Sentence examples for background levels of oil from inspiring English sources

After previous spills, NOAA has reopened fisheries when normal background levels of oil were detected in fish or shellfish samples.

Measurements in September of 1990 showed that the proportion of oil degrading bacteria had returned to background levels of under 1% of the total bacterial populations in pore waters.

The new study of 11,309 drinking water wells in northeastern Pennsylvania concludes that background levels of methane in the water are unrelated to the location of hundreds of oil and gas wells that tap hydraulically fractured, or fracked, rock formations.

"We still find background levels of DDT and chlordane," he explained.

A non-smoker group provided background levels of BoE.

Only background levels of staining were observed (data not shown).

Background levels of genetic alterations.

Although the general population is exposed to background levels of benzene, one of the major outdoor sources of personal exposure is vehicular exhaust; additionally, people living near chemical manufacturing facilities or oil refineries may also be exposed to elevated levels of benzene [ 4].

However, we previously reported that WKY rats exposed to Mount St Helen's ash, residual oil fly ash, or soluble zinc sulfate once weekly over 8 or 16 weeks, although having remarkable pulmonary pathology and slight increase in background levels of cardiac lesions, did not demonstrate as remarkable cardiac gene expression changes (Kodavanti et al. 2008) as seen presently in DE-exposed WKY rats.

Only background levels of 3-nitroTyr were detected with dONOO.

The fall-out reaching Scandinavia was only twice the natural background level of radiation.