Associations between exposure to polycyclic aromatic hydrocarbons and biomarkers of acute kidney injury among Chilean agricultural workers

Abstract

Polycyclic aromatic hydrocarbon (PAH) exposures from agricultural and household woodburning may adversely impact kidney health, but studies are limited in Latin America where these practices are prevalent. We aimed to characterize PAH exposures and examine their associations with kidney injury biomarkers among agricultural workers in Chile. Among 43 male agricultural workers from the Maule Cohort, we quantified urinary concentrations of five kidney injury biomarkers (IL-18, KIM-1, MCP-1, NGAL, YKL-40) and nine hydroxy-PAHs. Additionally, we measured 23 parent PAHs in wristbands, worn 8-11 days. We estimated percent differences in kidney biomarker concentrations and odds ratios of subclinical kidney injury (defined by two or more kidney biomarkers in the highest tertile) per interquartile range increase in PAH exposure concentration. All urinary PAH and kidney biomarkers were frequently detected (>70%) as were 13 parent PAH compounds in wristbands. We observed consistent positive associations of urinary IL-18 with select PAH exposures. Specifically, higher urinary IL-18 concentrations were observed in association with higher urinary concentrations of 1-PHE (80.4%; 95%CI: 33.8%, 143.3%), 2&3-PHE (44.1%; 95%CI: 12.7%, 84.2%), and 4-PHE (48.8%; 95%CI: 12.9%, 96.1%). Similarly, IL-18 concentrations were positively associated with higher wristband concentrations of anthracene (46.7%; 95%CI: 9.7%, 96.2%), phenanthrene (32.3%; 95%CI: 5.5%, 65.9%), fluorene (56.9%; 95%CI: 10.2%, 123.3%), and pyrene (34.1%; 95%CI: 3.2%, 74.3%) and among participants with naphthalene detected in their wristbands (51.5%; 95%CI: 1.3%, 126.7%). Wristband concentrations of benzo[e]pyrene, benzo[a]pyrene, and chrysene were associated with higher odds of subclinical AKI but not decreased kidney function. Our findings suggest that select PAH exposures may be associated with kidney injury, addressing major knowledge gaps and informing future studies of kidney health in agricultural communities.

Keywords: Acute kidney injury; Agricultural workers; Polycyclic aromatic hydrocarbons; Silicone wristbands; Urinary biomonitoring.