The phrase "approximately the same level as" is correct and usable in written English.
You can use it when comparing two or more things that are similar in degree, quality, or quantity, but not exactly equal.
Example: "The two candidates have approximately the same level as each other in terms of experience and qualifications."
Alternatives: "roughly equivalent to" or "about the same degree as".
The vaginal impedance during diestrus reached approximately the same level as on the weaning day.
They "were able to reduce the noise level to approximately the same level as a quiet land station," the Geophysical Union said in an accompanying article.
After 30 min annealing at 650 °C, the hardness of the shear bands and their matrixes reduced to approximately the same level as they were before deformation.
For 2016, the emissions from India (11.1 Mt yr−1, 9.5 12.6 Mt yr−1 considering the range of OMI/bottom-up ratios) are at approximately the same level as China (7.5 11.6 Mt yr−1).
The Gini coefficient reached in 2006 approximately the same level as in the second half of the 1990s, before the start of the 1999 2001 recession.
However, a splice variant was detected in the testis, and it was expressed at approximately the same level as the full-length BORIS mRNA.
ABGP polypeptides are expressed late in postnatal development to approximately the same levels as ankyrin, and comprise a significant fraction of brain membrane proteins.
This is apparently not because of a lack of expression of Arp in embryos: Arp mRNA is present at approximately the same levels as Ape1L and Ape2 mRNAs (M. Belmonte and J. Harada, NCBI gene expression omnibus accession number GSE11262).
Immunoblots probed with antibodies that recognize all three major carboxysome shell proteins (CsoS1A, CsoS1B and CsoS1C) clearly showed that the CsoS1 proteins were present in all mutant carboxysomes and empty shells at approximately the same levels as in the wild type (Figure 7A,C).
Western blotting with the anti-His antibody reveals that each mutant is expressed at approximately the same levels as WT LacY.
This makes it reasonable to estimate that pool workers have been exposed to NCl3 at approximately the same levels as reported in this study.
