1. Introduction

Many young children spend a large share of their waking hours outside the home in childcare. In the United States, about 8.3 million children under five attend licensed childcare facilities, and some spend around ten hours a day, five days a week, in these settings ^[1]. Childcare takes many forms, including large centers, faith-based and nonprofit programs, Head Start sites, and family childcare homes. Because of this variety, the physical environments children experience in care differ widely in age, construction, location, and upkeep.

Research since the early 2000s has shown that childcare environments can contain measurable levels of lead, pesticides, allergens, and indoor air pollutants ^[2][3][4]. At the same time, environmental standards for childcare have often lagged behind those for schools. Oversight is also spread across licensing, health, fire, and environmental agencies ^[5][6]. Environmental health in childcare is therefore both a scientific concern and a question of regulatory design.

2. Why Young Children Are More Vulnerable

Young children are not simply small adults when it comes to environmental exposure. They breathe, eat, and drink more relative to their body weight than adults do, and their organs and nervous systems are still developing. Their behavior also increases contact with contaminants. Infants and toddlers spend much of their time on or near the floor and frequently put their hands and objects in their mouths, which brings them into close contact with settled dust and soil ^[5]. Exposures during these early years can have lasting effects on development, so preventing exposure in childcare is a priority for children’s environmental health.

3. Major Hazards

3.1. Lead

Lead is one of the most studied hazards in childcare. No safe blood lead level in children has been identified, and even low-level exposure is linked to harm to cognitive development. Older buildings may contain lead-based paint that breaks down into dust and soil. The First National Environmental Health Survey of Child Care Centers sampled 168 licensed U.S. centers. It found significant lead hazards in about 14% of them, which corresponds to an estimated 470,000 children under six ^[2]. A later study of 40 California facilities detected lead in floor dust in nearly all of them, although generally not at levels expected to cause lead poisoning ^[4][7].

3.2. Pesticides

Pesticide use is common in childcare. In the national survey, about three-quarters of centers had applied pesticides indoors or outdoors in the previous year ^[2]. Among centers that reported applications, pyrethroids were the most commonly used. Facilities used between one and ten different products, and some applied them dozens of times a year ^[3]. Integrated pest management (IPM) prevents pests through sanitation, exclusion, and monitoring, and uses the least-toxic chemical controls only when needed. It is widely recommended as a way to reduce children’s exposure.

3.3. Indoor Air Quality

Children in care spend most of their time indoors, so indoor air quality is a central concern. A study funded by the California Air Resources Board measured a broad range of pollutants in 40 childcare facilities. These included volatile organic compounds, particulate matter, pesticides, flame retardants, phthalates, and perfluorinated compounds ^[4][7]. Most pollutant levels were similar to those found in California schools and homes. However, formaldehyde exceeded California health guideline levels in 35 of the 40 facilities ^[7]. Formaldehyde is released from pressed-wood furniture and building materials. For two brominated flame retardants, estimated doses from ingesting dust exceeded the U.S. EPA reference dose for infants in about one in ten facilities [4]. Ventilation, low-emitting furnishings, and cleaning methods that reduce dust were identified as practical ways to reduce these exposures ^[7].

3.4. Radon, Carbon Monoxide, Mold, and Allergens

Radon is a naturally occurring radioactive gas that can build up in buildings, especially in lower levels. Long-term exposure is a leading cause of lung cancer. Carbon monoxide from fuel-burning appliances is an acute poisoning risk. Moisture problems can lead to mold growth, and dust mite and cockroach allergens can trigger asthma and allergies. The national survey found allergen levels associated with asthma and allergic conditions in roughly 5% of centers [2]. U.S. state policies address these hazards very unevenly ^[6].

3.5. Drinking Water

Lead can enter drinking water from plumbing, fixtures, and fountains inside a building, even when the public water supply meets standards. Facilities served by private wells may also face other contaminants. In the United States, the Water Infrastructure Improvements for the Nation (WIIN) Act of 2016 created a voluntary grant program for lead testing in schools and childcare facilities ^[8]. Grantees must follow EPA’s “3Ts” guidance: Training, Testing, and Taking Action. Since 2019, the program has provided more than $150 million for testing and for removing lead sources ^[9].

3.6. Sanitation and Infection Control

Biological hazards are also a core environmental health concern in childcare. Key practices include hand hygiene, safe diaper-changing areas kept separate from food preparation, food safety, and proper cleaning and disinfection of surfaces and toys. These are routine parts of sanitarian inspections. Cleaning also involves a trade-off: frequent use of strong disinfectants can add chemical exposures, which has led to interest in safer cleaning and sanitizing products for childcare ^[5].

4. Site Hazards and Safe Siting

A facility can meet licensing standards and still be located on or near contamination. Examples include former industrial properties, dry cleaners, gas stations, and waste sites. Hazards can come from a site’s past use or from nearby activities that are still releasing pollution ^[10]. The U.S. Agency for Toxic Substances and Disease Registry (ATSDR) notes that most state licensing requirements do not consider environmental exposures. It estimated that about 1.35 million children attend programs that warrant further site evaluation, and about 174,000 children might currently be exposed to harmful contaminants ^[1].

In response, ATSDR developed the Choose Safe Places for Early Care and Education (CSPECE) program. CSPECE provides guidance, checklists, and funding to help states screen sites before and during operation ^[1][11]. Connecticut’s Child Day Care SAFER (Screening Assessment for Environmental Risk) program is an often-cited model. It is a proactive, non-regulatory approach that uses tools such as a property history questionnaire in the license application, inspector referral forms, and well-testing guidance ^[1][12].

5. Regulation and Inspection

In most jurisdictions, environmental conditions in childcare are governed by several sets of rules. These include childcare licensing regulations, building and fire codes, public health codes, and environmental laws. Different agencies may each inspect only part of the relevant hazards, and coordination between them is often limited ^[6]. As a result, a single inspection rarely gives a complete picture of a facility’s environmental risks. Voluntary tools help fill these gaps. They include environmental health checklists and endorsement programs that help providers assess and improve their own practices ^[13].

6. Prevention and Best Practices

Commonly recommended measures include:

• Screening sites for contamination before licensing
• Testing for lead in paint, dust, soil, and water in older buildings
• Testing for radon and installing carbon monoxide alarms
• Using integrated pest management instead of routine spraying
• Choosing low-emitting furniture and building materials and maintaining good ventilation
• Using wet cleaning and HEPA vacuuming to reduce contaminated dust
• Controlling moisture to prevent mold
• Following strong sanitation and food safety practices

Training childcare staff is essential, since many providers have limited background in environmental health ^[5][13].

7. Gaps and Future Directions

Several gaps remain. Family childcare homes and unlicensed care are often outside the scope of environmental screening programs, and the national survey’s findings cannot be applied to unlicensed settings ^[2]. Much of the published evidence comes from the United States. Comparable data are scarce for low- and middle-income countries, where regulatory frameworks may not treat childcare as a distinct high-risk category. Continued research on exposures, better coordination between agencies, and practical assessment tools for inspectors and providers are widely seen as the next steps in protecting children’s health in childcare settings.

This entry is adapted from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3672904/