The fact that children are facing so many toxic exposures is concerning enough. But adding insult to injury is the fact that kids are far more vulnerable to toxic chemicals than adults are. “In early childhood and the nine months before birth, there occur ‘windows of vulnerability, ‘” says Philip Landigran, a pediatrician who leads a unit on children and the environment at Mt. Sinai School of Medicine in New York. “We’re beginning to learn that a lot of diseases appear to be triggered by early exposures, but it takes years, even decades, for those to progress to diseases like cancer, like Parkinson’s disease, like Alzheimer’s.” (Morrison, Heath & Jervis, 2008)
There are 3 significant factors that leave kids more vulnerable to toxic exposures:
- Kids are exposed to toxic chemicals at higher doses
As compared to adults, children get a much higher dose of chemical exposure from the environment. There are a number of reasons for this higher exposure:
- Kids are more active and have a higher metabolism. So pound for pound they eat more, drink more, and breathe more than adults. Because they are recycling their environment through their body at a faster rate, they also end up with higher exposures.
- They breathe more air relative to body weight, which exposes them to more airborne pollutants. They also do more mouth-breathing, which bypasses some of the filters in nasal passages that help filter the air.
- Children are outside more, leading to increased exposure to some pollutants.
- Babies and young children frequently put hands and other things in their mouth, which leads to them ingesting more chemical residues.
- Due to their small stature, kids spend more time close to the ground or on the floor, where chemical residues and pesticides often accumulate. Concentrations of certain chemicals, particularly pesticides, are anywhere from 4 to 6 times higher near the floor where children play than they are at an adult’s breathing level. (Zahm & Ward, 1998)
True to this principle, studies have found that children have higher levels of toxic substances in their body than adults do. For example, research by Sonya Lunder of the Environmental Working Group has found that toddlers have levels of flame retardants in their bodies that are 3-times that of adults. (Szabo, 5-18-2011) A 1991 study by the American Academy of Pediatrics found that kids are exposed to 40-times more pesticides per pound of body weight than adults. (Shabecoff & Shabecoff, 2010, p. 32) School-age children have approximately 1 1/2 times more phthalates in their body per pound of body weight than adults, and children also test twice as high for many types of pesticides. (ibid, p. 43)
- Children lack the same defenses against toxic substances
A child’s still developing immune defenses are less able to fight off contaminants. Their immature kidneys and liver have a tougher time ridding their body of toxins. Children have lower levels of the antioxidant glutathione, which helps clear the body of oxidative stress, a byproduct that is produced when cells rid themselves of waste (both the natural and unnatural kind).
Organophosphates, a class of widely-used pesticides, can cause more problems in children because the enzyme needed to detoxify it from their body isn’t produced at normal levels until around the age of seven. Babies also lack an important liver enzyme that would break down BPA and rid it from their bodies. (Shabecoff & Shabecoff, 2010, p. 33)
The blood-brain barrier, a system at the base of the brain that works to prevent certain elements in the bloodstream from passing into the sensitive tissue of the brain, is not fully formed until a child is 6-months-old. (ibid) This means that early in infancy, children are at increased risk of neurological disorders from toxic exposures.
A combination of factors such as this mean that a child’s body just isn’t as adept at dealing with contaminants and ridding itself of toxic chemicals as that of an adult. For instance, children retain as much as half of the lead they ingest, whereas adults absorb only around one-tenth that. (ibid, p. 32)
- Children are still developing, which leaves them more vulnerable to toxic effects
A child’s high growth rate means lots of cells are growing and dividing, which makes them more vulnerable to toxic substances that might corrupt this process. And because they are so young and still growing, any potential damage that occurs has the potential to compound over time. It’s a lot like the difference between drawing a 2 inch X on a deflated balloon verses a fully inflated one. On a fully inflated balloon, the mark will leave an imprint, but it will remain a 2 inch mark… the size of the original exposure. The same scar on a deflated balloon, however, becomes much bigger as the balloon is blown up, and will expand in size. When fully inflated, the mark will be much larger than the one left on the balloon that had already grown to full size. This deflated balloon is akin to how children fare when it comes to chemical exposure.
Cancer, for instance, is a disease in which lethality depends on growth rate. If you had a magical tool that could spot cancerous cells in the body, you’d likely find that most (if not all) elderly people have cancer to some degree. Most will never be affected by it, because it’s growing too slowly to impact them in their lifetime. A child with the same slowly growing cancerous cells, however, may be riddled with problems while still in the prime of their life, simply because these problems have had that much more time to develop. Dr. Richard Jackson, former director of Environmental Health Programs for Children, refers to this principle as “the long shelf life of children.”
Also, because so much of a child’s body is still being built, any chemicals that hinder this process are going to affect how their body is built. Crucial body systems, such as the sex organs, skeletal system, and lungs, continue to develop from birth through adolescence. Imagine a wheelbarrow of cement. The purer the cement, the stronger the structure you build with it will be. But if I shovel a scoop of dirt into this cement, I may end up with an inferior product. Toxins that interfere with bodily functions are sort of like a pile of dirt thrown into the clay that a child is molded from.
Toxic chemicals & the increased vulnerability of children
Because of their biological frailty, their still developing bodies and the amount of air they breathe per pound of body weight, YOUNG KIDS ARE AT LEAST 10-TIMES MORE SUSCEPTIBLE TO TOXIC CHEMICALS THAN ADULTS. (Morrison, Heath & Jervis, 2008) Not only can they be damaged more profoundly by chronic exposure, but they are more sensitive to acute toxicity. Consider the case of acrylonitrile, a chemical used to make rubber and plastics. When adults are exposed to acrylonitrile vapors, it typically causes only minor nose and throat irritation. Yet the U.S. Centers for Disease Control and Prevention has cases on file where kids have died form inhaling these exact same vapors. Scarier still: this deadly chemical has been found in high concentrations outside some elementary schools. (Morrison & Heath, 2008; also see our chapter on Toxic Schools.)