<picture class="lw_image"> <source type="image/webp" srcset="/live/image/gid/108/width/400/30136_Paper.rev.1709127474.webp 1x, /live/image/scale/2x/gid/108/width/400/30136_Paper.rev.1709127474.webp 2x, /live/image/scale/3x/gid/108/width/400/30136_Paper.rev.1709127474.webp 3x"/> <source type="image/jpeg" srcset="/live/image/gid/108/width/400/30136_Paper.rev.1709127474.jpg 1x, /live/image/scale/2x/gid/108/width/400/30136_Paper.rev.1709127474.jpg 2x, /live/image/scale/3x/gid/108/width/400/30136_Paper.rev.1709127474.jpg 3x"/> <img src="/live/image/gid/108/width/400/30136_Paper.rev.1709127474.jpg" width="400" height="310" alt="Vertical stratification and seasonality of fecal indicator bacteria in New York City playground sandboxes, published in the journal Ecoto..." srcset="/live/image/scale/2x/gid/108/width/400/30136_Paper.rev.1709127474.jpg 2x, /live/image/scale/3x/gid/108/width/400/30136_Paper.rev.1709127474.jpg 3x" data-max-w="1222" data-max-h="947" loading="lazy"/></picture>
“Vertical stratification and seasonality of fecal indicator bacteria in New York City playground sandboxes,” published in the journal Ecotoxicology and Environmental Safety
Marjan Khan ’20 working in Prof. Leri’s biogeochemistry lab
Playground sandboxes are one of the joys of an urban childhood. But what lurks in the sand?
Outdoor sandboxes play a key role in child development, particularly for urban kids who have limited access to naturalistic play materials and play spaces. As open pits, playground sandboxes may receive visits from wild and domestic animals, posing a risk of exposing children to disease-causing fecal microbes. A team of researchers from Marymount Manhattan College set out to measure the degree of fecal contamination in playground sandboxes on the east side of Manhattan. Their study, published this week in Ecotoxicology and Environmental Safety, shows the omnipresence of the fecal bacteria E. coli and enterococci in playground sandboxes, with significantly higher levels in surface sand than in underlayers. Microbial source tracking identified birds and dogs as fecal hosts among the sandboxes.
The researchers also conducted controlled outdoor experiments in miniature sandbox “microcosms” stationed outdoors on the Marymount Manhattan campus in the heart of the Upper East Side. These experiments showed rapid fouling of sand in open microcosms, compared with no evidence of fecal contamination in adjacent closed microcosms.
The team was led by Professor of Chemistry Alessandra Leri, Ph.D. Bacterial measurements and data analysis were conducted by post-baccalaureate Biology student Eliana Fassihi following preliminary method development by Biology alum Marjan Khan ’20. Assistant Professor of Biology and Chair of Natural Sciences Matthew Lundquist, Ph.D., carried out the statistical analysis of the data. In addition to sparking the idea for the study, Professor Leri’s elementary-aged children helped with sampling and sample processing.
The ubiquity and abundance of fecal bacteria in playground sandboxes indicate a pathway for direct exposure of urban children to ample quantities of fecal pathogens. The paper provides estimates of potential dermal and ingestion exposure levels from typical sand play activities. Such exposures may be related to gastrointestinal illness and other adverse health consequences.
The study’s results indicate that increasing the frequency of sandbox refills and covering sandboxes during times of disuse would effectively decrease the levels of fecal pollution in playground sand. In the absence of such measures, good hygiene practices are essential.
“I am very pro-sandbox. Playing in sandboxes is one of the joys of childhood, and I still let my kids play in them, even after these disturbing findings,” said Professor Leri. “I just make sure to wash their hands and face right afterward.”
While this study focused on sandboxes in New York City, open sand pits are a common feature of children’s play areas throughout the world, making the results of this research relevant to an international audience.
