摘要：Objectives. We investigated sociodemographic disparities in alcohol environments and their relationship with adolescent drinking. Methods. We geocoded and mapped alcohol license data with ArcMap to construct circular buffers centered at 14 595 households with children that participated in the California Health Interview Survey. We calculated commercial sources of alcohol in each buffer. Multivariate logistic regression differentiated the effects of alcohol sales on adolescents' drinking from their individual, family, and neighborhood characteristics. Results. Alcohol availability, measured by mean and median number of licenses, was significantly higher around residences of minority and lower-income families. Binge drinking and driving after drinking among adolescents aged 12 to 17 years were significantly associated with the presence of alcohol retailers within 0.5 miles of home. Simulation of changes in the alcohol environment showed that if alcohol sales were reduced from the mean number of alcohol outlets around the lowest-income quartile of households to that of the highest quartile, prevalence of binge drinking would fall from 6.4% to 5.6% and driving after drinking from 7.9% to 5.9%. Conclusions. Alcohol outlets are concentrated in disadvantaged neighborhoods and can contribute to adolescent drinking. To reduce underage drinking, environmental interventions need to curb opportunities for youth to obtain alcohol from commercial sources by tightening licensure, enforcing minimum-age drinking laws, or other measures. Despite federal, state, and local interventions, underage drinking continues to be a serious problem. A national survey found that 17.6% of adolescents drank alcohol in the past 30 days, 11.1% were binge drinkers, and 2.7% were heavy drinkers. 1 Health and social problems associated with youths' drinking include motor vehicle crashes, 2 , 3 violence, 4 risky sexual behaviors, 5 , 6 assault and rapes, 7 and brain impairment. 8 – 11 Adolescent alcohol use has substantial societal costs. 12 Drinking at an early age also increases the risk of addiction and other alcohol-related problems in adulthood. 13 – 15 In 2007, the surgeon general responded to this problem in the Call to Action to Prevent and Reduce Underage Drinking , which emphasized environmental contributions to the problem. 16 Underage drinkers obtain their alcoholic beverages from a variety of sources, including parents' stocks, friends, parties, and commercial outlets. 17 In 1 study, buyers who looked underage were able to purchase alcohol with high success rates from both on-site (for consumption on the premises, such as bars and restaurants) and off-site (for consumption elsewhere, such as liquor stores) establishments. 18 , 19 Sales to minors have been found to be significantly associated with the percentage of Hispanic residents in a neighborhood and with population density. 20 As long as adolescents can obtain alcohol from commercial sources, neighborhood outlets are likely to play a role in underage drinking. Rhee et al. argued that environment plays an essential role in drinking initiation and that genetics are important in developing alcohol dependence. 21 Perceived alcohol availability was significantly associated with higher levels of alcohol consumption among young men 22 and with drinking in public locations for adolescent girls. 23 Density of outlets for alcohol in cities was associated with youths' drinking and driving and with riding in a car driven by a person under the influence of alcohol. 24 Differences in alcohol environments may exacerbate health disparities across sociodemographic groups. LaVeist and Wallace found that in Baltimore, MD, predominantly Black and low-income census tracts have more liquor stores per capita than do tracts of other race and income groups. 25 Gorman and Speer found retail liquor outlets abundantly located in poor and minority neighborhoods in a city in New Jersey. 26 Only 1 national study has been published, and it reported higher densities of liquor stores in zip codes with higher percentages of Blacks and lower-income non-Whites. 27 That study covered all urban areas in the United States, but the urban zip codes had a mean land area of 40.1 square miles and a mean population of 21 920 persons, 27 arguably too large to represent neighborhoods. Even census tracts may be too large and too dissimilar to capture neighborhood effects: in Los Angeles County they can range from 0.04 square miles to 322 square miles. The objectives of this study were (1) to describe the quantity and geographic pattern of alcohol retailers in small areas around individual homes and (2) to examine relationships between alcohol environments and adolescent drinking. We analyzed data from the entire state of California to investigate the effects of spatial accessibility on alcohol sales to adolescents.
