parts per million


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parts per million

The parts of a substance per million parts (by weight) of a solution; equal to 0.0001%. Abbr. ppm.
References in periodicals archive ?
Deftly layering humor, strong rhetoric, and human complexity, Parts per Million is inspiring without being preachy and gives a sense of the individual's role in fighting the wrongful status quo.
Vranka said EPA doesn't know how the sand play area could have less than 70 parts per million in 2003 and 725 parts per million in 2017.
It was only a matter of time that we would average 400 parts per million globally, "said Pieter Tans, lead scientist at NOAA's Global Greenhouse Gas Reference Network.
Levels are now growing about 2 parts per million per year - 100 times faster than at the end of the Ice Age.
The researchers found that the natural relationship displays a strong rise in sea level for CO2 increase from 180 to 400 parts per million, peaking at CO2 levels close to present-day values, with sea level at 24 +7/-15 metres above the present, at 68 per cent confidence limits.
2] was about 400 parts per million; the present-day level is 387 parts per million and is predicted to rise due to man-made carbon emissions.
Around the world, people held rallies aimed at focusing attention on the number 350 because scientists have insisted in recent years that 350 parts per million is the most carbon dioxide we can safely have in the atmosphere.
The normal level of CO for a non-smoker depends on background levels in the air, but it is usually between 0 and 8 parts per million.
Parts per Million raises important questions concerning civic and corporate responsibility, environmental toxicity, oil dependence and the restriction of public information.
In 2000, state toxics investigators detected methane gas between two portable classrooms measuring 150,000 parts per million -- three times the limit at which methane becomes explosive.
Lab tests indicate that nahcolite would precipitate out of salty, alkaline lakes only if atmospheric concentrations of carbon dioxide were above 1,125 parts per million (ppm), Tim K.
The new EPA guidelines mean that sulfur in gasoline must be reduced from 80 parts per million to 30 parts per million.