article_snippet.sent: The researchers, whose work is published in the journal Geophysical Research Letters, found that concentrations of desflurane reached 0.30 parts per trillion in 2014.
article_snippet.sent: Isoflurane, sevoflurane and halothane have reached 0.097, 0.13 and 0.0092 parts per trillion in the atmosphere respectively.
article_snippet.sent: The researchers, whose work is published in the journal Geophysical Research Letters have been taking air samples from remote sites around the Northern Hemisphere since 2000 while The researchers, whose work is published in the journal Geophysical Research Letters have also obtained air samples in the North Pacific and the South Shetland Islands in Antarctic.
article_snippet.sent: The researchers, whose work is published in the journal Geophysical Research Letters also used two hourly measurements at a high altitude observatory at Jungfraujoch, Switzerland since 2013 to track anaesthetic gases.
article_snippet.sent: The researchers, whose work is published in the journal Geophysical Research Letters then used computer modelling to produce global estimates for the concentrations of anaesthetic gases.
highlights_snippet.sent: New study finds New study concentrations are relatively low but are increasing .
  