T2007 Seattle, Washington Traffic and Alcohol: A study on alcohol-related traffic accident deaths in Sao Paulo Julio de Carvalho Ponce 1, Vilma Leyton 1, Gabriel Andreuccetti 1, Debora Goncalves de Carvalho 2, Daniel Romero Munoz 1 1 Department of Legal Medicine, University of Sao Paulo, Sao Paulo, SP, Brazil 2 Medico-Legal Institute of Sao Paulo (IML-SP), Sao Paulo, SP, Brazil Abstract Alcohol consumption by drivers is one of the main causes of traffic accidents, often with fatal victims. Brazilian studies which relate the association of alcohol and traffic deaths are rare. These data are important for the implementation of public policies capable of diminishing the number of victims and also the elevated costs of accidents. Our objective was to determine the prevalence of alcohol use by fatal victims of traffic accidents autopsied at the Medico-Legal Institute of Sao Paulo State. Data on 3,042 victims killed in traffic accidents, between January and December of 2005, were collected. Gender, age, type of accident (collision or pedestrian X vehicle accident) and blood alcohol concentration (BAC) were studied. In the sample studied, 43.95% of the victims had a positive BAC, with a mean value of 0.17%. Men represented 85.9% of the cases, and 47.8% of those had consumed alcohol. Among women, 21.2% had a positive BAC at the time of death. Almost half (48.5%) of the victims were aged 25 to 44. There was a statistically significant difference between pedestrians and car occupants, in regards to age and BAC distribution. From the study we concluded that nearly half of all fatal victims had ingested alcohol before the accidents, that the mean BAC was almost 3 times the maximum legal limit for driving in Brazil (0.06%) and that pedestrians who were killed were, on average, 10 years older and had drunk 1.2 times the amount that car occupants had. Introduction Alcohol, as a psychoactive substance, can alter perceptions and behaviors. Exum reports an increase in aggressiveness and decrease in attention after alcohol consumption [1]. In Brazil, the maximum permissible blood alcohol concentration (BAC) for drivers is 0.06%, for drivers [2]. In general, the risk of involvement in a fatal vehicle crash increased steadily with increasing BAC. A BAC as low as 0.02% has been shown to affect driving ability. The probability of a crash rises significantly after 0.05% and even more rapidly after about 0.08% [3]. In Brazil, 138,814 traffic accidents, with 175,623 victims, among fatal and non-fatal, were registered in 2005 [4]. Brazil has a rate of 6.3 accidents for every 10 thousand registered vehicles; the United States has a rate of 1.8 [4,5]. A reduction of 5.9% in the number of traffic accident deaths in the state of Sao Paulo has been observed between 1993 and 2003 but it still has an expressive participation in traffic accident deaths. In 2005 there were 7,256 traffic accident deaths, 20.5% of the total in the country [4,6]. In countries like the United States, Switzerland, Japan, Canada and France, among others, there has been a reduction in fatal victims of traffic accidents as high as 60% in 25 years, due to a combination of the factors, such as better engineering of road infrastructure, increased
knowledge and technology associated with medical care and treatment, tougher enforcement of drink-driving laws and safer vehicle designs [7]. In the United States, a federal law establishing a zero tolerance law for drivers younger than 21 years diminished significantly the number of young people killed in traffic accidents [8]. However, even after those efforts, according to a technical report released by the National Highway Traffic Safety Administration (NHTSA), it is estimated that the annual cost of traffic accidents in the United States amounts to US$ 230.6 billion in the year 2000, with 41,281 fatal victims, 5.3 million injured and 28 million vehicles damaged, alcohol being responsible for 22% of these costs (US$ 51 billion) [6]. In Brazilian roads, the total cost of accidents amounts to 12.3 billion dollars and an additional 2.7 billion dollars in urban areas [9]. Brazil has a high rate of traffic crashes but there are only a few studies, which indicate that traffic accidents caused by alcohol are an issue for concern. Nery et al [10] in a study conducted in four Brazilian cities, in the emergency services (1,169 victims) and in the medico-legal institutes (45 fatal victims), showed that 63.5% of men had a positive BAC, and 33.5% of those were above the legal limit (0.06%); among women, 53.7% has a positive BAC, and only 9.6% above the legal limit. Leyton et al [11] studied 2,360 fatal traffic accident victims in 1999, in Sao Paulo State, finding 47.0% of victims with positive BACs. The mean BAC for those with a positive result was 0.21%, more than three times the legal limit. Due to the need for data reporting the involvement of alcohol in traffic accidents in Brazil, so that efforts may be made regarding the preservation of life, the aim of this study was to determine the relation between traffic accidents with fatal victims (collisions and pedestrian X vehicle accidents) and the use of alcohol in Sao Paulo State, the most populated state in Brazil. Material and Methods Data on 3,042 victims (pedestrians and car occupants) were collected from the medical examiner s reports between January and December of 2005, in the Medico-Legal Institute of Sao Paulo State. The Institute is responsible for the medico-legal investigation and autopsies of all victims of violent deaths in the State. The variables studied were: gender, age, type of victim (pedestrian or car occupant) and BAC. The BAC determinations were conducted by gas chromatography using the headspace separation method. All samples with a concentration above 0.01% were considered positive. All mean BACs (unless otherwise noted) refer to the mean BAC found in victims with positive BACs. Results Table I presents the distribution of cases according to gender, age, type of accident and BAC. In the sample studied there was a great majority of men (85.9% of the cases). Table I - Gender, age, type of victim and BAC of persons killed in traffic accidents in Sao Paulo, 2005 Gender n Car % positive Mean BAC Mean Age Pedestrians occupants BAC (%) (yrs.) Male 2613 1840 773 47.8% 0.17 ± 0.08 36.27 Female 429 230 199 21.2% 0.14 ± 0.09 40.48 Total 3042 2070 972 44.0% 0.17 ± 0.08 36.87
Figure 1 shows the percentage of intoxicated victims who had BACs above the legal limit. 7.3% < 0.06% >= 0.06% 92.7% Fig. 1 - BAC levels of victims with positive BACs according to the Brazilian legal limit (0.06%). Figure 2 shows the number of victims according to BAC in each type of victim and age group. 450 400 Car Occupant Positive BAC Pedestrian Positive BAC Car Occupant Negative BAC Pedestrian Negative BAC 350 300 number of victims 250 200 150 100 50 0 <15 15-24 25-34 35-44 45-54 55-64 65-74 >74 na age groups Fig.2 - Distribution of cases according to BAC, age group and type of victim.
In Figure 3 the distribution of cases according to type of victims and BAC levels can be observed. The predominant BAC level for collisions was 0.11 to 0.15% and for pedestrians 0.21 to 0.25%. 300 250 Car occupant Pedestrian number of victims 200 150 100 50 0 0.01-0.05 0.06-0.1 0.11-0.15 0.16-0.20 0.21-0.25 0.26-0.30 > 0.30 BAC (%) Fig. 3 - Distribution of cases according to type of victim and BAC. Of the 2,070 victims of collisions, 911 (44.01%) had positive BACs, with a mean of 0.16 ± 0.08%. Of the 972 pedestrians, 426 (43.83%) were under the influence of alcohol, with a mean BAC of 0.20 ± 0.09%. There was a higher percentage of women in pedestrian X vehicle accidents (20.5%) than in collisions (11.11%). Discussion The association between the consumption of alcohol and accidents with fatal victims is observed in most countries. In our study, this became evident, because 44% of fatal victims evaluated had alcohol in their blood at the time of the accident. This percentage increases to 47.8% when only males, which represent 85.9% of the total victims, are analyzed. It can be observed (Table I) that the number of male victims is six times greater than the number of females, but the number of males with positive BACs is almost fourteen times greater than that of females with positive BACs. Almost half of the male victims had alcohol in their blood at their time of death (47.8%) while only 21.2% of the female victims were intoxicated. The relation between accidents and the victimization due to alcohol consumption is strengthened by the fact of that 92.7% of all intoxicated victims had a BAC above the legal limit of 0.06% (Fig. 1). The mean BAC, 0.17 %, was almost 3 times greater than the legal limit, indicating an excessive consumption of alcoholic beverages. The age group with most intoxicated victims, in absolute numbers, was from 25 to 34 years. The age group with the higher percentage of intoxicated victims was of those aged 35 to 44 years (54.5%) (Fig. 2). There was a statistically significant difference in case distribution by age group and type of accident (p<0.001), with pedestrians being typically older than collision victims. The mean age for pedestrians was 43.8 years, about 10 years above the mean age for collisions (33.7 years). The highest percentage of victims with a positive BAC was found in pedestrians, aged 35 to 44 (57.8%) and the lowest, with 1 case (4.7%), was found in collisions for victims under 15
(Fig. 2). Pedestrians had a BAC, on average, 1.2 times greater than car occupants. Compared to younger people, elderly victims have a higher mortality in pedestrian versus car type accidents [12], which could account for the greater mean age in those occurrences. The results of this study suggest the necessity of restricting consumption of alcohol by drivers and that it is important to improve specific programs, such as traffic education, among others, in order to decrease mortality in traffic accidents in Brazil. Conclusions In this study we concluded that 44% of the victims were intoxicated at the time of the accident. Men aged 15 to 34 were the most victimized group. Men and victims of pedestrian X vehicle accidents had the highest BAC levels, especially those aged 35 to 44. The mean BAC was, on average, almost 3 times higher than the legal limit in Brazil. Pedestrians had a BAC, on average, 1.2 times greater than car occupants, and were typically about 10 years older. Acknowledgements The authors thank Dr. Hideaki Kawata, director of the Medico-legal Institute for allowing us to collect the data, and Dr. Neide S.F. Oliveira, Maria das Gracas S. Jesus, Maria Heloisa D. Loureiro and Sueli A. Moraes for their valuable contributions. (LIM40-HCFMUSP) References 1. Exum ML. The application and robustness of the rational choice perspective in the study of intoxicated and angry intentions to aggress. Criminology 2002; 40 (4): 933-66. 2. BRASIL. Código de trânsito brasileiro, lei nº 9.503, de 23 de setembro de 1997. 3. Zador PL, Krawchuk AS, Voas RB. Alcohol related relative risk of driver fatalities and driver involvement in fatal crashes in relation to driver age and gender: an update using 1996 data. J Stud Alcohol. 2000; 61(3):387-95. 4. Anuário Estatístico Denatran 2005 [database on the internet]. Renaest Registro Nacional de Acidentes e Estatísticas de Transito. c2006 - [cited 2007 March 25]. Available from : http://www.infoseg.gov.br/renaest/inicio.do 5. Blincoe L, Seay A, Zaloshnja E, Miller T, Romano E, Luchter S, Spicer R. The Economic Impact of Motor Vehicle Crashes, 2000. Washington DC, USA. US Department of Transportation; 2002. Report No. DOT HS 809446 6. Waiselfisz JJ, Athias G. Mapa da violência de São Paulo. Brasília: UNESCO, 2005. pp 55-79. 7. Noland RB. Medical treatment and traffic fatality reductions in industrialized countries. Accid Anal Prev 2003; 35:877-83. 8. Voas RB, Tippetts S, Fell JC. Assessing the effectiveness of minimum legal drinking age and zero tolerance laws in the United States. Accid Anal Prev 2001; 35:579-87. 9. Instituto de Pesquisa Econômica Aplicada (IPEA), Associação Nacional de Transportes Públicos (ANTP). Impactos sociais e econômicos dos acidentes de trânsito nas aglomerações urbanas: relatório executivo. Brasília: IPEA, ANTP; 2003. 10. Nery AF; Medina MG; Melcope AG; Oliveira EM. Impacto do uso de álcool e outras drogas em vítimas de acidentes de trânsito; ABDETRAN: Brasília; 1997. 11. Leyton V, Greve JMD A, Carvalho DG, Muñoz DR. Perfil epidemiológico das vítimas fatais
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