The phrase "a persistent source of" is correct and usable in written English.
It can be used to describe something that consistently provides or causes a particular effect or situation over time.
Example: "The factory has been a persistent source of pollution in the nearby river."
Alternatives: "an ongoing source of" or "a continual source of".
This is a persistent source of strain and conflict in modern societies.
The ideology of American lawyers has been a persistent source of discussion and debate.
However, corruption allegations have been a persistent source of trouble for the DPA.
But the economy, he said, "is a persistent source of discontent," unlike the other two, which can ebb and flow depending on daily events.
China's military exports, particularly weapons sales to Pakistan and Iran, have been a persistent source of tension in relations between China and the United States.
Control over the site has been a persistent source of friction between Israel and the Palestinians, and has sparked violence between the two sides.
Besides detecting the powerful FRBs, the team also observed an ongoing, persistent source of weaker radio emission in the same region.
This is of notable importance because residual NAPL can act as a non negligible persistent source of contamination.
American and allied forces have choked the flow of foreign fighters coming into Iraq from Syria and Iran, curbing a small but persistent source of combatants that has fueled the insurgency, especially in the Sunni Muslim heartland, American military officers said Monday.
Furthermore, 70% of patients with VAP have been reported as having identical pathogens present within the endotracheal tube biofilm as encountered in the lung [8], suggesting that the biofilm represents a significant and persistent source of pathogenic bacteria.
Another persistent source of Arab human insecurity is high unemployment.
