Wearing work gloves, Stephanie Smith stood at North Avenue Beach, ready to take a quick stroll down to the water and back.

It had been a few weeks since the city's beaches opened and a new smoking ban had taken effect. So Smith, of the environmental organization Alliance of the Great Lakes, wondered: How many cigarette butts would she find?

Stuffing the butts into an Old Navy plastic bag—"Reuse and recycle, right?"—Smith paced in semihunch like a clue-hungry detective, her eyes narrowing into sharp focus as she plucked scraps from the damp sand. "It's hard to tell how long they've been here and that's part of the mystery," she said. "A lot of these are probably leftovers from a few days ago. Or even last season. Who knows?"

One thing is for certain: Smith never waited longer than a quick five-count before finding another butt, or a fistful. Filters were scattered everywhere, from water's edge to inches from new "NO SMOKING" signs adorning the north face of lifeguard stands. At the beach house—where similar signs were curiously, conspicuously absent—Smith dumped the contents onto a table. Though damp and in many cases shriveled with age, the butts reeked like an ashtray inhaled at close range. Smith recoiled in disgust.