Urban Air Pollution Profile Causes An Increased Airway Inflammatory Response

Main Category: Respiratory / Asthma
Also Included In: Water - Air Quality / Agriculture
Article Date: 29 May 2008 - 0:00 PDT

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Global increases in traffic, industrialisation, and expanding cities have all contributed to a rise in emissions and growing levels of air pollution, thus adding to an escalating concern surrounding their environmental and health-related impacts.

Over the last few decades, there has been mounting epidemiological and laboratory evidence regarding the negative short-term, as well as long-term, health effects of air pollutants on the respiratory and cardiovascular systems.

Ozone (O3) and diesel exhaust (DE) are two major contributors to traffic-related air pollution and have both been shown to trigger inflammation in the airways, causing symptoms such as wheezing, coughing and reduced lung function.

DE tends to reach its highest concentrations at peak rush hours, such as in the mornings. Conversely, O3 concentrations are inclined to culminate in the afternoons.

Therefore, Jenny Bosson (University Hospital, Umeå, Sweden) and her colleagues alleged that exposure to this urban pollution profile may cause these compounds to exhibit synergistic or additive properties in the airways.

In order to investigate the consequences of this sequential exposure pattern, healthy subjects underwent two separate exposure series within controlled walk-in chambers. These comprised a one-hour morning exposure to DE or filtered air followed five hours later by a two-hour exposure to O3.

Bronchial rinse samples were obtained via bronchoscopy 24 hours after the start of each morning exposure, with inflammatory cells and immune cell factors assessed.

Healthy subjects exposed in sequence to environmentally relevant levels of DE and O3 demonstrate significantly increased pro- inflammatory cells, revealing a potentially adverse amplification in airway inflammation.

Currently, standard limits for each pollutant are set independently of each other. These novel findings provide a basis towards comprehending the cumulative airway effects when exposed to an urban air pollution profile and may indicate a need for future co- regulations of exposure limits.

Title of original article-
Diesel exhaust exposure enhances the ozone-induced airway inflammation in healthy humans

The European Respiratory Journal is the peer-reviewed scientific publication of the European Respiratory Society (more than 8,000 specialists in lung diseases and respiratory medicine in Europe, the United States and Australia).

European Respiratory Journal