Association Between Biomass Fuel Use and Depression Symptoms in the Adult Population of Oaxaca, Mexico

The impact of biomass fuel exposure on mental health, along with the associated gender disparities, remains largely unexplored. This study aimed to examine the association between biomass fuel use and depressive symptoms in the population of Oaxaca, Mexico, while also identifying gender differences in this relationship.

This study used data from the 2022 National Health and Nutrition Survey (ENSANUT). Depressive symptoms, the outcome variable, were assessed using the Center for Epidemiologic Studies Depression Scale (CESD). The primary predictor variable was biomass fuel use, with gender, age, and residency stratum included as covariates. First, a binary logistic regression model was developed to estimate the dichotomous variable "depression symptoms". Subsequently, a second binary logistic regression model was constructed to evaluate potential interactions between the covariates and the predictor variable.

The sample included 1.4 million adults from Oaxaca, with a prevalence of depressive symptoms of 15%. Biomass fuel was used by 15.4% of the population. The first logistic regression model showed that women (Odds Ratio (OR): 1.249; 95% CI: 1.235-1.263; p < 0.001), individuals aged 60 years and older compared to the younger population group (OR: 12.192; 95% CI: 12.064-12.321; p < 0.001), those residing in rural areas (OR: 1.245; 95% CI: 1.232-1.259; p < 0.001), and individuals using firewood or charcoal for cooking (OR: 1.674; 95% CI: 1.651-1.697; p < 0.001) had higher odds of depressive symptoms. In the second binary logistic regression model, all associations and OR coefficients retained their direction, although the coefficients underwent a slight adjustment following the introduction of the interaction term, indicating the presence of an interaction.

The study findings suggest a gendered association between biomass fuel exposure and depressive symptoms in the adult population of Oaxaca, with older women and women dwelling in rural areas being the most vulnerable. Interventions aimed at reducing biomass air pollution exposure and strengthening mental health support for women are strongly recommended.