Posted by: Katherine Ashenburg - Author of The Dirt on Clean

When people hear that I’ve written a history of cleanliness, they often assume that I’m a clean-freak. I’m definitely not: on the spectrum from complete-slob to clean-freak, I’m around the mid-point. And my initial interest in The Dirt on Clean didn’t stem from cleanliness as much as my curiosity about the everyday lives of people in past ages. But lately, I’ve been rethinking my connections with hygiene. Strangely, the first book I withdrew with my brand-new library card, at 6, was a book about hygiene, with photographs of 1950s children brushing their teeth and wielding their wash-cloths. I read every word because I was charmed with my new skill, but this earnest tome was not my choice: a friend had taken my card to the library because for some reason I was unable to go. For years, I laughed at that unlikely start to my life as a reader. Little did I imagine that I would ever write a book about cleanliness!

As a dreamy child who spent her time reading novels, I was the exception in a very medical family. My father met my mother when he taught bacteriology to nursing students; later he became a doctor, as did two of my siblings. I was the one who never got above a C in biology. But while writing my book, when I needed to understand how the plagues traveled to medieval Europe or how the 19th century discoveries of Koch and Pasteur transformed our understanding of disease, I realized that biology is fascinating. My parents are dead now, but I like to imagine them in some celestial reading room, where they pass The Dirt on Clean back and forth while discussing their least scientific child. “Did you read her summary of the germ theory?” my father asks fondly, and my mother replies, “And wait until you get to her discussion of the Hygiene Hypothesis!”