Safe drinking water is a basic necessity for human health and well-being. While tap water is a widely available source of drinking water, there are growing concerns about its safety and quality.1 Despite tap water treatment to eliminate contaminants and adhere to regulatory standards, pollutants and toxins that pose potential health risks may still be present. This article discusses the potential hazards of drinking tap water, highlighting the presence of pharmaceuticals, PFAs, and other toxins that can be commonly found.
Pharmaceuticals are one of the contaminants detected in tap water in many parts of the world.2 Moreover, these contaminants can originate from diverse sources, such as inappropriate disposal of unused medications and excretion by humans and animals.3 While the concentration of pharmaceuticals in tap water is generally low, there are concerns about potential health risks such as endocrine disruption and antibiotic resistance.4 Examples of common pharmaceuticals found in tap water include ibuprofen, caffeine, and birth control hormones.5
Per- and poly-fluoroalkyl substances (PFAs) are a group of synthetic chemicals used in various industrial and consumer products, such as non-stick cookware and stain-resistant fabrics.6 PFAs have been detected in tap water in many parts of the world.7 Exposure to PFAs has been linked to various health effects, such as cancer, thyroid disease, and developmental and reproductive problems.8 Commonly found PFAs in tap water include perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).9
Tap water can contain other toxins from various sources, such as industrial and agricultural runoff, wastewater discharges, and natural sources, such as algae blooms and soil erosion. These toxins include lead, arsenic, and disinfection byproducts such as trihalomethanes.10 Exposure to these toxins can lead to a range of health effects, such as cancer, developmental problems, and neurological disorders.11
Chlorine is a commonly used disinfectant in tap water treatment to kill bacteria and viruses that can cause diseases. However, when chlorine reacts with organic matter in the water, it can form disinfection byproducts such as trihalomethanes and haloacetic acids that can pose potential health risks.12 Exposure to these disinfection byproducts has been linked to an increased risk of cancer, reproductive problems, and developmental issues.13 Regulatory agencies such as the Environmental Protection Agency (EPA) set the recommended chlorine levels in tap water.14
Many communities add synthetic fluoride to tap water to prevent tooth decay, although fluoride is a naturally occurring mineral.15 While fluoride effectively addresses tooth decay, there are concerns about associated health risks and relying on it as the primary resource to address tooth decay.16 Exposure to high levels of fluoride can cause dental fluorosis. This condition can cause white spots and discoloration on teeth, as well as skeletal fluorosis, which can cause joint pain and stiffness. Some studies have also shown a link between fluoride exposure and cancer.16
To ensure the safety of tap water, various filtration options are available to effectively remove harmful contaminants. Pitcher-style filters using activated carbon, faucet-mounted filters, reverse osmosis systems, and whole-house filtration systems are all popular options1 It is crucial to choose a certified filter to remove the specific contaminants you are concerned about, as not all filters are created equal.
In conclusion, tap water can contain various contaminants and toxins that pose potential health risks. While tap water is treated to eliminate contaminants and meet regulatory standards, it is essential to take steps to ensure the safety of the tap water consumed. Furthermore, filtering tap water can be an effective measure to eliminate harmful contaminants, and it is crucial to select a certified filter. Thus, by recognizing potential risks and taking preemptive measures to mitigate them, we can ensure access to safe and healthy drinking water.
- World Health Organization. (2011). Guidelines for drinking-water quality. Fourth edition. Geneva: World Health Organization.
- Li, W., Shi, Y., Gao, L., Liu, J., Cai, Y., Zhang, X., & Zhang, H. (2018). Pharmaceuticals in tap water: human health risk assessment and proposed monitoring framework in China. Environmental pollution (Barking, Essex: 1987), 242(Pt A), 130-139.
- Fatta-Kassinos, D., Meric, S., Nikolaou, A. (2011). Pharmaceutical residues in environmental waters and wastewater: current state of knowledge and future research. Analytical and Bioanalytical Chemistry, 399(1), 251-275.
- Kostich, M. S., Batt, A. L., & Lazorchak, J. M. (2014). Concentrations of prioritized pharmaceuticals in effluents from 50 large wastewater treatment plants in the US and implications for risk estimation. Environmental Pollution, 184, 354-359.
- Zeng, X., Liu, Y., Wu, L., & Wei, S. (2018). Occurrence, distribution, and risk assessment of pharmaceuticals in surface water, wastewater, and sediment in a typical urban-rural watershed in the south of China. Environmental Science and Pollution Research International, 25(10), 9927-9940.
- U.S. Environmental Protection Agency. (2020). Basic Information on PFAS.
- US National Library of Medicine National Institutes of Health. (2019). Per- and Polyfluoroalkyl Substances (PFASs) in Drinking Water.
- National Institute of Environmental Health Sciences. (2020). Per- and Polyfluoroalkyl Substances (PFAS).
- US Environmental Protection Agency. (2016).
- United States Geological Survey. (2019). Water Quality: What You Need to Know About Contaminants in Your Drinking Water.
- Agency for Toxic Substances and Disease Registry. (2019). ToxFAQs™ for Lead.
- United States Environmental Protection Agency. (2021). Drinking Water Contaminants.
- Chen, H., Liu, J., Zhao, Y., Wu, X., Zhang, Y., Cao, H., & Zhang, H. (2020). Association of disinfection byproducts in drinking water with cancer and reproductive health risks: A systematic review and meta-analysis. Environmental Research, 191, 110150.
- United States Environmental Protection Agency. (2019). National Primary Drinking Water Regulations.
- United States Centers for Disease Control and Prevention. (2021). Frequently Asked Questions About Community Water Fluoridation.
- United States National Cancer Institute. (2021). Fluoridated Water and Cancer Risk.