The phrase "a persistent smell" is correct and usable in written English.
It can be used to describe a smell that continues to be noticeable over time, often in a negative context.
Example: "After the rain, there was a persistent smell of damp earth that lingered in the air."
Alternatives: "an enduring odor" or "a lingering scent."
— Maria Newman NBC Bay Area: A bacon-themed restaurant in the Upper Haight neighborhood, ordered to close because of "failure to alleviate a persistent smell of bacon," was reprieved at the last minute.
Concerned about a persistent smell following the installation of a new roof at Jordan Middle School during the summer, officials moved a class out of one classroom and relocated 11 administrators and staff members from the campus' main office while they try to determine its cause.
On probing, some participants reported that they were aware of a condition characterized by leakage of urine, persistent smell of urine following difficult delivery, or women who constantly used clothes pads to prevent leakage of urine.
Days before the explosion, other residents said they complained about a persistent gas smell.
When it came, as a bundle of pale, waxy sticks which one had to keep under water, it had, nonetheless, a persistent garlicky smell — and this, I imagined, was the irremovable residue of its beastly, slaughterhouse origins.
Wear clean clothing, and remove mold from your house that may contribute to a persistent, unpleasant smell in clothing or accessories.
For years, Mid-Market has been a seedy, crime-plagued neighborhood so desolate that famed San Francisco Chronicle columnist Herb Caen once called it "le grand pissoir" for the persistent smell of urine.
We don't know for sure right now, but we think there may be people who permanently lose their sense of smell after this kind of episode". After a period of time, some victims report sensing a persistent, strange odor.
Once, McGinley said, there was a scene that called for a persistent, low-level gasoline smell.
Herman Miller, the Michigan-based manufacturer, acknowledges that 625 Aeron chairs were delivered with padded armrests that retained a persistent and distinctly unpleasant smell.
