The Buzz Around Swimming Pools
During the summer of 2007, epidemiologists were puzzled by an outbreak of West Nile virus in and around Bakersfield, Calif. The weather over the preceding months had been unusually hot and dry, making the region inhospitable for the mosquitoes that carry the virus. What could account for the 276 percent increase in cases?
Three words: abandoned swimming pools.
That's the suspicion raised by a team of scholars led by William K. Reisen of the University of California, Davis. In the November 2008 issue of the journal Emerging Infectious Diseases, the researchers note that "an aerial survey of Bakersfield showed an extensive number of green or neglected swimming pools, most of which were producing mosquitoes." (In swimming-pool lingo, "green" loses its normally friendly connotation, instead denoting an infestation of algae.)
Kern County was on the cutting edge of America's housing crisis: The region reported a 300 percent increase in delinquency notices from spring 2006 to spring 2007. With home values plummeting, many owners simply walked away from their properties, leaving behind pools, hot tubs and ornamental ponds. Many of these quickly became repurposed as "larval habitats," aka mosquito breeding grounds.
Realizing it had a problem, the local Mosquito and Vector Control District reassigned its rural field crews to urban areas in the spring of 2008, treating nearly 2,200 of these "problem pools." This apparently did the trick: Over the summer, Reisen reports in a follow-up letter, there was "almost no evidence" of West Nile virus in Bakersfield.
No causal connection between these phenomena has been proven, but the scholars make a convincing argument that a stagnant economy can lead to stagnant water. Given the scope of the mortgage meltdown, upwardly mobile mosquitoes looking to relocate and raise a family will have plenty of pools to choose from this summer.
A Deep Racial Disparity
With the era of segregated pools long behind us, one wouldn't think recreational swimming would be a racial issue. One would be wrong. Two separate 2006 studies examine the fact that the drowning rate among African Americans (2.7 deaths per 100,000 persons) is far higher than the rate for whites (1.2 per 100,000 persons).
One report, in the American Journal of Public Health, found that 678 U.S. residents between the ages of 5 and 24 drowned in pools between 1995 and 1998. Forty-seven percent of them were black, while 33 percent were white and 12 percent were Hispanic. African Americans accounted for an astonishing 71 percent of drowning in hotel/motel swimming pools during that period. Even after adjusting for income levels, the racial disparity persists, with black males aged 5 to 19 at particularly high risk.
"Drowning in Inequalities," a report in the Journal of Black Studies, attempts to answer the obvious question: Why? "The risk of accidental drowning increases for blacks as opportunities for swimming increase," the researchers note. "This puzzle is perhaps explained by the fact blacks do not swim as many times a year as whites. This difference in experience produces differences in ability, such as technical skill and knowledge of aquatic safety."
The research team led by Donald Hastings of the University of Tennessee made several recommendations, including building new pools "without deep-water drop-offs where swimmers can silently slip underwater and drown;" installing "sensors and underwater cameras to monitor for swimmers in distress;" and "upgrade water-safety knowledge of swimmers, emergency personnel and supervisory adults." States and municipalities still deciding how to spend your federal stimulus dollars, take note: Such snorkel-ready projects could save lives.
Just Ban Bikinis and Everything Will Be Fine
A 2007 study in the Journal of Pediatric Psychology suggests one simple and apparently effective technique for increasing pool safety: continuing education for lifeguards. A team led by University of Alabama at Birmingham psychologist David Schwebel monitored the behavior of both swimmers and lifeguards one recent summer at a Jewish community center pool.
Halfway through the eight-week season, all 14 lifeguards attended a mandatory meeting with members of the research team. The scholars told them they had observed "a relatively high rate" of risky behavior in the water, much of which was missed because the lifeguards on duty were distracted. The evening also included a discussion of a recent drowning death at a JCC pool in another state and a review of the American Red Cross' recommended strategies for pool surveillance.
The session clearly had an impact. "Both risky patron behavior and lifeguard distraction/inattention decreased noticeably following the intervention," the researchers report, adding "these decreases were maintained for the remainder of the summer swimming season." Why the change of behavior on the part of swimmers, who didn't participate in the class? "One likely explanation is that swimming patrons sensed that lifeguards were watching the pool more carefully and therefore obeyed rules better."
We Vote for Lifeguard Lung, But Hot Tub Lung Does Have a Sexy Undertone
Given the catchy, alliterative name, it's surprising that the affliction "lifeguard lung" hasn't received more media attention. The term was apparently coined in a 1998 paper in which a team led by the University of Colorado's Cecile Rose examined two outbreaks of granulomatous pneumonitis, a treatable but serious inflammation of lung tissue. The victims were lifeguards who worked long hours at a complex of three indoor pools that featured waterfalls and sprays — amenities that greatly increased their exposure to bacterial endotoxins.
A 2005 Mayo Clinic report used the equally evocative name "hot tub lung" to describe the condition, which has apparently spread from the lifeguard community to the much larger population of spa aficionados. A 2007 follow-up in the journal Environmental Health Perspectives noted that an increasing number of spas and hot tubs feature "aerosol-generating hot water sources," which greatly increase one's chances of inhaling the mycobacteria that apparently cause the affliction.
The best way to avoid the problem seems to be a combination of aggressive maintenance (the little buggers are resistant to chlorine) and effective ventilation, which can be an issue with indoor spas and pools. Or you can simply opt for the beach. Ocean spray can be refreshing; swimming pool spray, not so much.
How Many Aquaphoic Scholars Does it Take to ...
Finally, we couldn't head for the showers without sharing this startling finding from the March 2009 Archives of Pediatrics and Adolescent Medicine. A case-control study that examined drowning deaths in various American counties between mid-2003 and mid-2005 concluded: "Participation in formal swimming lessons was associated with an 88 percent reduction in the risk of drowning in 1-to-4-year-old children."
It took seven scholars to come to that realization. A light bulb joke comes to mind, but you don't want to play with anything electrical while sitting close to the pool.
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