Pathogens, pathogens, pathogens . . .
| Waterborne disease | Causative organism | Source of
| Symptom |
| Gastroenteritis | Salmonella
| Animal or human feces | Acute diarrhea and vomiting |
| Typhoid | Salmonella typhosa (bacteria) | Human feces | Inflamed intestine, enlarged spleen, high temperature; can be fatal |
| Dysentery | Vibrio cholerae
| Human feces | Diarrhea: rarely fatal |
| Cholera | Vibrio cholerae (bacteria) | Human feces | Vomiting, severe diarrhea, rapid dehydration, mineral loss: often fatal |
| Infectious hepatitis | Virus | Human feces, shellfish grown in polluted waters | Yellowed skin, enlarged liver, abdominal pain: lasts up to 4 months, seldom fatal |
| Amebic dysentery | Entamoeba histolytica(protozoa) | Human feces | Mild diarrhea, chronic dysentery |
| Giardiasis | Giardia lamblia (protozoa) | Animal or human feces | Diarrhea, cramps, nausea and general weakness; lasts 1 week to 30 weeks, not fatal |
Source: Reprinted by permission from Introduction to Water Treatment: Principles and Practices of Water Supply Operations, vol. 2, p. 284. Copyright 1984, American Water Works Association.
Giardiasis, the last condition on the chart, is caused by the most common pathogenic parasite in the
What else?
There are quite a few diseases that are of concern in a disaster situation, but we are concentrating on the water supply, post disaster threats. So, here are some other potential water borne risks . . .
1. Poliomyelitis (polio): With the use of an aggressive vaccine program and outbreak surveillance program, poliomyelitis has been radically controlled, but it could opportunistically make a come back if the water treatment system failed due to an earthquake. Poliomyelitis is caused by a waterborne viral infection. The virus lives in the throat and intestinal tract. It is most often spread through person-to-person contact with the stool of an infected person and may also be spread through oral/nasal secretions. Link http://www.waterandhealth.org/drinkingwater/12749.html
Polio can be imported from other countries by infected people. In the event of an earthquake, recent immigrants or visitors living in the poor sanitary conditions post disaster could be the mechanism of transmission and an outbreak of polio. From 1980 through 1999, there were 152 confirmed cases of paralytic polio cases reported in the
History: Polio was one of the most dreaded childhood diseases of the 20th Century in the
2. Cryptosporidium parvum: Cryptosporidium parvum is a parasitic protozoa transmitted through water. I mention this particular disease because it has caused problems in swimming pools through indirect person-to-person transmission. This is especially important as it has been suggested that the standard chlorination treatments used are insufficient against these durable and tiny oocytes. Link http://www.who.int/water_sanitation_health/dwq/en/admicrob5.pdf
3. Legionnaires hemophile: Although the "traditional" bacterial diseases of cholera and typhoid have largely been brought under control in this country, other microorganisms are constantly being identified and connected to waterborne illness. For example, the Legionnaires hemophile bacteria--the cause of legionnaires' disease-has recently been found in community water supplies (Stout et al. 1992), and tiny waterborne rotaviruses have been shown to be a major cause of acute gastroenteritis in infants and young children (Craun 1986). Link http://www.waterandhealth.org/drinkingwater/12749.html.
This list goes on, but I want to focus on the big names. So, changing gears let’s talk about water treatment.
Water treatment
Having said that, how much chlorine does it take to effectively disinfect drinking water? If you are prepared to treat drinking water in a disaster, 72Hours.org instructs you to – “Strain any large particles of dirt by pouring the water through layers of paper towels or clean cloth. Next, purify the water one of two ways:
- Boil – bring to a rolling boil and maintain for 3-5 minutes. After the water cools, pour it back and forth between two clean containers to add oxygen back; this will improve its taste.
- Disinfect – If the water is clear, add 8 drops (1/8 teaspoon) of bleach per gallon of water. If it is cloudy, add 16 drops (1/4 teaspoon) per gallon. Make sure you are using regular bleach— 5.25% percent sodium hypochlorite— rather than the “ultra” or “color safe” bleaches. Shake or stir, then let stand 30 minutes. A slight chlorine taste and smell is normal.” Link to 72Hours.org: http://72hours.org/water.html
So, what do water districts do? “The effectiveness of the chlorination process depends upon a variety of factors: chlorine concentration, contact time, water temperature, pH value, and level of turbidity (AWWA 1984). Disinfectant concentrations and contact times used by different water utilities vary widely, usually depending on the characteristics of the water being treated. Several states and advisory groups suggest minimum requirements or recommendations for these parameters, but there are no federal standards for them (Hoff and Akin 1986).” Link http://www.waterandhealth.org/drinkingwater/12749.html “Most municipal drinking water supplies maintain chlorine levels such that the concentrations of chloroform in the systems range from 0.02 to 0.05 milligrams per liter (
Basic Guidelines for Pool Treatment
Carefully read and follow the manufacture’s instructions printed on the chlorine treatment package. Test the water regularly – it’s a simple process to use a test kit. You want to maintain water balance by measuring:
- Free available chlorine (FAC), which should never fall below 1.0 ppm (parts per million)
- Monitor the total chlorine, to assure that combined available chlorine (CAC) levels are less than 0.2 ppm
- Monitor the pH level pH is to be kept between 7.2 and 7.8, indicating that the chlorine is working effectively
- Monitor the total alkalinity to make sure that pH levels stay steady
- Monitor the calcium hardness of the water to protect pool surfaces from corrosion.
How Much of What?
The guidelines set by the National Spa and Pool Institute are widely used, but to be certain, you should also check the health codes of the jurisdiction where you live. The chemicals a pool needs to maintain the required standards differ from pool to pool – and day to day. Keeping records to "get to know" a pool can help you interpret its characteristics and perform the correct task.| NATIONAL SPA AND POOL INSTITUTE
| |
| Free chlorine, ppm | 1.0 - 4.0 |
| Combined chlorine, ppm | None |
| pH | 7.2 - 7.8
|
| Total alkalinity, ppm
| 80 - 100 |
| (for gas chlorine, dichlor, trichlor and bromine compounds) | 100 - 120 |
| Total dissolved solids, ppm | Not to exceed 1500 greater than at pool start-up |
| Calcium hardness, ppm | 200 - 400 |
| Cyanuric acid, ppm | 30 - 50 |
Let’s say you did have to drink that clinic’s physical therapy pool water . . .
Some people might be inclined to add more chlorine just to be safe. What happens though if you take pool water that was presumably treated already, but you decide to treat it again just to be cautious during a disaster? Here is something else to think about. . . Studies show that chlorine causes cancer and, predictably, too much more so. Consider this . . .
Side Effects of Chlorine
There are many known carcinogenic disinfectant byproducts formed by adding chlorine to drinking water called organochlorines. Regulating chlorinated drinking water is a problematic at best because of the many public health benefits of killing waterborne pathogens. “While the EPA denies that there is "conclusive" causation linking chlorinated drinking water and health effects, the point is not reassuring. A growing number of studies have linked chlorinated drinking water to cancer and reproductive harm in humans. The most respected cancer study is a compilation of 10 separate epidemiological studies on chlorinated drinking water and cancer known as the Morris study. It found disinfection by-products in chlorinated water to be responsible for 9% of all bladder cancers and 15% of rectal cancers in the
The Big Conclusion
As so many diseases are effectively controlled through the chlorination of water, it would be disastrous not to chlorinate the drinking water supply. If you are concerned about the carcinogenic effects of over chlorinating pool water, for example, consider boiling it instead, but understand that chlorination is the accepted industry standard for safe drinking water. Another consideration, in an emergency or a disaster, is that you may not have the ability to boil water so be sure to stockpile water purification tablets or regular bleach to ensure safe drinking water.
Enjoy your next effortless glass of water although you may now decide that ignorance is bliss!!!!!