The outdoor environment immediately surrounding the home is where many children spend a significant portion of their active time — playing on the lawn, touching garden soil, running barefoot through grass, and bringing whatever is on their hands and feet into their mouths with the frequency that characterizes early childhood. The chemical inputs to this outdoor environment — lawn pesticides, herbicides, fertilizers, and the residues from neighbors’ applications that drift across property lines — represent a significant and frequently overlooked category of childhood chemical exposure that parents who carefully manage the indoor environment often have not addressed with the same rigor.
The research on childhood pesticide exposure is among the most concerning in the environmental health literature. Multiple epidemiological studies have found associations between residential pesticide use — specifically lawn and garden pesticide application — and increased rates of childhood leukemia, brain tumors, and non-Hodgkin lymphoma. A 2015 meta-analysis published in Pediatrics found that home pesticide exposure was associated with a 47% increased risk of childhood leukemia. The National Institutes of Health’s Agricultural Health Study has documented associations between parental pesticide exposure and childhood cancer that are consistent with a causal relationship between residential pesticide use and pediatric malignancy.
The mechanism of particular concern is the route of exposure for children playing on treated outdoor surfaces. Children playing on a lawn treated with pesticides — even several days after application — contact residues on grass and soil with their hands, transfer them to their mouths directly or via food, and inhale volatilized compounds at ground level where concentrations are higher than at adult breathing height. The combination of more time at floor or ground level, more frequent hand-to-mouth behavior, higher respiration rates per unit of body mass, and less mature detoxification capacity makes children’s pesticide exposure from residential lawns qualitatively different from adult occupational exposure.
The transition to a pesticide-free lawn management approach is more accessible than most homeowners assume. Healthy soil that supports dense, deep-rooted turf grass naturally crowds out the weeds that pesticides are used to manage. The transition typically involves a period of soil improvement — aeration, overseeding with appropriate grass varieties for the climate and sunlight conditions, top-dressing with compost, and adjusting watering schedules to encourage deep root development — followed by a significant reduction in the weed pressure that drives pesticide use in the first place. Organic alternatives to conventional pesticides exist for specific pest and disease management needs that arise in the transition period.
The shoes-off policy at the home entry is the most effective single practice for preventing the transfer of outdoor pesticide residues to indoor surfaces. Research has consistently documented that the majority of pesticide residue found on indoor floors arrives via shoe soles. The combination of a pesticide-free or reduced-pesticide outdoor management approach with a shoes-off indoor policy addresses both the outdoor exposure and the route by which outdoor residues contaminate the indoor environment where children spend even more time.
The outdoor environment is not separate from the health of the home. It is the threshold between the home and the world, and the chemical management decisions made in that threshold space have direct consequences for the children who move between them continuously throughout the day.