When it comes to harmful environmental exposures, children cannot be considered “little adults.” Their bodies take in proportionately greater amounts of environmental toxins than adults, their rapid development makes them more vulnerable to environmental interference, and their normal behavior patterns place them at greater risk to some toxins.
Children can be exposed to environmental toxins even before birth if the mother is exposed during pregnancy to toxins that can cross the placenta, such as carbon monoxide or lead. Children’s organs, including the brain, lungs, and reproductive systems, begin developing during the fetal stage and continue to develop through adolescence. Organ growth occurs in spurts, and it is during key growth periods that organ systems are most vulnerable to permanent damage. The Environmental Protection Agency recently acknowledged the enhanced risk to children from environmental exposures when it released draft supplemental guidelines for assessing cancer risk from early-life exposure to carcinogens.
Children are exposed to greater amounts of environmental toxins
Pound for pound, children breathe more air, consume more food, and drink more water than adults, due to their substantial growth and high metabolism. For example, a resting infant takes in twice as much air per pound of body weight as an adult. Subject to the same airborne toxin, an infant therefore would inhale proportionally twice as much as an adult.
Children also drink proportionally more water than adults. Pound for pound, infants and children drink more than 2½ times as much water as adults. A formula-fed infant consumes about one seventh of its body weight in water each day—the equivalent of a 154-pound man drinking nearly 6½ gallons of water per day. Standards for most waterborne contaminants are established based on the health impacts on adults, so current standards may not suffice to protect children.
Children also may be exposed to greater amounts of toxins in the environment due to the fact that they spend significant amounts of time on the floor and ground. As a result, they are more likely to come into contact with toxins found in dust, carpets, and soil, such as lead. Some airborne contaminants, such as radon, mercury, and some pesticide vapors concentrate in greater quantities at ground level, so small children would be exposed to higher concentrations of these toxins than adults in the same room.
Young children (ages six months to about two years) have a natural urge to place objects in their mouths. This normal hand-to-mouth activity can cause them to ingest toxins in their environment to which adults would not necessarily be exposed. For example, in homes with high dust lead levels, children may ingest lead when they put their hands or toys in their mouths. Children also may be exposed to arsenic and creosote, two toxic chemicals used to pressure-treat wood, if they play on playground equipment, decks, or porches treated with these chemicals.
Small children also more readily absorb nutrients (and toxins) they ingest. For example, children require more calcium than adults because their bones are growing, and they can absorb more calcium from the same food sources. Although this enhanced ability is a plus when it comes to nutrients, it also can increase a child’s exposure to toxins such as lead. A toddler will absorb about 50 percent of ingested lead, whereas an adult will absorb about 15 percent.
Children’s developing bodies are more susceptible to harm
During the first months and years of life, children’s organs are developing rapidly, making them more prone to functional damage. For example, the nervous system continues to develop throughout childhood and therefore is especially vulnerable to environmental factors. At the same time, the nervous system is not well equipped to repair any structural damage caused by environmental toxins. If a child is exposed to neurotoxins such as lead or mercury, the resulting loss of intelligence or behavioral problems can be irreversible.
Especially during the first year of life, a child’s ability to metabolize, detoxify, and excrete toxins differs from that of an adult. In some cases, this works to a child’s advantage, as when they are unable to break down a relatively harmless substance into harmful byproducts. However, children also may be more susceptible to some toxins because their liver and kidneys are not fully mature and cannot detoxify and excrete harmful substances as readily as adults.
Children have more time to develop latent diseases
Many environmentally related diseases take decades before symptoms develop. Because children have more years to live, they have more time to develop latent diseases. For example, mesothelioma, which is caused by exposure to asbestos, takes years to develop. Early exposure to neurotoxins may lead to Parkinson’s disease later in life, and pesticide exposures may result in cancer years later. Because of the long latency period of these diseases, exposures in childhood are more likely to result in disease than exposures in adulthood.
Sources and Additional Information:
Bearer, C.F., “Environmental Health Hazards: How Children Are Different from Adults,” The Future of Children: Critical Issues For Children and Youths, Vol. 5, No. 2 – Summer/Fall 1995, – http://www.futureofchildren.org/pubs-info2825/pubs-info.htm?doc_id=70953
Children’s Environmental Health Network – http://www.cehn.org
Goldman, L.R., “Case Studies of Environmental Risks to Children,” The Future of Children: Critical Issues For Children and Youths, Vol. 5, No. 2 – Summer/Fall 1995 – http://www.futureofchildren.org/pubs-info2825/pubs-info.htm?doc_id=70953
International Programme On Chemical Safety, Commission Of The European Communities, Principles for Evaluating Risks from Chemicals During Infancy and Early Childhood: The Need for a Special Approach – http://www.inchem.org/documents/ehc/ehc/ehc59.htm
Landrigan, P.J. and Carlson, J.E., “Environmental Policy and Children’s Health,” The Future of Children: Critical Issues For Children and Youths, Vol. 5, No. 2 – Summer/Fall 1995 –http://www.futureofchildren.org/pubs-info2825/pubs-info.htm?doc_id=70953