The phrase "at such low levels" is correct and usable in written English.
It can be used when discussing quantities, concentrations, or measurements that are notably minimal or below a certain threshold.
Example: "The chemical was found to be effective even at such low levels in the environment."
Alternatives: "at these minimal levels" or "at these reduced levels".
When asked what the chances were that Contador's positive test, even at such low levels, was a result of the meat he ate, Ramos said, "I can say 99 percent, it's impossible".
The last time it was at such low levels was January 1966.
Just because a residue exists does not mean it is toxic at such low levels.
With trust at such low levels, the question of how to rein in bad police is all the more pressing.
They reasoned that, even at such low levels, this O2 may have been sufficient to feed aerobic, sterol-producing organisms.
Moreover, students in Edison schools start at such low levels that they are more likely to make larger gains than students at better schools.
This is important because three of the four remaining populations of saiga are at such low levels that an event like this could wipe them out completely.
With oil prices at such low levels, it's hard to see shareholders approving other companies' projects soon.
They should not, however, assume that the spike will be a one-off, since grain stocks are at such low levels that bad harvests in 2013 would see rocketing prices, probably accompanied by panic-buying, export bans and food riots.
As students of high-school chemistry will already have deduced, AgION uses ions of silver -- Ag" on the periodic chart -- which is toxic to microorganisms but safe, at such low levels, for humans.
"Key question: When has the stock market fallen sharply when this ratio has been at such low levels?" The answer is "never," but some analysts prefer to say "not yet".
