Principles of Pediatric Environmental Health
What Are Factors Affecting Children's Susceptibility to Exposures?
CE Original Date: February 15, 2012
CE Renewal Date: February 15, 2014
CE Expiration Date: February 15, 2016
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Upon completion of this section, you will be able to
Children's caregivers have a direct effect on child safety. And health caregivers are entrusted to protect children from danger as well as consult child health care providers when appropriate. A child relies on adults for protection from such toxic exposures
Having access to an excellent caregiver is essential for a child's optimal growth and development. Even if a child has excellent caregivers, however, he or she is often at increased risk from environmental exposures, especially when compared with adults. Among a caregiver's responsibilities is protection of children from environmental hazards.
Exposures and vulnerabilities
Compared with adults, children's exposures put them at greater risk for harm from exposure to environmental hazards. Their vulnerabilities to exposure include
Opportunities for exposure-related change increase as a child grows from total dependence on parents or other caregivers to adolescent independence. Socioeconomic circumstances, diet, behaviors, life-stage development, and environmental regulations can restrict or augment pediatric exposure risks.
Multiple factors enhance a child's opportunity for exposure. Children may experience exposures in a wide range of settings including home, child care, school, and play environments.
Examples of children's increased exposure risk
In a home contaminated with mercury (e.g., caused by spillage or mercury carried home on work shoes), a toddler's high respiratory rate, proximity to surfaces likely to be contaminated, and playful rolling around on the floor will increase the risk of mercury exposure. Other possible contaminants that settle near the floor are
And children crawling on a lawn may come into contact with lawn chemicals, pesticides and herbicides.
Infants and children's behaviors and activities often increase exposures. Oral exploratory behavior, hand-mouth behavior, poor hand washing, and curiosity in exploration all contribute to a child's increased risk of contaminant exposure.
Children who eat nonfood items exhibit pica behavior. Soil pica may involve the recurrent ingestion of unusually high amounts of soil (i.e., on the order of 1,000 milligrams (mg)-5,000 mg per day). Groups at risk of soil-pica behavior include children age six years and younger, and children who are developmentally delayed. The Agency for Toxic Substances and Disease Registry (ATSDR) uses 5,000 mg soil per day as an estimate of soil intake for children with soil-pica behavior [ATSDR 2001a]. Other studies, including Binder et al. , have demonstrated that through normal outdoor play, children have a soil intake of about 180-1800 mg/day.
Because of socioeconomic disparities, more children live in poverty than any other age group in the United States. Their families are more likely to live in public housing or in neighborhoods in close proximity to industry, with higher degrees of environmental contamination. For example, children living in poverty-ridden urban areas may be exposed to benzene, a gasoline component and a known carcinogen. Benzene levels in air correlate with heavy automobile traffic; children playing in the streets in poor neighborhoods have disproportionately high exposures [Weaver et al. 1996].
Parents of children living in poverty often have no access to healthcare services. Asthma and atopic disease are often underdiagnosed. The prevalence of physician-undiagnosed asthma among urban Detroit schoolchildren in 3rd to 5th grade was estimated as high as 14.3% [Joseph et al. 1996]. The prevalence of asthma among children living in the Bronx, NY, was found to be twice the U.S. average, with higher prevalence rates among both Hispanic and lower-income groups [Crain et al. 1994]. Childhood asthma may have racial as well as socioeconomic determinants, with black children - independent of income - generally more affected than whites [Weitzman et al. 1992; Cunningham et al. 1996].
Socioeconomic status accounts for racial and ethnic disparities in childhood lead poisoning. Lead poisoning is found disproportionately among black and Hispanic children exposed to lead-containing dust found in older, dilapidated housing. New immigrants and migrant families are more likely to live in low-cost, hazardous housing. These families are often unfamiliar with, or are unable to access the community's health system or other services for their children [CDC - NCEH 2011].
Hazardous waste sites and landfills are frequently located in or near to poorer neighborhoods. This disparity has sparked attention to the need for environmental justice.
The U.S. Environmental Protection Agency (EPA) defines environmental justice [Executive Order 12989, EPA 1994] as
In addition to these specific obvious toxic environments, recent substantial scientific evidence has shown that aspects of the "built environment" can have profound, directly measurable effects on physical and mental health, particularly adding to the burden of illness among ethnic minority populations and low-income communities [Hood 2005]. Negative aspects of the built environment include
The "built environment"
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