Contrasting biological potency of particulate matter collected at sites impacted by distinct industrial sources

Errol M Thomson; Dalibor Breznan; Subramanian Karthikeyan; Christine MacKinnon-Roy; Ngoc Q Vuong; Ewa Dabek-Zlotorzynska; Valbona Celo; Jean-Pierre Charland; Prem Kumarathasan; Jeffrey R Brook; Renaud Vincent

doi:10.1186/s12989-016-0176-y

Contrasting biological potency of particulate matter collected at sites impacted by distinct industrial sources

Part Fibre Toxicol. 2016 Dec 1;13(1):65. doi: 10.1186/s12989-016-0176-y.

Affiliations

¹ Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, K1A 0K9, Canada. errol.thomson@canada.ca.
² Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, K1A 0K9, Canada.
³ Analysis and Air Quality Section, Air Quality Research Division, Atmospheric Science and Technology Directorate, Environment and Climate Change Canada, Ottawa, ON, K1A 0H3, Canada.
⁴ Air Quality Processes Research Section, Air Quality Research Division, Atmospheric Science and Technology Directorate, Environment and Climate Change Canada, Toronto, ON, M3H 5T4, Canada.
⁵ Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, K1A 0K9, Canada. renaud.vincent@canada.ca.

Abstract

Background: Industrial sources contribute a significant proportion of anthropogenic particulate matter (PM) emissions, producing particles of varying composition that may differentially impact health. This study investigated the in vitro toxicity of ambient PM collected near industrial sites in relation to particle size and composition.

Methods: Size-fractionated particles (ultrafine, PM_0.1-2.5, PM_2.5-10, PM_>10) were collected in the vicinity of steel, copper, aluminium, and petrochemical industrial sites. Human lung epithelial-like A549 and murine macrophage-like J774A.1 cells were exposed for 24 h to particle suspensions (0, 30, 100, 300 μg/cm²). Particle potency was assessed using cytotoxic (resazurin reduction, lactate dehydrogenase (LDH) release) and inflammatory (cytokine release) assays, and regressed against composition (metals, polycyclic aromatic hydrocarbons (PAHs), endotoxin).

Results: Coarse (PM_2.5-10, PM_>10) particle fractions were composed primarily of iron and aluminium; in contrast, ultrafine and fine (PM_0.1-2.5) fractions displayed considerable variability in metal composition (especially water-soluble metals) across collection sites consistent with source contributions. Semi-volatile and PM-associated PAHs were enriched in the fine and coarse fractions collected near metal industry. Cell responses to exposure at equivalent mass concentrations displayed striking differences among sites (SITE x SIZE and SITE x DOSE interactions, p < 0.05), suggesting that particle composition, in addition to size, impacted particle toxicity. While both J774A.1 and A549 cells exhibited clear particle size-dependent effects, site-dependent differences were more pronounced in J774A.1 cells, suggesting greater sensitivity to particle composition. Plotting particle potency according to cytotoxic and inflammatory response grouped particles by size and site, and showed that particles of similar composition tended to cluster together. Cytotoxic effects in J774A.1 cells correlated with metal and PAH content, while inflammatory responses were associated primarily with endotoxin content in coarse particles.

Conclusions: Industrial sources produce particulate emissions with varying chemical composition that differ in their in vitro potency in relation to particle size and the levels of specific constituents.

Keywords: Air pollution; Endotoxin; Industry; Inflammation; Metals; Particle; Polycyclic aromatic hydrocarbons; Size; Source; Toxicity.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cell Line
Cytokines / metabolism
Humans
Industry*
Mice
Particulate Matter / toxicity*

Substances

Cytokines
Particulate Matter