The phrase "a general reduction in" is correct and usable in written English.
It can be used when discussing a decrease or decline in a broad or overall sense, often in contexts like economics, health, or statistics.
Example: "The study indicated a general reduction in air pollution levels over the past decade."
Alternatives: "a widespread decrease in" or "an overall decline in".
"People nowadays, because there has been such a general reduction in quality of service, they have lower expectations about flying.
Saturday's bombings, like many recently, appeared intended to kill Shiite civilians and inflame sectarian tensions that continue to simmer despite a general reduction in violence in recent years.
But the attacks have declined in frequency and scale since late 2004, mirroring a general reduction in the pace and intensity of guerrilla fighting in Russia's southwest.
This situation has contributed to a general reduction in risk capital directed towards life sciences compared to other industries.
Whether a general reduction in salt intake reduces or actually enhances cardiovascular mortality in man remains an issue of controversy.
There has been a general reduction in magnitudes of flooding, erosion, and sedimentation since the mid-20th century, largely in response to better land conservation practices.
Gait patterns of the elderly are often adjusted to accommodate for reduced function in the balance control system and a general reduction in skeletal muscle strength.
Such spending and tax cuts, and a general reduction in tax revenues because of a slowing economy, will push this year's budget deficit to about 3percentt of G.D.P., a modern record.
Notably, at 35 dpf, the differences in proliferation between the islet's anterior and the posterior regions equalized, together with a general reduction in the overall percentage of proliferating cells (Fig. 6d, e).
For visual form recognition, a significant effect of time was found (F 2,18)=15.4, P<0.001), due to a general reduction in the number of correct recognitions in the course of the day.
The experimental results showed a general reduction in the properties of the concrete cast and cured outdoors, especially the concrete which did not receive adequate moist curing.
