Hydration plays a critical role in both mental and physical health. Fluid status supports mood, sports performance, cardiovascular function, body temperature regulation, and balances blood pressure and hormones.^1-3 Hydration status is tightly regulated in the body and under as well as overhydration are problematic. Studies have shown that underhydration is common and athletes ranging from youth to collegiate and professional sports commonly arrive at their workouts inadequately hydrated.⁴ As more research emerges about the quality of water, nanoplastics in water, and how these compounds can affect human health, healthcare practitioners need to be able to educate clients confidently on hydration and water quality safety. 

Dehydration, defined as >2% body weight loss during an activity or sport, can negatively impact exercise performance and harm physical health.^1-3,5 Research has shown that the average person consumes just over 2 liters of water per day (with an average range of 0.5 L/d – 4.0 L/d) and athletes and active people need more to replace fluid lost in their activities through sweat.⁴ Studies suggest that 24-hour urine osmolality should be maintained at <500 mmol/kg, a measurement not commonly done on an average person for managing hydration. Research done on 99 people (50 women, 49 men) found that the National Academy of Medicine recommendations of 2.7 L/d of water for women and 3.7 L/d water for men should be sufficient for most people to achieve the recommended urine osmolality though this amount is likely more than the average person consumes.⁶ Hydration status can be assessed via thirst perception, body mass, urine concentration (assessing the color of urine), or more invasive techniques such as urine or plasma osmolality assessments.^2,4,6 Healthcare providers can also simply ask a patient about their 24-hour fluid recall as well as climate and physical activity to assess if they are meeting their needs, and if not, how far off they are.²

Micro and Nanoplastics in Drinking Water

Water quality is complex and includes physical, chemical, and microbiological characteristics. Contaminants ranging from metals (aluminum, arsenic, lead, iron, etc), to inorganic non-metals (sulfide, chlorine, fluoride, etc), organic compounds (volatile organic compounds, polychlorinated biphenyls, polynuclear aromatic hydrocarbons, etc), and microplastics (MPs; <5 mm in diameter) and nanoplastics (NPs;  <100 nm in diameter) can be measured.^2,7,8 The impact of these contaminants on human and environmental health is an emerging area of research.^2,7-12

Nanoparticles and microplastics come from the degradation and discharging of small plastic particles of larger plastics into the environment and from plastic production.^7,8 Current estimates project that by 2050, 12 billion metric tons of plastic waste will end up in landfills or the natural environment, exponentially higher than the current 4.9 billion metric tons assessed in 2015.^7,10 This is a problem for human health because microplastic exposure comes partially from plastic waste in the environment as it degrades and binds to other compounds and environmental pollutants, causing it to spread into water and air, as well as consuming both plant and animal foods (through bioaccumulation in animal fat and tissue), food additives, beverages, and from plastic food packaging.¹¹

The potential risk and extent of health problems from ingesting micro and nanoplastics is still yet to be fully explored.^7-9 Researchers estimate that microplastic exposure is now inevitable and that the annual intake is approximately 11,000 particles from seafood, up to 73,000 particles from salt (through seawater contamination), 4,000 particles from tap water, and 90,000 particles from bottled water.^1,9,10 Marine plastic litter including wastewater treatment plants, aquaculture, and even shipwrecks are a major contributor of microplastic contamination.^13-15 Researchers have warned that microplastic accumulation in sea salt, mussels, and shrimp could soon cause food safety concerns.^13-15 Microplastics have also been found at high levels in food such as honey, sugar, beer, milk, tea, and canned fish.¹⁵ Living organisms can accumulate microplastics in both cells and body tissues and exposure may be linked to health problems ranging from gastrointestinal problems, respiratory disorders, certain cancers, and even fertility problems or chromosome alterations.^11,13,15

Studies are underway, including fecal samples collected from patients both with and without inflammatory bowel disease (IBD). Researchers have found that the concentration of microplastics was significantly higher in people with IBD (41.8 items/g dm) than those without (28.0 items/g dm). The researchers found 15 types of microplastics in the samples, the most dominant were poly(ethylene terephthalate) and polyamides.⁹ These researchers concluded that plastic packaging from drinking water and food, and dust are major sources of human exposure to microplastics.^9,15   

Strategies for reducing exposure should focus on two key areas. First, tap water should be prioritized over bottled water as drinking water source appears to cause the largest amount of intake of microplastics and tap water contains only low levels of potential contaminants.¹⁰ Researchers estimate that the annual intake of microplastics in the US are 4,000 if only tap water is consumed versus 90,000 if only bottled water is consumed – a 22-fold difference.¹⁰ Studies have shown that ~93% of water bottles may be contaminated with microplastics, at levels twice as high or more than those found in tap water.¹⁵ Metal and glass materials are chemically inactive and do not react when in contact with food, offering a safer alternative to plastic.¹⁵ Using reusable metal or glass drinking bottles is a great first step. Secondly, taking steps to reduce plastic trash in the environment and landfills can help protect from large amounts of future exposure which have been projected if the current trajectory is not changed.¹⁰ 

Takeaways for providers

Hydration and water safety should be an important focus of education for patients, especially active clients who are at increased risk of dehydration. From asking about fluid intake on intake forms or during initial appointments, to setting goals around better meeting hydration needs through personalized hydration assessments and intake recommendations, healthcare professionals can help their clients improve both physical and mental/emotional well-being by getting enough fluid daily. Patients can be encouraged to consume filtered tap water from reusable metal bottles or glasses rather than relying on plastic water bottles which could leach microplastics into their cells and tissues more easily and at higher levels. While exposure to microplastics is still an emerging area of research, studies indicate potential dangers to human health. Safe hydration is an easy way for healthcare providers to empower their patients to reduce their risk while focusing on adequate water intake to support their activities.

References:

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