
Tobacco Retailer Proximity and Density and Nicotine Dependence Among Smokers With Serious Mental Illness. examined the density and proximity of tobacco retailers and associations with smoking behavior and mental health in a diverse sample of 1061 smokers with serious mental illness (SMI) residing in the San Francisco Bay Area of California. Participants' addresses were geocoded and linked with retailer licensing data to determine the distance between participants' residence and the nearest retailer (proximity) and the number of retailers within 500-meter and 1-kilometer service areas (density).