Pollution Free Cities: How Does Exposure to Air Pollution Affect Deaths from Pneumonia?

Monday, December 23, 2013

How Does Exposure to Air Pollution Affect Deaths from Pneumonia?

English: Main symptoms of infectious pneumonia. Sources are found in main article: Wikipedia:Pneumonia#Signs_and_symptoms. To discuss image, please see Template_talk:Häggström diagrams (Photo credit: Wikipedia)

Has the short-term effect of black smoke exposure on pneumonia mortality been underestimated because hospitalisation is ignored: findings from a case-crossover study(19 page pdf, Matthew Gittins, Roseanne McNamee, Melanie Carder, Iain Beverland, Raymond M Agius, Environmental Health, Nov.7, 2013)

Today we review research into the location and exposure of those with pneumonia prior to being hospitalized and dying prematurely as a result of particulate pollution. Results indicate that location is an important factor and this adds another aspect that should be included in air pollution - mortality studies in general.

Key Quotes:

“We tested the primary hypothesis that estimated association would be greater in subjects who spent the exposure period in the ‘community’ (i.e. not in hospital) compared to those who spent some or all of the period in hospital.”

“Pneumonia occurs usually as a result of bacterial or viral infection. Often progressing rapidly within 24 hours, it presents symptoms such as coughing, chest pain, shortness of breath, and fever”

“significant associations between BS and pneumonia mortality may have been overlooked in previous studies that have not taken into account location during exposure.”

“Change in exposure effects on differing underlying causes of pneumonia may be a possible explanation for higher relative risk in CDP deaths.”

“Mortality displacement, also known as harvesting, is the accelerated progression of a frail sub-population to death followed by a delay in its replenishment…. Pneumonia mortality may be more susceptible to ‘harvesting’ as pneumonia is prevalent in the elderly [9,49] and is often the final cause in the chain of causes leading to death, implying a high incidence in the frail sub-population compared to the general population.”

“evidence suggests that a subject’s location is an important factor in relation to their likelihood of pneumonia mortality due to particulate pollution exposure.”