health Organization, Geneva. 1996.
9. WHO. Guidelines for drinking-water quality, 2nd edition, Volume 1: Recommendations. World Health Organization, Geneva. 1993.
10. WHO. Guidelines for drinking-water quality, 4th edition. World Health Organization, Geneva. 2011.
11. EPA. National primary drinking water standards.
12. EPA. Comprehensive disinfectants and disinfection byproducts rules (Stage 1 and Stage 2): Quick reference guide. 2010.
13. EPA. Integrated Risk Information System.
14. Lantagne DS, Blount BC, Cardinali F, Quick R. Disinfection by-product formation and mitigation strategies in point-of-use chlorination of turbid and non-turbid waters in western Kenya. J Water Health. 2008;6(1):67-82.
15. Lantagne DS, Cardinali F, Blount BC. Disinfection by-product formation and mitigation strategies in point-of-use chlorination with sodium dichloroisocyanurate in Tanzania. Am J Trop Med Hyg. 2010;83(1):135-43.