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Children Exposed to Pollutant Found in Tobacco Show Signs ofChromosomal Damage May 31, 2012 According to a new study, children exposed to high levels of thecommon air pollutant naphthalene are at increased risk forchromosomal aberrations (CAs), which have been previouslyassociated with cancer. These include chromosomal translocations, apotentially more harmful and long-lasting subtype of CAs. Researchers from the Columbia Center for Children's EnvironmentalHealth (CCCEH) at the Mailman School of Public Health, ColumbiaUniversity Medical Center, and the Centers for Disease Control andPrevention (CDC) report the new findings in Cancer, Epidemiology,Biomarkers & Prevention, a journal of the American Associationfor Cancer Research. Naphthalene is found in both outdoor and indoor urban air. It ispresent in automotive exhaust, tobacco smoke, and is the primarycomponent of household mothball fumes. Classified as a possiblecarcinogen by the International Agency for Cancer Research,naphthalene belongs to a class of air pollutants called polycyclicaromatic hydrocarbons (PAH). Prior research at the CCCEH hasestablished a link between prenatal exposure to PAH and increasedrisk for childhood obesity, IQ deficits, and CAs. The new study isthe first to present evidence in humans of CAs, includingtranslocations, associated with exposure to one specific PAH --naphthalene -- during childhood. The researchers followed 113 children, age 5, who are part of alarger cohort study in New York City. They assessed the children'sexposure to naphthalene; a CDC laboratory measured levels of itsmetabolites -- 1- and 2-naphthol -- in urine samples. (Metabolitesare products of the body's metabolism, and can serve as marker forthe presence of a chemical.) Researchers also measured CAs in thechildren's white blood cells using a technique called fluorescentin situ hybridization. Chromosomal aberrations were present in 30children; of these, 11 had translocations. With every doubling oflevels of 1- and 2-naphthol, translocations were 1.55 and 1.92times more likely, respectively, to occur. CAs have been associated with increased cancer risk in adults.Translocations are of special concern as they result in a portionof one chromosome being juxtaposed to a portion of anotherchromosome, potentially scrambling the genetic script."Translocations can persist for years after exposure. Someaccumulated damage will be repaired, but not everyone's repaircapacity is the same. Previous studies have suggested thatchromosomal breaks can double an adult's lifetime risk for cancer,though implications for children are unknown," says first authorManuela A. Orjuela, MD, ScM, assistant professor of clinicalenvironmental health sciences and pediatrics (oncology) at ColumbiaUniversity Medical Center and a pediatric oncologist atNewYork-Presbyterian Morgan Stanley Children's Hospital. To obtain a better sense of the long-term consequences ofnaphthalene exposure, Dr. Orjuela and other CCCEH investigators arefollowing some of the children in the study as they reach fourthgrade. While they expect to see further translocations, they do notexpect to see any signs of cancer in the white blood cells. "Sofar, the translocations seem to be random, and there has been noevidence of the specific translocations that are known to beassociated with leukemia. This is entirely expected; leukemia isvery rare." Frederica Perera, DrPH, senior author on the paper,adds that "the findings provide yet more evidence of thevulnerability of the young child to carcinogenic air pollutants." The researchers hypothesized that naphthalene exposure wasprimarily from mothballs, which can release high levels of thechemical. Furthermore, according to previous research, someCaribbean immigrant families use mothballs as an air freshener.Other important sources of naphthalene in indoor air are tobaccosmoke, paint fumes, cooking, and heating. The new findings haveimplications beyond the urban environment as elevated levels ofnaphthalene metabolites have been documented in rural communitiesusing biomass-burning stoves (coal, wood) -- another source of PAHexposure. The e-commerce company in China offers quality products such as Diode Laser Hair Removal , Cavitation Slimming Machine Manufacturer, and more. For more , please visit Lipo Laser Weight Loss today!
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