Overview & Anticipated Public Health Outcomes of the Model Aquatic Health Code (MAHC)
It is important that public pools and spas are designed, constructed, operated, and inspected to keep swimmers healthy and safe. In the United States, there is no federal regulatory agency responsible for aquatic facilities. As a result, most pools and spas are regulated at the state or local level; 68% of local health departments have public pool inspection programs 1. Those same state and/or local public health agencies individually devote significant time and resources to regularly develop, review, and update their pool codes, which govern the design, construction, operation, and maintenance of swimming pools and other aquatic facilities. This translates into considerable variation in requirements for preventing and responding to recreational water illnesses, injuries, and drowning among local and state agencies across the United States.
To assist state and local agencies, CDC has led a collaborative effort with public health, industry, and academic partners from across the United States to develop guidance to prevent drowning, chemical injuries, and the spread of recreational water illnesses at public swimming pools and spas. This guidance document, called the Model Aquatic Health Code (MAHC), integrates the latest knowledge based on science and best practices with specific code language and explanatory materials covering the design, construction, operation, and maintenance of swimming pools, spas, hot tubs, and other public disinfected aquatic facilities. As a result, local and state agencies needing to create or update swimming pool and spa codes, rules, regulations, guidance, laws, or standards can now use the MAHC as a resource to improve health and safety while conserving valuable time and resources previously used to write or update code language. To further assist users, CDC is working with public health and aquatics industry partners such as the Conference for the Model Aquatic Health Code (CMAHC), to ensure the MAHC is regularly updated so it stays current with the latest science, industry advances, and public health findings.
Rationale, Regulations, Recommendations, & Outcomes
Over 300 million visits to aquatic venues occur each year making swimming the fourth most popular recreational activity in the United States and the most popular recreational activity for children and teens 2. However, over the past several decades, public aquatic venues have been associated with significant increases in disease outbreaks and the continued occurrence of drowning and injuries. These health and safety issues include:
- Drowning. Drowning is one of the top causes of unintentional injury death for children older than 1 year 3-5.
- Injuries and emergency department (ED) visits. A high number of children under the age of 10 — more than 30,000 — visit the ED for swimming-related issues each year 6. Injuries from pool chemicals accounted for nearly 5,000 ED visits in 2012 7-9.
- Waterborne illness outbreaks. The number of illness outbreaks associated with recreational water has increased significantly since CDC began collecting these data in 1978 10. Most of the increase is due to outbreaks caused by the chlorine-tolerant parasite Cryptosporidium 11.
- Public pool and hot tub closings because of public health hazards. Recent studies found that as many as 12% (one out of eight) of inspected public pools 12 and 11% (one out of nine) of inspected public hot tubs 13 were closed immediately for serious violations.
- Evidence of pool water contamination. Sampling of public pool filters shows evidence of contamination (59% [95/161] of samples Pseudomonas aeruginosa positive) and from feces (58% [93/161] of samples E. coli positive) 14. In another U.S. study of pool filters, 8.1% (13/161) of samples were positive for Cryptosporidium, Giardia, or both 15.
Regulation of Aquatics in the United States
The health and safety at public disinfected aquatic facilities (e.g. swimming pools, water parks, etc.) is regulated by state and local jurisdictions since, in the United States, there is no federal regulatory authority responsible for these aquatic facilities 16. All public pool codes are developed, reviewed, and approved by state and/or local public health officials or legislatures. Consequently, there is no uniform national guidance informing the design, construction, operation, and maintenance of public swimming pools and other disinfected aquatic facilities. As a result, the code requirements for preventing and responding to recreational water illnesses (RWIs), drowning, and injuries can vary significantly among local and state agencies. State and local jurisdictions spend a great deal of time, personnel, and resources creating and updating their individual codes on a periodic basis.
Recommendation for Creating Model National Guidance
The effort to create the MAHC stems from a CDC-sponsored national workshop called "Recreational Water Illness Prevention at Disinfected Swimming Venues" that was convened on February 15-17, 2005, in Atlanta, Georgia. The workshop assembled persons from different disciplines working in state, local, and federal public health agencies, the aquatics industry, and academia to discuss ways to minimize the spread of recreational water illnesses at disinfected swimming venues. The major recommendation from this workshop was that CDC lead a national partnership to create an open-access model guidance document that helps local and state agencies incorporate science-based practices into their swimming pool codes and programs without having to "recreate the wheel" each time they create or revise their pool codes. The attendees also recommended that this effort be all-encompassing so that it covered the spread of illness but also included drowning and injury prevention. Such an effort should increase the evidence base for aquatic facility design, construction, and operation while reducing the time, personnel, and resources needed to create or improve pool codes across the country. Since 2007, CDC has been working with public health, industry, and academic representatives from across the United States to create this guidance document. Although, the initial workshop was responding to the significant increases in disease outbreaks at swimming pools, the MAHC is a complete aquatic facility guidance document with the goal of reducing the spread of disease and occurrence of drowning and injuries at public aquatic facilities.
MAHC Vision, Mission, and Anticipated Health Outcomes
The Model Aquatic Health Code’s (MAHC) vision is "Healthy and Safe Aquatic Experiences for Everyone." The MAHC’s mission is to provide guidance on how state and local officials can transform a typical health department pool program into a data-driven, knowledge-based, risk reduction effort to prevent disease and injuries and promote healthy recreational water experiences. The MAHC will provide local and state agencies with uniform guidelines and wording covering design and construction, operation and maintenance, and policies and management of swimming pools and other public disinfected aquatic facilities. The availability of the MAHC should provide state and local agencies the best available guidance for protecting public health so they can use it to create or update their swimming pool codes. The guidance will be regularly updated using input from a national stakeholder partnership called the Conference for the Model Aquatic Health Code (CMAHC) to keep the MAHC up to date and current with the latest advances in the aquatics industry while also responding to public health reports of disease and injury.
Short-term Outcomes: Use of the MAHC should help reduce the risk of diseases and injuries and promote healthy and safe swimming. We anticipate that the practices promoted in the MAHC will initially lead to the following system improvements:
- Fewer pool and facility closures
- More-meaningful inspection and tracking/surveillance data
- An established research agenda to drive future iterations of the MAHC
- Enhanced collaboration among stakeholders
Long-term Outcomes: By adopting the practices outlined in the MAHC, jurisdictions should also be able to improve the long-term health and safety of aquatic facilities. This should include a reduced risk of the following:
- Outbreaks of waterborne illnesses
- Drowning incidents
- Injuries from pool chemicals and disinfection by-products
- Swimming-related emergency department visits
CDC is developing systems to track the impact and potential health improvements related to this national public health effort.
- National Association of County and City Health Officials (NACCHO). National profile of local health departments [PDF - 76 pages].
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- Mack KA. Swimming related injuries among children age 0-9 years treated in emergency departments, NEISS-AIP 2001-2006. Presented at American Public Health Association, Nov. 7-11, 2009.
- CDC. Pool chemical–associated health events in public and residential settings — United States, 1983–2007. MMWR Morb Mortal Wkly Rep. 2009;58(18):489-93.
- CDC. Acute illness and injury from swimming pool disinfectants and other chemicals — United States, 2002-2008. MMWR Morb Mortal Wkly Rep. 2011:60(39):1343-1347.
- Hlavsa MC, Robinson TJ, Collier SA, Beach MJ. Pool chemical–associated health events in public and residential settings — United States, 2003–2012, and Minnesota, 2013. MMWR Morb Mortal Wkly Rep. 2014;63(19):427-30.
- Hlavsa MC, Roberts VA, Kahler AM, Hilborn ED, Wade TJ, Backer LC, Yoder, JS. Recreational water–associated disease outbreaks — United States, 2009–2010. MMWR Morb Mortal Wkly Rep. 2014;63(1):6-10.
- Yoder JS, Beach MJ. Cryptosporidium surveillance and risk factors in the United States. Exp Parasitol. 2010;124:31-9.
- CDC. Violations identified from routine swimming pool inspections — Selected states and counties, United States, 2008. MMWR Morb Mortal Wkly Rep. 2010;59(19):582-7.
- CDC. Surveillance data from public spa inspections — United States, May-September 2002. MMWR Morb Mortal Wkly Rep. 2004;53(25):553-5.
- CDC. Microbes in pool filter backwash as evidence of the need for improved swimmer hygiene — metro-Atlanta, Georgia, 2012. MMWR Morb Mortal Wkly Rep. 2013;62(19):385-88.
- Shields JM, Gleim ER, Beach MJ. Prevalence of Cryptosporidium spp. and Giardia intestinalis in swimming pools, Atlanta, Georgia. Emerg Infect Dis. 2008;14(6):948-950.
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