Journal of Public Health | Vol. 35, No. 2, pp. 223 –227 | doi:10.1093/pubmed/fds095 | Advance Access Publication 23 November 2012
Suicide by burning barbecue charcoal in England
Ying-Yeh Chen1,2, Olive Bennewith3, Keith Hawton4, Sue Simkin4, Jayne Cooper5,
Nav Kapur5, David Gunnell3
1
Taipei City Psychiatric Center, Taipei City Hospital, Taipei, Taiwan
Institute of Public Health and Department of Public Health, National Yang-Ming University, Taipei, Taiwan
3
School of Social and Community Medicine, University of Bristol, Bristol, UK
4
Department of Psychiatry, Centre for Suicide Research, University of Oxford, Oxford, UK
5
Centre for Suicide Prevention, Community Based Medicine, University of Manchester, Manchester, UK
Address correspondence to David Gunnell, E-mail: [email protected]
2
A B S T R AC T
Background Suicide by carbon monoxide poisoning from burning barbecue charcoal has become a common method of suicide in several Asian
countries over the last 15 years. The characteristics of people using this method in Western countries have received little attention.
Method We reviewed the inquest reports of 12 English Coroners (11% of all Coroners) to identify charcoal-burning suicides. We compared
socio-demographic and clinical characteristics of suicide by charcoal burning occurring between 2005 and 2007 with suicides using other
methods in 2005.
Results Eleven charcoal-burning suicides were identified; people using this method were younger (mean age 33.4 versus 44.8 years,
P ¼ 0.02), and more likely to be unemployed (70.0 versus 30.1%, P ¼ 0.01) and unmarried (100 versus 70%, P ¼ 0.04) than those using
other methods. Charcoal-burning suicides had higher levels of contact with psychiatric services (80.0 versus 59.1%) and previous self-harm
(63.6 versus 53.0%) compared with suicides using other methods, but these differences did not reach conventional levels of statistical
significance. Over one-third of people dying by charcoal burning obtained information on this method from the Internet.
Conclusions Working with media, including Internet Service Providers, and close monitoring of changes in the incidence of suicide using this
method might help prevent an epidemic of charcoal-burning suicides such as that seen in some Asian countries.
Keywords charcoal burning, suicide, suicide method
Introduction
An epidemic rise in suicide by carbon monoxide poisoning
from burning barbecue charcoal has occurred in several East
Asian countries over the last 15 years. This method accounted
for 20% of suicides in Hong Kong (in 2007–09), 30% in
Taiwan (2008–10) and 8% in Japan (2007).1 – 4 Although the
method is not commonly used in the West, it could potentially
become so, as information about methods of suicide is easily
accessible on the Internet.5
In East Asia, the epidemic of charcoal-burning suicides
began in the context of the Asian Financial Crisis (1998)
and the method was predominantly adopted by economically
active middle-aged men with financial difficulties but no
pre-existing history of psychiatric or physical illness.6 – 8 To
the best of our knowledge, the characteristics of suicides
using this method in Western countries have received little
attention. Our aim was to investigate the socio-demographic
characteristics of early adopters of charcoal-burning suicide
in England identified through Coroners’ records. The results
may help highlight potential targets for interventions to
prevent future spread of this new suicide method.
Ying-Yeh Chen, Associate Professor
Olive Bennewith, Research Associate
Keith Hawton, Professor of Psychiatry and Director
Sue Simkin, Research Associate
Jayne Cooper, Senior Research Fellow
Nav Kapur, Professor of Psychiatry and Population Health
David Gunnell, Professor of Epidemiology
# The Author 2012, Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved
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Methods
We systematically identified the records of all possible cases
of charcoal-burning suicides in a sample of 12 (11%) of the
107 Coroners in England in 2005 –07. These Coroners
investigated 11% of all suicides in England in 2005. The
Coroners jurisdictions included in our study comprised
those where the three collaborating research centres are
based (the cities of Bristol, Oxford and Manchester) and a
random sample of nine further jurisdictions within 90 min
travel time of each of these cities. For comparison, we identified the records of all suicides occurring in 2005 in the 12
jurisdictions.
A detailed account of the study methods which also
included suicides occurring in 1990, and 1998 has been
published.9 Data for all deaths given a verdict of suicide
and, for those given open, accidental or narrative verdicts
where the inquest record suggested that suicide was a possibility were abstracted by experienced researchers (O.B., S.S.,
J.C. and other colleagues) on to standard recording sheets.
The information abstracted included basic demographic
characteristics, employment status, history of psychiatric
contact, history of affective disorders, history of previous
self-harm and whether alcohol was involved in the suicide
process. Possible Internet involvement in the death was also
noted; if this was found, the researchers described the
details of such involvement. Current contact with psychiatric
services was coded as such where information in the coroner’s file (usually in GP letters and/or psychiatric reports)
indicated that the deceased had been in receipt of services at
the time of death, i.e. they had been in receipt of such care
and had not been discharged. History of affective disorder
was assessed from GP letters or/and psychiatric reports and
from witness statements included in the coroners’ files. Both
unipolar depression and bipolar affective disorder were
included within the diagnosis of affective disorder.
For deaths given open, accident/misadventure or narrative verdicts, accounts of up to 800 words in length were
written describing the circumstances of the death. These
accounts, together with descriptive data relevant to each
case, were independently reviewed by three experienced
suicide researchers (D.G., K.H., N.K.) who rated the likelihood that the death was suicide. Where there was disagreement, the raters discussed the case and a consensus was
reached. All deaths rated as high or moderate probability of
being suicide were included in our sample. The coding procedures have been described in previous reports.10 – 12
We compared the socio-demographic and clinical characteristics and the psychiatric or self-harm histories of charcoalburning cases with all suicides (excluding charcoal-burning
cases). Logistic regression analysis was used to compare the
differences between charcoal-burning cases with other suicides after adjusting for age. A similar comparison was
carried out for car exhaust gas suicide as this is currently the
most common method of gas suicide in the UK.
Results
We identified 11 cases of charcoal-burning suicide—four in
2005, six in 2006 and one in 2007. As the study coroners
investigated 11% of all suicides in England, this means
there may have been about 100 charcoal-burning suicides in
England over the 3-year study period. No cases were identified in 1990 or 1998.
The mean age of the charcoal-burning suicides was 33.4
years (range 18 – 47 years), about 10 years younger than suicides who used other methods (44.8 years, range 12 – 93,
t-test 2.31, P ¼ 0.02) (Table 1). The proportions of males
and people of white ethnicity were similar among charcoalburning suicides compared with those using other methods.
None of the charcoal-burning cases were married at the time
of death, compared with nearly one-third (30.0%) of those
who had died by other methods of suicide. They were also
more likely to be unemployed. Cases of charcoal-burning suicides were more likely to have a history of self-harm and to
have had contact with psychiatric services, but statistical evidence for these differences was weak. No prominent difference was found in the prevalence of affective disorders and
current psychiatric care in these two groups. Controlling for
age using logistic regression models did not greatly alter the
strength of the associations, although statistical evidence for
an association with unemployment was weakened.
Alcohol consumption was recorded in three cases. An
additional method was reported in one case, in which charcoal burning was combined with citalopram poisoning.
There was evidence of Internet involvement in 4 of the
11 charcoal-burning cases (36.4%); better here three of
these occurred in 2005, one in 2006. One individual printed
a webpage related to charcoal-burning suicide, one conducted research into the ‘barbecue method’ on their home
computer, one accessed a research publication describing
charcoal-burning suicide three times in the week before
death and one had looked online at how people in Japan
had died by the use of charcoal burning. The inquest record
indicated that the youngest person (18 years of age) to die
by charcoal-burning suicide might have obtained knowledge
about carbon monoxide poisoning at school. One case was
a murder–suicide: a 30-year-old mother killed her
5-year-old son in the suicide incident.
SU I C ID E BY BU R N IN G BA RB EC U E C H A RCOA L
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Table 1 Comparison between characteristics of charcoal burning suicide (2005 – 2007) and all suicides (2005)
Charcoal burning
All other methods
(n ¼ 11), n (%)
(n ¼ 589), n (%)
Mean age (years)
33.4 range 18 –47
44.8 range 12 –93
Male
8 (72.7)
449 (76.2)
White
9 (90.0)
Currently married
0 (0.0)
Unemployed
t-test
x2
P-value**
Crude OR
Age-adjusted
(95% CI)
OR (95% CI)
0.02
0.95 (0.90, 0.99)*,#
—
0.07
0.73
0.83 (0.22, 3.18)
0.80 (0.21, 3.07)
461 (95.1)
0.52
0.41
0.47 (0.06, 3.85)
0.50 (0.06, 4.16)
176 (30.0)
4.67
0.04
—
—
7 (70.0)
171 (30.1)
7.34
0.01
5.42 (1.38, 21.20)*
3.92 (0.99, 15.48)
Past self-harm
7 (63.6)
276 (53.0)
0.49
0.55
1.55 (0.45, 5.37)
1.21 (0.35 , 4.26)
History of contact with psychiatric
8 (80.0)
301 (59.1)
1.77
0.21
2.76 (0.58, 13.14)
2.53 (0.53, 12.10)
History of affective disorder
5 (62.5)
299 (70.0)
0.21
0.70
0.71 (0.17, 3.03)
0.93 (0.21, 4.08)
Current psychiatric care
5 (50.0)
150 (30.6)
1.72
0.30
2.27 (0.65, 7.95)
2.21 (0.63, 7.79)
Alcohol involvement
3 (37.5)
190 (42.3)
0.07
1.00
0.82 (0.19, 3.46)
0.74 (0.18, 3.17)
22.31
services
The denominator varies between 8 and 11 for charcoal-burning suicide and 427 and 589 for all other methods
**P-value for the mean age was based on t-test, for differences in proportions were based on two-sided Fisher’s exact test.
*P , 0.05.
#
The change in OR per 1 year increase in age.
We also compared individuals who died by charcoal
burning with the 19 who died by car exhaust gas suicide in
2005. Those who used charcoal burning differed in terms
of age (mean age 33.4 versus 56.3, P , 0.0004), marital
status (married: 0 versus 57.9%, P ¼ 0.0016) and employment status (unemployed: 70.0 versus 10.5%, P ¼ 0.0021).
These differences remained significant after controlling for
age. A higher proportion of those who died by charcoal
burning were under current psychiatric care at the time of
death (50.0 versus 15.8%, P ¼ 0.08), although the statistical
evidence for this difference was marginal.
Discussion
Main findings of this study
These early cases of charcoal-burning suicide in England
were more likely to be young, unemployed and less likely to
be married compared with those who used other methods
of suicide. There is some evidence suggesting that the
charcoal-burning case series was more likely to have had a
history of contact with psychiatric services and higher rates
of previous self-harm compared with the suicides using
other methods, although statistical evidence for these differences was weak. Over one-third of these individuals had
obtained information on suicide method from the Internet,
a figure that was considerably higher than that for all people
who died by suicide (1.5%), in our previous study of
Internet-related suicides in 2005.11 As previously reported,
the methods used by people who obtained information on
suicide from the Internet are more likely to be uncommon
and highly lethal.5,11
What is already known on this topic
The finding that these early cases of charcoal-burning
suicide are younger is in keeping with evidence that younger
individuals are more likely to adopt new technologies.13
Similarly, people who died by suicide using charcoal burning
in the early stage of the epidemic in Hong Kong and
Taiwan were more likely to be young (,30 years), or
middle-aged (30 –49 years).2
High rates of psychiatric contact (80.0%) and past history
of self-harm (63.6%) among these charcoal-burning cases
suggest that people using this method in England are different from charcoal-burning cases reported in East Asia
where low levels of mental healthcare utilization were
found.6 – 8 Suicide by charcoal burning received widespread
media coverage when it first appeared in Hong Kong and
Taiwan,14 whereas in the UK, the method has not been
widely publicized. Hence, it is possible that in England, the
method has only attracted a small number of individuals
suffering from psychiatric illness and who have researched
their suicide method on the Internet.
The differences in characteristics between people dying by
charcoal burning and those using car exhaust gas for suicides suggest that these charcoal-burning cases were a distinct group, rather than a subgroup of people who use
charcoal burning as an alternative to car exhaust gas suicide.
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J O U RN A L O F P U B L I C H E A LTH
One of our case series involved maternal filicide –suicide.
Although a recent review on murder– suicide suggests that
its incidence is very low (0.2 – 0.3 per 100 000);15 charcoalburning suicide has, however, been reported to be related to
an increase in the prevalence of homicide – suicide in both
Taiwan and Hong Kong.16,17 Such deaths are likely to attract
media attention,18 creating a further risk of its potential
uptake in the wider population of people at risk of suicide.
Mental Health and Social Care Trust. The views and opinions expressed in this paper are those of the authors and
do not necessarily reflect those of the NIHR, NHS or the
Department of Health. The NIHR and Department of
Health had no role in study design, the collection, analysis
and interpretation of data, the writing of the report, and the
decision to submit the paper for publication. We thank the
Coroners who allowed us access to their files, and their staff
and Record Office staff who assisted us.
What this study adds
In England, these early cases of charcoal-burning suicide
differed from suicides using other methods, appearing to
occur among a group of people with high suicide intent, as
indexed by their research of the method online and somewhat higher levels of psychiatric contact. The link between
charcoal-burning suicide and Internet use indicates the potential role of the Internet in spreading novel and lethal
suicide methods. Close monitoring of changes in the incidence of this method may help with timely intervention.
The incidence of charcoal-burning suicide in England and
the West is considerably lower than that seen in Hong Kong
and Taiwan, where it has been endemic for over a decade.2 It
is unclear why the method has not become popular in the
West. A possible explanation is the lack of media publicity
given to this method in the west and the absence of high
profile cases of suicide using this method. The use of this
method in Hong Kong is thought to have followed the high
profile reporting of a single case,6,14 whereas in Taiwan,
greater reporting intensity of charcoal-burning suicide compared with other suicide methods has been documented.18
Limitations of this study
Funding
This presentation presents independent research commissioned by the National Institute for Health Research
(NIHR) under its Programme Grants for Applied Research
scheme (RP-PG-0606-1247). The views expressed in this
publication are those of the author(s) and not necessarily
those of the NHS, the NIHR or the Department of Health.
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However, our study has several limitations. First, it is not possible to thoroughly pursue the reasons contributing to the
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charcoal burning and those using other suicide methods.
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