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					On Tap


                The
         Microbial Quality
            and Safety
         of Bottled Water
                                                By Kelly A. Reynolds, MSPH, Ph.D.




T
         he bottled water market has               Purified water—distilled, deionized or    be, sterile. Heterotrophic plate count
         steadily increased over the last     treated with reverse osmosis or other          (HPC) bacteria are commonly found in
         decade and is now the second larg-   suitable processes.                            bottled water, as well as most other drink-
est category of commercial beverage by             Mineral water—contains >250 ppm of        ing water sources, and can grow over
volume sold in the United States (carbon-     natural dissolved solids (i.e., mineral and    time, reaching concentrations of up to
ated soft drinks rank first). Consumers       trace elements).                               10,000 to 100,000 HPC bacteria per ml
like the ease and portability of bottled           Sparkling water—contains carbon di-       (Table 1). These generally harmless bac-
water and presumably have confidence          oxide.                                         teria are normal components of our en-
in the quality relative to taste, odor and         Artesian water—well water from a          vironment and can be found on our skin,
public health benefits. Like tap water and    confined underground aquifer.                  in soil and in very high numbers in food
POU treated water, bottled water is not            Well water —collected from under-         products. Fruits, vegetables, meats,
sterile. Unlike tap water, it is not regu-    ground aquifers.                               cheeses, yogurt and pasteurized milk
lated by the U.S. Environmental Protec-             Although many bottled water com-         commonly contain tens of thousands to
tion Agency (U.S. EPA) but rather the Food    panies pride themselves on having              millions of HPC bacteria that are accept-
and Drug Administration (FDA), as a food      highly protected natural sour ces (i.e.,       able and consumed unnoticed4,5.
product. These two facts, in part, have led   springs and artesian wells), historical             In 1999, the Natural Resources De-
to some misconceptions about the safety       disease outbreaks in tap water utilizing       fense Council (NRDC) posted what was
and quality of bottled water.                 groundwater supplies have raised new           perceived as a generally negative report
                                              questions about the quality of these un-       on bottled water (Bottled Water: Pur e
Bottled water statistics                      treated sources subject to contamination       Drink or Pure Hype? www.nrdc.org), cit-
     According to a W  ater Quality Asso-     from animal populations and excessive          ing discrepancies in U.S. EPA tap water
ciation survey1 , 39 percent of home oc-      runoff during severe storms. Although          standards and regulations versus FDA
cupants reported drinking bottled water.      the majority of gr oundwater is still          bottled water standards. Also cited was
Globally, the bottled water industry is       thought to be free of disease-causing mi-      less stringent monitoring requirements
growing at a phenomenal rate and in the       crobes, increased surveillance with im-        for bottled water and a four-year survey
U.S. alone, the total (U.S.) category vol-    proved methodology has presented evi-          where they concluded that bottled water
ume is expected to exceed 7.3 billion gal-    dence that human enteric viruses,              was not as pure as consumers were led
lons in 2005; an 8.1 percent incr ease over   ulcer-causing bacteria and harmful proto-      to believe.
2004’s volume level (Beverage Marketing       zoa (Crypto-sporidium) can be found in
Corporation, 2005. Available at www.          groundwater (reviewed in On Tap, Dec.
                                                                                              Table 1. Heterotrophic
ibwa.org). The average volume con-            2004). Of the 751 drinking waterborne
                                                                                              bacterial concentrations in
sumed per person in 2005 is estimated at      disease outbreaks that occurred in the U.
                                                                                              different water sources6
25.7 gallons.                                 S. from 1971-2000, 467 (62 percent) were
                                                                                                                  Heterotrophic
                                              linked to groundwater systems2. During
                                                                                                                 concentration
Pristine water sources                        the 1999-2000 surveillance period, 29 of
                                                                                              Water source        range per mL
     Bottled waters differ primarily due      the 39 drinking water outbreaks (74.4 per-
to the type of source water from which        cent), including an outbreak associated         Public water         1-6.0 x 102
they are collected and the additional         with bottled water, were associated with        Rural well water     10-1.9 x 104
treatments that are imposed on those          groundwater sources (wells and springs)3 .      POU device          <10-1.7 x 105
source waters, including:                                                                     Bottled water       <10-3.9 x 105
     Spring water—from a natural under-       Bottled water gets a bad rap                    Drinking fountain    35-2.7 x 104
ground source.                                    Bottled water is not, nor should it
                                                                                              Cistern             <10-2.3 x 107
S EPTEMBER 2005                                                                             Water Conditioning & Purification         39
      Later that year a rebut- Table 2. Documented bottled water outbreaks                                         crobial character of consumed
tal from the Drinking Water Location                                                                               food and drinking water, ”
                                                          Outbreak details                Reference                Critical Review in Microbiol-
Research Foundation (DWRF;                                                                                         ogy, 28: 249-279, 2002.
                                 U.S. multi-state         Salmonella infection risk       CDC SODA, 20023
http://www.dwrf. info/
                                 outbreak                 linked to bottled water                                  6. Geldreich, E.E. 2002. Het-
nrdc_ bottled_water. htm)
was posted in defense            Florida                  Chemical outbreak, spring       Barwick et al., 2000 7 erotrophic bacteria as indica-
                                                                                                                   tors of water quality. In: Bitton,
against the allegations by the                            source                                                   G. (ed.) Encyclopedia of Envi-
NRDC. While both reports Saipan, N. Mariana               Treated well water source.      Kramer et al., 1996 8    ronmental Micr obiology, Vol.
exhibit the fine art of split- Islands, U.S. Territory Improper bottle disinfection                                3. Wiley, N.Y. pp. 1,540-1,552.
ting hairs, points are still                              suspected                                                7. Barwick, R.S.; Levy, D.A.;
                                                                                                                   Craun, G.F.; Beach, M.J.,
scored on each side.             Pennsylvania             Not available                   CDC, 1980  9
                                                                                                                   Calderon RL. Surveillance for
      • While experts predict New Jersey                  Not available                   CDC, 197310              waterborne disease out-
that a low level of disease in-                                                                                    breaks—United States, 1997-
cidence associated with bottled water            disaster events. Generally, bottled water          1998. In: CDC Surveillance Summaries, May
might go unnoticed, untreated and unre-          offers a safe, convenient alternative to           26, 2000. MMWR 2000;49(No. SS-4):1-35.
ported, the facts are that very few out-         tap water and many consumers report                8. Kramer, M.H.; Herwaldt, B.L.; Craun, G.F.;
breaks have been associated with bottled         that they prefer the taste of bottled wa-          Calderon, R.L.; Juranek DD. Surveillance for
                                                                                                    waterborne-disease outbreaks—United
water, especially in comparison with tap         ter. Consumers are advised to be in-               States, 1993-1994. In: CDC Surveillance
water (Table 2).                                 formed about the source water quality              Summaries, April 12, 1996. MMWR
      • Regulations for bottled water are        and treatment level of bottled water con-          1996;45(No. SS-1):1-33.
imposed at the federal (FDA), state and          sumed, especially when traveling abroad.           9. CDC. Water-r elated outbreaks [Annual
industry level via the International             Immunocompromised individuals who                  summary 1980]. Atlanta, GA: U.S. Depart-
Bottled Water Association (IBWA Model            are at increased risk of microbial disease         ment of Health and Human Services, CDC,
                                                                                                    1981. Publication no. 82-8385.
Bottled Water Code).                             are cautioned against tap water con-
      • The FDA is required by law to meet       sumption and should also be wary of                10. CDC. Foodborne & waterborne disease
                                                                                                    outbreaks [Annual summary 1973]. At-
or exceed U.S. EPA water quality stan-           bottled waters that do not employ U.S.             lanta, GA: U.S. Department of Health, Edu-
dards within 180 days of being imple-            EPA approved methods for Cryptosporid-             cation, and Welfare, CDC, 1974. Publica-
mented or provide an explanation as to           ium removal11.                                     tion no. 76-8185.
why the standard would not be appli-                                                                11. EPA/CDC. 1999. Safe Drinking Water
cable to bottled water.                          Adapted from instructions provided by Ken          Guidance for people with severely weakened
      • IBWA members must meet strict            Orom, Calgary Board of Education, and Ken          immune systems. EPA 816-F-99-005.
industry standards that can exceed FDA           Reynolds, Calgary Health Services.                 12. Oliphant, J.A.; Ryan, M.C.; Chu, A. 2002.
or U.S. EPA drinking water standards, but                                                           Bacterial water quality in the personal water
                                                                                                    bottles of elementary students. Can J Public
membership is voluntary and standards            References                                         Health. 93(5):366-7
are not enforceable.                             1. WQA. 2001. Water Quality Association.
      • Although more total samples are          2001 Statistical & Market Data. Water Qual-
                                                 ity Association, Lisle, Illinois.                  About the author
collected by water utilities for contami-                                                              Dr. Kelly A. Reynolds is a research scientist
nant monitoring, on a per capita analy-          2. Calderon, R.L. Measuring benefits of drink-     at the University of Ari-
sis, bottled water is monitored more fre-        ing water technology: “ten” years of drinking
                                                 water epidemiology. NEWWA Water Qual-
                                                                                                    zona with a focus on devel-
quently than tap water.                                                                             opment of rapid methods
                                                    ity Symposium, May 20, 2004. Boxborough,
                                                    Mass.                                               for detecting human
Conclusion                                                                                              pathogenic viruses in
     Not all bottled waters are the same            3. CDC. Surveillance for Waterborne-Disease
                                                    Outbreaks—United States, 1999-2000 CDC.             drinking water. She holds
and surveys reporting a variety of con-             MMWR November 22, 2002 / 51(SS08); 1-               a master of science degree
taminants can be randomly found                     28                                                  in public health (MSPH)
around the globe. Despite criticisms, the                                                               from the University of
safety record of bottled water is exem-             4. Stine, S.W.; Pepper, I.L.; Gerba, C.P. 2005.
                                                    Contribution of drinking water to the weekly        South Florida and doctorate in microbiology
plary and it is potentially a life-saving           intake of heterotrophic bacteria from diet in       from the University of Arizona. Reynolds has
product for those who do not have ac-               the United States. Water Research. 39:257-          been a member of the WC&P technical review
cess to adequately treated water supplies,          263.                                                committee since 1997. She can be reached via
including supplies contaminated during              5. Wadhwa, S.G., et al., “Comparative mi-           email, reynolds@u.arizona.edu

     Maintaining the quality of bottled water is often in the hands of the        • Buy sealed products only.
     consumer. Improper maintenance of bottled water coolers or the               • Wash or wipe off the bottle top before using.
     reuse of water or other plastic beverage bottles can lead to contami-
     nation with human fecal bacteria, or other harmful microbes, and             • Store refrigerated or in a cool, dark environment.
     with harmful chemical by-products that can leach into the water. A           • Discard after one year of storage.
     2003 study found that 8.9 percent of 68 and 64.4 percent of 76 water         • Clean water coolers with every bottle change using a diluted
     samples collected from personal water bottles of elementary school           bleach solution (fill reservoir and drain through faucets 100
     children were contaminated with fecal coliform and HPC counts,               ppm active chlorine bleach solution for 2-5 minutes, rinse
     respectively, that exceeded federal standards. 12                            thoroughly) or manufacturer recommended disinfectant.
     The following general guidelines are suggested:                              • Wash hands prior to replacing new cooler bottles, wipe bottle
     • Do not refill old bottles—buy new from the manufacturer.                   top and neck with dilute bleach solution or rubbing alcohol
     • When traveling, drink carbonated or disinfected bottled water only.        and allow to evaporate.

40          Water Conditioning & Purification                                                                                       SE P T E M B E R 2 0 0 5

				
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