Exposure to multiple heavy metals associated with levels of inflammatory cytokines in workers in vulnerable conditions

Individuals in occupational environments are particularly susceptible to the impacts of pollutants; making it crucial to assess systemic inflammation markers. The study aimed to evaluate the immune response to inflammation through the assessment of a cytokine profile in individuals working in vulnerable conditions exposed to heavy metals. A total of 137 adults participated in this study from three work environments: brickyards, waste scavenging and quarries. Levels of 12 metals were evaluated in urine using inductively coupled plasma mass spectrometry (ICP-MS), and serum levels of 6 cytokines were analyzed using Multi-Bead Cytokine Assay. In the brickyard scenario, a significant percentage of subjects presented concentrations above the reference levels of Hg, As, and Pb (83.7%, 62.8%, and 16.3%; respectively). The waste scavenging and quarry workers scenario exhibited percentages of 100% and 49% for Ni, respectively. Additionally, the brickyard and waste scavenging scenarios showed the highest levels of TNF-α and INF-γ and, lower levels of IL-4 and IL-10. In the quarry scenario, an increase of IL-6 and a decrease in INF-γ were observed. Furthermore, a clustering pattern based on the type of scenario was identified, indicating a higher exposure to As, Pb, and Hg in the brickyard scenario, along with TNF-α, IL-4, and IL-10 levels. The results suggest that exposure to heavy metals in workers with precarious work conditions, present elevated levels of inflammatory cytokines, which are related to the type of occupational environment.