National Geographic's Green Guide, Tracy Tullis
Published June 5, 2007
Among parents, sandboxes may trigger worries about sharp objects or about cats or rodents that might visit after dark. Wooden jungle gyms may inspire histories of scraped knees or bumped chins. But most parents don't consider that the sand or the wood itself might be a health hazard.
Twenty years ago, the Health Research Group, a division of Public Citizen, raised an alarm about sand safety after a geologist found play sand contained traces of the fibrous mineral tremolite, a form of the human carcinogen asbestos. But the stone industry insisted the sand was safe, and the Consumer Product Safety Commission declined to take action.
Of course, the risk of asbestos exposure is greatest to workers who handle the material every day—far more intense and prolonged than the exposure of a tot in the sandbox. Still, as Philip Landrigan, M.D., director of the Center for Children's Health and the Environment at Mt. Sinai School of Medicine, points out, children breathe proportionately more air than adults, and they play close to the ground, where airborne particles swirl about. Most importantly, he says, malignant mesothelioma—a lung cancer caused almost exclusively by asbestos—is extremely sensitive to limited exposure. "Even very small doses of asbestos exposure," Landrigan says, "can increase the risk of malignant mesothelioma for four or five or six decades."
Tremolite isn't the only potential hazard. A parent purchasing a bag of play sand may be startled to discover a warning label that the bag contains a substance "known to the State of California to cause cancer." California requires these labels because the primary ingredient in sand, crystalline silica, has been determined a human carcinogen by the International Agency for Research on Cancer. However, no reports exist of the disease in children exposed to silica-containing sand.
Finally, because the sandbox may indeed attract critters, infections are possible, especially from E. coli bacteria; keep cuts and scrapes well bandaged.
Or just follow Landrigan's advice: "I encourage my grandchildren to stay out of the sandbox," he says. He guides them instead toward the swings or the jungle gym.
That jungle gym warrants a second look, too. Many are made of wood preserved with chromated copper arsenate (CCA), the basis of which is arsenic, a carcinogenic chemical that can leach out of CCA-treated wood onto children's hands and into soil and groundwater. Although CCA has been banned in residential uses since 2004, millions of CCA-treated play sets still exist.
A newer alternative, ammoniacal copper quaternary, is considered less toxic to children than arsenic compounds, but its effect on the environment is still unknown. The most responsible choice remains naturally rot-resistant woods like cedar or redwood. Look for Forest Stewardship Council (FSC)-certified wood, or choose play sets made from recycled plastics.
As a final precaution, avoid older sets with cracked, chipped or peeling paint, which may be lead-based. Lead, a neurotoxin, can cause learning disabilities and behavioral disorders.
If arsenic and dirty sand threaten your fun, consider leaving the confines of the playground altogether and find a small corner of nature to explore: inspect the veins of a leaf, lead a neighborhood bird safari or dig in a muddy puddle. You know you want to.
What You Can Do
- Test your local playground's sand for asbestos; find a lab through the EPA's asbestos info line: 202-554-1404.
- In home sandboxes, avoid "all-purpose" sand, which has not been washed to screen out breathable particles. The Safe Sand Company sells asbestos- and silica-free sand (www.safesand.com, 415-971-1776). Replace sand regularly to avoid contamination.
- In indoor sand tables, use beans or rice instead of sand—not great for molding but nice for pouring, measuring or bulldozing.
- If a wooden play structure has a greenish tinge, it has almost certainly been treated with copper, if not CCA. Test wood and soil for arsenic with a kit from the Environmental Working Group ($20; http://www.ewg.org/reports/poisonwoodrivals/orderform); treated wood should be sealed every six months with water-based sealants, like those from AFM, or latex paint. And always wash children's hands after they have been playing on any wooden structure—particularly before eating.
* For recycled-plastic or FSC-certified play sets, see our Backyard Playground Equipment product report.
