Water & Children

One of the most important factors in understanding how children interact with household water is body weight. A young child may weigh only a fraction of what an adult weighs, yet they can consume a comparable volume of water relative to their size. For example, an infant who drinks formula mixed with tap water may take in significantly more water per pound of body weight than an adult drinking from the same tap throughout the day.

This proportional difference means that any substance present in water -- whether naturally occurring minerals, disinfection byproducts, or trace contaminants -- is encountered at a higher ratio relative to body mass in children compared to adults. Public health researchers often refer to this as a higher "dose-to-weight" ratio. It does not necessarily mean that something harmful is occurring, but it does mean that children and adults are not experiencing the same water supply in exactly the same way.

Being aware of this proportional difference can help parents and caregivers make more informed choices about the water used for drinking, cooking, and preparing infant formula -- particularly in households where water quality has not been recently tested.

Children are not simply smaller versions of adults. Their bodies are actively growing and developing, and many of the biological systems responsible for processing and filtering substances are still maturing. The kidneys, liver, digestive tract, and neurological pathways all undergo significant development during infancy and early childhood.

Because these systems are still forming, children may process substances differently than adults do. The rate at which the body absorbs, distributes, and eliminates various compounds can vary at different stages of development. This is a well-understood principle in pediatric science and is one reason why recommended guidelines for children often differ from those established for the general adult population.

This does not mean that tap water is inherently unsafe for children. Municipal water systems in the United States are regulated to meet safety standards under the Safe Drinking Water Act. However, understanding that children's developing bodies interact with their environment differently than fully mature adult systems can help families approach household water with an appropriate level of awareness and care.

Lead in household water is not typically an issue with the water source itself, but rather with the plumbing that delivers water to the tap. Homes built before 1986 are more likely to have lead solder, lead pipes, or brass fixtures that contain lead. In some communities, lead service lines -- the pipes connecting a home to the public water main -- remain in use, particularly in older cities and neighborhoods.

When water sits in contact with lead-containing plumbing materials for extended periods, small amounts of lead can leach into the water. This is more likely to occur with hot water, water that has been stagnant overnight, or in systems where water chemistry is particularly corrosive. The EPA and many water utilities apply corrosion control treatments to reduce this risk, but the effectiveness can vary depending on local conditions and the age of the infrastructure.

Young children are a population of particular interest in discussions about lead in water because of the developmental factors discussed above. The EPA has set an action level for lead in drinking water at 15 parts per billion, while many public health organizations advocate for even lower thresholds when children are present in the household. Knowing the age and material of your home's plumbing is a practical first step toward understanding your household's specific context.

Young children, especially infants and toddlers, are typically bathed frequently -- often daily or even multiple times per day. These baths can involve extended periods of full-body immersion or sustained skin contact with water, which is different from the quick showers that many adults take.

During bath time, children may also inadvertently swallow small amounts of water, particularly during play. Warm bath water can also release certain volatile compounds into the air in an enclosed bathroom, where both the child and the caregiver may breathe them in. Chlorine and chloramine, commonly used as disinfectants in municipal water, are among the substances that can become airborne in warm, steamy environments.

None of this is cause for alarm. Municipal disinfection is an important public health measure that has dramatically reduced waterborne illness. However, understanding that bath time represents a unique form of water interaction for young children -- combining skin contact, potential ingestion, and inhalation -- can help parents think holistically about their family's relationship with household water.

A child's skin, particularly in infancy, is structurally different from adult skin. The outermost layer of skin -- the stratum corneum -- is thinner in young children, and the overall skin barrier is still developing. This means that a child's skin can be more permeable, allowing substances to pass through more readily than they would through mature adult skin.

Additionally, children have a higher surface-area-to-body-weight ratio than adults. This means that for their size, more of their body is in direct contact with bath water, clothing washed in tap water, or any other water-related exposure. Combined with the thinner skin barrier, this creates a situation where dermal (skin) contact is a more significant pathway for children than it is for most adults.

Some families notice that their children's skin reacts to changes in water quality -- for instance, appearing drier or more irritated after bathing in water with higher mineral content or stronger disinfectant levels. While individual sensitivity varies widely, this observation aligns with what we know about the developing skin barrier in young children. Paying attention to how your child's skin responds after bathing can be a useful indicator of your household water's characteristics.

There are several straightforward, low-cost practices that families can adopt to be more thoughtful about household water use, especially when young children are present. These suggestions are rooted in general awareness rather than a response to any specific hazard.

Run cold water before use. If water has been sitting in your pipes for several hours -- such as first thing in the morning or after returning home -- let the cold water tap run for 30 seconds to two minutes before using it for drinking or cooking. This helps flush out water that has been in prolonged contact with your home's plumbing materials.

Use cold water for cooking and formula preparation. Hot water is more likely to leach metals from pipes and fixtures. When preparing food, beverages, or infant formula, starting with cold tap water and heating it on the stove or in a kettle is a simple precaution recommended by the EPA.

Know your plumbing. If you live in an older home, consider learning about the materials used in your plumbing system. Your local water utility may be able to tell you whether your area has lead service lines, and a licensed plumber can help identify the materials used within your home.

Flush infrequently used taps. Bathrooms, utility sinks, or fixtures that are not used regularly can accumulate stagnant water. Running these taps periodically helps keep water moving through the system.

Stay informed about your water quality. Most municipal water systems publish annual Consumer Confidence Reports (also called water quality reports) that detail what is in your local water supply. Reviewing this document is a free and easy way to understand what your family's water contains.

These practices are not a substitute for professional water testing, but they represent a reasonable baseline of awareness for any household with young children.