Evaluation of cytokine expression in BEAS cells exposed to fine particulate matter (PM_2.5) from specialized indoor environments

Abstract

Fine particles were collected in three indoor environments and an outdoor reference site. Samples were acid and aqueous extracted for metal analyses and cytokine expression study using a BEAS-2B line. Results revealed that the average PM_2.5 concentration indoors was 5.8 μg/m³ while outside, it was 9.4 μg/m³. The airborne metal concentrations in indoor air ranged from 0.01 ng/m³ (Cd) to 620 ng/m³ (Al). All metals analyzed were higher indoors when compared to outdoor (I/O ratio) indicating a contribution from the workplace. Some metals were more efficiently extracted (e.g., Ni, V, As) in the aqueous phase than others (e.g., Fe and Al). Toxicological assays showed that the aqueous extracts at 20% induced IL-6 and subsequently inhibited it at a higher concentration (50%); both IL-8 and MCP-1 were inhibited at 20 and 50%. As, Ni and V concentrations seem to be the most important metals associated with the cytokine induction/inhibition response probably due to the higher bioavailability.

Keywords:

• air pollutant concentrations
• dust
• exposure assessment
• heavy metals
• indoor

Acknowledgments

This work was supported in part by the grants: Minority Biomedical Research Support – Support of Continuous Research Excellence (MBRS-SCORE), National Institutes of Heath [grant number 5S06-GM008224]; Research Center in Minority Institutions (RCMI) Program at the University of Puerto Rico Medical Sciences Campus from the National Center for Research Resources, National Institutes of Heath [grant number G12RR03051]; Minority Biomedical Research Support – Research Initiative for Scientific Enhancement (MBRS-RISE), National Institutes of Heath [grant numbers 5R25GM061838-08, 2R25GM061838-09]; and the Center for Environmental and Toxicological Research at the University of Puerto Rico Medical Sciences Campus.