----- Forwarded by Richard L Whitman/BRD/USGS/DOI on 06/27/2005 03:48 PM
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"Miki Ferenczy"
<mferenczy@pangae To: <rmarante@cityofchicago.org>, <rwhitman@usgs.gov>,
atech.com> <kyam@glc.org>
cc:
06/27/2005 12:27 Subject: nice article
PM
More tests mean more swim bans
June 27, 2005
BY LORI RACKL Health Reporter
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The number of swim bans in Illinois has shot up dramatically in the last
decade, and so have doubts about the way decisions are made to keep people
from taking a dip in the water. "We really don't know what kind of water
people are swimming in. We only know what kind of water they were swimming
in yesterday," said Richard Whitman, whose main area of research is beach
closures for the U.S. Geological Survey. "And by the time we know, it's a
little late to tell them."
That's why the drumbeat is getting louder for better, faster tests to
monitor when the water is safe for swimming. Some promising possibilities
are undergoing trial runs at a few beaches in Chicago and Lake County.
For several years, E. coli has been the marker scientists looked for in
water samples to determine whether it's safe to swim. This common bacteria
found in the guts of warm-blooded creatures -- humans, dogs, gulls -- can
be a sign that the water is polluted with fecal matter and pathogens that
can trigger anything from a mild stomach infection to life-threatening
illness.
Related Story
Are gulls guilty of fouling
beaches?
Nothing spoils a day at the
beach like these two
dreaded words: swim
ban.Summer only officially
started last week, and the
Chicago Park District
already has hoisted the red
flag that renders beaches
off limits for swimming 23
times.
"Part of the emerging science is calling into question whether E. coli is
an appropriate indicator for human health risks," said Cameron Davis,
director of the Alliance for the Great Lakes, formerly known as the Lake
Michigan Federation. "That jury is still out."
In the meantime, would-be bathers are getting beached on the beach more
than ever.
Less fun in the sun
The number of swim bans in the state jumped from 10 in 1994 to 397 in 2003,
according to the most recent figures available from the Alliance for the
Great Lakes.
At Chicago's 31 public beaches, swimming was off-limits 128 times last year
-- more than double the number of swim bans issued in 2000, when the
Chicago Park District began tracking the data.
Many experts attribute the spike in swim bans to more vigilant monitoring
in recent years. In Chicago, water along the sandy shores of Lake Michigan
gets analyzed for E. coli at least five days a week during swim season.
Lakefront suburbs test daily.
"We have the most monitored beaches in the Midwest," said Mark Pfister,
aquatic biologist with the Lake County Health Department, which oversees
beaches from Highland Park to the Wisconsin border. "The more you look, the
more you find."
Problem is, current testing does a lousy job of keeping swimmers out of the
water when they should be. The flip side is true, too: The way we test for
E. coli means people can be taking a dip when bacteria counts are high.
These things happen because E. coli levels can fluctuate wildly in the 18
to 24 hours it takes to get test results, prompting Whitman to call the
process "no better than random."
Others wonder if swim bans do more harm than good.
"The beaches are overly safe," said Don Coursey, a University of Chicago
public policy professor who concluded in a recent study that swim bans have
almost no effect on health but a big impact on summer fun. "The lost
recreational benefits on days when [the beach] is closed and safe
overwhelms the small number of people who get sick on days when the beach
is dirty."
Indiana this year has a new policy that will leave it up to beach managers
if there should be a swim ban or simply an advisory when E. coli levels are
high.
In Illinois, officials with the state, city, suburban Cook County and Lake
County health departments said they have had no reports of anyone getting
sick after swimming at a Lake Michigan beach. Doctors caution that doesn't
necessarily mean swimmers aren't falling ill; they just might be blaming
their upset stomach on bad potato salad instead of polluted beaches.
All E. coli not created equal
Generally accepted guidelines say it's too risky to swim if E. coli counts
surpass 235 colony-forming units in the equivalent of about three shot
glasses of water. This magic number is based on studies done in the 1980s
that found that when E. coli levels reached that 235 threshold, there was a
75 percent chance that at least eight out of 1,000 people in the water
would come down with some sort of gastroenteritis, an infection that can
cause mild to severe symptoms of diarrhea, nausea and vomiting.
But this research largely looked at E. coli stemming from human fecal
pollution. It's unclear if the water is as risky if the E. coli is coming
from sources other than human waste, such as birds. And gulls are a big
contributor of E. coli at Illinois' Lake Michigan beaches.
"There's all this E. coli floating around in the environment, and we're
closing beaches over it," Whitman said, "but we don't really know what the
health implications are."
We'll likely have some answers soon. The U.S. Environmental Protection
Agency has been doing studies at freshwater beaches that will be used early
next year to propose new testing methods and criteria that will "allow
beach managers to make decisions within two to three hours as to whether
the beach should be closed that day," said Rebecca Calderon, director of
the EPA's human studies division.
Faster testing is key when it comes to making smart calls on swim bans.
Take Lake Forest Beach -- whenever E. coli counts were high there in 2003,
they subsided by the next day -- the day the beach was closed.
"We were 100 percent wrong," Pfister said. "We had 12 swim bans at Lake
Forest Beach for no reason, and people were swimming on 12 days when they
shouldn't have been."
Pfister and others have come up with mathematical formulas that take into
account wind speed, rainfall, water temperature and wave height, among
other things, to predict when E. coli counts are high enough to threaten
the health of swimmers. The model proved 85 percent accurate last year at a
couple of Lake County beaches, and it's being tested again this summer. A
similar model is being tried out at Chicago's 63rd Street Beach.
"Depending on how it goes this year, we might expand it to other beaches
next year," said Renante Marante, an environmental engineer with the city's
Environment Department.
Another approach is rapid testing, which Chicago has tried in the past but
with little success. This year, the city will try again, using a different
bacterium from E. coli. Swim bans will still be based on traditional E.
coli monitoring for now, but the lab will also be on the lookout for the
intestinal organism called enterococci.
Sadhu Johnston, acting commissioner of Chicago's Environment Department,
said the city plans to survey swimmers about their health at a couple of
beaches this August, much like the EPA did in its recent studies.
Enterococci levels will be monitored throughout these days. Surveyors will
follow up with the beachgoers about two weeks later to see if they suffered
any symptoms that could be linked to swimming -- and if there's a
correlation between sickness and enterococci. Depending on results, the
city might abandon monitoring E. coli in favor of enterococci.
"We sometimes feel like we're spinning our wheels doing all this testing,"
Johnston said, "and we're not sure we're testing for the right thing."
Contributing: Andrew Herrmann, Gary Wisby and Chris Fusco
No red flags in city until 2nd check done
BY LORI RACKL Health Reporter
A glance at the top 10 Illinois beaches closed to swimmers in 2003 is
missing something, and that something is a strong Chicago presence.
Chicago claims only one of the 10 beaches -- 63rd Street Beach -- with the
highest number of swim bans for that year, the most recent data available
from the Alliance for the Great Lakes show.
So the water at Chicago beaches must be a lot cleaner than the sandy shores
to the north, right?
Not necessarily.
Beaches in Lake County, Glencoe, Wilmette, Winnetka and Evanston ban
swimming as soon as water test results show E. coli levels have reached 235
colony-forming units per 100 milliliters of water -- the level studies have
shown as being too risky for swimming from a health standpoint. Test
results take about a day to get, so too much E. coli in the water Monday,
wouldn't be known until Tuesday, at which point the beach would be closed.
The Chicago Park District holds off issuing a swim ban until it gets
another round of test results the next day. If these results show E. coli
levels are still high after two consecutive days, then the Park District
hoists the red flag that signals no swimming.
So E. coli counts would have to be high Monday and Tuesday for the beach to
be closed to bathers Wednesday.
"We want to be sure, especially when it's nice out," said Andre Taylor,
director of risk management for the Park District. "If it's nice, people
want to go to the beach."
E. coli levels often fluctuate from day to day, so Chicago ends up not
issuing swim bans as frequently as other Illinois beaches on Lake Michigan.
Taylor said he's not worried that Chicago's policy jeopardizes swimmers'
health.
"I've been here five years," he said, "and I've never heard of anyone
getting sick from swimming in the lake."
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Miki S. Ferenczy
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