We hear about deaths from cancer – and how the rates are going down (1). And that’s fabulous – but the sad fact is that the incidence of cancer seems to be going up (2). The reason is complicated – we’re getting older, true – but we’re also getting better at fighting it:
The number of new cancer cases have increased 0.6% every year since 1975 – overall, that’s an increase of 21% in the past 36 years (3) . What I find particularly disturbing is the rise in the reported incidence of cancer among young children and adolescents, especially brain cancer, testicular cancer, and acute lymphocytic leukemia. Sadly, after injuries and violence, cancer is the leading cause of death in our children (4).
At the risk of showing my bias, in case there are those among you who didn’t already know, I think part of the problem is because our environment contains many chemicals that are known to cause these cancers. But I’m not alone: the New York Times, in a recent editorial, urged the reform of the current law which purports to protect Americans from these chemicals (5), and the 2011 report of the President’s Cancer Panel has said that the “true burden of environmentally induced cancers has been grossly underestimated.” (6)
Besides cosmetics, shampoos, detergents and building products, fabric processing uses a wide variety of synthetic chemicals, many of which remain in the fabrics. A short list of the many chemicals used in textile processing – many of which remain in the fabrics we live with – includes the following chemicals, which are all linked to cancer:
• Formaldehyde is known to cause cancer (and asthma), yet rates of formaldehyde in indoor air have grown from 14 ppb in 1980 to 200 ppb in 2010 – and these rates are increasing.
• Higher rates of chemicals called Polychlorinated Biphenyls, or PCBs, used in the production of plastics – and therefore all synthetic fabrics – also are linked with higher rates of leukemia.
• Benzene, used in the production of nylon and other synthetics, in textile dyestuffs and in the pigment printing process – is linked to leukemia, breast cancer, lymphatic and hematopoietic cancers.
• Chromium Hexavalent compounds, used in leather tanning, and the manufacture of dyes and pigments, are linked to lung, nasal and nasopharyngeal cancers.
• Bisphenol A, used in the production of polyester and other synthetic fibers and as an intermediate in the production of dyestuffs, is an endocrine disruptor linked to breast and prostate cancer.
Children are at greater risk because they are exposed at a higher rate than adults, their behaviors exacerbate exposure and they have increased susceptibility to the chemicals:
Pound for pound, children breathe twice as much air as an adult, drink two and a half times as much water, and eat three to four times more. Also – the typical newborn weighs 1/20th that of an adult male, but the infant’s surface area is just 1/8th as great. This means that the infant’s total skin area is 2.5 times more per unit of body weight than an adult (7).
Their breathing rates, at rest, are higher than those of adults, and greater levels of physical activity can increase their breathing rates even further. Their play is often at ground level, while adults breathe four to six feet above the floor. So children have greater inhalation and dermal exposure to chemicals present on floors, carpets, grass or dirt, where heavier chemicals such as lead and particulates settle.
Children put everything into their mouths when exploring their environment. This increases their ingestion of substances in soil, household dust, floors and carpets, as well as the objects themselves.
Some children will gleefully jump into a lake – even before they could swim! This lack of fear as they grow can further increase their exposure to environmental hazards.
Childhood is characterized by rapid physical and mental growth. Accordingly, certain organs may not be fully developed and may be more vulnerable to injury. Children absorb, metabolize, and excrete compounds differently than adults.
• In some instances, children may be more susceptible than adults due to their increased rates of absorption or decreased rates of elimination of foreign compounds. In other cases, the opposite may be true. Children will absorb about 50 percent of lead ingested, whereas adults will absorb only about 10 to 15 percent(8). Kidneys are the principal pathway for elimination of most chemicals from the body. At birth an infant’s kidney’s filtration rate is a fraction of adult values; by age one the rate is at adult levels. (9)
• Longer lifetimes: many diseases initiated by chemical hazards take decades to develop, so early exposure to toxicants may be more likely to lead to disease than the same exposures experienced later in life.
The fetus is particularly sensitive to environmental toxicants (10). Chemicals can affect the children born to women exposed during pregnancy, while the women remain unaffected. For example, the children of women from Michigan who ate two to three meals of fish contaminated with PCBs per month for six years before pregnancy had lower birth weights, memory deficits at seven months and four years of age, and cognitive deficits persisted at eleven years of age (11). In Iraq, children born to women who during pregnancy inadvertently ate seed grain treated with mercury to prevent fungus had severe developmental and mental deficits (12).
(1) Jemal A, Siegel R, Ward E, Hao Y, Xu J, Thun MJ. Cancer statistics, 2009. CA: A Cancer Journal for Clinicians 2009;59(4):225–249.
(2) Data from cancer tracking suggest that childhood cancer is increasing, although the data is not consistent from year to year; the National Cancer Institute reported that for infants less than one year old, the rate of cancer rose by 36% from 1976-84, but some say that these increases are due to improved detection rather than representing true increases in cancer.
(3) Center for Children’s Health and the Environment, Mt. Sinai School of Medicine (http://www.pbs.org/odyssey/odyssey/toxics_brain_cancer.pdf)
(7) Our Children at Risk, The Natural Resrouces Defense Council, http://www.nrdc.org/health/kids/ocar/chap2.asp
(8) Royce, S. and H. Needleman, Case Studies in Environmental Medicine: Lead Toxicity, Agency for Toxic Substances and Disease Registry, 1995.
(9) Bearer, C., “How Are Children Different from Adults?” Environmental Health Perspectives, vol. 103, supp. 6, September 1995, pp. 7-12.
(10) Birnbaum, L.S., “Endocrine Effects of Prenatal Exposures to PCBs, Dioxins, and Other Xenobiotics: Implications for Policy and Future Research,” Environmental Health Perspectives, vol. 102, no. 8, 1994, pp.676-679. Y.L. Guo et al., “Growth Abnormalities in the Population Exposed in Utero and Early Postnatally to Polychlorinated Biphenyls and Dibenzrofurans,” Environmental Health Perspectives, vol. 105, suppl. 6, September 1995, pp.117-122.
(11) Jacobson, J.L. et al., “The Transfer of Polychlorinated Biphenyls (PCBs) and Polybrominated Biphenyls (PBBs) across the Human Placenta and into Maternal Milk,” American Journal of Public Health, vol. 74, 1984, pp.378-9. J. Jacobson et al., “Effects of In Utero Exposure to Polychlorinated Biphenyls and Related Contaminants on Cognitive Functioning in Young Children,” Pediatrics, vol. 116, 1990, pp.38-45. S.W. Jacobson et al., “The Effect of Intrauterine PCB Exposure on Visual Recognition Memory,” Child Dev, vol. 56,1985, pp.853-60. J.L. Jacobson et al., “Effects of Exposure to PCBs and Related Compounds on Growth and Activity in Children,” Neurotoxicol. Teratol., vol.12, 1990, pp. 319-26.
(12) Gilbert, S. G. and K. Grant-Webster, “Neurobehavioral Effects of Developmental Methyl-Mercury Exposure,” Environmental Health Perspectives, vol. 103, supp. 6, September 1995, pp. 135-142.