California neighborhoods where cannabis retailers are located tend to have higher proportions of Hispanic and Black residents, and lower proportions of whites, while also being poorer than those areas without such retailers. That’s according to a new study co-authored by researchers from the KSOM Department of Preventive Medicine and USC Dornsife’s Spatial Sciences Institute and published in the September issue of Preventive Medicine Reports.

The research shows that “minority populations in California are disproportionately exposed to unlicensed cannabis retailers,” the authors wrote. The study examined areas where both licensed and unlicensed retailers are located. Overall, neighborhoods served by any retailer represented 42% of the state’s population.

Recreational use of cannabis by adults became legal in California in 2016, and state and local licenses were issued starting in 2018. Only 20% of California cities allow retail sales, but according to the study’s findings, a thriving black market exists where unlicensed cannabis retailers operate.

The researchers identified 1,110 cannabis retailers in the state—448 licensed and 662 unlicensed. Relative to neighborhoods without retailers, neighborhoods with retailers had higher proportions of Hispanics, African Americans, and residents living below the poverty level. Compared with neighborhoods with only licensed retailers, neighborhoods with only unlicensed retailers had higher proportions of Hispanics and African Americans, and lower proportions of non-Hispanic whites. Neighborhoods with both licensed and unlicensed retailers had higher proportions of African Americans, Asian Americans, and people living in poverty, relative to neighborhoods with only licensed retailers.

The paper noted that unincorporated areas lack enforcement capabilities to inspect stores for product quality, to ensure minors aren’t being sold the products, and to close down retailers who violate the law, “thereby potentially exacerbating health disparities within these communities.”