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Showing posts with label bacteria. Show all posts
Showing posts with label bacteria. Show all posts

Tuesday, September 01, 2015

NYC's Legionnaire Outbreak Over, Leading to New Requirements for Building Owners.

The recent legionnaire's disease outbreak in the Bronx, is over according to the New York City Health Department.  The impact of this disease outbreak seems to have not had an impact on the Opera House Hotel (according to the New York Times) which was at the center of the outbreak.  A far cry from the first legionnaire outbreak back in 1976.  That outbreak caused the closing of the Bellevue Stratford Hotel, four months after the outbreak and it did not reopen until 1979.

English: Bellevue-Stratford Hotel, Philadelphia
English: Bellevue-Stratford Hotel, Philadelphia (Photo credit: Wikipedia)

Legionnaire's disease is caused by a common gram negative rod-shaped bacterium called Legionella. It is widely distributed natural inhabitant of waters.  There are approximately 50 species and 70 serogroups have been described.  The 1976 occurrence in Philadelphia had 221 people that were treated and 34 deaths.  Legionella bacterium was found in the cooling tower of the hotel's air conditioning system.

Legionnaire's disease symptoms include fever, chills, cough, muscle aches, headache, tiredness, loss of appetite, loss of coordination and occasionally diarrhea and vomiting.  Typically takes 2-10 days to incubate.  Many cases go undiagnosed and transmission is not person to person.  It is treatable with antibiotics if diagnosed early enough.

The infection occurs from inhaling water droplets that originated from a water source contaminated with Legionella.  Typical manmade sources include cooling towers, evaporative coolers, hot water systems, showers, whirlpool spas, architectural fountains, room-air humidifiers, ice-making machines and misting equipment.  Environmental sources are freshwater ponds, rivers and creeks. 

A forced draft cooling tower
A forced draft cooling tower (Photo credit: Wikipedia)

Commonly used method of analysis is the methodology from the Centers for Disease Control (CDC) which involves collecting a sample of the water source. Culture Analysis is considered the "gold standard" and analysis can take 10-14 days.  The OSHA Technical Manual offers the following guidelines for interpreting Legionella analysis results (numbers are in colony forming units per milliliter (cfu/ml)):

ACTION    COOLING TOWER   DOMESTIC WATER    HUMIDIFIER
  1                     100                           10                     1
  2                    1000                         100                    10

Action 1: Prompt cleaning and/or biocide treatment of the system.
Action 2: Immediate cleaning and/or biocide treatment.
As part of the outbreak, the New York City Commissioner of Health and Mental Hygiene (DOHMH) issued a mandatory order to have cooling systems inspected and remediated within 14 days of receipt of the order.  New York City has recently passed new requirements (Local Law 77 of 2015) for the registration of cooling towers and evaporating condensers.  Existing cooling towers and evaporative condensers must be registered with the New York City Building Department (NYC DOB) by September 17, 2015.  Visit the NYC DOB website for more info.  The DOHMH order requires building owners to hire environmental consultants experienced in disinfection using current industry standard protocols including the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) Standard 188P and Cooling Technology Institute Guidelines WTB-148. 

Disinfection will require the use of biocides, biocides are regulated by the Environmental Protection Agency (EPA) under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and by New York State Department of Environmental Conservation (NYS DEC).  EPA regulates the labeling and use of biocides.  NYS DEC requires a commercial pesticide applicator certification in Category 7G - Cooling Towers, Pulp & Paper Process.

Will these new requirements prevent another outbreak?  Only if the regulations are enforced.  There are many laws on the books, however, how many of them are enforced.  You can almost say instead of "the devil is in the details", you should say "the devil is in enforcement".  Be Safe!

Wednesday, December 03, 2014

Legionella Found in Windshield Washer Fluid

Interesting research from Arizona State University found that the bacteria Legionella, commonly found in fresh water, was able to survive in certain automobile windshield washer fluids and can grow in washer fluid reservoirs.  This could potentially lead to people being exposed to the bacteria and maybe developing Legionnaire's disease or Pontiac Fever.

Windshield washer fluid
Windshield washer fluid (Photo credit: Wikipedia)

The Arizona State University research was conducted by Otto Schwake, an Arizona State University student pursuing a doctoral degree in Microbiology under the supervision of Morteza Abbaszadegan, a professor in the School of Sustainable Engineering and the Built Environment. Although windshield washer fluid was not normally associated with spreading disease, this research was begun after a series of epidemiological studies found motor vehicle use to be associated with increased risk for Legionnaires' disease.  One such study attributed nearly 20% of Legionnaires' disease cases in the United Kingdom not associated with hospitals or outbreaks to automobile windshield washer fluid.


Based on a recent webinar held by EMLab P&K featuring the Dr. Harriet Burge, Legionella is a gram negative bacterium that is a widely distributed natural inhabitants of water and is common in many environments.  It is heat loving and will proliferate in temperatures between 20 degrees Celsius to 45 degrees Celsius.  Growth is promoted by other micro organisms.  Legionella is the causative agent of Legionellosis (Legionnaires' disease and Pontiac fever).

The first recognized outbreak of Legionnaires disease occurred in Philadelphia in 1976.  As many as 221 people were treated and 34 deaths occurred.  The source was identified as the Legionella bacterium and found in the cooling tower of the hotel's air conditioning system.  Over 90% of legionelloses are caused by Legionella pneumophila.

English: A silver stain of Legionella pneumoph...
English: A silver stain of Legionella pneumophila , the bacteria that causes Legionellosis. Although I got this image from a commercial website it is clearly labeled as from the CDC. This website routinely uses images from Wikipedia, which is a good thing, so no issue should be taken with using an presumably public domain image from their website. (Photo credit: Wikipedia)
Legionellosis takes two distinct forms:

  • Pontiac Fever: respiratory illness without pneumonia, symptoms resemble acute influenza
  • Legionnaires' Disease: symptoms include fever, chills, cough, muscle achees, headache, tiredness, loss of appetite, loss of coordination (ataxia), and occasionally diarrhea & vomiting.
Legionellosis incubates in 2-10 days.  It is one of the top three causes of community-acquired pneumonia. Legionellosis affect 8,000 to 18,000 people in the United States each year. Transmission is not person to person. Legionellosis infection occurs after inhaling droplets that originated from a water source contaminated with Legionella. Environmental sources include freshwater ponds, rivers and creeks.  Typical manmade water sources that can be a source of Legionella include: cooling towers, evaporative coolers, hot water systems, showers, whirlpool spas, architectural fountains, room-air humidifiers, ice-making machines, and misting equipment.  Based on the above research now windshield washer fluid reservoirs, may be added to this list.

Related Articles:

Wednesday, March 11, 2009

Keeping Your Family Safe - Dangers in the Basement

Monday, March 9, 2009, we had the pleasure of interviewing Mr. Bob Krell, President and Certified Indoor Environment Consultant for IAQ Technologies for our internet radio program “Keeping Your Family Safe” (find it at www.voiceamerica.com on the Green Talk Network). IAQ Technologies is an indoor environmental and building performance firm offering consulting, mitigation, and training services to a variety of clients throughout the country. Mr. Krell discussed various dangers we can find in basements that homeowners should be aware of and some ways to protect themselves. In our program, we covered the following points:
  • Asbestos
  • Radon
  • Mold and Bacteria (Differences between black, grey, and clear water)
  • Better Building Materials and Dehumidification to help prevent mold growth

This Monday, March 16, 2009, we will be discussing “Audubon at Home” with Aaron Virgin Executive Director of the Theodore Roosevelt Sanctuary and Audubon Center.

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