Center for Health, Environment and Justice
Everyone's Backyard
 

Science Feature

Children and Environmental Health
 

It has only been in the past few years that government has acknowledged the magnitude of the  health threats facing children exposed to toxic chemicals. This past April, President Bill Clinton followed his convention speech promise that "no child should live next to a toxic dump site" by signing an executive order called "Protection of Children from Environmental Health Risks and Safety Risks." This order requires all federal activities, programs and policies to "address" the disproportionate risks children face from exposures to toxic chemicals.

The statistics are frightening.  Asthma in children has increased by more than one-third in the past 15 years, affecting an estimated 4.2 million children under the age of 18 according to the American Lung Association. Asthma is now the leading cause of hospital admissions for our nation's children. It has reached epidemic proportions according to Dr. Philip Landrigan, professor of Community Medicine at the Mt. Sinai Medical Center in New York. The number one disease related cause of death in children is cancer, and the rate of childhood cancer continues to rise.  Brain and nervous system cancer in children increased 32% between 1973 and 1990.  During that same time period, acute lymphocytic leukemia in children increased 27%. A study by the National Cancer Institute found that bone cancer increased 40% in boys and 33% in girls from 1979 to 1991. Other increases were found in eye and soft-tissue cancers. Eight thousand children ranging from 0 to 14 years of age were diagnosed with cancer in 1993.

Children with asthma and cancer do not smoke cigarettes, drink alcohol,  or work in dirty industries, nor is the cancer they develop a result of something unidentifiable they were exposed to twenty years ago. Our children's exposures come from industrial pollution released into the environment that contaminates our food, water and air.

Children Are Uniquely Different

Children are not little adults. There are significant differences in the susceptibility children and adults have to the effects of toxic substances.  Children eat proportionately more food, drink more fluids, and breathe more air per pound of body weight than adults. For this reason, a child who is exposed at the same time as an adult to a toxic substance will receive a "dose" of this substance that is more concentrated than the adult. This means that a child is more likely to develop illnesses and disease than an adult exposed to the same amount of a toxic substance.

Children are more vulnerable to environmental toxins because of their habits and activities. Their behavior exposes them to different environmental hazards. An infant who crawls on the ground or plays outside is more likely to be exposed to contaminated dust and soil, lead paint, household chemicals, garden chemicals and other potentially hazardous substances. Children are also less able to protect themselves. A young infant's natural curiosity and tendency to explore leaves him/her open to health risks adults can more easily avoid. A child plays in mud, splashes in a nearby creek, and inadvertently ingests small amounts of dirt. Many old industrial sites are irresistible places for children to play.

Children Are Rapidly Growing

Children are more susceptible to toxic chemicals than adults because they are growing and many of their organ systems are still developing. Many toxic chemicals, especially those that cause cancer, damage rapidly dividing cells more readily than they damage resting cells. In a child, almost all cells are dividing rapidly in comparison to adults, and thus children are more affected by toxins than adults. At any time during this growth period, chemical influences can alter the  normal growth pattern and/or stimulate the growth of unwanted cells such as cancer.

From infancy through adolescence, children move through several stages of rapid growth and development, especially for the nervous system, the lungs, the reproductive organs and the immune system. The permanent structures of these organs are established in childhood. In the nervous system, for example, critical connections are formed during this time between regions of the developing brain. If these connections fail to form at the proper time, the opportunity to create them is lost forever. The consequence can be lifelong loss of intelligence or alteration of behavior. The human nervous system has no capacity to repair itself once injured.

Likewise, if the developing lung is damaged by exposure to environmental toxins such as air pollutants, it can fail to develop its normal architecture and fail to achieve its full growth. The result can be a lung that is permanently vulnerable to infection or other illness or an increased frequency of chronic lung disease in later life. Similarly, the infant immune system is not fully developed, so children are less able than healthy adults to recover from exposure to common viruses or to bacteria found in drinking water. A child exposed to toxins affecting the immune system will have more ear infections, more colds, more pneumonia and more flu.

Children also have different absorption, distribution, metabolism and excretion capacities than adults. Because their metabolic systems are immature, children's vulnerability to many toxins is quite different from that of adults. Their inability to breakdown and excrete toxic substances increases the likelihood that they could develop a wide array of environmental diseases, including cancer, neurological problems, and immune impairment.

Exposure in Utero

The most critical time in a child's growth and development is while still in the mother's womb. Exposure to chemicals during this time and just after birth can have significant consequences to the developing child because of their rapid growth rate.  During in utero development, infancy and adolescence, children are growing and adding new tissue more rapidly than any other period of their life.  In addition, different organs and tissues mature at different rates. For example, the brain achieves 50% of adult weight by six months, while 50% of the adult weight of the liver, heart and kidneys is not reached until the child is about nine years old (see chart).

A child often receives his/her first exposure to chemicals while still in the womb.  At one time, scientists thought that the placenta was a barrier protecting the fetus from harmful chemicals. We know now know that many chemicals such as mercury, dioxin and PCBs can cross the placental barrier and that these chemicals can interfere with normal growth and development. For example, dioxin interferes with the function of  thyroid hormones critical to the normal development of the brain and nervous system, by either decreasing or mimicking the biological action of the thyroid hormones in the body.  Deficiencies in thyroid hormone levels in the mother during pregnancy, or in the fetus or infant during critical periods of neurological development are likely to result in permanent brain damage. This will result in mental retardation, hearing loss and speech problems, impaired learning and memory, hyperactive behavior and attention deficit disorder. Chemical substances that interfere with normal hormone functions are commonly referred to as endocrine disruptors, or environmental hormones, and have been linked to reproductive cancers.

Do Federal Standards Protect Children?

No. As mentioned above, children receive a much higher concentration of a chemical than an adult exposed to an equal amount of the same contaminant. When safety standards are set, they are based on exposure of an adult to a single chemical. The fact that children get a higher dose is not taken into account in evaluating health risks and taking action. However, President Clinton's Executive Order does require federal agencies to consider the special situation of children. If Clinton is true to his word, then exposures that involve children should result in new, lower standards for everyone.

What You Can Do to Protect Children

We need to begin to reduce the exposure of children and all people to chemicals in our air, water, soils, and food. We must protect children from exposures to environmental threats.  But it is not enough to only protect the children after they are born - we need to protect them through the protection of their parents. Mothers pass their body's accumulation of chemicals to their children during pregnancy and through breast-feeding.  Men are also at risk.  Some men do not have the ability to produce an adequate amount of sperm for the purpose of fathering a child, and men can pass on damaged gene pools which could result in children born with birth defects and learning disabilities.

Protecting future parents and children is not about lifestyle changes alone. We cannot "lifestyle" our way out of this crisis. There is a need to change our current practice of allowing chemicals to be released in our environment. Even if you ate only organic foods and were a vegetarian you and your child would still be at risk. The solution to protecting our children and ourselves is to begin eliminating all possible sources of chemicals which get into our food, air, drinking water and soil.

Resources

USEPA, Office of the Administrator. Environmental Threats to Children. Washington: U.S. Environmental Protection Agency, Sept. 1996.

The White House, Office of the Press Secretary.  Protection of Children From Environmental Health Risks and Safety Risks. Washington, The White House, April 21, 1997.

Environmental Health Perspectives Supplement. "Preventing Child Exposures to Environmental Hazards: Research and Policy Issues."  v.103, supp. 6, September 1995.  National Institute of Environmental Health Sciences.

Goldman, Lynn R. "Children- Unique and Vulnerable: Environmental Risks Facing Children and Recommendations for Response." Environmental Health Perspectives Supplement. Vol. 103 supp.6, September 1995.

National Research Council (U.S.). Committee on Pesticides in the Diets of Infants and Children.(1993) Pesticides in the Diets of Infants and Children. Washington D.C.: National Academy Press.

Needleman, H.L., and Landrigan, P.L. (1994) Raising Children Toxic Free. New York: Farrar, Strauss, Giroux.

Meadows, Robin. "Growing Pains." Environmental Health Perspectives: v.104, n.2, February 1996.

Freedberg, Louis.  America's Poisoned Playgrounds: Children and Toxic Chemicals. Oakland: Youth News, 1983.

Colborn, T.; Dumanoski , D.; and Myers, J.P.  (1996) Our Stolen Future.  New York: Dutton.

Children's Health Environmental Coalition. P.O. Box 846, Malibu, CA 90265. (213) 656-8715, fax (310) 589-5465.

Related Articles:

Protecting Baby's First Food (Spring 2000)
Dioxin Update: Children Are the Most Vulnerable (Winter 1999-2000)
Children and Chemicals (Fall 1998)

Originally published in Everyone's Backyard, Vol. 15, No. 2 (Summer 1997)

Center For Health Environment and Justice
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