Respiratory health effects of diesel particulate matter

Abstract

Particulate matter (PM) emissions involve a complex mixture of solid and liquid particles suspended in a gas, where it is noted that PM emissions from diesel engines are a major contributor to the ambient air pollution problem. While epidemiological studies have shown a link between increased ambient PM emissions and respiratory morbidity and mortality, studies of this design are not able to identify the PM constituents responsible for driving adverse respiratory health effects. This review explores in detail the physico-chemical properties of diesel PM (DPM) and identifies the constituents of this pollution source that are responsible for the development of respiratory disease. In particular, this review shows that the DPM surface area and adsorbed organic compounds play a significant role in manifesting chemical and cellular processes that if sustained can lead to the development of adverse respiratory health effects. The mechanisms of injury involved included inflammation, innate and acquired immunity, and oxidative stress. Understanding the mechanisms of lung injury from DPM will enhance efforts to protect at-risk individuals from the harmful respiratory effects of air pollutants.

Particulate Air Pollutants and Respiratory Diseases

“…Growing epidemiologic evidence indicates that inhalation of airborne PM increases respiratory and cardiac mortality and morbidity, and produces a range of adverse respiratory health outcomes such as asthma, lung function decline, lung cancer, and chronic obstructive pulmonary disease (COPD) (Ayres et al, 2008, Ristovski et al, 2011. Epidemiologic data indicate that air pollution also aggravates asthma, with the exacerbation correlating with levels of environmental particles (Schwartz et al 1993).…”

“…The physical properties of PM including the mass, surface area, and number/size/ distribution of particles, as well as their physical state, influence respiratory health in different ways (Ristovski et al, 2011). The primary exposure mechanism to PM and other particle sources is by inhalation (Ristovski et al, 2011).…”

“…PM is a complex, multi-pollutant mixture of solid and liquid particles suspended in gas (Ristovski et al, 2011). PM originates from a variety of manmade and natural sources.…”

“…The primary exposure mechanism to PM and other particle sources is by inhalation (Ristovski et al, 2011).…”

“…Vehicle emissions are the predominant source of fine PM (2.5 PM with an aerodynamic diameter <2.5 m) in urban areas, where most people live globally (Ristovski et al, 2011). Airborne PM less than 10m in aerodynamic diameter (PM 10) is a complex mixture of materials with a carbonaceous core and associated materials such as organic compounds, acids, and fine metal particles (Pagan et al, 2003).…”