There's something in the air: knowing the causes and warning signs of lifeguard lung can help indoor waterparks prevent this growing affliction.
In each case, the symptoms begin a few hours after arrival at the pool and seem to resolve themselves overnight, or when the sufferer is away from the pool area for an extended period.
The pool operator has checked the pool-chemical and air-analysis logs and found that all is in order. The health department cultures for pathogenic organisms were negative. The outbreak of symptoms could be coincidence ... or it could be lifeguard lung.
Though lifeguard lung, or LGL, is largely unrecognized, it's believed to be occurring with greater frequency as more and more indoor waterparks and leisure pools are built. Common factors include repeated exposure to conditions of improper or inadequate ventilation, improper or inadequate water quality, and aerosolization caused by sprayers, geysers and patrons splashing into water-slide catch pools.
A single condition, or a combination of factors, may play a role in triggering an LGL response -- and repeated exposures can lead to development of scarring in the airways, a condition called granulomatous pneumonities, an irreversible condition.
While the health of the aquatics staff is of the utmost importance, LGL can become an expensive worker's compensation issue: Permanent damage from repeated exposure can result in costly disability awards.
To avoid the personal injuries and high costs associated with LGL, facility designers must be aware of the special needs of indoor waterparks, and operators must know the warning signs so they can take immediate action to correct deficiencies in air and water quality.
Lifeguard lung is a form of sick building syndrome that occurs primarily in indoor aquatics facilities. It's an immune disorder medically categorized as hypersensitivity pneumonitis (HP), or inflammation of the lungs due to an immune response.
Lifeguards -- who, by the nature of their jobs, spend long hours at poolside -- are most commonly afflicted. The illness, however, can affect pool operators, aquatic therapists, competitive swimmers, aerobic exercise participants, other aquatics personnel and even guests who experience prolonged exposure to the pool environment.
Doctors suspect HP when pulmonary and systemic symptoms occur repeatedly within several hours of exposure to a specific environment. Hypersensitivity pneumonitis occurs after individuals repeatedly inhale organic material, including fungi spores often found in humid environments. Researchers have also implicated active chemicals such as chloramines (Ando et al. 1999).
Cell walls from dead microorganisms, the sensitizing part of microbes, often are found in air and water systems. Thus, the stimuli are transmitted via ventilation systems and aerosolization from sprays, slides, geysers, hydrotherapy jets, waterfalls, children's play structures and patron splashing.
Accumulation of bacteria
A stimulus such as bacteria can be introduced into an indoor aquatic environment in many fashions:
* A patron shouts or sneezes.
* A patron has an open wound.
* The pool experiences heavy organic loads.
* A patron introduces body fluids or fecal matter into the pool.
* Normal skin and hair shedding.
* A patron does not shower before entering the pool.
* Patron use of skin, body and hair-care products. (Swim caps are not a good solution because they contribute to hair loss in the pool when patrons vigorously or abruptly remove the caps and rinse their heads in the pool.)
A properly maintained pool sanitation system can usually kill bacteria. But high patron loads, inadequate turnover time, insufficient filter exposure time, and inadequate filter effectiveness and sizing can allow dead bacteria to remain in the water. Though dead, these bacteria can produce endotoxins, which trigger stimulation of the immune system and, ultimately, HP.
When the staff slows or shuts off waterfeature pumps overnight, water stagnates; corrosion and calcification will build up over time, which creates an ideal setting for microbe growth. Dead bacteria accumulate in the pipes of spray devices, play features and hydrotherapy jets, even though the circulation system remains in operation.
Then when the staff restarts the waterfeature pumps the next day, large amounts of bacteria -- and the endotoxins they produce -- are released into the air. The bacteria are then circulated via the ventilation system and staff and patrons inhale these stimuli, which trigger an immune response. Competitive swimmers and aerobic fitness participants take these stimuli even deeper into their lungs because of their intense level of activity.
Pool chlorination and even super-chlorination often are ineffective: The internal pipes of water-spray devices may not be exposed to chemicals due to stagnation during shutdown periods (Rose et al. 1998). Also, bacteria can sometimes "hide" in mineral deposits in the pipes.
Design issues also play a role. Circulation systems that pump water to a spray feature directly from the pool rather than from the pump room limits the amount of sanitizer that reaches the spray-feature pipes. Also, an inadequate number of chemical-injection points, or injection points too remote from spray outlets, decreases their effectiveness.
In addition to bacteria, organic chloramines can contribute to staff and patron discomfort. A natatorium suffering from inadequate ventilation, water circulation, sanitation and filtration can create airborne chloramines, which can contribute to airway irritation, eye irritation, and wheezing among people at the facility (Shaw 1986).
Only within the last several years have researchers identified indoor natatoriums as sources of endemic lung disease (Rose et al. 1998). This is most likely a result, in part, of newer heating, ventilating and air-conditioning systems.
In efforts to conserve energy and heat, engineers and architects now design facilities with more insulation, sealed windows and closed-loop, energy-recovery HVAC systems. These systems recycle a large percentage of air while limiting the introduction of fresh air. Result: Chloramines, dissipated pool chemicals, cleaning products and other chemical vapors are circulated rather than vented outside.
Additionally, designers often improperly supply air through ductwork installed close to the ceiling, usually because such designs reduce the cost of extending ductwork down from the ceiling and through the walls. To minimize heat loss, and thus save money, new air-handling designs limit the amount of fresh air introduced into the system and limit cross-ventilation over pool surfaces to avoid heat loss through evaporation (Osinski 1997).
If the aquatics staff or frequent patrons demonstrate symptoms of LGL, operators should take the following steps:
* Have medical personnel evaluate and treat affected staffers. Try to find medical personnel familiar with occupational exposures. At minimum, medical tests should include a complete physical exam, oxygen saturation of the blood during exercise, a chest X-ray, pulmonary function testing and complete blood count with differential. If symptoms persist, refer patients to a pulmonologist to perform a biopsy of the large airways, a bronchoscopy and an immune-system evaluation (Ando et al. 1999).
* Close the facility if medical findings are consistent with HP.
* Identify the source of the problem by conducting appropriate air and water testing. Give special attention to air and water quality near slides, sprayers, spas and hydrotherapy jets, during periods of use and nonuse.
* Avoid quick fixes and shortcuts, which serve only to prolong and perpetuate the problem. Facilities that have tried venting through existing, attached systems or tried adding more chemicals have experienced a recurrence of the problem. Moving lifeguards away from a spray device merely postpones their exposure.
* Check that each air exchange introduces a minimum of 40 percent fresh air, Strive for eight complete air exchanges per hour.
* Maintain air temperature 2 to 5 degrees Fahrenheit above water temperature.
* Keep relative humidity between 40 and 60 percent (50 percent is ideal).
* Cover all pools, especially warm-water pools and spas, with thermal insulating blankets when not in use.
* Maintain ventilation rates at 0.5 cubic feet per minute per square foot of facility, plus 20 to 25 cfm for each anticipated patron, including spectators. Ventilation-rate testing is commonly performed by a mechanical engineer.
* Ensure that air is distributed from deck level to ceiling, and across the pool surface. Air should be introduced and exhausted on all sides of the pool for proper cross-ventilation.
* Comply with OSHA and industry exposure standards.
* Frequently sample and analyze facility air quality.
* Keep CO2 levels at less than 1,000 ppm (0.1 percent).
* Maintain positive indoor air pressure in relation to outdoor pressure to allow noxious elements to vent from positive to lower pressure areas.
* Avoid changes in air and water temperatures caused by drafts and thermocline formation.
RELATED ARTICLE: First detection
In 1989, Cecile Rose, a physician at the National Jewish Medical and Research Center in Denver, identified lifeguard lung, or LGL, in a number of symptomatic young people employed as lifeguards at an indoor leisure pool in Westminster, Colo.
Symptoms began in 1986 and included coughing, shortness of breath, fever, chills, muscle aches, wheezing, eye irritation, headache and difficulty concentrating. Individuals demonstrated some, but not necessarily all, of these symptoms (Rose et al. 1998).
The symptoms would develop as late as the evening following a shift at the pool and often resolve themselves by the next day. No apparent correlation existed regarding an individual's prior history, of allergies, asthma or smoking, and the symptoms did not affect all individuals. Those who were affected experienced a range of symptoms (Rose et al. 1998).
Physical exam findings were nonspecific. Some individuals experienced abnormal lung sounds and chest X-rays, but often these were totally normal. Pulmonary' function tests were also normal. Of note, however, was a significant decrease in the oxygen level of the blood during exercise in affected individuals. Individuals with greater exposures, that is, more hours per day and per week in the natatorium, appeared to have an increased likelihood of symptoms (Rose et al. 1998).
S.S. and A.O.
Diligent pool-water maintenance will assist operators in reaching proper air quality.
Operators must keep oxidation-reduction potential levels above 750 millivolts in all areas of the pool. This means testing and monitoring the various spray and waterfeatures throughout the day, including during periods of nonuse. Operators should keep pH/ORP controllers properly calibrated and keep the probes clean.
Most states require six-hour turnover periods for commercial pools, but this may not be adequate for some facilities. Special-use pools often require more rapid turnovers and higher flow rates. Facility use and bather load also may necessitate more rapid turnovers and flow rates than those required by code.
It's important to also periodically check circulation patterns to detect potential eddies or "dead spots," which can serve as collection areas for chemicals, chloramines and bacteria. Periodic dye testing to evaluate proper circulation and flow will help provide early recognition of dead spots.
S.S. and A.O.
Ando, M; Suga, M; and Kohrogi, H (1999). "A new look at bypersensitivity pneumonits." Current Opinion in Pulmonary Medicine. 5(5) (Sept.): 229-304. Review.
Osinski, A (1997). "Breathing fresh air into your therapeutic pool facility." Aquatics International. 9(5) (Sept./Oct.): 31-35.
Rose, CS; Martyny, JW; Newman, LS; Milton, DK; King Jr., TE; Beebe, JL; McCammon, JB; Hoffman, RE; Kreiss, K (1998). "Lifeguard lung: Endemic granulomatous pneumonitis in an indoor swimming pool." American Journal of Public Health. 88(12) (Dec.): 1795-1800.
Shaw, JW (1986). "The indoor air quality of swimming pool enclosures." Conference proceedings of the American Society of Heating, Refrigeration, and Air-Conditioning Engineers. April 20-23, Atlanta.
Sue Skaros, PA-C, is a physician assistant in occupational medicine, based in Milwaukee. She can be contacted at email@example.com. Alison Osinksi, Ph.D., is owner of Aquatic Consulting Services of San Diego. She can be contacted at firstname.lastname@example.org.
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|Author:||Skaros, Susan; Osinski, Alison|
|Date:||Sep 1, 2001|
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