Drug abuse among workers in Brazilian regions

Correspondence to: Mauricio Yonamine Faculdade de Ciências Farmacêuticas Toxicologia USP Av. Prof. Lineu Prestes, 580, B13B 05508-900 São Paulo, SP, Brasil E-mail: yonamine@usp.br Received on 9/4/2003. Reviewed on 4/12/2003. Approved on 19/2/2004.


INTRODUCTION
Brazil is the fifth largest country in the world (territorial area of 8,557,403 km 2 ) with a population of approximately 170 million people.Brazil borders drug-producer countries in the west and its large coastland in the east is bordered by the Atlantic Ocean.This geography makes the Brazilian territory the main drug trafficking route to Europe and the United States.From regular drug trafficking route, Brazil turned out to be a potential market of drug users.Drug availability, extreme economic deprivation, and lack of effective law enforcement actions in the borders were the preponderant factors which allowed for establishing an illicit drug market in the country.Despite significant national efforts, drug abuse remains a serious public health and security problem for the society.
According to studies on drug abuse in Brazil performed by the United Nations Office on Drug and Crime (UNODC) during the period of 2000-2001, 5.8% of the population above 15 years old had already used marijuana, 0.8% cocaine, and 0.7% amphetamines. 11 extensive study performed in 2001 among the general population from 107 large Brazilian cities showed that 6.8% reported marijuana use, 2.3% cocaine, and 1.5% amphetamines. 1ployer's concern with drug use by Brazilian workers and its impact on job-related behavior made some business companies adopt drug testing programs in their workplace.Similar programs are widespread in US and are now increasing in importance in some parts of Europe. 12The organized structure of some companies provides a suitable environment for employee assistance programs to offer rehabilitation rather than layoff and disciplinary measures.
Although it is not mandatory, some Brazilian companies have been participating in drug testing programs in the workplace since 1992.Nowadays, more than 300 companies all over the country have been sending periodically their employees' urine samples to the drug analysis laboratory of Universidade de São Paulo.The standard test protocol includes testing for marijuana, cocaine, and amphetamines using the recommended cutoffs for screening and confirmatory results. 4udies on the prevalence of illicit drug use among employed and unemployed people are relatively scarce in the literature. 5,7A USA study performed from October 1990 through March 1992 showed that, of 2 million workplace drug tests, almost 4% were positive for one or more illicit drugs.Marijuana was the most commonly detected drug (2%) followed by cocaine (1%), opiates (0.6%), and benzodiazepines (0.5%). 7In another study conducted by Normand et al, 8 5,465 job applicants to the US Postal Service were tested for drug use.The results were as follows: 9.4% positive for illicit drugs; 6.2% marijuana, 2.6% cocaine, and 0.2% other drugs.
The aim of this study was to profile drug abuse among workers of the five Brazilian geographical regions (south, southeast, north, northeast, and central west) from business companies that have adopted drug testing programs.A total of 12,700 urine samples from adults of both sexes and several job activities were collected in five different Brazilian regions since 1992: southeast (9,139), northeast (1,753), southern (1,003), central west (730), and northern (75).Urine collection was performed under direct observation of sampling officers.Plastic bottles used to collect the samples were sealed with numbered seals.All the administrative route and complete documentation involving the custody chain were rigorously performed according to recommended procedures, assuring sample integrity, confidentiality and validity of results. 4IT (enzyme multiplied immunoassay technique) analyses of the selected drugs were performed by the automated ETS Plus System from Syva Co. (Palo Alto, CA).The following cutoff values were used in the screening step: cannabinoids 50 ng/ml; cocaine metabolite 300 ng/ml, and amphetamine 300 ng/ml. 4e samples were analyzed according to previously published methods GC/MS (gas chromatography/mass spectrometry). 6,9,13The following cutoff values were adopted for the confirmatory technique: 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid 15 ng/ ml; benzoylecgonine 150 ng/ml, and amphetamine 200 ng/ml. 4Hewlett-Packard gas-chromatograph (Palo Alto, CA) (model 6890) with a mass selective detector (MSD 5972) was used in the analyses.Results were processed in a HP 1701AA ChemStation version A. The MSD was operated in the electron impact (EI) mode at 70 eV.

RESULTS
Figure 1 shows sample distribution according to geographical Brazilian regions.The largest number of samples analyzed (72%) was collected in the southeast region.This is by far the most powerful and developed region of the country where it can be found the most important industrial areas (cities of São Paulo and Rio de Janeiro, Brazil).Urine samples collected in other regions were as follows: 13.8% from northeast, 7.9% southern, 5.7% central west, and only 0.6% from the northern region where it lays the Amazon rain forest.
Marijuana was the most commonly detected drug among workers, with 59.9% of all positive results, followed by cocaine (17.7%), and amphetamine (14.6%).Association of two drugs was found in 7.7% of positive results, being 6.5% of marijuana/cocaine, 0.9% marijuana/amphetamine, and only 0.4% cocaine/amphetamine (Figure 3).

DISCUSSION
Social, economic and cultural differences are often seen in Brazil due to its large territorial area and clearly affect drug use patterns in the general population including the workforce.The highest drug use seen in the southeast region can be explained by its high demographic density and high purchase power of its population.The lowest use was seen in the southern region.
Marijuana was detected in samples collected in all regions and was also the only drug present in samples from northern and southern regions.
Marijuana is the least expensive of the studied drugs.It is widely distributed throughout the country because cannabis is cultivated in Brazil (northern and northeast regions) and in some other South American countries and is affordable.Besides, the main metabolite of marijuana, tetrahydrocannabinol carboxylic acid, can be detected several days after exposure.
Cocaine was detected in urine samples collected in central west and southeast regions probably because the area is part of the trafficking route of the drug produced in neighboring countries.Cocaine hydrochloride is the main form of cocaine consumed in the city of Rio de Janeiro.Crack cocaine is more prevalent in the city of São Paulo.In the central west region, the drug is consumed as cocaine paste known as "merla".Amphetamine was found in northeast, central west and southeast regions.It is probably from the use of fenproporex, as amphetamine is one of its metabolites. 3Fenproporex is a licit substance for therapeutic use prescribed as appetite suppressor.It has been widely used as drug of abuse in some occupations in Brazil, like truck drivers who need to drive long distances. 10More than 50% of urine samples collected were from highway transportation companies, what could explain the positive results for amphetamine found in this study.
Marijuana was the most commonly detected drug among workers, with 59.9% of all positive results, followed by cocaine (17.7%), and amphetamine (14.6%).Association of two drugs was found in 7.7% of positive results, being 6.5% of marijuana/cocaine, 0.9% marijuana/amphetamine, and only 0.4% cocaine/amphetamine (Figure 3).Drug testing in the workplace has been considered a great initiative to minimize the problem associated to drug use.The decision to implement such program in business companies is based on matters of employees' health and safety.Other considerations involve the attempt to reduce absenteeism in the workplace and incompatibility of drug use with some jobs. 2 However, lack of information about a detailed evaluation of the program has yielded some criticism.Other epidemiological studies are needed to assess the effectiveness, costs, and benefits of such programs at the workplace and could provide important information for the development of national drug policies.

Figure 1 -Figure 2 -
Figure 1 -Distribution of samples according to Brazilian geographical regions.
percentage of positive results N o r th N o r th e a s t C e n tr a l W e s t S o u th e a s t S .usp.br/rsp Drug abuse among workers in Brazil Silva OA & Yonamine M

Figure 3 -
Figure 3 -Frequency of drug use among Brazilian workers.