parts per million (ppm)

基本解釋

One group ate food with 0.3 parts per million (ppm) methylmercury, which most U. S. states would regard as too high for human consumption.
一組的食物含千萬份之三的甲基水銀，這個含量在美國大多數(shù)州都被認為是超出人體承受的。
However, none of the melamine concentrations in the eggs exceeded the FDA's maximum allowable level -- 2.5 parts per million (ppm) in foods.
然而，所產雞蛋中的三聚氰胺含量都沒有超過美國食品與藥物管理局設置的最高允許水平——食品中含2.5ppm的三聚氰胺。
Levels of the gas at the Zeppelin research station on Svalbard, northern Norway, last week peaked at over 397 parts per million (ppm), an increase of more than 2.5ppm on 2008.
挪威北部斯瓦爾巴群島上的齊柏林研究站上周記錄的二氧化碳氣體水平最高值超過397個百萬分點，比2008年的水平增加了2.5個百萬分點。

According to Roberto, the wastewater starts with about 35, 000 parts per million (ppm) of gunk and junk.
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Using a technique called secondary ion mass spectrometry, the team determined that the mantle from which the meteorites derived contained between 70 and 300 parts per million (ppm) of water.
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Before we started torching carbon stored in forests and then carbon stored underground as coal and oil, the carbon dioxide concentration of our atmosphere was about 280 parts per million (ppm).
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