The phrase "a harmful impact" is correct and usable in written English.
It can be used when discussing the negative effects or consequences of an action, event, or situation.
Example: "The study revealed that pollution has a harmful impact on marine life."
Alternatives: "a detrimental effect" or "a negative influence".
"There is a harmful impact and, ironically, the people it most harms are the ones people are most engaged with and have most respect for – the songwriters, composers and musicians.
No, this technology may have a harmful impact on my behavior.
Nutt and his colleagues argued that the limitations of cannabis research had had a harmful impact on UK pharmaceutical productivity.
There has been concern for instance that Scottish government decision to reduce air passenger duty is going to have a harmful impact on airports in northern England.
Giant quantities of fats and sugars have not, historically, been available to a developing fetus, so it wouldn't be surprising if they do have a harmful impact.
We have significant concerns that reducing support will not only have a harmful impact on financial wellbeing but will also push disabled people further from the workplace".
Natalie Molnar, who founded the Mulan petition, writes that so-called whitewashing has a "direct, harmful impact on not only the movie itself but the audience".
The committee heard claims that the charity's founder, Camila Batmanghelidjh, would write to ministers warning that without more state cash the charity would fold, with a potentially harmful impact on the prime minister's "big society" agenda.
While it is important to socialize, be aware that these things can have a more harmful impact on you than your peers.
Alcohol consumption has a substantial harmful impact on the HIV epidemic in sub-Saharan Africa.
Excess mortality might have potentially resulted from using too many drugs and/or too complex drug regimens, leading to undesirable drug drug interactions with a potentially harmful impact on patients' health.
