The Built Environment and Pediatric Health

Community design elements such as buildings, parks, and roads (all part of what is called the “built environment”) influence children’s physical and mental health, as well as health equity. This technical report will focus on urban design and, to a lesser extent, rural environments, because a preponderance of research addresses urban settings and because most children live in cities and metropolitan areas. However, unique aspects of the rural built environment will be identified that impact child health and that deserve further study.

The built environment contributes to risks of injury, respiratory illness, infectious diseases, mood disorders, and poor birth outcomes, among other child health concerns. These outcomes carry particular relevance to children from low-income and historically marginalized communities, who suffer disproportionate harms from them.^1,2  There is substantial evidence that discriminatory housing, lending, and investment policies and practices underlie these disparities.^3–5  For example, racist housing and lending policies, known as “redlining” (from New Deal-era neighborhood maps outlining areas considered high risk for investment—largely Black neighborhoods, as well as other neighborhoods with historically marginalized populations—in red), resulted in systematically disinvested, disadvantaged, segregated neighborhoods that continue to bear disproportionate exposures to environmental health hazards.⁶  Racial discrimination in mortgage lending and racial disparities in homeownership persist today.^7,8 

During the 20th century, American families’ shift from cities to suburbs and to cars for transportation fundamentally changed how children live.⁹  With commercial and governmental promotion of home and automobile ownership, along with zoning laws originally designed to separate residential neighborhoods from industrial pollution, more space and land were required to implement this community design strategy. As a result, residential communities often are distant from commercial areas, schools, places of employment, and other regular destinations. These changes in community design and lifestyle occurred in parallel with increases in obesity, asthma, mental health disorders, and other chronic conditions. Importantly, urban highway planning during the mid-20th century reinforced racial segregation: In many American cities, historically Black neighborhoods were often razed to make way for highways, and these multilane roads were placed to create a physical divide between Black and white communities.^10,11  These practices solidified segregation by race and income, economic disenfranchisement, and barriers to access for essential services, including health care, facilitating persistent disparities in social and environmental determinants of health outcomes.

Community design features can mitigate the risk of chronic conditions, promote child health, and advance health equity. Walkways, bikeways, green spaces, and parks provide opportunities for physical activity and social cohesion.^12–15  They also mitigate air pollution,^16,17  as well as traffic-related and other safety risks.¹⁸  Trees and green spaces may benefit mental health, cognitive development, and school performance.^19–22  Access to affordable and healthy food, resilient infrastructure, and features promoting the perception of safety and community connectedness are additional examples of health-promoting community design attributes. Policies that support mixed-income residential development can help to address place-based disparities in access to amenities and services.

Elements of the built environment, including transportation, commercial and residential buildings, and land use all contribute significantly to US greenhouse gas emissions²³  and climate change, which is an urgent health threat that disproportionately affects children.²⁴  The built environment influences resilience to climate-change–related extreme weather events such as severe storms, extreme heat waves, flooding, and wildfires. Climate-smart community design practices (including strategies that are described below to reduce sprawl and increase walking, biking, and public transportation, and to mitigate heat exposure, manage stormwater, and withstand natural disasters) can confer immediate child health benefits, reduce greenhouse gas emissions, and bolster climate change resilience.

This technical report summarizes key child health impacts of community design practices and policies, including but not limited to: Injuries, asthma, birth outcomes, obesity, and mental health. An accompanying policy statement²⁵  provides recommendations for health promotion through community design solutions. Indoor environments, including homes and schools, will be addressed in 2 separate reports and will not be covered here.

Because of the expansion of suburban and exurban (areas beyond the suburbs with typically low housing density and wealthier residents) construction and reliance on automobiles for transportation, road infrastructure is often designed to maximize the speed of car traffic entering and exiting urban centers. High traffic speeds,²⁶  wide road lanes, and lack of safe pedestrian walkways²⁷  contribute to pedestrian injuries. Protective traffic-calming measures can include physical interventions such as speed humps and raised intersections, as well as reduction in the width or number of lanes.²⁸  In 2018, traffic accidents resulted in the deaths of 329 child pedestrians 0 to 14 years of age and 270 teenagers 15 to 19 years of age.²⁹ 

Pedestrian injury from road traffic may be more likely for some children than others because of systemic racism. Risks are particularly high for Black children, who are significantly more likely to experience and be hospitalized for pedestrian injury than non-Hispanic white children.³⁰  Urban, predominantly nonwhite, and low-income residential areas also have been found to have higher rates of child pedestrian injuries.³¹  These racial and socioeconomic disparities may relate to a higher prevalence of large, high-speed roads in low-income urban neighborhoods; lack of access to safe and continuous pedestrian walkways; and possible racial bias in drivers’ yielding to pedestrians.^32,33 

Bicyclists are also at risk from unsafe roadways. Adults 50 to 59 years of age have the highest bicycle fatality rates, but children and adolescents (5–19 years of age) experience the highest rates of nonfatal bicycle accidents, accounting for one-third of all bicycle-related injuries treated in US emergency departments.²⁹  Most bicycle deaths occur in urban areas and not at intersections.³⁴  Bicycle paths and traffic calming measures help to prevent injuries to bicyclists.³⁵ 

Road and pedestrian infrastructure can especially affect the mobility and safety of children with disabilities and special health care needs. When adults with mobility impairment were surveyed, the severity of their self-reported outdoor mobility disability was correlated with road conditions in their neighborhoods—for example, cracks and broken curbs.^36,37  Individuals who use wheelchairs may be at higher risk of fatal traffic injuries because of inadequate road and pedestrian infrastructure.³⁸  Similarly, children with disabilities are significantly more likely to be hit by a motor vehicle as pedestrians or bicyclists than children without disabilities.³⁷ 

Transportation infrastructure that privileges car traffic over other modes of transportation (including walking, biking, and public transit) and that supports urban sprawl (uncontrolled geographic expansion of cities and towns into surrounding undeveloped land, creating suburbs and less densely developed and distant exurbs) also contributes to greenhouse gas emissions that cause climate change.^39–41 

Another major element of the built environment that contributes to childhood injury is playgrounds. Properly maintained playgrounds have child health benefits. However, every year, more than 200 000 playground-related injuries in children younger than 14 years of age are treated in US emergency departments,⁴²  and injuries have been associated with poorly maintained playgrounds with broken or rusted equipment.⁴³ 

Neighborhood risks for lead exposure are related to the age and maintenance of infrastructure, including housing and water service lines that may contain lead. Children of low-income and historically marginalized communities are at disproportionate risk of lead exposure. Between 2007 and 2014, non-Hispanic Black children were about twice as likely to have elevated blood lead levels than white children.⁴⁴  Systematic disinvestment in minority neighborhoods, which occurred through redlining, for example, may be associated with greater neighborhood lead hazards.⁴⁵  Lead poisoning in children is addressed in greater detail in the American Academy of Pediatrics policy statement “Prevention of Childhood Lead Toxicity,”⁴⁶  and will also be addressed, along with other exposure risks more pertinent to indoor environments (such as asbestos and exposures related to drinking water) in separate reports dedicated to healthy homes and schools.

Children’s exposure to pesticides (including herbicides, insecticides, and rodenticides) can occur around residential areas and other outdoor areas. Exposure can occur through dermal absorption, inhalation, contact with mucous membranes, and ingestion, and can cause skin, eye, and respiratory irritation, and allergic reactions. Effects of chronic exposure to pesticides include increased risks of neurodevelopmental problems, cancer, and birth defects.⁴⁷  On the basis of animal and human epidemiologic studies, chronic pesticide exposure can have endocrine-disrupting effects that can alter the timing of puberty.^48–51 

Children can be exposed to herbicides, which are used to kill unwanted plants, in places where they walk, play, and ride bicycles, including lawns, gardens, parks, athletic fields, and along roadways. “Green landscaping” practices can be employed to minimize the use of chemical herbicides and can include strategies such as the use of pesticide-free fertilizers and mulch and cultivating fields and parks with a diversity of species (as opposed to single varieties of grass). These practices can be used in public spaces and encouraged or required to be employed in residential communities.

Although insecticides and rodenticides can have benefits in controlling pests, including those that transmit disease, exposure to chemical insecticides can also cause acute and chronic toxicity in children. These chemicals result in large numbers of toxic exposures to children in the United States. In 2018, for example, approximately 35 000, or 4% of all reported toxic ingestions in children 5 years or younger, involved pesticides.⁵²  The need for the use of many of these chemicals has grown less clear over time as new methods of insect and animal control have shown equal or greater efficacy without risks of toxic exposure. Integrated pest management (IPM) describes the use of a combination of chemical and nonchemical methods to minimize toxicity of pest control methods. Nonchemical methods include physical and mechanical barriers and pest-restricting agricultural planting strategies. Regular pest monitoring can also be used to determine the need for additional interventions, and chemical treatments are chosen and timed to maximize efficacy while minimizing hazards to people and the environment. Studies have demonstrated that IPM is superior in efficacy to conventional pest control methods in many settings and can reduce exposure to pesticides.⁵³  In buildings, for instance, studies have shown IPM to be superior to pesticide use for control of cockroaches, mice, and allergens.⁵⁴ 

The wood preservative chromated copper arsenate, used in pressure-treated wood, was banned for residential use in 2004, but older outdoor wood structures, including playground equipment, may still contain arsenic, which is a known human carcinogen.⁵⁵  Of note, there is little evidence that chromated copper arsenate transferred from the wood via hand-to-mouth is a significant source of arsenic exposure.⁵⁶ 

Measurement of soil hazards is important when making siting decisions and determining the need for mitigation measures for residential, agricultural, and recreational (eg, parks and athletic fields) development. Children can be exposed to contaminants in soil through hand-to-mouth behaviors, inhalation, dermal contact, and contamination of produce grown on a polluted site. Hazardous waste from previous industrial or agricultural use must be treated. For example, toxic heavy metals such as lead, arsenic, and cadmium are common soil contaminants. Mitigation can include covering or replacing soil, use of raised beds for planting, and selection of crops that are less likely to become contaminated (for example, avoiding root vegetables).

Recycled tire crumb, or crumb rubber, is used for synthetic turf on sports fields, and on playgrounds as a cushioned surface. This material has been the subject of concern because tires may be manufactured with or acquire hazardous chemicals and heavy metals, including lead. Questions have been raised about potential exposure to these chemicals from playing on crumb rubber surfaces. Ongoing studies from the US Centers for Disease Control and Prevention, Environmental Protection Agency, and Consumer Product Safety Commission seek to better characterize exposures and health implications from crumb rubber surfaces.⁵⁷ 

Roughly 1 in 7 children worldwide and 1 in 5 children in the United States with asthma develop the disease because of exposure to outdoor air pollution. For children living in cities, air pollution is responsible for a far greater share of asthma diagnoses, with air pollution accounting for 1 in 7 asthmatic children worldwide and nearly 1 in 5 in the United States, with even higher incidence among children living in certain cities.^58,59 

Where children live is strongly associated with their exposure to air pollution. Living downwind of major roadways (particularly those with higher percentages of diesel-fueled vehicles) or near fossil fuel extraction, processing, or combustion sites such as power plants and factories, as examples, has been shown to increase exposure to air pollutants associated with asthma incidence and severity.^60–62  Other important sources of asthma-inducing air pollution include idling vehicles (eg, school buses and cars in attached garages), as well as neighborhood construction sites.⁶³ 

Cities may have higher concentrations of particulate matter and ozone air pollution, each of which can contribute to asthma exacerbations. Particulate matter pollution can have many sources, including regional power plants that are upwind, but in many cities, local roadway and buildings are often major sources of fossil fuel burning and particulate matter. Ozone is formed from a mixture of chemicals, known as ozone precursor chemicals, that can be produced from burning fossil fuels (eg, gasoline or diesel) that get exposed to UV light and heat. Many parts of cities may be warmer than surrounding areas because they have darker surfaces that absorb more heat, which results in what is known as the urban heat island effect. Warmer temperatures promote more ozone formation. Cities also tend to have more fossil fuel combustion, which provides for more ozone precursor chemical formation, as well as higher urban carbon dioxide (CO₂) concentrations, known as “CO₂ domes,” that can contribute to urban heat and ozone formation.⁶⁴ 

Exposure to outdoor air pollution does not occur equally for all children. Studies have routinely found that poorer children, children of color, and especially Black and Hispanic children, breathe more polluted air.⁶⁵  Children of color are more likely to live near road traffic and be exposed to more traffic-related air pollution and pollution from power plants.⁶⁶ 

Airborne pollen and mold or mold spores are common triggers of allergy symptoms among the 1 in 7 children in the United States with hay fever or respiratory allergies. Exposure to these allergens is influenced by the built environment. As a result of climate change, pollen seasons are growing longer and more intense. The pollen season may be one or several weeks longer today than it was decades ago because of warming temperatures.⁶⁷  In addition, urban heat islands make many parts of cities warmer than surrounding areas. Higher atmospheric CO₂ levels that have resulted from burning fossil fuels and other sources of greenhouse gas emissions also promote greater pollen production from allergenic plants, such as ragweed.⁶⁸  Just as with heat, concentrations of CO₂ in the air can be higher in cities than surrounding areas because of concentrated fossil fuel combustion.⁶⁹  Warmer temperatures and higher CO₂ concentrations can extend pollen seasons and raise pollen counts higher than in surrounding areas.⁷⁰  Even within cities, exposure to allergenic pollen can vary widely and can be heavily influenced by the amount of vegetation present in a neighborhood.^71,72  Some evidence suggests that children raised in more urban environments may be more likely to become sensitized to allergenic pollens,⁷³  and greater tree canopy around a prenatal address has been associated with greater likelihood of allergic sensitization to tree pollen.⁷⁴  Given the potential of urban trees to contribute to allergies, guides have been developed to identify low-pollen–bearing plants and tree species for urban tree-planting campaigns.⁷⁵ 

The built environment also contributes to risks of flooding and mold exposure. The balance of relatively impervious surface to green space, the capacity and functionality of storm sewer systems, and water impoundments such as levees and dikes all factor into local risks for flooding when storms occur. Whatever vulnerabilities the built environment creates to flooding may be amplified under the influence of climate change, which is expected to increase the odds of heavy downpours.⁷⁶  Mold growth follows after floods, and exposure to molds can result in allergic dermatitis, asthma exacerbations, and allergic rhinitis.^77,78 

The communities where children live influence their chances of contracting infections. Particulate matter air pollution, which most children are exposed to from exhaust from vehicles, factories, and power plants, has been found to increase the incidence of respiratory infections in children.^79,80  Respiratory infections also are readily spread in overcrowded apartments and homes, as has been observed during the coronavirus disease 2019 pandemic.^81,82  Overcrowded residences may result from a lack of affordable housing, especially in cities.⁸³ 

Outbreaks of waterborne diseases, including bacterial dysentery, hepatitis A, cryptosporidiosis, and giardiasis have been associated with heavy rainfall and floods,^84–86  which are occurring more frequently in many regions as a result of climate change.⁷⁶  Children living in communities with combined sewer systems (ie, with sewage and stormwater runoff using the same drainage pipes) or who have private wells that supply water may be more at risk for waterborne disease after heavy rainfall.^87,88 

Runoff from rainfall can capture crop fertilizer and other sources of plant nutrients on land and deliver them to coastal areas and promote the development of harmful algal blooms. These events were rare in the early part of the 20th century and are now commonplace along the US oceanic coasts and in the Great Lakes, because climate change has resulted in both increased frequency of heavy rainfall and increased water temperature, which together create conditions conducive to algal blooms. Algal toxins can cause rashes and, if ingested, systemic symptoms including vomiting, diarrhea, and numbness and tingling. Algal toxins can also aerosolize and trigger asthma and dyspnea.^89,90 

Elements of the built environment also influence the spread of vector-borne diseases. Lyme disease most often occurs in fragmented forest ecosystems, and suburban sprawl has been a major factor in forest fragmentation, as well as situating people in high-risk ecosystems where they are more likely to contract the disease.^91,92  Urbanites are not immune from Lyme disease, and urban parks that have higher connectivity to other green space may harbor a greater prevalence of infected nymphal ticks.⁹³  Urbanized areas appear to also be higher risk for West Nile virus infection, the most common mosquito-borne disease in the United States.⁹⁴  Climate change may have already, and is anticipated to, accelerate a shift in the habitats where insect disease vectors may live. Some currently meteorologically unfavorable areas for their presence may become more favorable, whereas other areas that are now suitable for insect vectors may become less so with climate change.⁹⁵ 

When the built environment is conducive to the proliferation of disease vectors, pesticide use may increase. Children may be exposed to insecticides when aerial spraying of insecticides is used to contain outbreaks of mosquito-borne diseases. Aerial spraying of insecticides occurred with the emergence of West Nile virus and Zika virus in the United States and has often been used with outbreaks of eastern equine encephalitis. The fetal and childhood toxicity of the insecticides applied, which include Malathion (New York City for West Nile virus 1999), Naled (Miami for Zika 2016), Anvil 10 + 10, or permethrin (Massachusetts for eastern equine encephalitis 2020), has not been well studied.

There is substantial evidence to support a relationship between community design and weight-related behaviors and obesity.¹³  The majority of research defines a child’s built environment on the basis of geographically defined or perceived area around their place of residence. However, school and child care centers also influence obesity risk in children.^96–98  Community design features related to obesity and weight-related behaviors include the recreational built environment, the food environment, air quality, and socioenvironmental factors.

The recreational built environment refers to the features of urban design that may promote physical activity and thereby decrease obesity risk. These features include the presence of green spaces or parks and recreational facilities.¹⁴  Parks and green spaces appear to benefit child physical activity and obesity.^99–101  The recreational built environment can also foster active transportation through sidewalks and adjacent commercial and residential areas that allow for easy pedestrian or cycling access. Pedestrian safety features, such as traffic calming areas, can also encourage walking.^14,102  Similarly, paths for bikes, strollers, and wheelchairs render physical activity more accessible to children and adults with diverse needs¹⁰³  and, thus, encourage child and family physical activity. Access to public transit also promotes physical activity and has been linked with lower obesity risk.¹⁰⁴ 

Community design can also support active transit to school, which increases physical activity.¹⁰⁵  Neighborhood walkability, mixed-land use, and street connectivity, as well as coordination with supervising adults, facilitate the success of active transit programs such as Safe Routes to School and Walking School Bus. Such initiatives can promote physical activity and teach children about traffic safety in urban and rural areas.^106,107 

The food environment, defined as the environmental factors that influence the purchase or consumption of food, also influences childhood obesity risk. Although there is substantial variability because of differences in measurement, a handful of studies have shown a relationship between the food environment and child diet.^108,109  Additionally, the quality of the food environment appears to be associated with child obesity independent of parent weight status, suggesting a direct influence between the local food environment and obesity risk.¹¹⁰  Proximity to grocery stores, fast-food restaurants, and corner stores is associated with childhood obesity risk,^111,112  with grocery stores buffering and fast-food restaurants and corner stores promoting obesity. Some evidence suggests outdoor food advertising may play a role in family and child dietary intake.¹¹³  Although the relationship between obesity and climate change is complex, some studies have proposed that alterations in food supply and prices attributable to climate change may contribute to obesity risk by reducing access to affordable healthy food.¹¹⁴ 

Air pollution from road traffic, from industrial sources, or within homes also contributes to child obesity risk and metabolic syndrome.^115,116  Exposure to particulate matter with a diameter of ≤2.5 μm (particulate matter_2.5) is associated with elevated systolic blood pressure in children. Exposures to particulate matter _2.5 and particulate matter with a diameter of ≤10 μm (particulate matter ₁₀) are associated with elevated fasting blood glucose levels. Ongoing lifetime exposure to air pollution, including in utero exposure, may increase children’s risk for cardiometabolic disease in adulthood.¹¹⁷ 

Socioenvironmental factors affect the relationship between community design and obesity.^118,119  How individuals perceive the built environment may alter how they engage with it.^120,121  Safety is the most cited socioenvironmental factor influencing perceptions of the built environment.^118,122  Safety is an individual’s perception of their own risk of being involved in undesired or criminal activity.¹²²  A lack of perceived safety can reduce the use of recreational features in the built environment even when they are accessible. Similarly, neighborhood disorder (the presence of unsafe or poorly maintained built environment features, drug paraphernalia, or criminal activity) can discourage the use of parks, playgrounds, and other built environment features that promote physical activity.¹⁰²  Finally, built environment use may depend on whether individuals feel that they belong within specific spaces such as playgrounds and recreational facilities.^107,123  Any messaging indicating that an individual is not welcome because of age, ability, race/ethnicity, gender, or sexual orientation can diminish the appeal and use of a park, playground, or other recreational facility.

Urban community design may differ depending on racial, ethnic, or socioeconomic characteristics, which may contribute to a higher prevalence of obesity in certain groups including Black, Hispanic, and low-income children. Black, Hispanic, and low-income children are more likely to live in neighborhoods with a dearth of safe opportunities for recreation and healthy, affordable food choices.^124,125  Perceived safety, affordability, and a sense of inclusion also may limit access to health-fostering community design features for nonwhite children and families.¹⁰⁷ 

The built environment has been found to influence mental health from early childhood through young adulthood.^126,127  Cognitive development and school performance are also connected to built environment characteristics. Built environment characteristics linked to mental health, cognitive development, or school performance outcomes include green spaces, neighborhood disorder, extreme heat and air, and noise and light pollution.

When asked to describe factors that contribute to their own self-defined well-being, children associated open natural spaces with calmness and relaxation.^29,128  These qualitative findings are supported by studies demonstrating that nature exposure improves blood pressure and cortisol, physiologic indicators of stress.^129,130  The term “biophilic design” is often used to describe a design approach that includes natural elements, and promotes contact with nature—biophilic design can include green spaces such as parks but can also include urban trees, organic elements in streetscapes, and ecological restoration.

Access to neighborhood green spaces including parks and playgrounds may reduce mental health problems including hyperactivity and inattention, internal/externalizing behavior, and depression.^19,20  A study of nearly 1 million Danish children found that children who grew up in neighborhoods in the highest quartile of green space around their homes had nearly half the rates of mental health diagnoses later in life after accounting for other predictors of mental health outcomes including socioeconomic factors, parental history of mental illness, and parental age.¹³¹ 

Community design elements that promote positive sensory and social interactions can encourage the communal use of public spaces and promote social cohesion and their attendant benefits. Green spaces can promote social interaction, autonomy, and self-efficacy for children, which may promote healthy social development. Community green spaces may serve as places for caregivers to congregate and develop supportive relationships and share knowledge.^15,132  Children’s enjoyment of walking to school is affected by the quality of natural, recreational, or retail spaces on their route.¹³³ 

Beyond mental health outcomes, green space has been considered as a possible determinant of cognitive and developmental outcomes, including working memory development, attention, and self-regulation.^21,134  Green space exposure has been linked to improved academic performance among primary school children. However, evidence for this association is mixed.^135,136  High school students randomly assigned to classrooms with views of green spaces demonstrated better stress recovery and attentional functioning than children without views of green spaces.¹³⁷  Similarly, teaching in outdoor spaces has been associated with improvements in reading performance and school motivation.^22,138  Outdoor exposure in school-aged children has been linked to decreased myopia.¹³⁹  These studies collectively highlight the importance of playgrounds and school outdoor green spaces for child health. Similar to mental health, associations between green space and cognitive development may be mediated by decreased traffic-related air pollution, noise reduction, or increased physical activity.¹⁴⁰ 

Although less well studied than other aspects of the built environment, neighborhood disorder, which may be defined as “observed or perceived physical and social features of neighborhoods that may signal the breakdown of order and social control,”¹⁴¹  is also a potentially important contributor to child mental health. Neighborhood disorder is associated with impaired child functioning and depression.¹⁴²  Neighborhood disorder may also contribute to adolescent risk-taking behavior.¹⁴³  Notably, neighborhood social cohesion or mutual trust among neighbors may protect against child mental health harms of neighborhood disorder.¹⁴⁴ 

Although the causes of neighborhood disorder are multifactorial and systemic, built environment features may play an important role in improvement and prevention. Community infrastructure, such as parks, painted and marked crosswalks, and maintained vacant lots, can influence the perception of safety and benefit mental and behavioral health. These features are associated with a reduction in adolescent homicides, perhaps because of an interplay of factors including greater physical activity and social interaction.¹⁴⁵ 

School performance and learning can also be negatively impacted by extreme heat, with students from low-income families or historically marginalized populations in the United States being disproportionately affected.¹⁴⁶  These students are more likely to attend schools without air conditioning, and neighborhoods that have been historically redlined or marginalized experience higher urban heat island effects.¹⁴⁷  Heat exposure may contribute to and worsen disparities in educational attainment, whereas community design features that reduce heat exposure, such as tree canopy,^16,17  green spaces, shading, and less absorptive building materials, might reduce them. Exposure to extreme heat may also influence mental health; for example, higher ambient temperatures are associated with increased suicide risk.¹⁴⁸  As a result of climate change, heat waves are becoming more frequent and severe in many parts of the country.¹⁴⁹ 

Exposure to ambient air pollution, even prenatally, is associated with decrements in memory and attention,¹⁵⁰  lower cognitive outcomes,¹⁵¹  neurodevelopmental and psychiatric disorders such as autism and schizophrenia,^67,152  and disruptions in sleep.¹⁵³  Community design decisions such as transportation planning influence the degree of air pollution and also influence racial and economic disparities in exposure to pollution sources, and may contribute to disparities in neurodevelopment and school performance.

Evidence linking noise pollution to learning is substantially more limited than for air pollution, but research has found lower reading comprehension and elevated blood pressure in children, a marker of stress, when they are exposed to noise.^154–156  Similarly, light pollution may affect children’s circadian rhythms, resulting in sleep disorders, and potentially affect mental health.¹⁵⁷ 

Eating breakfast, micronutrient sufficiency, and healthy dietary patterns have been demonstrated to be associated with healthier neurodevelopmental outcomes in children,¹⁵⁸  with impacts on school performance, learning, cognition, and behavior. Although the determinants of healthy dietary patterns are multifactorial, the relationship between the food environment and children’s diets was described earlier. The food environment, therefore, can play a role in children’s cognitive development and academic performance.

Racial, ethnic, and socioeconomic disparities in mental health, cognitive development, and academic performance are well described.^159–161  Data are lacking to describe how these disparities may depend on differential access to health-promoting community design based on race, ethnicity, or socioeconomic status.^162,163  The effects of green spaces may differ by population, because certain populations may have less ability to travel farther from home because of financial limitations, and the environments nearest their homes, schools, or places of work may be noxious.^164,165  Communities designed for racial and economic segregation also contribute to educational inequities through disparities in funding and resources for public school districts. Mixed-income residential development may help to mitigate these disparities. Additional research can further describe how green spaces and other health-promoting built environment features may shape disparities in mental health, cognitive development, and school performance, and identify the populations who would benefit most from improved access to these features.

Exposure to air pollution during pregnancy, including nitrogen dioxide, particulate matter₁₀, and particulate matter_2.5, increases the risk of low birth weight and preterm birth.¹⁶⁶  In addition, proximity to industrial and vehicular sources of these air pollutants disproportionately impacts Black and Hispanic communities.¹⁶⁷  Prenatal traffic-related noise exposure is also associated with increased risk of preterm birth¹⁶⁸  and low birth weight.¹⁶⁹  These findings have implications for the siting of residential development, planning traffic patterns, investing in multimodal transportation, and urban tree canopy as strategies that can contribute to improving birth outcomes.

Maternal nutritional status, obesity, and stress may increase risk for low birth weight and preterm birth. Community design features influence access to healthy food, opportunities for physical activity, and air quality, all of which impact maternal nutrition and obesity. Exposure to extreme heat is also associated with increases in preterm birth, stillbirth, and infant death.^170,171  Historically redlined neighborhoods have been shown to be associated with increased risk of adverse birth outcomes,^172,173  possibly because of higher stress environments that include disproportionate exposure to heat,¹⁴⁷  unsafe housing, deficits in safe outdoor public spaces, and barriers in access to transportation and essential amenities.

Mixed-income residential development can provide collective benefits for safety, community resources, and shared amenities. However, gentrification of low-income neighborhoods can result in displacement of low-income families and other challenges that can affect child health.¹²⁴  The rising price of housing, food, and other commodities in gentrifying neighborhoods can lead to housing insecurity and food insecurity. Gentrification has been linked to higher incidence of preterm birth among non-Hispanic Black populations, as well as child anxiety.^174,175  Furthermore, gentrification and resulting displacement may lead to the disruption of potentially protective social networks which provide support for low-income families and families of color.¹²⁴  Because gentrification disproportionately affects non-Hispanic Black and low-income families, gentrification has the potential to worsen existing health inequities and is an important multidisciplinary equity concern that warrants ongoing research.¹⁷⁶  The negative effects of gentrification may be decreased by policies that foster mixed-income housing developments and cooperative land ownership.¹⁸ 

Nearly 20% of US children live in rural areas. The effects of community design on the health of rural children are understudied. Rural children have less access to pediatric care, and nearly 1 in 3 rural counties have no pediatrician.¹⁷⁷  They are more likely to have obesity, suffer injuries, and die in infancy.^178–180  Unique aspects of rural communities’ design may contribute to these outcomes. High vehicular speed, unleashed dogs, and fewer destinations within walking distance may impact the physical activity and risk of injury of rural children.¹⁸¹  Rural children may have less access to grocery stores. Between 1990 and 2015, the percentage of rural counties with fewer than 8 food retailers per 10 000 people increased from 11% to 27%, and the number of food retailers per capita decreased by 19%.¹⁸² 

Most agriculture occurs in rural communities, and agricultural practices may result in excess exposures to certain harmful exposures, including fumes from fertilizers, diesel exhaust from machinery, ammonia air pollution from livestock, and water pollution from agricultural runoff.¹⁸³  Rural communities are also more likely to rely on well water, which may expose children to chemical pollution and pathogens.¹⁸⁴ 

Patterns of injury differ between urban and rural children. Rural children are more likely to be injured in a motor vehicle accident and die by suicide than urban peers.¹⁷⁸  Rural children may also have more severe traffic-related pedestrian injuries than urban children.¹⁸⁵  Rural–urban differences in the built environment and effects on child health underscore the need for more research on rural community design and child health.¹⁸⁶ 

Built environment elements including transportation infrastructure, zoning practices, and parks and green space, as well as development practices resulting in racial and economic segregation, can have profound effects on child health. These aspects of community design affect the most pressing health challenges facing American children, such as obesity, asthma, and mental health disorders. Persistent place-based health inequities are influenced by community design practices that perpetuate disparities in access to clean air, safe housing, and essential amenities and services. Because these inequities have been created by design, they can be undone through design solutions. The built environment also forms a cornerstone of climate change mitigation and resilience. Pediatricians’ understanding of how community design and the built environment affect their patients’ health can contribute to higher quality care and better advocacy for communities that are designed to protect and enhance the health of all children.

Aparna Bole, MD, FAAP

Aaron Bernstein, MD, MPH, FAAP

Michelle J. White, MD, MPH, FAAP

Aparna Bole, MD, FAAP, Chairperson

Sophie J. Balk, MD, FAAP

Lori G. Byron, MD, FAAP

Gredia Maria Huerta-Montañez, MD, FAAP

Philip J. Landrigan, MD, FAAP

Steven M. Marcus, MD, FAAP

Abby L. Nerlinger, MD, FAAP

Lisa H. Patel, MD, FAAP

Rebecca Philipsborn, MD, FAAP

Alan D. Woolf, MD, MPH, FAAP

Lauren Zajac, MD, MHP, FAAP

Kimberly A. Gray, PhD – National Institute of Environmental Health Sciences

Jeanne Briskin – US Environmental Protection Agency

Nathaniel G. DeNicola, MD, MSc – American College of Obstetricians and Gynecologists

CDR Matt Karwowski, MD, MPH, FAAP – Centers for Disease Control and Prevention National Center for Environmental Health and Agency for Toxic Substances and Disease Registry

Mary H. Ward, PhD – National Cancer Institute

Paul Spire

Nia Heard Garris, MD, MSc, FAAP, Chairperson

Kimberly Brown, MD, FAAP

Nathan Chomilo, MD, FAAP

Nathaniel Jones, MD

Patricia Rodriguez, MD, FAAP

Valencia Walker, MD, FAAP

Ngozi Onyema-Melton

We thank Mr David Jurca, an urban designer, whose expertise and insight informed the research and development of this manuscript.

CO₂

carbon dioxide

IPM

integrated pest management