Manter-se acordado : a vulnerabilidade dos caminhoneiros no Rio Grande do Sul Staying awake : truck drivers ’ vulnerability in Rio Grande do Sul , Southern Brazil

MÉTODOS: Survey com 854 motoristas em oito locais de concentração de caminhoneiros (sete postos de gasolina e um posto aduaneiro em região de fronteira) em cinco municípios do Rio Grande do Sul, em 2006. O desfecho “uso de rebite” foi categorizado em “sim” ou “não”. Foi realizada análise de regressão de Poisson com variância robusta para a seleção de variáveis do modelo, que foi composto por níveis socioeconômicos, demográfi cos, de informações sobre a profi ssão e sobre o consumo de álcool.


INTRODUCTION
a,b The national vehicle fl eet has more than 1.9 million trucks.c The exact number of truck drivers is unknown, but it is estimated that more than one million people work in road haulage.Data from National Land Transport Agency (ANTT -Agência Nacional de Transportes Terrestres) point to the existence of almost 700 thousand truck drivers who are autonomous professionals or work in cooperatives. 18ta from Instituto Brasileiro de Geografi a e Estatística (IBGE -Brazilian Institute of Geography and Statistics) indicate that the Brazilian Land Transport Sector is a male universe, in which 93% of workers are male who work specially in road haulaged, d mainly in the Southeast and South of Brazil. 18me characteristics of the truck driver's professional activity are common in different countries: the work is executed with the same instruments and techniques and requires skilled driving.Truck drivers form a population with great mobility (and with well-defi ned mobility patterns, due to their organization around specifi c routes).They remain during variable periods of time in transit, away from home and have long workdays.d This population presents sleep disorders 5,15,16 and the daily routine is described as tiresome, monotonous and lonely. 8rking conditions put truck drivers in dangerous situations, for example accidents on highways and robberies, which make them be in constant vigilance.e Therefore, truck drivers' working conditions can be considered dangerous and stressful.
These working conditions may lead them to feel isolated and lonely.Truck drivers stay many days or weeks away from home, sleeping on the highway (in their trucks or in external accommodations), which generates tension and confl icts with their families.Incentives or pressure on part of the companies contribute to the driver having long workdays and remaining long periods without sleeping.f Truck drivers present high consumption of cigarettes, alcohol and caffeinated beverages, besides amphetamines in different countries 7-9,14,20,d A market of specifi c services and products has been created to meet the demand of a large amount of men who stay long periods away from home -a market that offers sexual services and licit and illicit substances, both to stay awake and for recreational use, among other things. 8ruck drivers' vulnerability to the AIDS epidemic, in its individual, social and programmatic dimensions, has been discussed by national and international agencies and researchers.d It is possible to say that truck drivers are vulnerable in social terms, given the few material and symbolical resources that they have and their restricted access to goods and to health, education, work and leisure services and equipment.In view of this scenario of vulnerability imposed by truck drivers' working conditions, the present paper aimed to analyze the factors associated with their use of substances to stay awake.

METHODS
A survey with 854 drivers was carried out at eight truck stops (seven gas stations and one border patrol post) located at fi ve cities in the State of Rio Grande do Sul (Southern Brazil) in 2006.
A qualitative study was conducted in order to investigate the number of trucks that circulated and remained parked at different establishments.The context of the present research involved eight truck stops (seven gas stations and one border patrol post) located in fi ve municipalities of the State of Rio Grande do Sul (Southern Brazil): Chuí, Rio Grande, Canoas, Gravataí and Porto Alegre.
For quantitative stage, the sample of truck drivers was estimated based on a pilot study that registered an average of 3,590 trucks per day at the researched venues.The sample was calculated with maximum error of 5% and confi dence interval of 95%, and resulted in 847 truck drivers, with an estimate 10% loss.We used a nonprobability process per quotas established by shift and by drivers' circulation places inside the gas stations (parking lot, carriers, restaurant, mechanic services, among others) for sample selection, as there are no records of the researched population.
A pilot study was carried out with 58 drivers, using a questionnaire designed by the researchers based on the results of the qualitative stage, and on the review of similar studies conducted with drivers.The survey was performed with the same instrument tested in the pilot project.Final sample was composed by 854 drivers, exceeding the number that had been initially estimated for the sample.Information was collected using questionnaires.No biological material was collected for laboratory analysis.
Data were systematized in a database using Sphinx Léxica g , with double entry and subsequent comparison and database cleaning.question used to compose the outcome was: "Do you currently use anything to stay awake?" (yes; no; did not answer; does not know/does not remember).Those who answered yes were asked a stimulated multiple answer question "What do you usually take to stay awake?" [amphetamines; caffeine (coffee, mate [chimarrão], coca-cola); guaraná in powder, energy drink (red-bull, bad-boy), snorting cocaine and other (the interviewer wrote in full the answer that was given)].The variable for the analysis was "Use of amphetamines to stay awake?" (yes; no).PAWS software, version 18, h was used in statistical analysis.A descriptive analysis of the sample was performed, as well as univariate analysis using Poisson regression with robust variance, in order to select the variables that would be included in the model, by means of the modifi cation of the likelihood ratio (p<0.20).The model was composed by socioeconomic and demographic variables and information on the profession and on alcohol consumption (Tables 1, 2 and 3).The variables that were signifi cance were included in a multivariable model, while variables with p > 0.05 were excluded from the model, while variables with at least one category with p < 0.05 in the Wald test were considered statistically signifi cant associated with the outcome.

RESULTS
The majority of the interviewees declared to be white, aged 30 to 49 years and with complete primary education.Approximately one fourth of the truck drivers received up to 3.3 minimum salaries, while more than one fourth had income higher than 6.7 minimum salaries.This income was the main source of the family budget for the major part of the interviewees.The majority of them declared that they were married (or living with a partner) and had one or two children.A signifi cant portion (19.4%) stated not having any religious practice, but the majority declared that they had a religion (Table 1).
A large part had had another profession before (78.5%) and the majority (60.2%) did not own the truck they drove (employee or autonomous professional) (Table 2).Autonomous drivers needed to negotiate a load (and the value of the freight) with carriers in each destination at which they arrived.Drivers traveled alone (88.1%) and the majority (66.5%) had some family member who was also a truck driver.The trip lasted approximately one week (mean 6.7 days, standard deviation 7.7, median 4.0) and a few drivers made long trips (5.5% stayed between 15 and 90 days on the road) (Table 2).
The use of some substance to stay awake was reported by 23.0% of the interviewees.Amphetamine was the main substance consumed, mentioned by 106 truck drivers, in isolation or combined with other substances (coffee, guaraná powder, energy drinks and snorted cocaine).The consumption of alcoholic drinks was mentioned by more than 70% of the interviewees; 45.1% reported that they used alcohol at least once a week (Table 3).Use of amphetamine was associated in univariate analysis with self-reported skin color, age, income, marital status, having children, attending a religion and which religion, having another profession, trip duration and alcohol consumption (Table 4).The association amphetamine use and younger age, higher income, longer trips and alcohol consumption remained in the multivariable model (Table 5).

DISCUSSION
The conditions for being a professional truck driver are possibly related to the use of stimulants.The majority of the interviewees did not report the use of any substances to stay awake, but almost one fourth mentioned the use of some substance, mainly amphetamine.
The high use of amphetamines among truck drivers has been indicated in other studies.Souza et al 17 found a prevalence of 11.1% among Brazilian truck drivers, fi ndings that are similar similar to ours (12.4%).Leyton et al 7 tested urine samples and found a prevalence of 5.8% for amphetamines among truck drivers on the highways of the State of São Paulo.In the present study, 16.6% of the interviewees stated having used amphetamines at least once in their lives, and 7.5% reported regular use of amphetamines to stay awake.Silva et al 14 detected the presence of amphetamines in truck drivers' urine in Southeast, Northeast and South of Brazil, with prevalence of 4.8%.The highest prevalence was observed in the South (6.0%) and the lowest, in the Northeast (3.7%).
Studies with urine testing involved drivers circulating on highways, while our research was conducted with drivers at truck stops (where those who work in an autonomous way tend to concentrate).The higher prevalence of amphetamine use among drivers who have stopped somewhere compared to drivers circulating on highways may be explained by the greater diversity of working conditions among drivers who are in circulation.The most cited substance in this study was amphetamine.Amphetamine was also the most present drug among the positive samples for drugs in two studies with laboratory tests. 7,14Our research did not involve laboratory tests.
According to Ferreira et al, 4 69.8% of the interviewed truck drivers used amphetamines during their lives and 39.1% used it in the year in which the research was conducted.In the study carried out by Teles et al, 19 the prevalence of amphetamine use was of 30%.In the work of Silva-Júnior et al, 13 35% of the interviewees reported using stimulants, of whom 90.6% reported consumption of these substances by their colleagues.In these three studies, the prevalence that was found is higher than in the present research.It should be highlighted that in two of the studies 4,19 the sample was composed of long distance drivers, who therefore stay away from home during longer periods of time, in conformity with our data.In addition, data collection instrument, its application and form of measuring amphetamine consumption were not the same in the three studies, as there were interviews and self-administered questionnaires, as well as questions about consumption some time in life, in the previous year or without specifying time frame.
Consumption of amphetamines by professional drivers is higher than consumption in in the general population.A study with drivers in general 3 on the margin of Australian highways found a prevalence of  amphetamine use of 1.4%, a value that is similar to the one found in the United States with victims of accidents on highways (1.1%). 6cohol consumption is a recurrent practice among the interviewees: 73.1% reported alcohol consumption in the 30 days that preceded the interview.This consumption may be related to characteristics of the profession: being fundamentally male; having as "stops" places where alcohol consumption is favored, like gas stations with restaurants and convenience stores, and bars which are located nearby; being carried out in a solitary way (the majority of the interviewees travel alone).
Other studies have found prevalence rates that were similar to the present one (45.1% consumed alcoholic drinks regularly -at least once a week in the previous month).Souza et al 17 observed that 50.9% of the Brazilian truck drivers consumed the substance regularly.Penteado et al 12 identifi ed a prevalence of 43% of alcohol use in the Northeast of Brazil.In the study conducted by Silva-Júnior et al, 13 carried out in the city of Fortaleza (Northeastern Brazil), 48.3% of the interviewees reported consuming alcohol during workdays and 88.6% reported that their colleagues maintained this practice.Ferreira et al 4 showed that 41.9% of the truck drivers who traveled along routes in the interior of the State of São Paulo reported using alcohol in the seven days that preceded the research.
Amphetamine use and alcohol use have important implications to public health, both in relation to truck drivers' health and to the risk of traffi c accidents. 7esides the risks inherent in the drugs themselves, the use of amphetamines and alcohol among truck drivers is related to the practice of unprotected sex, greater infection by sexually transmitted diseases (STD) and higher risk of depression. 4,8,13,19uck drivers are a group that has a low-level of schooling, but whose remuneration is higher than national average.i The profession of truck driver seems to depend more on a network of family relations than on level of schooling.
The truck drivers' working conditions are precarious.The majority of drivers does not own the truck and an important portion state that they work "on their own" or in an autonomous way.This probably causes an increase in the workday and restricts labor rights (holidays, thirteenth salary, j among others).A similar situation is reported by Penteado et al: 12 in which more than half of the interviewees (59.5%) are autonomous and work an average of 12.7 hours per day, which has important implications for health and quality of life.Silva-Júnior et al 13 also found 51.3% of autonomous professionals with a workday of more than ten hours per day (information reported by 68.6% of the interviewees).However, the truck drivers who have formal jobs also present long workdays, according to that study.Silva et al 14 describe that the drivers are young, they own the truck, and have workdays of ten to 14 hours per day.National and international studies have shown the relationship between drivers' working conditions and increased risk for cardiovascular and musculoskeletal diseases. 10,11Drivers' fatigue has been pointed as one of the main risk factors for accidents on highways.
In our research, staying more days away from home while working is associated with amphetamine consumption.
Amphetamine consumption is associated with higher income, which suggests that increased remuneration implies an increase in the workload.More work, in turn, produces physical and emotional stress, leading the drivers to search for a temporary solution for this problem in amphetamine consumption.The association of amphetamine consumption with the younger age groups indicates that these are more vulnerable, possibly as a consequence of their reduced experience in the profession, which causes more diffi culty in dealing with work pressures.Greater vulnerability of young truck drivers is highlighted by Leyton et al 7 and by Silva et al, 14 who have shown higher prevalence of drug use in young drivers, as well as higher risk of depression (Silva-Júnior et al). 13is scenario should be understood within a broader context, characterized by low-level of schooling, long periods truck drivers stay away from their homes and families and precarious working conditions, as poor conditions of the highways and of the places where they stay during their trips (gas stations, customhouses, companies' yards).Professional drivers are hired per freight, so the form and value of the payment (per task and load) stimulate long workdays (aiming at reducing delivery time) and individual work (avoiding costs with another driver in the same vehicle).
The heavy workload, combined with the lack of any offer of health and education services and few leisure options at the places in which they remain parked favor the consumption of substances to stay awake, like amphetamines, alcohol and other drugs.The truck drivers are in a situation of vulnerability deriving from their working conditions, gender imperatives, restricted social and cultural opportunities, and from the absence of specifi c programs and policies that meet their health and education needs.According to the theoretical benchmark of vulnerability, 2 in its individual, social and programmatic dimensions, truck drivers are more susceptible to health problems like STD and HIV infection and regular use of amphetamines, alcohol and other drugs.
The outcome was the driver's us of a substance to stay awake.If the interviewee declared having used any, he was asked about what substance he had used.The h Statistical Product and Service Solutions.PAWS statistics 18 [software].Chicago; 2009. 1 d Leal A. "No peito e na raça": a construção da vulnerabilidade de caminhoneiros.Um estudo antropológico de políticas públicas para HIV/ AIDS no Sul do Brasil [tese de doutorado].Porto Alegre Universidade Federal do Rio Grande do Sul; 2008.e Sena MFM.As condições e causas dos acidentes de trabalho dos caminhoneiros [dissertação de mestrado].Rio de Janeiro.Universidade Federal do Rio de Janeiro; 2005.f Douglas E. Putting on the brakes: preventing HIV transmission along truck routes.a research-based fi eld resource supported by the synergy APDIME toolkit.Washington: University of Washington; 2000 [cited 2006 May 01].Available from: http://pdf.usaid.gov/pdf_docs/PNACW331.pdfg Sphinx Brasil.Sphinx Léxica [software].Canoas; 1997.

Table 1 .
Truck drivers' socioeconomic and demographic characteristics.Rio Grande do Sul, 2006

Table 3 .
Characteristics of the reported consumption of licit and illicit substances by truck drivers.Rio Grande do Sul, 2006.
* Question of multiple answers, percentage calculated on the total of quotations

Table 4 .
Univariate analysis of the association between predictors and amphetamine use by means of Poisson regression with robust variance.a Rio Grande do Sul, 2006.
a The variables that were not signifi cant in the univariate analysis (p > 0.20) were excluded from the table.b The minimum salary at the time the data were collected was R$300.00 (Law 11164/2005, 04/22/2005, DOU).

Table 5 .
Multiple analysis to verify the association between predictors and amphetamine use, by means of Poisson regression with robust variance.a Rio Grande do Sul, 2006.