In recent years, there has been increasing consumer concern regarding emerging contaminants in drinking water. The majority of contaminants traditionally found in drinking water either have a known adverse effect on human health or a known effect on taste. Emerging contaminants, also known as incidental contaminants, do not have substantial evidence to show adverse health effects at the trace levels at which they currently are found. However, the mere presence of these contaminants in drinking water has resulted in increased consumer concern.
Emerging contaminants in drinking water come from a multitude of sources, including detergents, personal care products, herbicides, pesticides and prescription drugs. The health risks associated with trace amounts of emerging contaminants are not fully understood, which could explain why consumers are increasingly concerned about their presence in drinking water.
The convenience factor associated with improper use or disposal of these products by throwing them in the garbage or flushing them down the toilet is resulting in increasing trace levels. Ultimately, with ever-growing public awareness about the potential adverse health effects of these emerging contaminants, proper disposal techniques will be adapted to curb the potential health effects they have on drinking water.
In 2014, an independent survey conducted on behalf of NSF Intl. asked consumers to rate their concern about trace levels of emerging contaminants in drinking water. The results of the survey showed that a vast majority of surveyed consumers were concerned about emerging contaminants. Of the 82% who responded they were concerned, 31% said they were very concerned.
In response to continued media reports and consumer concerns, NSF/ANSI Standard 401: Emerging Contaminants/Incidental Compounds was established. Point-of-use (POU) and point-of-entry (POE) systems can be tested to meet NSF/ANSI 401 requirements through third-party certification. The standard verifies the ability of POU or POE water treatment devices to reduce up to 15 emerging contaminants. It does not address health effects because these compounds have no identified health effects at the trace levels at which they are currently found. These 15 contaminants represent those pharmaceutical, personal care and endocrine-disrupting compounds that occur with the highest frequency and/or at the highest levels.
PFOA & PFOS
Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) are part of a group of chemicals commonly referred to as perfluoroalkyl substances or perfluorinated compounds (PFCs). They are not currently regulated in public drinking water supplies. Historically, PFOA and PFOS were used in a variety of products due to their ability to resist water, oil and heat. Applications included cookware, furniture fabric, clothing, packaging and firefighting foam. Given their resistance to a variety of environmental factors, PFOA and PFOS take a long time to degrade, which allows them to be easily available for transport throughout the environment. The potential health concerns of PFOA and PFOS are rooted in their ability to bioaccumulate in the human body at levels that can result in adverse health outcomes.
Given the prevalence of these compounds in the environment, the U.S. Environmental Protection Agency (EPA) developed a public health advisory for PFOA and PFOS in drinking water based on peer-reviewed studies. The EPA health advisory concluded that exposure to PFOA and PFOS at elevated levels could result in harmful health effects, including developmental effects in fetuses, liver damage, and immune and thyroid effects.
As consumer knowledge about these emerging contaminants increases, the demand to see reduction claims for them on water filtration devices also will increase. A new protocol, NSF P473, is being developed to define test procedures for addressing health effects and verifying PFOA/PFOS reduction claims and will be available in the fall of 2016.
As new products, pharmaceuticals and pesticides are introduced into the marketplace, they may find their way into drinking water sources. As a result, the list of emerging contaminants found in drinking water almost certainly will grow as laboratory analytical techniques will congruently evolve to search for potentially hazardous compounds. To keep drinking water safe and clean, it is important to consult third-party certification bodies to test for these emerging contaminants. The one consistent message will always be the importance of protecting the quality of our drinking water.