Editor,—In Mexico approximately 9% of smokers are aged between 12–17 years, and from 1988 to 1998 the prevalence of current smoking among minors increased from 7.7% to 11.6%.1-3 Data from the National Addictions Survey (NAS-98) indicate that 61.4% of adult smokers in Mexico became regular smokers before the age of 18.4 5

We sought to assess compliance with the law forbidding sale of tobacco products to minors in two Mexican cities (Mexico City and Ciudad Juárez).6 Compliance monitoring teams were formed, consisting of an adult and two minors. The minors were of both sexes, trained before the start of the study. The adult in each team served as an escort and observer.

Teams attempted to make one purchase per store, the adult entering the store 30 seconds before one of the minors and noting whether age-of-sale warning signs were posted and observing the transaction to purchase a pack of cigarettes between the retailer and the minor. An illegal sale was defined as a transaction in which a retailer sold a pack of cigarettes to a minor. The survey questionnaire was filled in by the adult in each team.

Stores were selected using a non-systematic sampling method by quota, with an unplanned route, in each of the 16 districts in Mexico City, from 23 March to 24 April 1997.

Five hundred and sixty one stores were visited. Data analysis used χ² tests to calculate statistical differences in the sales rates associated with the variables.7

In February 1999 a similar study was conducted in Ciudad Juárez. The sample was selected by using a stratified cluster design since no lists of cigarette outlets exist. Twenty three clusters were randomly selected. All stores within the selected cluster were visited. Two hundred and forty stores were visited and sampling weights were calculated using SUDAAN.8

Of 561 tobacco outlets surveyed in Mexico City, cigarettes were successfully purchased by minors in 443 (79%) stores. In 439/443 occasions, the minors bought the cigarettes directly from the vendors, and not by self service. Warning signs prohibiting the sale of tobacco to minors were present in only 64 stores (11.8%) and were not associated with lower sales rates. Only four (0.7%) vendors requested the minors' age; one requested identification; and 30 (5.3%) asked for whom the cigarettes were being purchased.7

In the Ciudad Juarez study 240 tobacco outlets was surveyed. The attempt to buy cigarettes was successful in 231 (98.1%) stores. Warning signs prohibiting the sale of tobacco to minors were present in three stores (1.3%). Few of the vendors requested the minors' age (eight, 3.3%), identification (two, 0.8%), or for whom the cigarettes were being purchased (eight, 80%).8

This study shows that almost eight out of 10 minors in Mexico City and almost all in Ciudad Juárez, Chihuahua, can easily obtain cigarettes directly from a vendor, despite the sale of tobacco products being prohibited by law.9 10 Most vendors did not ask the minors attempting to purchase cigarettes about their age, nor did they request identification. Even the few outlets with warning signs did not show a reduction in tobacco sales to minors. This shows a need to improve vendor compliance, particularly in the formal tobacco outlets, if a reduction in adolescent tobacco use and smoking initiation is to be achieved.11