INTERPRETING THE NUMBERS
The "1.52mg per litre" level in Cobain is one several standard measurements referring to the blood level of morphine. For example, 1.52 mg per litre could also be expressed as "152 mcg per 100 ml," because mathematically they are the same amounts. Those unfamiliar with metric conversions should note that basically, a litre is 1000 ml, so 1 mg per 1000 ml is equivalent to 0.1 mg per 100 ml. Those of you more familiar with metric will note that 100 ml is one-tenth of a litre, thus the abbreviation "dL" stands for "decilitre," which is of course the very same 100 ml. Throughout this report, whenever a source is quoted using a blood drug amount in a format other than mg per litre, I have supplied a non-italicized, bracketed conversion following the quoted figure, eg. "93.0 mcg/dL...(0.93 mg/L, ed.)."

TESTING METHODS ACCURATE
Approximately 25 years ago, it became increasingly clear that accurate postmortem detection of morphine in blood was a problem which had finally been resolved scientifically. Garriott & Sturner, in 1973, note that "With the recent advent of improved methodology for the determination of morphine in the blood...it has now become possible to quantitate small amounts of this narcotic drug metabolite some time after the last previous heroin injection (28)." Nakamura explained in 1979 that "Until recently, the toxicologic determination of heroin death was extremely difficult because of the lack of a sensitive method for the detection and quantitation of small amounts of morphine in postmortem blood and other tissues. " (63). Data is not available regarding the testing method used to determine the level of morphine in Cobain's blood, although the scientific literature suggests strongly that GC (Gas Chromatography) is the current standard method. Other major testing methods exist, such as GLC (Gas-Liquid Chromatography), GC-MS (Gas Chromatography-Mass Spectroscopy), HPLC (High Pressure Liquid Chromatography), RIA (Radio-immuno Assay), and all of these methods have been determined to be very reliable indicators for establishing the levels of morphine in postmortem blood.

HEROIN TURNS INTO MORPHINE
There will be no discussion blood "heroin" levels, because heroin is almost instantly transformed into morphine when it enters the blood. Heroin itself can indeed be measured in the blood and other tissues, especially the urine, but it should be noted that heroin levels are largely irrelevant to this case. Special laboratory conditions are often elaborately constructed to measure these actual "heroin levels," because in everyday life they almost never exist. Again, simply put, when heroin is injected into the blood it rapidly transforms into morphine. There is virtually no heroin left in the blood as "heroin" after about nine minutes, with the heroin going through a deacetylation process, sometimes called de-esterfication. This is known as a "pharmakokinetic" process, and is known to continue after death. Consequently, it is virtually always that morphine, instead of heroin, is measured in the blood of both the living and dead to give forensic scientists an indication of the amount of heroin originally injected, the likely time of injection, and very importantly, an indication as to the events following the injection. Morphine toxicity, whether found in the blood, bile, urine, liver, or other tissues, is the standard measurement for opioid toxicity in general, and heroin in particular, because heroin immediately turns into morphine in the body.

TOLERANCE TESTS IN SEVERE ADDICTS
One study involved a small group of severe addicts who used high doses ranging from 150 mg to 200 mg of morphine four times daily (75). This is equivalent to an intake of approximately 45 mg to 60 mg of heroin, four times daily. These addicts showed some signs of serious effects, but continued for several years without fatality and showing average blood levels of 0.3 mg per liter. Another study points to the potential lethality of even low doses, with 5 fatalities showing an average of a mere 0.021 mg per liter of blood, representing an approximate intake of 3 mg, i.e the average functioning dose. The average person without pain or addiction will overdose with 60 mg of morphine (18 mg heroin), yet a patient in serious pain will likely require the same dose, 60 mg of morphine (18 mg heroin) to relieve such serious pain symptoms. Platt also mentions a particular study where severe heroin addicts were monitored, and the maximum dose seen was a daily total of 260 mg heroin, taken in four divided doses, i.e. 65 mg heroin each dose (75). Again, the maximum lethal dose of heroin is shown to be 75 mg - 80 mg for a 150 lb. severe addict. Such a lethal dose, of about 75 mg - 80 mg heroin, will give the soon-to-be-dead individual a blood morphine level of approximately 0.5 mg of morphine per litre of blood. Astonishingly, this is less than one-third of the level that was found in Cobain's tiny body at least three days after his death.