Lifetime marijuana use in relation to cadmium body burden of US adults: results from the national health and nutrition examination surveys, 2009-2016.

OBJECTIVES: Low-level cadmium exposure has been linked to chronic diseases, but the importance of marijuana use as a source of cadmium remains unknown. We aimed to determine the association of marijuana use with blood cadmium (BCd) and urinary cadmium (UCd) levels. METHODS: We abstracted data from the National Health and Nutrition Examination Surveys, 2009-2016. We modeled lifetime marijuana exposure accounting for both duration and frequency of exposure. We used adjusted ratio of geometric means (ARM) and 95% confidence intervals (95% CIs) to compare outcomes among groups of marijuana exposure, relative to never users. The UCd level was adjusted for creatinine excretion. RESULTS: We included 163,250 adults (mean age, 38.7 years; 50% women). The ARM of BCd was 1.28 (95% CI = 1.04, 1.57), 1.40 (95% CI = 1.11, 1.76), and 1.77 (95% CI = 1.51, 2.09) in current users with <2 uses per week, 2-3 uses per week, and ≥4 uses per week, respectively. Marijuana use for ≥15 years was associated with both higher cadmium burden in adults with <2 uses per week (ARM of 1.30 (95% CI = 1.04-1.62) for BCd and 1.48 (95% CI: 1.05, 2.09) for UCd or ≥4 uses per week (ARM of 1.69 (95% CI = 1.40, 2.05) for BCd and 1.38 (95% CI = 1.11, 1.72) for UCd. In former users, marijuana use was significantly associated with higher UCd levels in those with ≥15 years of use [ARM of 1.39 (95% CI = 1.14, 1.69) for those with <2 uses/week and 1.51 (95% CI = 1.19, 1.92) for those with ≥4 uses/week]. CONCLUSIONS: The BCd level was higher in both current and former marijuana users than in never users. Marijuana use was also associated with higher UCd levels after a long-term use.

Effort--reward imbalance and medically certified absence for mental health problems: a prospective study of white-collar workers.

OBJECTIVE: Little is known about the effects of psychosocial work factors on objectively assessed mental health problems leading to medically certified absence. Only one study has evaluated the prospective effects of effort-reward imbalance (ERI) at work with regards to this outcome. The present study aimed to evaluate the effects of ERI on the incidence of medically certified absence for mental health problems. METHODS: The study included 2086 white-collar workers (63.3% women) employed in public organisations in Quebec city. Participants were followed over a 9-year period. Medical absences from work were collected from employers' files and psychosocial factors were measured using the ERI questionnaire. Cox regression models were used to estimate the incidence of certified sickness absence due to mental health problems that lasted 5 workdays or more, while controlling for confounders. RESULTS: Workers exposed to ERI had a higher risk of a first spell of medically certified absence for mental health problems (HR=1.38, 95% CI 1.08 to 1.76) compared with unexposed workers. Low reward was significantly associated with a high risk among men (HR=2.80, 95% CI 1.34 to 5.89) but not in women. (HR=1.24, 95% CI 0.90 to 1.73). Effort at work had no effect on certified absence. All these effects were adjusted for potential confounders. CONCLUSIONS: ERI and low reward at work were prospectively associated with medically certified absence for mental health problems. These effects seem to differ by gender. Primary prevention that is aimed at reducing these stressors should be considered to help reduce the incidence of such severe mental health problems.