While legislation regardingmedical and amateur cannabisuse may have been relaxed in numerous country over recent geezerhood , driving while stoned remain a reprehensible offense everywhere , and for good reason . However , enforce this vulgar - sense police is not as easy as it might vocalize , with novel enquiry indicate that roadside tests for marihuana are wildly inaccurate . Tetrahydrocannabinol(THC ) , the main psychotropic chemical compound in cannabis , has been found to slow reaction times and impair wakefulness in driver , while also reducing their power todrive in a straight line . Because of these and several other reason , police in many legal power have a bun in the oven roadside testing kits that are supposed to give away if a person has any THC in their spit . However , an as yet unpublished paper by researcher at the University of Sydney find that the examination devices used by officers in New South Wales give put on results 20 percent of the time . The discipline generator conducted an raiment of tests on hundreds of drivers who had been given vary concentration of THC , to see how this affected their driving . When they then try participants ’ saliva , they were shock at the imprecision of their results . utter toABC News , pass researcher Ian McGregor explained that “ we had someone test electropositive for THC who was using a placebo , ” while others who had ingested gamey tightness of the compound tested negative . This research follow on from a paper that appear earlier this year in the journalPublic Health , break down the performance of the eight most commonly used roadside examination machine . The generator found that on the whole , these kits were very bad at detect high concentration of THC in spit , meaning the great unwashed who are dangerously high could come back a negative sampling . Furthermore , the tendency of these gadget to detect marijuana in the spittle of those who have not smoked elevate the opening that they may be picking up THC from passive smoke . This had antecedently been thought unacceptable , and the result of this enquiry therefore reveal just how much we do n’t know about the drug ’s interactions with the body . For this reasonableness , an Australian woman who tested positive for marihuana while driving recently had her charge dismissed after police force could n’t disprove her claims that she had ingested THC through passive smoking . Most wayside examination devices are thought to be capable to detect cannabis for up to four hours after use , and when someone tests positive , samples are send to a testing ground for further examen . THC canremain detectablein urine for up to a month , in blood for around two weeks , and in pilus for three months . However , even these lab trial are not without their limitations , as one survey found thatmarijuana smokecan get into the hair of nearby non - smokers . All things look at , it seems the best option is to just not push .
[ H / T : ABC News ]
