(June 5, 2001)
By Sanford M. Brown
The summer swimming season is fast approaching. Between May and August, Americans will make more than 300 million visits to residential and public pools. Private pool owners and operators of public facilities are making preparations to accommodate the throngs of swimmers. Protection from contaminated recreational water will play an essential role in providing swimmers with a safe and enjoyable experience.
Indeed, the U.S. Centers for Disease Control and Prevention (CDC) likens swimming to “communal bathing” and encourages everyone entering the water and guarding over it to take special precautions to minimize the risk of transmitting and contracting swimming-related illnesses.
Bacteria, viruses and other microbes exist naturally on most surfaces that are exposed to air, including water. Although many are harmless, some of these contaminants may cause infection and disease. Pools and spas are particularly vulnerable to illness-causing bacteria and germs introduced into the water by swimmers and spa users.
Contaminated recreational water can cause a variety of diseases such as diarrhea and skin, ear and upper respiratory infections. In 1997 and 1998, the most recent years for which figures are available, 2,128 people were sickened by the water at public pools. During one incident at an Atlanta waterpark, seven children suffered kidney failure and one child died from swimming in water contaminated with E. coli.
The regular and proper use of a sanitizer in the water will destroy the vast majority of these organisms before they have a chance to strike.
Choosing a sanitizer
Consumers and community pool operators have a number of options for cleaning and sanitizing their pools. Virtually all public pools and 9 out of 10 residential pools are sanitized with chlorine, primarily because chlorine-based sanitizers are effective, inexpensive, easy-to-use and provide residual protection. Chlorine-based sanitizers for pool use come in many forms — chlorine gas, sodium hypochlorite, calcium hypochlorite, lithium hypochlorite and chlorinated isocyanurates.
New technologies such as ozone, ultraviolet radiation (UV) and mixed oxidants also are used. However, it should be noted that neither UV nor ozone provide residual protection, and should therefore be used in conjunction with chlorine for proper sanitization.
Public and private pools
While choosing an effective sanitizer is an important safety measure for all pool owners and operators, there are unique precautions that swimming pool operators and residential pool owners each must be aware of. The following information provides general guidelines for the maintenance and operation of both public and residential pools.
Guidance for public swimming pool operators
The CDC recommends four specific areas for swimming pool operators to focus on in order to reduce the chance of disease transmission: pool design, water quality and equipment maintenance, staff and patron education and preparation of an outbreak plan.
Evaluating your pool design
Because kiddie pools likely have higher concentrations of contaminants due to fecal accidents, their filtration systems should be separate from those for other pools. Increasing the water turnover rate in kiddie pools also may decrease the length of time that swimmers are exposed to germs.
Additionally, diaper changing areas should be made available and should be regularly cleaned in order to discourage the common practice of changing diapers on tables and lounge chairs.
Maintaining water quality and equipment
It is important to keep the chemical feed equipment and chemicals at optimal levels within state and local government regulations. Maintaining the proper chemical levels will prevent most bacterial outbreaks such as E. coli. Because of the environmental sensitivities of pools and the importance of maintaining a proper chemical balance in the water, many states require hourly testing for public pools.
The National Spa and Pool Institute developed the following guidelines for the use of chemicals in swimming pools. Unique community health and the particular chemical needs of individual pools may differ and should therefore be taken into account in establishing the standards for each pool.
|National Spa and Pool Institute|
|Suggested Chemical Standards for Swimming Pools|
|Free chlorine, parts per million (ppm)||1.0-3.0|
|Combined chlorine, ppm||None|
|Total alkalinity, ppm|
|(liquid chlorine, cal hypo, lithium hypo)||80-100|
|(gas chlorine, dichlor, trichlor and bromine)||100-120|
|Total dissolved solids, ppm||1000-2000|
|Calcium hardness, ppm||200-400|
|Cyuranic acid, ppm||30-50|
Educating patrons and staff
Educating staff and patrons on proper prevention efforts will help to reduce the risk of disease transmission. Staff should be aware of simple tips to promote health, hygiene and safety around the pool. They should also be trained to communicate these messages to patrons. These safety tips also can be posted on prominent signage throughout the swimming facility.
The CDC recommends utilizing the following Healthy Swimming Tips for staff training and patron education:
|Tips for Everyone
Tips for Parents
Preparing an Outbreak Plan
Most public pool operators already have a plan for injuries and drowning, but many do not have plans for a disease outbreak. Every facility should develop a policy to follow in the event of an outbreak, including an immediate health and safety response as well as a strategy for communicating information about the incident to the public, local health department officials and the media.
Operators also are advised to develop a written fecal accident policy and to maintain records of chemical dosages, pH levels and equipment repairs so that the cause of problems can be more easily traced and prevented from happening again.
Advice for residential pool owners
Like public pools, residential pools rely on a system of support equipment and chemicals to keep the pool fresh, clean and free from contaminants that may cause illness. Unlike public pool operators, private pool owners may be unaware of the specific safety practices that should be employed in maintaining their pools and handling pool chemicals.
Handling pool chemicals safely
Pool chemicals are essential to protecting the swimming pool water from disease-causing organisms. In order to be effective, they must be administered properly and handled with care. Chemical levels should be checked daily and adjusted accordingly.
Following are suggestions developed by the Water Quality & Health Council and the Chlorine Chemistry Council for the safe handling of pool chemicals.
|Safe chemical practices at pools and spas
Click here for additional safety suggestions for handling pool chemicals.
In addition to the proper handling, use and disposal of pool chemicals, it is essential to take the necessary precautions to minimize risks from physical injury and drowning. Indeed, nearly 1,000 children under the age of 15 drown in the United States each year.
SafeUSA, an organization dedicated to reducing preventable injuries in the U.S., recommends that residential pool owners should install an isolation fence with self-closing and self-latching gates around the pool. They also suggest that parents should remove all toys from the pool immediately after use so that children are not tempted to lean into the pool and grab them.
Following is a broad set of simple swimming pool safety tips to help families enjoy a safe and healthy summer poolside.
|Swimming Safety Tips
Enjoying the swimming season
Given the potential dangers associated with swimming pools, safety tips and health guidelines should always be followed. The preceding guidelines should help to reduce these risks for children and adults alike. With proper preparation and due diligence throughout the pending summer season, both public pool operators and residential pool owners can help make commonplace injuries and illnesses a thing of the past for one of America’s favorite pastimes – swimming.
Sanford M. Brown, MPH, Ph.D., is a Registered Environmental Health Specialist and a Professor of Health Science at California State University, Fresno. He also serves as a member of the Water Quality & Health Council.
For more information on pools and pool safety, visit the following sites: