The legalization of marijuana across the U.S. is beginning to reveal a treasure trove of information. Before, it was difficult to do research on the usage of pot because it was illegal, and people tend not to admit to doing things that are illegal.
However, with both the law and the public's attitude relaxing toward marijuana, people are opening up about their wacky tobaccy habits. The CDC took advantage of this and surveyed people aged 18 and over in Colorado, which legalized recreational pot in 2014.
The study population included only those respondents who (1) answered (either positively or negatively) whether they had ever consumed marijuana and (2) were currently employed or had been unemployed for less than one year. This whittled the study down to 10,169 respondents, who were then asked about current marijuana use (defined as at least once within the past 30 days) and occupation.
The results (shown without confidence intervals for clarity) are depicted below:
In the chart, the blue bars represent the prevalence (as a percentage of the population) who currently uses marijuana in a given occupation. Food preparation/serving had the highest percentage of pot users, followed by arts/design/entertainment/sports/media. Perhaps slightly concerning, there is substantial use of marijuana among people who have jobs in which safety is a key concern. (These are marked by an asterisk *). For example, more than 16% of people in farming/fishing/forestry and construction/extraction admit to currently using marijuana.
Let's hope it's not while on the job. One study showed that fatal car accidents are higher by 12% on April 20, the unofficial "marijuana holiday."
The red bars show age-adjusted prevalence figures. In epidemiology, age-adjustment is a way to account for the fact that some groups (in this case, professions) have different proportions of young and old people. For instance, we would expect more young people (who are likelier to smoke pot) to be in jobs like food preparation/serving, while we would expect more older people (who are less likely to smoke pot) to be in jobs such as management.
Age-adjustment, therefore, pretends that all professions have the same proportion of young and old people. After performing this adjustment, the arts/design/entertainment/sports/media occupation group comes out as Colorado's top pot smokers. The least likely to use pot? Protective services. That's probably a good thing.