For younger children, a day at the playground is not complete without some sandbox time. Long a favorite of children and parents, sandboxes could also be sheltering dangerous pathogens.
In a study in the journal Zoonoses and Public Health, scientists looked for potentially-deadly microbes in sandboxes used by children and found the possibility of infection could cast a shadow over a sunny day at play.
In backyards or playgrounds, sandboxes are rarely covered. Because of feces and debris that fall into sandboxes from domestic and wild animals, the Centers for Disease Control and Prevention has long advised parents to keep sandboxes covered when not in use. But if you have ever tried to cover and uncover a larger sandbox, over time, the cover is usually discarded. Even in fenced backyards, cats, nocturnal animals, and rodents can find the warmth and safety of the sand appealing.
In this study, researchers in Spain analyzed the microbial content of sand samples from sandboxes used by children and other sandy areas used by dogs. The research team collected, preserved, and incubated samples from 20 pairs of sandboxes used for children, and for dogs. A total of 40 sites were sampled and genotyped for their microbial community members before being statistically analyzed.
Overall, a particularly nasty bacteria, Clostridium difficile, was found in 53% of the sand sites sampled. Of those 12 of the dog boxes tested positive for C. diff, while nine of the children's sandboxes were contaminated. While they expected to find microbes in these sandboxes, C. diff is a particularly dangerous one.
C. diff is a harmful pathogen usually hovering around the top of lists of bacteria known to be antibiotic-resistant. The bacterium causes a severe diarrheal infection that can be serious to the very young, the elderly, and those with compromised immune function. Rates of the recurring form of this infection — when it comes back again and again — have skyrocketed in recent years. One of the reasons suggested is the emergence of diverse infection-causing strains of the pathogen.
In this study, authors report the strains of C. difficile they analyzed in these samples "were genetically diverse and displayed resistance to several antibiotics."
Transferring sandy hands to mouth make for easy transmission of C. diff and other common sandbox baddies. Mud pies, sand cookies, and just a snack of sand are fun for children but contain more than imaginary ingredients. In a review of public places, earlier research named public park sandboxes as the most bacterially active space in your community (followed by restaurant trays and school musical instruments).
While living in a too-sanitized world is not a healthy way to develop an immune system, it is a mistake to believe that letting a child and a cat share a sandbox is healthy. Because it isn't just cats, it is dogs, raccoons, and rodents. While bacteria are troubling, parasites are common in sandboxes, including roundworms carried by raccoons, pinworms, or parasites like Toxoplasma gondii.
These pathogens can often be dangerous, but the purpose of highlighting them here is not to frighten — but to inform. It is important to practice sandbox safety and to teach your child from a young age to wash hands after being outside. Here are some other tips about keeping your sandbox as clean as possible:
- Buy clean beach or river sand. Stay clear of crushed minerals, composite products, or dusty or dirty sand from someone getting rid of their sandbox.
- Create a coverable space for your sandbox. Either purchase or build a box that keeps out critters.
- Just like a litterbox, keep your sandbox clean, scoop out insects, watch for signs of rodents — and keep your pets out.
Most of us played in sandboxes when young and survived. But the fact is that most sandboxes are filthy and full of stuff you don't want your children to ingest. Keep it clean and enjoy a few minutes of peace while your child builds their next sandy superhighway.