Curbside particulate matter and susceptibility to SARS-CoV-2 infection.

Background: Biologic plausibility for the association between exposure to particulate matter (PM) less than 10 μm in aerodynamic diameter (PM) and coronavirus disease 2019 (COVID-19) morbidity in epidemiologic studies has not been determined. The upregulation of angiotensin-converting enzyme 2 (ACE2), the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) entry receptor on host cells, by PM is a putative mechanism.

Objective: We sought to assess the effect of PM on SARS-CoV-2 infection of cells .

Confocal microscopy 3D imaging and bioreactivity of La Palma volcanic ash particles.

In September 2021 an eruption began of Cumbre Vieja, La Palma (Spain) that lasted 3 months. Previous studies have shown that volcanic ash particles can be associated with adverse effects on human health however, the reasons for this are unclear. Particle shape has been shown to contribute to cellular uptake in prostate cancer cells.

Defining the in vivo mechanism of air pollutant toxicity using murine stress response biomarkers.

Air pollution can cause a wide range of serious human diseases. For the informed instigation of interventions which prevent these outcomes there is an urgent need to develop robust in vivo biomarkers which provide insights into mechanisms of toxicity and relate pollutants to specific adverse outcomes. We exemplify for a first time the application of in vivo stress response reporters in establishing mechanisms of air pollution toxicity and the application of this knowledge in epidemiological studies.

Underground railway particulate matter and susceptibility to pneumococcal infection.

Background: Concentrations of particulate matter less than 10 microns (PM) on underground railways are higher than those near urban roads. Traffic-related PM increases pneumococcal infection via increasing the expression of platelet-activating factor receptor (PAFR), a receptor co-opted by pneumococci to adhere to cells. To date, it is unknown whether underground railway PM increases pneumococcal infection.

The presence of air pollution particulate matter in cryopreserved placental tissue cells.

https://bit.ly/3yANbRi.

Confocal microscopy 3D imaging of diesel particulate matter.

To date, diesel particulate matter (DPM) has been described as aggregates of spherule particles with a smooth appearing surface. We have used a new colour confocal microscope imaging method to study the 3D shape of diesel particulate matter (DPM); we observed that the particles can have sharp jagged appearing edges and consistent with these findings, 2D light microscopy demonstrated that DPM adheres to human lung epithelial cells. Importantly, the slide preparation and confocal microscopy method applied avoids possible alteration to the particles' surfaces and enables colour 3D visualisation of the particles.

Prostaglandin E and phagocytosis of inhaled particulate matter by airway macrophages in cystic fibrosis.

Background: Exposure to particulate matter (PM) air pollution is associated with adverse health outcomes in children with cystic fibrosis (CF). Airway macrophages (AM) phagocytose and retain inhaled PM in vivo, and the area of carbon in AM reflects both inhaled PM dose and phagocytic function. Since airway prostaglandin-E (PGE) is increased in CF, and PGE suppresses AM phagocytosis, we sought evidence for PGE-mediated suppression of AM phagocytosis of inhaled carbonaceous PM in CF.

Evidence for the presence of air pollution nanoparticles in placental tissue cells.

Inhaled particulate matter (PM) from combustion- and friction-sourced air pollution adversely affects organs distant from the lung. A putative mechanism for the remote effect of inhaled PM is that ultrafine, nano-sized fraction (<100 nm) translocates across the air-tissue barrier, directly interacting with phagocytic tissue cells. Although PM is reported in other tissues, whether it is phagocytosed by non-respiratory tissue resident cells is unclear.

E-cigarettes and respiratory health: the latest evidence.

The E-cigarette market continues to expand at an alarming rate with thousands of flavours available for purchase and continuously evolving devices. Now that it is a multi-billion dollar industry and one without stringent regulation, there is rising concern over the safety of vaping products. Since June 2019, over 2800 cases of E-cigarette-associated acute lung toxicity have been reported in the USA, over 60 of which resulted in death.

Airway dendritic cell maturation in children exposed to air pollution.

Urban particulate matter (PM) enhances airway dendritic cell (DC) maturation in vitro. However, to date, there are no data on the association between exposure to urban PM and DC maturation in vivo. We sought to determine whether exposure of school-age children (8 to 14 y) to PM was associated with expression of CD86, a marker of maturation of airway conventional DCs (cDC).

Exposure to diesel exhaust particles increases susceptibility to invasive pneumococcal disease.

Background: The World Health Organization estimates that air pollution is responsible for 7 million deaths per annum, with 7% of these attributable to pneumonia. Many of these fatalities have been linked to exposure to high levels of airborne particulates, such as diesel exhaust particles (DEPs).

Objectives: We sought to determine whether exposure to DEPs could promote the progression of asymptomatic nasopharyngeal carriage of Streptococcus pneumoniae to invasive pneumococcal disease.

Use of cleaner-burning biomass stoves and airway macrophage black carbon in Malawian women.

Exposure to particulate matter (PM) from burning of biomass for cooking is associated with adverse health effects. It is unknown whether or not cleaner burning biomass-fuelled cookstoves reduce the amount of PM inhaled by women compared with traditional open fires. We sought to assess whether airway macrophage black carbon (AMBC) - a marker of inhaled dose of carbonaceous PM from biomass and fossil fuel combustion - is lower in Malawian women using a cleaner burning biomass-fuelled cookstove compared with those using open fires for cooking.

E-cigarette vapour enhances pneumococcal adherence to airway epithelial cells.

E-cigarette vapour contains free radicals with the potential to induce oxidative stress. Since oxidative stress in airway cells increases platelet-activating factor receptor (PAFR) expression, and PAFR is co-opted by pneumococci to adhere to host cells, we hypothesised that E-cigarette vapour increases pneumococcal adhesion to airway cells.Nasal epithelial PAFR was assessed in non-vaping controls, and in adults before and after 5 min of vaping.

Pneumococcal infection of respiratory cells exposed to welding fumes; Role of oxidative stress and HIF-1 alpha.

Welders are more susceptible to pneumococcal pneumonia. The mechanisms are yet unclear. Pneumococci co-opt the platelet activating factor receptor (PAFR) to infect respiratory epithelial cells.

Immunotoxicity in mice induced by short-term exposure to methoxychlor, parathion, or piperonyl butoxide.

Exposure to environmental agents can compromise numerous immunological functions. Immunotoxicology focuses on the evaluation of the potential adverse effects of xenobiotics on immune mechanisms that can lead to harmful changes in host responses such as: increased susceptibility to infectious diseases and tumorigenesis; the induction of hypersensitivity reactions; or an increased incidence of autoimmune disease. In order to assess the immunosuppressive response to short-term exposure to some commonly used pesticides, the studies here focused on the response of mice after exposures to the organochlorine pesticide methoxychlor, the organophosphorus pesticide parathion, or the agricultural insecticide synergist piperonyl butoxide.