# Immunotoxicity of Inhalable Organic Dust Samples Based on In Vitro Analysis of Human Respiratory Epithelial Cells

## TL;DR

This study examines how inhalable organic dust from different workplaces affects human respiratory cells, identifying which dust components are most harmful.

## Contribution

The study introduces a statistical method linking dust composition to in vitro immunotoxicity, highlighting key hazardous agents in organic dust.

## Key findings

- Sewage treatment plant dust showed the highest cytotoxicity, while poultry farm dust had the lowest.
- Respirable crystalline silica, bacteria, fungi, PGN, and GLU were identified as major contributors to cytokine release.
- Composting plant dust posed the highest health risk, while biomass-fired power plant dust posed the lowest.

## Abstract

Airborne organic dust has rarely been subject to immunotoxicological analysis. A pilot study was undertaken to link exposure metrics (respirable crystalline silica (RCS), bacteria, fungi, endotoxins (END), peptidoglycans (PGN), (1 → 3)-β-D-glucans (GLU)) with in vitro cytotoxicity and cytokine responses based on analysis of airborne organic dust samples collected during a single work shift at six different facilities. The A549 and BEAS-2B cell lines were used to assess cytotoxicity and proinflammatory cytokine release. The general linear model (GLM) and taxonomic linear ordering were used to identify key determinants and rank facilities by the hazard level they pose. The highest cytotoxicity of organic dust was observed at the sewage treatment plant, while the lowest was at the poultry farm. The most hazardous agents present in organic dust included RCS, aerobic bacteria, fungi, PGN, and GLU. They significantly affected cytokine release, particularly of IL-6 and IL-8. The use of a synthetic measure showed that inhalable organic dust from the composting plant presented the highest potential to induce adverse effects on human health, while the lowest one was characterized by the biomass-fired power plant samples. The open-ended statistical method can significantly increase awareness of occupational hazards and promote more responsible protection for exposed workers.