Parental Smoking And Childhood Cancer
Written and compiled by Wanda Hamilton
According to the National Cancer Institute, the rate of childhood cancer has been rising since the l970s, and the rate of increase has amounted to nearly 1 percent a year. Experts claim a newborn child today "faces a risk of about 1 in 600 of contracting cancer by age 10" ("U.S. Reshaping Cancer Strategy as Incidence in Children Rises," John H. Cushman, Jr., New York Times, 9/29/97).
"Cancer rates among children increased 10.5 percent between l973 and l994 with childhood cancers of the brain and other parts of the central nervous system rising 35.1 percent in the same period" ("Kids twist in toxic turmoil," Jane Kay, San Francisco Examiner, 11/15/97, p. A6).
"In the United States, cancer is diagnosed each year in an estimated 8,000 children below the age of 15. Cancer, although it kills fewer children than accidents do, is the most common form of fatal childhood disease, accounting for about 10 percent of all deaths in childhood," (Cushman, NYT, 9/29/97).
No one knows why this is happening, though some experts believe that toxins in the air, food, dust, soil and drinking water may be at fault. Among other things, an estimated 75,000 new synthetic chemicals have been introduced in the last 50 years (Cushman, NYT, 9/29/97).
Interestingly, parental smoking, the politically correct whipping boy for all sorts of disease, has not been implicated by scientists as a factor in this rapid increase in childhood cancer. Thus far, researchers have been unable to demonstrate any correlation between childhood cancer and parental smoking (including maternal smoking during pregnancy) or environmental tobacco smoke. In fact, it would be difficult to establish such a correlation since the smoking rates in the U.S. have shown a steady decline during the same period that childhood cancer has been increasing. Many studies have found that children of smoking parents (including mothers who smoked during pregnancy) have a slightly lowerrisk of developing cancer.
"No statistically significant associations were found between childhood malignancy and infant sex, twinning, birthweight, non-chromosomal malformation, maternal smoking or complications during pregnancy."
"Pregnancy and delivery characteristics of women whose infants develop child cancer," Forsberg JG, Kallen B, Dept. of Anatomy, Lund University, Sweden, APMIS 1990 Jan; 98(1): 37-42.
"By age 8 years, cancer had occurred in 1.4 per 1,000 children whose mothers did not smoke during pregnancy, compared with 0.9 per 1,000 children whose mothers smoked." In all cancers the rate was higher among those children whose mothers did NOT smoke (RR 0.60 for children of smoking mothers), as it was specifically for leukemia (RR 0.82 for children of smoking mothers). Data was collected from a cohort of 54,795 liveborn children in the Collaborative Perinatal Project (l959-1966).
"Maternal smoking during pregnancy and childhood cancer," Klebanoff MA, Clemens JD, Read JS, National Institute of Child Health and Human Development, National Institutes of Health, Am J Epidemiol1996 Dec 1; 144(11):1028-1033.
"The overall relative risk for cancer in children with mothers reporting smoking during pregnancy was 0.99." A relative risk of less than 1.0 means that mothers who smoked during pregnancy had slightly LOWER risk of having children who developed childhood cancer than non-smoking mothers.
"Maternal smoking in pregnancy: does it increase the risk of childhood cancer?" Pershagen G; Ericson A, et al, International Journal of Epidemiology, Feb l992, 21(1):1-5.
"We found no increased risk [of lung cancer] for childhood exposure [to environmental tobacco smoke], a result that is in line with most available data."
Zaridze D, Institute of Carcinogenesis, Moscow, International Journal of Cancer, l998; 75:335-338.
"The results of this analysis are consistent with results from several prior epidemiological studies that showed no significant association between CBTs [childhood brain tumors] and maternal smoking before or during pregnancy or maternal exposure to passive smoke during pregnancy."
"Prenatal exposure to tobacco smoke and childhood brain tumors: results from the United States West Coast childhood brin tumor study," Norman MA, Holly EA, Ahn DK, Preston-Martin S, Mueller BA, Bracci PM. Cancer Epidemiol Biomarkers Prev, Feb l996; 5(2):127-133.