A stack of colorful children's books piled on top of a table

Are Rented or Secondhand Books Hygienic for Kids? What the Research Actually Shows

A rented or hand-me-down book arrives a little soft at the corners, maybe with a faint sticker-residue ghost on the cover, and there's a small pause before you hand it over — who else held this, and is that actually fine? It's a completely reasonable thing to wonder before you decide whether renting, borrowing, or buying secondhand books makes sense for your family.

What the research actually found

A 2019 study swabbed 42 children's books across four public libraries in the United States and tested them using proteomics analysis (Roh, Jung, Kim, Bhatt & Choi, 2019, International Journal of Environmental Research and Public Health). Every single book tested positive for some bacterial growth, including a few species that can, under the right circumstances, cause illness. That sounds alarming on its own — but context changes the picture a lot.

The bigger picture: presence of bacteria isn't the same as real-world risk

Infectious disease physician Michael Z. David, asked directly about this by the Wall Street Journal, put it plainly: while bacteria and viruses can survive on paper for a while, the actual infection risk from reading a shared book is very, very low, and he'd never heard of anyone getting sick from one. That gap — bacteria detectable in a lab versus anyone actually getting sick — matters. Doorknobs, playground equipment, tablets, and toy bins all carry comparable or higher bacterial loads than a book, and none of them are typically treated as things a child shouldn't touch.

Where it's genuinely uncertain: the 2019 study itself was small — 42 books, four libraries, one country — and it measured what was present, not how often (if ever) it actually made a child sick. The researchers themselves called for follow-up work to properly assess real health risk rather than treating detectable bacteria as proof of danger. So the honest summary is: yes, books that pass through many hands carry germs, and no, that alone isn't a reason to rule out renting or borrowing books for your child.

What this means this week

  • A quick wipe of the cover with a damp cloth when a book arrives is a reasonable, low-effort habit — not a sign you need to sterilize every page.
  • Keep the same handwashing-before-snacks habit you'd use after playground equipment or shared toys; it covers this too.
  • If a book has been heavily handled or a child was unwell while reading it, airing it out in sunlight for a day is a sensible, simple step.
  • Don't let hygiene worry be the deciding factor between renting, borrowing, or buying — cost, how often your child outgrows books, and shelf space are usually the more useful questions.

Sources

  • Roh, J. H., Jung, R. H., Kim, M., Bhatt, B., & Choi, J. M. (2019). Identification of pathogenic bacteria from public libraries via proteomics analysis. International Journal of Environmental Research and Public Health, 16(6), 912.
  • David, M. Z., quoted in "Just How Gross Are Library Books, Exactly?" reporting on library book contamination research.

Related reading

Find the right books for your 3-year-old, rented or otherwise — take the 2-minute reading assessment

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