There are many benefits associated with showers regarding relaxation and comfort, but they also pose a potential health risk regarding Legionella bacteria proliferation in the shower. Legionella is a harmful infection that can grow in warm water systems, including shower water.
Throughout this article, we will discuss the importance of Legionella prevention in showers and how water filtration at the point of use can be a crucial component of a comprehensive risk mitigation strategy to reduce the risk of Legionella infection.
First, it is essential to understand Legionella and the risks associated with it. Legionella bacteria are known to thrive in water temperatures between 68°F and 131°F (20°C and 55°C)¹, and they can multiply in stagnant water as well. The water droplets in a shower can be aerosolized and inhaled, making them the perfect environment for Legionella to grow and cause respiratory infections, such as Legionnaire’s disease — a severe form of respiratory illness.
Due to the high temperature of the hot water, the lines of hot water may be free of Legionella. After mixing with the cold, the temperature will drop to 68-131 degrees Fahrenheit, considered a dangerous range for health. For this reason, we need point-of-use filtration systems since, despite hot water killing bacteria, warm water will encourage them to increase more quickly and cause the bacteria to multiply even more rapidly.
THE ROLE OF SHOWERS IN LEGIONELLA TRANSMISSION
During heating, moisture builds up, stagnating in the plumbing system and allowing Legionella to multiply. In showers, a contaminated source of water can be aerosolized, which can lead to the spread of bacteria. When these substances are inhaled, respiratory infections can develop.
Biofilm formation is a process that occurs in several ways. An accumulation of microorganisms called biofilm can occur on the surfaces of pipes and other surface fixtures. These biofilms can be a breeding ground for Legionella bacteria, which makes eradicating them challenging, considering the difficulty of eliminating them. Biofilm is difficult to remove from the plumbing system, and that is why, after a hyperchlorination, the Legionella returns to the system. We have to set the biocide up to succeed. Inconsistency of water temperature, which is common in showers, can create an environment that supports the growth of Legionella. Bacteria can survive in warm pockets within the water system. In situations where biocide concentrations are low, cold water can be the main carrier of bacteria.
CURRENT METHODS OF BACTERIA PREVENTION INCLUDE:
- Routine maintenance and comprehensive water management plans. Comprehensive water management plans are essential for Legionella prevention. This includes measures such as regular flushing of pipes, monitoring water temperatures, and implementing disinfection strategies.
- Point-of-entry (POE) treatment. Some buildings or facilities treat and filter water at the entry point. It is mainly used to remove particles such as metal, hardness, and more, as well as bacteria (including Legionella). It is the facility’s first water supply defense line.
- Point-of-use (POU) treatment. POU filtration systems with specialized filters can effectively capture and remove bacteria, including Legionella. This provides additional protection against bacteria transmission through aerosolized water droplets. POU filtration is very popular and even mandatory in Europe to complete a POE system.
Integrating POU filtration will provide an active barrier to stop and prevent bacteria — this is the last line of defense against contamination. POU filters are available with 0.085-micron technology, which stops any organisms sized larger than that. To avoid clogging, a pre-filter can be used to filter when there is no POE in place. The cost of point-of-use filtration shouldn’t be prohibitive, but the payback is exponential.
QUESTIONS AND ASSUMPTIONS ABOUT POU FILTRATION DEVICES AND SYSTEMS: ARE THESE DEVICES AND SYSTEMS REGULATED IN ANY WAY?
There are different organizations, such as ASTM International and NSF international, that provide standards and certifications for these devices. ASSE International also has a Listing Evaluation Criteria (LEC) standard — ASSE LEC 2011-2022, Product Performance Requirements for Legionella Reduction and Treatment Devices. Products conforming to ASSE LEC 2011-2022 reduce the quantity of potentially harmful Legionella bacteria that exit the device and help reduce downstream exposure risk.
WHY ARE WATERBORNE PATHOGENS, SUCH AS LEGIONELLA, INCREASING?
Some reasons include increased awareness, regular testing, and clearer codes. There is an understanding that the problem must be eradicated before it spreads, harms people, and endangers lives. Regulations for setting filters at the point of use are more relevant today than ever. This is especially true when extensive tests are done and Legionella is detected in more places. ASSE LEC 2011-2022 was a milestone in determining prevention methods and practical solutions to eradicating bacteria, especially at the point of use. Certification to this LEC gives customers a feeling of security.
WHAT IS THE DIFFERENCE BETWEEN NSF P376 AND P231?
NSF P376 reduces bacteria and fungus. NSF P231 reduces bacteria and viruses, which require nanofiltration media and will shorten the filter service life.
WHICH ELEMENTS SHOULD I LOOK AT IN POU FILTRATION DEVICES?
Medical grade body, an antibacterial component integrated into the body surface, and a non-return water check valve to ensure the filter doesn’t contaminate the water source.
ARE THESE DEVICES EASY TO INSTALL AND MAINTAIN?
The shower connection on these devices is universal and effortless to place on the flexible pipe or a wall shower. The only maintenance required is to replace the clogged filter once the water flow has been reduced or stopped.
ARE THESE DEVICES AFFORDABLE FOR ANYONE?
A POU shower should be available at a cost of 50-99 cents per shower, depending on water quality and if a pre-filter is needed. As far as its capacity is concerned, it can filter water for up to 120 days (depending on water quality). Shelf life can be extended by adding a pre-filter, allowing the POU filter media to last longer. These are generally more expensive in the beginning since it is a complete shower that needs to be installed.
Legionella prevention in showers is essential to ensure the health and safety of the public. POU filtration systems play a crucial role in mitigating Legionella risks by regulating water temperature, removing bacteria by creating an active barrier, and facilitating regular maintenance. As the understanding of waterborne pathogens advances, the integration of POU filtration systems in the design and maintenance of buildings becomes increasingly important as we develop a better understanding of these pathogens. Investing in preventative measures will make showers a place of comfort and ensure that they are an environment that prioritizes individuals’ health and well-being.
