Clinical Toxicology (2014), 52, 171–175 Copyright © 2014 Informa Healthcare USA, Inc. ISSN: 1556-3650 print / 1556-9519 online DOI: 10.3109/15563650.2014.888734

RESEARCH ARTICLE

Suicide by non-pharmaceutical poisons in San Diego County LEE CANTRELL1 and JONATHAN LUCAS2 1California

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2San

Poison Control System-San Diego, San Diego, CA, USA Diego County Medical Examiner Office, San Diego, CA, USA

Background. In 2010, 6,599 poisoning suicides were reported in the United States (US). While medications remain the primary substances involved in completed poisoning suicides, successful fatal poisonings with non-pharmaceutical substances occur with some regularity. The goal of this study was to identify successful suicides caused by non-pharmaceutical self-poisoning in a large US county over the last 12 years. Methods. A large US-county medical-examiner’s database was queried for all suicides in which exposure to nonpharmaceuticals was listed as the cause of death from 2000 to 2012. Substances were categorized by specific toxin when available and by product type when unavailable. Decedent age, sex, and circumstances surrounding each case were also reviewed. Results. Ages ranged from 18 to 95 (median 48) years. There were 159 (77%) males and 48 females. A total of 11 poisons were utilized. Discussion. Worldwide, intentional CO inhalation is a common method for committing suicide and intentional CO inhalation was the most common method of non-pharmaceutical self-poisoning suicide in our data. Other relatively common poisons including ethylene glycol and cyanide were employed in a relatively constant manner over time as well. Surprisingly, there have been an increasing number of helium-inhalation deaths in recent years. Conclusion. Inhaled toxins are the most popular (81%) in non-pharmaceutical suicides, likely due to their rapidity of death. Although much less frequently, individuals successfully employ a broad spectrum of other toxins to commit suicide. Keywords

Fatal; Poisoning; Inhalation

In 2010, 38,364 suicides were reported in the United States (US) for an overall rate of 12.1 per 100,000 population. The same year the national rate of fatal self-poisonings was 2.1 per 100,000 population.1 San Diego County has a population of approximately 3.1 million,2 covers 4,526 square miles, and has a varied population with urban and suburban areas and a large rural component. The Medical Examiner’s Office for San Diego County processes roughly 350 suicides annually, and investigated 371 (rate 12.0) suicides in 2010 and 413 (rate 13.1) in 2012. Firearms represent the most common method and are followed by intoxications or poisonings of any kind, with an average of 80 per year3 (rate 2.6/100,00). While pharmaceutical agents remain the primary substances involved in poisoning suicides, fatal self-poisonings with non-pharmaceutical substances occur with some regularity. The goal of this study was to identify the methods used over the last 13 years in fatal non-pharmaceutical self-poisoning in the 5th most populous county in the US.

cals was listed as the primary cause of death from 2000 to 2012 and a retrospective review was performed. These deidentified California death reports are in the public domain and do not require IRB review. California law requires that deaths known or suspected to be the result of suicide be reported to the Medical Examiner’s office. A death is certified as suicide after a thorough scene investigation, investigation of the individual’s medical and social history, postmortem examination, and toxicological testing. Intent to harm oneself must be demonstrated. All sudden and unexpected deaths as well as those known or suspected to be as a result of suicide routinely undergo a full autopsy. In all suspected suicides, toxicology screening and quantification is routinely performed using enzyme-linked immunosorbent assay (ELISA), gas chromatography–mass spectrometry (GC–MS), liquid chromatography–mass spectrometry (LC– MS), and gas chromatography–nitrogen phosphorus detector (GC–NPD). Poisons identified on screening were quantified in all cases unless, as in rare circumstances, appropriate blood samples were not available such as in delayed deaths or advanced decomposition. Substances were categorized by specific poison when available and by product type when unavailable. The circumstances surrounding each case along with age and sex were also reviewed.

Methods The San Diego County Medical Examiner’s database was queried for all suicides in which exposure to non-pharmaceutiReceived 23 October 2013; accepted 24 January 2014.

Results

Address correspondence to Dr. Lee Cantrell, California Poison Control System-San Diego, San Diego, CA 92103-8925, USA. Tel: ⫹(619) 4978501. Fax: ⫹(858) 715-6323. E-mail: [email protected]

There were a total of 213 fatal non-pharmaceutical selfpoisonings during the 13-year study period, with an average 171

172

L. Cantrell & J. Lucas All Suicides in San Diego County

Number of cases

500 400 300 200 100 0

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2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

Non-pharmaceutical poisonings

Medications (+/– ethannol)

All other methods

Fig. 1. All methods for suicides in San Diego County, 2000–2012.

of 16.3 per year. During this period, San Diego County saw 4,537 suicides (average 350 per year), with an overall increase in suicides in recent years. This increase is present when adjusted for population growth as well. Non-pharmaceutical self-poisoning deaths represented an average of 4.7% of all suicides with the comparative data available in Fig. 1. Age and sex breakdown by toxin can be found in Table 1. Temporal incidence by poison can be found in Table 2. Carbon monoxide (CO) sources are listed

in Table 3. Figure 2 lists poisons by gender in decreasing frequency.

Discussion In San Diego County over the 13-year period, the male:female ratio of non-pharmaceutical suicides was 3.3:1. This is similar to the overall ratio of male to female suicides by all methods over the same period (3.2:1). Nationally, the ratio

Table 1. Age and gender by poison. Poison Carbon monoxide Helium Ethylene glycol Cyanide Caustic/corrosive Rodenticides Brodifacoum NOS (Unknown) Zinc phosphide Strychnine Organophosphate insecticide Bag over head (non-helium substance) Duster aerosol (Difluoroethane) Auto Air conditioner refrigerant (Dichlorodifluoromethane) Starter fluid (ether, propane, butane, heptane) Nitrogen Hydrogen sulfide Gasoline Water Total

Age range (Years)

Median age (Years)

M

F

Total

19–89 18–95 20–81 20–88 35–79 28–59 55 59 35–52 28–31 31–75

45 56 40 34 58 44

77 50 7 8 5 5

26 15 5 1 1 1

57

1 2 2 4

103 65 12 8 6 6 1 1 2 2 4

26–62

53

3

1

4

1

1

26 62

1

1

56

1

1

1 3 1 1 164

1 3 1 1 213

49 25,38,70 40 34 18–95

48

49

M ⫽ male, F ⫽ female Clinical Toxicology vol. 52 no. 3 2014

Suicides by non-pharmaceutical poisons 173 Table 2. Number of deaths per year by substance. Substance

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CO Helium Ethylene glycol Cyanide Rodenticide Caustic Organophosphate insecticide Bag over head (filled with non-helium gas) Hydrogen sulfide Water Gasoline Totals

2000 13

2001

2002

6 2

5 4

2 1 1

1

2003 7 2

1 1 1

2004

2005

11 4 2

8 2 2

1

2006 6 3 1 1

2007 15 4 1

2008 9 4 2 1

1 1

1

2009

2010

2011

2012

Total

7 9 1 1 1

6 12 1

7 6 1

3 13 1 1

103 65 12 8 6 6 4 4

1 1

1 1

2

3 1

1

2

1 1

1 17

12

10

10

17

of male to female suicides by all methods is higher at 4.1:1,4 and the national male:female ratio for non-drug poisonings is closer to our data (3.5:1).4 Intentional CO inhalation was the most common method of non-pharmaceutical self-poisoning suicide (49% of all non-pharmaceutical self-poisoning cases) in our data and these cases temporally remained relatively constant throughout the study period. Similarly, worldwide, intentional CO inhalation is a common method for committing suicide.5 Despite the widespread implementation of catalytic converters in automobiles, the generation of CO from vehicle exhaust accounts for the majority of CO suicides in the US6 and our data reflected similar findings (Table 3). During the 13-year period of the study, 66% of the CO suicides were from vehicle exhaust. The intentional burning of charcoal in an enclosed area has also been reported to be another popular method in non-pharmaceutical selfpoisoning7 and this was the second most popular method for generating CO in our study, representing 33% of CO suicides. There were four additional CO suicides (neither vehicle exhaust nor charcoal) during the time period: one inhalation of CO from a pressurized cylinder tank, two from portable generator exhaust, and one CO poisoning from an intentionally-set house fire. Surprisingly, we found that helium inhalation was the second most common method of non-pharmaceutical selfpoisoning (31% of all cases), with an increasing number of deaths occurring over the last 4 years. All but one of the decedents were found with a hose or tube which was attached to helium tank and inserted into a plastic bag placed over their heads. One decedent fashioned a mask Table 3. Sources of carbon monoxide. Carbon monoxide sources Automobile exhaust Charcoal Generator House fire* Pressurized tank Total *Lethal CO level obtained. Copyright © Informa Healthcare USA, Inc. 2014

Cases 66 33 2 1 1 103

14

12

20

17

20

23

18

23

3 1 1 213

from a 15 oz. plastic spreadable butter tub attached to tubing which in turn attached to a helium tank. Many of the decedents with a bag over their head used a so-called “suicide bag”. This bag was specifically made for this purpose and has an elasticized opening lined by a soft material such as felt or terrycloth, often has a hole at the opening through which the tubing is passed, and may have a soft felt piece that fits over the end of the plastic tubing. This method was advocated by “right to die” activists as early as 19998 and first published in the medical literature in 2002.9 Subsequent studies have described increasing numbers of helium-related suicides outside of the United States.10 Three individuals placed bags over their heads and inhaled substances other than helium: a duster aerosol (difluoroethane), an auto air conditioner refrigerant (dichlorodifluoromethane), and starter fluid (ether, propane, butane, heptane). Overall, inhaled poisons accounted for 81% of all nonpharmaceutical self-poisoning deaths in our sample. The rationale for choosing this route of administration is likely ease of administration and product acquisition combined with the rapidity in which death occurs. As mentioned previously, many pro-euthanasia resources advocate the use of inert gasses (helium in particular) as the non-pharmaceutical self-poisoning suicidal method of choice.11 Step-by-step instructions can readily be found on the internet, including via video.12 In one particular text,13 authors assign ratings to various methods for committing suicide based upon eight criteria: reliability, peacefulness, availability, preparation and administration, undetectability, speed of effect, safety to others, and storage of materials until needed. Of all methods described, helium inhalation totaled a rating score second only to ingestion of pentobarbital, which has previously described as occurring within our region.14 Varieties of other poisons were utilized and were not particularly remarkable either temporally or quantitatively due to their ubiquitous availability (ethylene glycol, pesticides, household products). Noteworthy exceptions were three recent cases of hydrogen sulfide poisoning. This novel method of non-pharmaceutical self-poisoning was first described widely in Japan in 2007 and continues to be used with some regularity across the US.15 All cases involved

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174

L. Cantrell & J. Lucas

Fig. 2. Non-pharmaceutical poisonings in San Diego County.

males who mixed calcium polysulfide solutions with a strong acid in their closed vehicles. Characteristic warning notes were found on car windows in all three cases.

substantially rising proportion. As the findings of this study may not be unique to our region, forensic personnel and consulting toxicologists should be aware of developing trends in non-pharmaceutical self-poisoning.

Limitations While all cases were tabulated based on the listed primary cause of death, co-intoxicants were found upon postmortem analysis in many cases. It is impossible to determine the influence on ultimate demise that these substances contributed. Additionally, although California has legislation that mandate notification of the coroner or medical examiner following known or suspected suicides,16 there is no certainty that there was complete adherence to these regulations during the study period. In addition, an individual with an endstage disease who commits suicide using a helium tank and bag, could have a friend or relative to remove the bag and tank leaving no evidence of the suicidal act. In fact, the book Final Exit suggests removal of the bag and tank after the death. The helium-bag deaths often leave no physical finding on the body to suggest the method of death used and toxicological analysis for helium might not be performed. In this fashion, the death could be staged as a natural death and not reported to the medical examiner or coroner.9

Conclusions In our region, individuals successfully employed a broad spectrum of non-pharmaceutical poisons to commit suicide. Inhaled poisons are the most popular agents in fatal nonpharmaceutical self-poisoning, with helium representing a

Declaration of interest The author report no declarations of interest. The authors alone are responsible for the content and writing of the paper.

References 1. Baker SP, Hu G, Wilcox HC, Baker TD. Increase in suicide by hanging/ suffocation in the U.S., 2000-2010. Am J Prev Med 2013; 44:146–149. 2. United States Census Bureau, United States Department of Commerce, http://www.quickfacts.census.gov/qfd/states/06/06073.html. Accessed October 17, 2013. 3. Electronic case records of the San Diego County Medical Examiner, 2000–2012. 4. Centers for Disease Control and Prevention, National Center for Injury Prevention and Control. Web- based Injury Statistics Query and Reporting System (WISQARS) [online]. Accessed January 5, 2014. 5. Denning DG, Conwell Y, King D, Cox C. Method choice, intent, and gender in completed suicide. Suicide Life Threat Behav 2000; 30:282–288. 6. Mott JA, Wolfe MI, Alverson CJ, Macdonald SC, Bailey CR, Ball LB, et al. National vehicle emissions policies and practices and declining US carbon monoxide-related mortality. JAMA 2002; 288: 988–995. 7. Schmitt MW, Williams TL, Woodard KR, Harruff RC. Trends in suicide by carbon monoxide inhalation in King County, Washington: 1996-2009. J Forensic Sci 2011; 56:652–655. 8. Ogden RD. Observation of two suicides by helium inhalation in a prefilled environment. Am J Forensic Med Pathol 2010; 31:156–161. Clinical Toxicology vol. 52 no. 3 2014

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9. Ogden RD, Wooten RH. Asphyxial suicide with helium and a plastic bag. Am J Forensic Med Pathol 2002; 23:234–237. 10. Austin A, Winskog C, van den Heuvel C, Byard RW. Recent trends in suicides utilizing helium. J Forensic Sci. 2011; 56:649–651. 11. The EXIT euthanasia blog. http://www.exiteuthanasia.wordpress. com/tag/helium/.Accessed October 18, 2013. 12. Final Exit on DVD Video. http://www.youtube.com/watch?v ⫽ wCqmj69XyGk. Accessed October 18, 2013. 13. Nitschke P, Stewart F. The Peaceful Pill Handbook. Washington: Exit International US Ltd; 2009:52–54.

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14. Cantrell FL, Nordt S, McIntyre I, Schneir A. Death on the doorstep of a border community - intentional self-poisoning with veterinary pentobarbital. Clin Toxicol (Phila) 2010; 48:849–850. 15. Reedy SJ, Schwartz MD, Morgan BW. Suicide fads: frequency and characteristics of hydrogen sulfide suicides in the United States. West J Emerg Med 2011; 12:300–304. 16. California Health and Safety Code, Section 1028560. http: //www.leginfo.ca.gov/cgi-bin/displaycode?section ⫽ hsc & group ⫽ 102001-103000&file ⫽ 102850-102870. Accessed October 18, 2013.

Suicide by non-pharmaceutical poisons in San Diego County.

In 2010, 6,599 poisoning suicides were reported in the United States (US). While medications remain the primary substances involved in completed poiso...
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