我们是否可以通过检测头发样本来确定一个人有没有吸食大麻呢？而我们又能不能确定检测结果呈阳性时是因为被检测者主动吸食了大麻还是曾置身于有大麻烟的环境呢？近日发表在Drug Testing and Analysis上一篇文章对大麻烟在头发表面残留的时间进行了研究，试图找出更精确的方法来进行检测。该项研究针对三名参与者开展了分析，这三名参与者连续三周在每个工作日都会置身于有大麻烟的环境。
对头部不同区域的30多份头发样本的的检测发现，在被动接触大麻烟后的七周时间内，都能检测出大麻残留物质。因此，研究结果表示，燃烧大麻的烟雾能对头发产生大量且持续的大麻素污染。
Exposure to Passive Cannabis Smoke Contaminates Hair for Seven Weeks
From: Drug Testing and Analysis
Is it possible to test for cannabis use by sampling a suspected user’s hair, and could you tell if a positive result is due to use or third-hand passive smoking? Research in Drug Testing and Analysis explored condensation of cannabis smoke on hair surface to discover a more accurate method of testing for external contamination. The research analyzed three participants who were exposed to the smoke of one joint every weekday over three weeks.
Traces of 30 hair samples from various regions of the head were obtained up to seven weeks after exposure. The results demonstrated that sidestream cannabis smoke can lead to a considerable and persisting cannabinoid contamination in hair samples.
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