Microbiome alterations associated with phthalate exposures in a US-based sample of Latino workers

Low-wage service sector jobs are largely occupied by racial/ethnic minority workers who often experience an increased risk of elevated chemical exposures, including chemicals like phthalates, compared to the general public. Phthalates have been linked with adverse health effects, including increased risk of atopy and asthma. An important etiological component in respiratory disease, including asthma, is the role of the upper respiratory microbiota in atopic disease development. However, it is unclear how the upper respiratory microbiome is affected by chemical exposures, and how this may impact respiratory outcomes. As Latino workers are often disproportionately exposed to increased concentrations of chemicals and Hispanics have higher rates of adverse respiratory health conditions such as asthma, the aim of this pilot study was to evaluate the effects of 10 unique phthalate urinary biomarkers on the 16S rRNA nasal microbiome. Nasal and urinary samples were collected from 20 facility workers (plumbers, landscapers, electricians) and 20 custodial workers. Our analysis revealed altered microbial composition and diversity according to phthalate urinary biomarker concentration within the two worker groups. Higher urinary biomarker concentrations of select phthalates (MBP, MBIP, and ∑DEHP) were associated with increased Moraxella relative abundance, which has been positively associated with asthma. Within-sample alpha diversity levels were decreased in facility workers and were generally inversely associated with most phthalate urinary biomarker concentrations. Our research suggests that exposure to chemicals in this vulnerable worker group may impact the respiratory microbiome, which may increase risk of development of adverse health conditions. Further research is warranted to refine the mechanistic pathways that underpin the relationships between phthalate exposures and respiratory microbial communities to provide key insights on respiratory pathologies and, most importantly, to identify modifiable risk factors that can be used to direct mitigation efforts aimed at ameliorating the harmful effects of chemical exposures in this understudied occupational population.