The phrase "a deadly effect" is correct and usable in written English.
It can be used to describe an impact or consequence that is lethal or extremely harmful.
Example: "The new virus has a deadly effect on those with weakened immune systems."
Alternatives: "a lethal impact" or "a fatal consequence".
Tourists and governments accept that too much tourism can have a deadly effect on the environment and nature.
[Page C10.] Lighter Cars May Cost Lives Federal auto regulators released a study that asserts that reducing vehicle weights would have a deadly effect over all.
It was my sense that the environmental disaster, so long misrepresented by the polluting chemical companies, had a deadly effect upon all who lived in its vicinity.
IN "THE RING", a Hollywood remake of a Japanese horror film, a videotape has a deadly effect on those who watch it.
It means that even when the individual risk factors are low, they can have a deadly effect when combined with others on the list.
Social media has also had a deadly effect in India, where a recent spate of mob lynchings were linked to child abduction rumours spreading over WhatsApp.
Before Jamie Dornan made his debut as kinky billionaire Christian Grey in the big-screen adaptation of "Fifty Shades of Grey," the 32-year-old Irish actor was playing another guy with a fetish -- one with a more deadly effect -- in the BBC's psychological crime thriller "The Fall".
But, with accusations flying of ballot-stuffing and ghost voters, the concern is that tensions might boil over in the intervening weeks and that the Taliban might renew their vow to disrupt the electoral process with a more deadly effect the second time around.
One of the most common herbicides atrazine appears to have an added deadly effect: It makes tiger salamanders more vulnerable to certain infections.
In "that vein, I quote from another socialist who mastered 'big lie' propaganda to a maximum, and deadly, effect," Brooks added before reading a section from Mein Kampf, which he failed to mention was written by Hitler about Jews.
The centrepiece was his heroic, muscular and glistening Tamburlaine in Peter Hall's 1976 defiant staging of Marlowe's two-part mighty epic, twirling an axe to deadly effect.
