wo

REFERENCES

+ Bailey K. The value of the Duquenois test for cannabis, a survey.

J. Forensic Sci. 1979; 24(4):817-41.

« Hawks R. The constituents of cannabis and the disposition and metab—

olism of cannabinoids. In: Hawks RL, ed. The analysis of cannabinoids
in biological fluids. NIDA Research Monograph 42:125-37. National
Institute of Drug Abuse’, Rockville, MD, 1982.

Lacefield DJ, Roberts PA, Blossom CW. Agricultural aviation versus
other general aviation: toxicological findings in fatal accidents.
Report No. FAA-AM-78-31. Washington, DC: Federal Aviation Adminis-—
tration, Office of Aviation Medicine, 1978.

Schwartz RH, Hawks RL. Laboratory detection of marijuana use.
J. Am. Med. Assoc. 1985; 254:788-92.


Although field investigators were asked to obtain samples on all
pilot fatalities, only 35.7 percent (or 289 of the 809 pilots killed who
were sampled for other toxicological reasons) were sampled for marijuana in
the 2-year period of October 1982 through September 1984.

FINDINGS.

Six (2.1 percent) of the 289 samples yielded a positive test for mari-
juana. Supplemental verification that the positive tests corresponded to
recent marijuana use was obtained from relatives or business associates in
five of the cases. Although a large amount of marijuana was found in the
wreckage of the sixth case, associates were advised by counsel not to discuss
the pilot's habits.

DISCUSSION.

The finding of cannabinoids in finger and mouth washings cannot be
used as evidence that the individual was under the influence of the drug,
but only indicates a relatively recent use of marijuana. Although sensi-
tive immunological techniques are available for urine metabolites, past
use cannot be determined more specifically than 1 hour to possibly as long
as several weeks prior to testing because of the relatively long detection
period of cannabinoid metabolites in urine; but since tetrahydrocannabinol
(THC) does not traverse the blood-saliva barrier, that found in mouth
washings was sequestered during smoking (2,4). Depending on food and
drink intake, THC is not detectable after about 12 hours in saliva.

To this point in our routine toxicological screening, we have not
quantified THC or its metabolites in the blood, but three techniques are
available for the quantitation of THC and the two important metabolites
9-carboxy-THC and 11-hydroxy-THC in blood and urine. Gas chromatography,
high-performance liquid chromatography, and mass spectrometry are all
capable of measuring in the low nanogram-per-milliliter range under
optimum operating conditions.

In spite of the technical capability to measure THC, 9~COOH-THC,
and 11-OH-THC, a controversy persists amoung workers in the field of
marijuana detection as to the meaning of levels usually seen. The half-
life of THC is about 10 minutes in the blood; thus, 88 percent will have
disappeared by the time of maximal psychological effect, assumed to be
approximately one-half hour after initiation of smoking THC. A plasma
level of 10 ng/mL is probably still indicative of "under the influence,"
and 20 ng/mL is accepted as "intoxication." A great deal of work remains to
be done before the meanings of specific levels of THC are clear and any
given level may be related to the performance of a pilot in any specific
accident. As part of an expanded profile of testing for drugs of abuse,
we will be adding qualitative and quantitative blood and urine marijuana
determinations to the future toxicological screening profile, and we may
be able to contribute data to the relevance of specific marijuana levels
in aviation accident causation.




Technical Report Documentation Page

T. Report No. 2. Government Accession No.

DOT/FAA-AM~85-8

3. Recipient's Catalog No.

‘4. Title ond Subtitle
Drugs of Abuse in Aviation Fatalities: 1. Marijuana

5, Report Date

AUGUST 1985

étbsrt J. Lacefield, Patricia A. Roberts, and
Paula M. Grape

6. Performing Orgonization Code

2

[8. Performing Organization Report No.

DOT/FAA-AM-85-8

9. Performing Orgoni zation Nome ond Address
FAA Civil Aeromedical Institute

P.O. Box 25082
Oklahoma City, Oklahoma 73125

10. Work Unit No. (TRAIS)

11. Contract or Grant No.

12. Sponsoring Agency Name ond Address
Office of Aviation Medicine

Federal Aviation Administration
800 Independence Avenue, SW.
Washington, DC 20591

13. Type of Report and Period Covered

OAM Report

Ta. Sponsoring Agency Code

15. Supplementary Notes

This work was performed under task AM-A-83/84-TOX~47,

16. Abstroct

Isopropyl alcohol swabs taken from the oral cavities of pilots killed in general
aviation accidents were analyzed for marijuana by the modified Duquenois—Levine

test.

During the 2-year period from October 1982 through September 1984, 289

pilot fatalities (of 809 sampled for other toxicological reasons) were sampled

for marijuana; a positive test indicated the recent use of marijuana.

pilots' samples (2.1 percent) were positive.

Six of the

17. Key Words
Marijuana

Drugs of abuse
Toxicology
General aviation

18. Distribution Stotement
Document is available to the public
through the National Technical Information
Service, Springfield, Virginia 22161,

19. Security Classif. (of this report) 20. Security Classif. (of this page)

Unclassified Unclassified

21. No. of Pages | 22. Price

3

Form DOT F 1700.7 (8-72)

Reproduction of completed page authorized





DRUGS OF ABUSE IN AVIATION FATALITIES:
1. MARIJUANA

INTRODUCTION.

The indiscriminate use of drugs, both legal and illegal, can have an
unfavorable effect on a pilot's ability to think and perform in a manner
consistent with safe and successful flying. Medical certification by the
Federal Aviation Administration (FAA) is necessary before a pilot's
license can be obtained and maintained, and many medical conditions requiring
the use of drugs are disqualifying for certification. However, the ready
availability of stimulants, sedatives, tranquilizers, hypnotics, and hal-
lucinogens has led to their abuse by a significant segment of the popula-—
tion. Toxicological analyses of body tissues and fluids from over 5,000
pilots killed in general aviation accidents during the time period 1968-
1984 have revealed the use of compounds from each of the aforementioned
groups. The role of the legal drug ethyl alcohol in aviation fatalities
has been reported previously (3).

In 1982, the FAA undertook a project to determine the number of
private pilots involved in fatal aviation accidents who used marijuana.
The project was carried out as an addendum to the usual postaccident
toxicology analysis done on victims of fatal accidents. Kits for the
collection of samples from fatalities are maintained at select FAA,
National Transportation Safety Board (NTSB), state and local medical
examiners', and aviation medical examiners' (AME) offices. The usual
supplies in these kits were supplemented with isopropyl alcohol swabs
in snap-cap vials; instructions for swabbing the fingers and oral cavity
were provided. The alcohol swab technique for marijuana detection was
chosen because of the ready availability of sealed test packets; in con-
trast, petroleum ether is utilized by most laboratories. Although solu-
bility of marijuana is high in both solvents, the ease of distributing
the collection media dictated our choice.

METHODS.

In an extensive review that encompassed 400 herbally derived and
botanical materials, Bailey (1) stated, "There is no published report of
an obviously botanical material apart from cannabis that gives a positive
Duquenois-Levine test.'"' Because of the highly selective nature of this
test, it was chosen for this study rather than thin-layer chromatography,
which yields some 3 percent false positives.

The marijuana-containing swabs were extracted with petroleum ether,
and the extract was evaporated to dryness; this residue was then reacted
with the Duquenois reagent. One minute later, concentrated hydrochloric
acid is added to the reaction mixture; this mixture is subsequently ex-
tracted with chloroform. If marijuana is present, a blue-purple color is
seen in the acid phase and a violet hue is transferred to the chloroform
layer.

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