Robin Nagle's "Picking Up," about the Department of Sanitation in New York City, is a mostly riveting book with mildly uneven aspects. Riveting, of course, because the subject itself is, to some degree, fascinating: We'd rather not think about the curb-dragged bag of dirty diapers, yet who isn't at least slightly amazed by the fact that Manhattan itself has been extended into the Hudson and East Rivers by building on its own trash?

Nagle's central claim is best articulated in her "postlude": "It's wise to remember how profoundly we depend on the slender vanguard of Sanitation that stands between our lives and the torrents of waste that would otherwise overwhelm us." Sanitation workers (known as "san men") of course end up saving us from ourselves, from the waste that is the side effect and packaging of our own desires, and Nagle spends a good bit of time detailing the fact that many of us think of these workers almost the way we think of the trash they collect: We'd like it all to be invisible.

Nagle, a professor at NYU and the Sanitation Department's anthropologist-in-residence, worked routes with these men and women, collecting trash, riding in street sweepers and plowing snow, and the reader is given a welcome-to-the-world view of things. Some of what you'd expect — like any mention of the Mafia's supposed association with trash collection — is absent, and some of what you absolutely would not expect — episodes that cast a fairly harsh light on workers — is here. In the chapter "Lost in the Bronx," for instance, she writes of a san man who, to stick it to his foreman, drives aimlessly around the Bronx for hours like a petulant child, Nagle in a truck behind him, both of them wasting fuel and leaving trash unpicked-up.

That story, however, is an outlier. Nagle spends more of her time documenting the job's hazards and history, from listing particularly gruesome ways sanitation workers have been killed on the job (it's the nation's seventh-most-hazardous occupation) to devoting a chapter to an 1892 storm that swept garbage barges and their crew 150 miles to sea (though eventually recovered), to detailing the rich jargon of the industry (for instance, "mongo," the term for objects retrieved by sanitation workers from the refuse, used as both a noun and a verb), to detailing battles between bureaucratic efficiency-boosting measures and the harder algebra of the actual work of sanitation collection. Some of these aspects stretch even the most curious reader's engagement (the details of trash collecting in the 19th century is not a conversation topic for a reason), but the book has plenty of other rewards for the engaged reader.

Weston Cutter is from Minnesota and the author of the story collection "You'd Be a Stranger, Too."