Shu-Sen Chang and colleagues describe the epidemiology of an epidemic of suicide by charcoal burning in Taiwan and discuss possible reasons for its spread.
An epidemic of carbon monoxide poisoning suicide by burning barbecue charcoal has occurred in East Asia in the last decade. We investigated the spatial and temporal evolution of the epidemic to assess its impact on the epidemiology of suicide in Taiwan.
Methods and Findings
Age-standardised rates of suicide and undetermined death by charcoal burning were mapped across townships (median population aged 15 y or over = 27,000) in Taiwan for the periods 1999–2001, 2002–2004, and 2005–2007. Smoothed standardised mortality ratios of charcoal-burning and non-charcoal-burning suicide and undetermined death across townships were estimated using Bayesian hierarchical models. Trends in overall and method-specific rates were compared between urban and rural areas for the period 1991–2007. The epidemic of charcoal-burning suicide in Taiwan emerged more prominently in urban than rural areas, without a single point of origin, and rates of charcoal-burning suicide remained highest in the metropolitan regions throughout the epidemic. The rural excess in overall suicide rates prior to 1998 diminished as rates of charcoal-burning suicide increased to a greater extent in urban than rural areas.
The charcoal-burning epidemic has altered the geography of suicide in Taiwan. The observed pattern and its changes in the past decade suggest that widespread media coverage of this suicide method and easy access to barbecue charcoal may have contributed to the epidemic. Prevention strategies targeted at these factors, such as introducing and enforcing guidelines on media reporting and restricting access to charcoal, may help tackle the increase of charcoal-burning suicides.
Please see later in the article for the Editors' Summary
Every year, about a million people take their own lives. Most people who die by suicide are mentally ill but some people take their lives because stressful events (the loss of a partner, for example) have made life seem worthless or too painful to bear. Strategies to reduce suicide rates include better treatment of mental illness and programs that help people at high risk of suicide deal with stress. Suicide rates can also be reduced by limiting access to common suicide methods. These methods differ from place to place. Hanging is the predominant suicide method in many countries but, in Hong Kong, for example, jumping from a high building is the commonest method. Suicide methods also vary over time. In 1998, a woman in Hong Kong took her life by burning barbecue charcoal in a sealed room (a process that produces high levels of the toxic gas carbon monoxide). This method was unheard of before and was extensively reported by the mass media; by the end of 2004, charcoal-burning suicide became the second most common form of suicide in Hong Kong.
Why Was This Study Done?
The epidemic of charcoal-burning suicide that started in Hong Kong has rapidly spread to other countries in East Asia, including Taiwan, where it is also now the second most common method of suicide. It would be useful to identify the factors that have contributed to the spread of this particular form of suicide because such knowledge might help to improve strategies for preventing charcoal-burning suicide. One way to identify these factors is to examine the space–time clustering of charcoal-burning suicides. Clustering of specific types of suicides in both time and space usually occurs in settings such as institutions where the individuals who die by suicide have been in social contact. By contrast, clustering of specific types of suicide in time more than place is often associated with media coverage of events such as celebrity suicides, which can lead to imitative suicides. In this study, therefore, the researchers investigate the evolution of the epidemic of charcoal-burning suicide over time and across areas in Taiwan.
What Did the Researchers Do and Find?
The researchers obtained data on suicides and undetermined deaths (most “missed” suicides are recorded as undetermined deaths) from 1999 to 2007 from the Taiwan Department of Health. They then used statistical methods to estimate the standardized mortality rates (the ratio of the observed to the expected numbers of deaths) of charcoal-burning and non-charcoal-burning suicides and undetermined deaths in different areas of Taiwan. The proportion of suicides that were charcoal-burning suicides rose from 0.1% in 1991 to 26.6% in 2007, they report, and the epidemic of charcoal-burning suicide was more marked in urban than in rural areas. However, there was no single point of origin of the epidemic. Finally, they report, rates of charcoal-burning suicide were consistently higher in urban than in rural areas throughout the study period, a result that means that, although overall suicide rates were higher in rural than in urban regions of Taiwan prior to the epidemic of charcoal-burning suicide, the difference has now almost disappeared.
What Do These Findings Mean?
These findings suggest that the epidemic of charcoal-burning suicide may underlie recent changes in the geography of suicide in Taiwan. However, the study's findings may not be numerically accurate because of some of the assumptions made by the researchers. For example, there is no specific code for charcoal-burning suicides in official records so the researchers assumed that suicides classified as “poisoning using nondomestic gas” were all charcoal-burning suicides, although other studies have shown that nearly 90% of deaths in the category were indeed charcoal-burning suicides. Nevertheless, the observed geographical pattern of charcoal-burning suicides and the changes in this pattern over time suggest that widespread media coverage and easy access to barbecue coal in supermarkets and convenience stores may have contributed to the epidemic of charcoal-burning suicide and to the increase in overall suicide rate in Taiwan and elsewhere in East Asia. Thus, guidelines that encourage responsible media reporting of charcoal-burning suicide (that is, reporting that does not contain detailed descriptions of the method or suggest that this type of suicide is easy and painless) and strategies that restrict access to barbecue charcoal may help to halt the epidemic of charcoal-burning suicide in East Asia.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000212.
Another PLoS Medicine research article by David Studdert and colleagues investigates the relationship between changes in vehicle emissions laws and the incidence of suicide by motor vehicle exhaust gas in Australia
The World Health Organization provides information on the global burden of suicide and on suicide prevention (in several languages); see also the article Methods of Suicide: International Suicide Patterns Derived from the WHO Mortality Database
The US National Institute of Mental Health provides information on suicide and suicide prevention
The UK National Health Service Choices website has detailed information about suicide and its prevention
MedlinePlus provides links to further resources about suicide (in English and Spanish)
The Taiwan Suicide Prevention Center provides information on suicide and its prevention in Taiwan (in Chinese)
The Centre for Suicide Research and Prevention, the University of Hong Kong, provides information on suicide and its prevention in Hong Kong (in Chinese and English)