The phrase "a strong negative effect" is correct and usable in written English.
It can be used when discussing the impact of something that is detrimental or harmful in nature.
Example: "The new policy has had a strong negative effect on employee morale and productivity."
Alternatives: "a significant adverse impact" or "a considerable detrimental effect".
The results of both designs suggest that intelligence has a strong negative effect on religiosity.
We found that agricultural land cover at the local scale had a strong negative effect.
They report that "both increases in taxes and increases in government spending have a strong negative effect on private investment spending.
This habitat loss has had a strong negative effect on many meadow-living insect populations, including butterflies.
A strong negative effect related to ΔNDVI was also observed, suggestive that new growth lowers average stress levels.
Poverty means poor nutrition, substandard health care, environmental toxins and little access to books, all of which have a strong negative effect on school success.
Though crabs were predicted to have a strong negative effect on oysters via direct predation, the presence of oyster drills had the strongest impact on oyster survival.
We find a strong positive effect of diet/caloric intake and a strong negative effect of smoking on weight and BMI.
Results indicate that exposure to disadvantaged neighborhoods, particularly during adolescence, has a strong negative effect on high school graduation and that this negative effect is more severe for children from poor families.
High temperatures had a strong negative effect on corn yield response in the United States, in agreement with the data, but the predominate effect of heat in the model was via increased water stress.
In addition, there was a strong negative effect of Fe on coral calcification, since Fe enrichment partially inhibited the positive effect of manganese on calcification rates under thermal stress.
