Biomagnetic Characterization of Air Pollution Particulates in Lahore, Pakistan

Abstract

Epidemiological studies have associated particulate air pollution with reduced cognitive performance (Zhang et al., 2018), development of diseases in the pulmonary and cardiovascular systems (Devlin et al., 2014;Schwarze et al., 2006;Seaton et al., 1995), and dementia (H. Chen et al., 2017). The biological mechanisms behind higher risk of cardio-respiratory diseases in an air-polluted urban environment have been studied and associated with ultrafine particles (Leitte et al., 2012;Miller et al., 2017;Penttinen et al., 2001). The size, morphology, and chemical composition of particles are critical in gauging detrimental effects to human health. Conventional air pollution indices classify and monitor PM as a function of its aerodynamic diameter: Exposure to PM 0.1 (≤0.1 μm), often referred to as ultrafine particles (UFPs), is of increasing focus and concern because of UFPs potential adverse health implications, as small particles can exert higher toxicity than larger particles (Ohlwein et al., 2019). UFPs can be drawn into the body via ingestion (Calderón-Garcidueñas et al., 2020), skin (Araviiskaia et al., 2019), olfactory transport, and through the lungs, entering the alveoli and penetrating biological membranes, effectively translocating to almost all organs (

Magnetic and microscopic investigation of airborne iron oxide nanoparticles in the London Underground

“…The peak of the backfield coercivity distribution for all our air filter samples lie at around 65 mT (Fig. 1A), similar to coercivity values for vehicular brake residue samples and higher than vehicular exhaust emissions from a previous study 31 . No direct evidence of metallic Fe was found in our microscopy data.…”

SIGMA: Spectral Interpretation Using Gaussian Mixtures and Autoencoder

“…Thus, it is critical to identify and quantify the abundant presence of Fe‐bearing ultrafine particles in urban microenvironments. In a previous study (Sheikh et al., 2022), the task to identify these particles was manually conducted by individually analyzing backscattered electron (BSE) images and their associated EDS elemental maps, which is an inefficient and time‐consuming process.…”

“…More details about the specimen can be found in Sheikh et al. (2022). The dimensions of the raw EDS data set are 738 × 672‐pixel × 1,595‐spectral‐channel, and the average counts per pixel is 35.08.…”

“…The particulate matter specimen was collected by scraping the inside of an exhaust pipe of a petrol-powered vehicle in Lahore, Pakistan using an A5 paper. More details about the specimen can be found in Sheikh et al (2022).…”

Within-city spatial variations in PM2.5 magnetite nanoparticles and brain cancer incidence in Toronto and Montreal, Canada

“…Given the potential relevance of UFPs to brain health, a possible direction for future research could be the measurement of magnetic parameters on the ultrafine fraction of particulate matter: for example, Gonet et al analyzed isothermal remanent magnetization (IRM, a measure of magnetic remanence which results from short-term exposure to strong magnetizing fields) on size-fractionated particles sampled from brake-wear emissions (using 14 size fractions ranging from 0.016 to 10 µm) 43 . Although an increasing body of literature exists describing magnetic parameters of particles collected from air samples 44 , 45 or from tree leaf surfaces near roadways 9 , 46 – 48 , it remains to be determined which particle magnetic properties and which particle size fractions are most relevant in health studies; future studies may consider size-resolved evaluation of magnetic characteristics of particles as a step towards assessment of their potential health impact. Additionally, a focus on low-temperature (LT) magnetic measurements may better characterize the UFP fraction.…”