At an American Legion Convention in Philadelphia in 1976, 34 deaths were attributed to a type of bacterial pneumonia which came to be known as Legionnaires Disease. It was determined that the most probable source of the disease causing bacteria, Legionella Pneumophilia was the air conditioning system.

During the most infectious stage of its growth, the Legionnaires Disease Bacterium can become airborne, making the evaporative cooling tower an ideal medium for broadcasting the disease. Ozone has been shown to significantly reduce bacterial populations in cooling tower water, including Legionella Pneumophilia.

References

1. Department of Energy LEGIONAIRES DISEASE; Guidelines for Minimizing the Risk, ENVIRONMENTAL SAFETY AND HEALTH DOES/ES-0051/2 No. 11

2. Tyndal, R.L., Concentration Serotypic Profile and Infectivity of LDR Population in Cooling Towers Zoology Department, University of Tennessee, JOURNAL OF THE COOLING TOWER INSTITUTE; Vol. 3. No. 2, 1982.

3. Pope, Daniel et al: The Effects of Ozone on Legionella Pneumophilia and Other Bacterial Populations in Cooling Towers; Fresh Water Institute and Department of Biology, Rensselear Polytechnic Institute, Troy, New York, 12181.

LEPTOSPIRA

Leptospira is a genus of spirochaete, a spiral shaped bacteria. Spirochetes are unique in that they are motil, having endocellular flagella. Spirochetes are characteristically found in a liquid environment, mud, water, blood and lymph.

According to Taber's Cyclopedic Medical Dictionary, the three types of leptospira and the diseases they cause, are:

1. L. Autumnalis Species first isolated in Japan. Causes a nonicteric (not jaundice) infection in man called Fort Bragg Fever

2. L. Hebdomadis Species causing Seven Day Fever of Japan.

3. L. Icterohaemorrhagiae Species causing infectious, hemorrhagic, spirochetal jaundice known as Weil's Disease.

Leptospires are carried by rodents and some domestic animals. The animals excrete live, fully virulent organisms in their urine and contaminate the environment outside the animal body. Leptospires can live for several weeks in fresh water. Infection takes place by direct contact with urine of infected animals or by indirect contact with contaminated food or water. Leptospires can readily penetrate mucous membranes but probably not gain entrance into the body through intact skin. A scratch or abrasion, as well as the nasal mucosa and eye, are excellent portals of entry, thus the origin of many infections can be traced to contact with water containing virulent leptospires. The incidence in humans depends upon the opportunity for exposure. Clinical evidence varies depending upon the infecting type of leptospire (see above). Usually after an incubation period of about a week, fever, weakness, and pains in the legs, back, and abdominal muscles are noted. Nausea, vomiting, and diarrhea are not uncommon. One characteristic symptom is congestion of the conjunctival blood vessels around the corneas of the eyes. Jaundice may occur after the first week of illness. The death rate is approximately 30% of the severely ill and jaundiced patients.

Leptospirosis is an acute systemic illness characterized by extensive inflammation of the blood vessels. The first symptoms to arise are the abrupt onset of fever, chills, muscle aches, headache, abdominal pain, vomiting, and red eyes. After a latent period of five to seven days, during which the infected person may improve, fever returns and the infection may involve the brain.

In another form of leptospirosis, destruction of red blood cells, liver disease, kidney failure and heart dysfunction occur.

In treating an environment where there is suspected leptospira contamination, extreme care must be taken. The bacteria is capable of "swimming" through its environment, using its flagella. The bacteria can exist in water or other liquid for several weeks.

EFFECT OF OZONE ON AIRBORNE MICROORGANISMS

THE FOLLOWING WAS TRANSLATED FROM AN ARTICLE WRITTEN BY Heindel T.H., Steib R., and Botzenhart K. of the University Tubingen. The study was conducted during 1993, 1994, 1995 and 1996

Testing against these species: Staphyloccus epidermidis, Micrcoccus luteus, Arthrobacter citreus, Bacillus subtilis (veg.), Escherichia coli, Salmonella typhimurium, Serratia marcescens, Pseudomonas fluorescens and Candida albicans, the microbicidal effect of ozone in air was tested at concentrations between 50 and 600 micrograms/m3. The microorganisms were exposed on membrane filters at 60-755 relative humidity and 21.5-22.5 degrees C. The filters were exposed from between I min. and 1 hour, and then incubated on appropriate agar media. The effect of ozone was determined by comparing the number of colonies on exposed filters to the number on exposed filters. The die-off curves (colony count against time) became steeper with increasing time of exposure rather than being rectilinear.

The velocity of reduction increased more than proportional with concentration of ozone. The bacterial decay doesn't seem to follow first order reaction kinetics. The values presented for K (constant of the velocity of die-off) and D (decimal reduction time) are valid only for narrow ranges of the initial part of the exposure. Concentrations of 50 to 100 micrograms (0)3/m3 for one hour resulted only in little reduction.
At 500 to 600 micrograms/m3 for one hour, 99% reduction in all bacterial species was observed. Gram-positive species seemed to be more sensitive (to the ozone) than the gram-negative species. C. Albicans (a fungus) proved to be more resistant than the bacteria.

All models of Marhoc Ozone Generators produce ozone at a concentration of 0.7 grams/m3. This is comparable to 500 to 600 micrograms/m3.

Only the Marhoc Ozone Generator with its superior technology and the ability to HARNESS THE OZONE™ , resulting in the ozone leaving the enclosure through a narrow (3/8 inch) poly tube makes it possible to bubble ozone through liquids. We suggest that in cases of suspected Leptospira contamination that bubbling ozone into the water may result in significantly reducing the risk of infection. Ozone acts 6000 times faster than chlorine in air and 3000 times faster in water. Bubbling time will depend on volume of water.

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