Oxidative Stress, Cytotoxic and Inflammatory Effects of Urban Ultrafine Road-Deposited Dust from the UK and Mexico in Human Epithelial Lung (Calu-3) Cells

Abstract

Road-deposited dust (RD) is a pervasive form of particulate pollution identified (typically via epidemiological or mathematical modelling) as hazardous to human health. Finer RD particle sizes, the most abundant (by number, not mass), may pose greater risk as they can access all major organs. Here, the first in vitro exposure of human lung epithelial (Calu-3) cells to 0–300 µg/mL of the ultrafine (<220 nm) fraction of road dust (UF-RDPs) from three contrasting cities (Lancaster and Birmingham, UK, and Mexico City, Mexico) resulted in differential oxidative, cytotoxic, and inflammatory responses. Except for Cd, Na, and Pb, analysed metals were most abundant in Mexico City UF-RDPs, which were most cytotoxic. Birmingham UF-RDPs provoked greatest ROS release (only at 300 µg/mL) and greatest increase in pro-inflammatory cytokine release. Lancaster UF-RDPs increased cell viability. All three UF-RDP samples stimulated ROS production and pro-inflammatory cytokine release. Mass-based PM limits seem inappropriate given the location-specific PM compositions and health impacts evidenced here. A combination of new, biologically relevant metrics and localised regulations appears critical to mitigating the global pandemic of health impacts of particulate air pollution and road-deposited dust.

Toxicological Assessment of Particulate and Metal Hazards Associated with Vaping Frequency and Device Age

“…While assessing relevant human exposure levels is critically important in determining the safety of ENDS, understanding various particle reaction dynamics that may occur within biological systems is essential for a holistic appraisal of potential cellular outcomes [ 53 ]. One of the reactions that occurs during complex particle-cell interactions is the Fenton reaction, which involves the generation of oxidizing agents such as hydroxyl radicals through the decomposition of hydrogen peroxide in the presence of ferrous cations or other transition metals [ 54 , 55 ]. Among the six metals that our metal analysis detected at an elevated level in the later puff fraction (101–150), three transition metals (Cu, Cr, and Al) are considered Fenton reagents.…”

“…Among the six metals that our metal analysis detected at an elevated level in the later puff fraction (101–150), three transition metals (Cu, Cr, and Al) are considered Fenton reagents. Fenton reagents can induce Fenton-like reactions and increase reactive oxygen species (ROS) production [ 55 , 56 ]. This correlates with our toxicological observations, which showed elevated ROS caused by later puff fraction exposure, suggesting metal-induced oxidative stress.…”

Measuring magnetic susceptibility of particulate matter collected on filters

“…In recent times, there has been an increase in social and scientific interest in improving air quality in urban areas due to the health risks posed by pollutants like particulate matter (PM), sulfur dioxide, ozone, benzene, nitrogen oxides, and carbon monoxide (Zheng et al 2015 , Thurston et al 2016 ; Weichenthal et al 2017 ; Wu et al 2018 ; Harrison et al 2017 ; Strak et al 2017 ; Čabanová et al 2019 ; Pope et al 2020 ; Rachwał et al 2020 ; Hammond et al 2022 ; Adamiec et al 2022 ; Loaiza-Ceballos et al 2022 ). Of these pollutants, airborne particles with aerodynamic diameters less than 10 µm (PM10), less than 2.5 µm (PM2.5), and smaller are particularly harmful to human health as they can easily penetrate deep into the lungs and circulatory system, leading to serious respiratory and cardiovascular diseases, cancer, and even mortality (Maher et al 2016 ; Thurston et al 2016 ; Miller et al 2017 ; Weichenthal et al 2017 ; Bové et al 2019 ; Calderón-Garcidueñas et al 2020 ; Nadali et al 2022 ).…”

Efficacy of Green Infrastructure in Reducing Exposure to Local, Traffic-Related Sources of Airborne Particulate Matter (Pm)

“…In urban areas, exposure to traffic-related air pollution has been linked to adverse health outcomes, to which young children are especially vulnerable (Makri and Stilianakis, 2008;Rovelli et al, 2014;Schwartz, 2004;Sunyer et al, 2015). The spatial distribution of PM varies significantly according to location (Maher et al, 2022;Sanders et al, 2003;Yang et al, 2015), with major roads and industrial areas having different "mixes" of airborne pollutants, some of which are more harmful than others (Hammond et al, 2022).…”