|English: Preindustrial and contemporary PM2.5 emissions. (Photo credit: Wikipedia)|
Review of evidence on health aspects of air pollution (REVIHAAP)(33 page pdf, World Health Organization Regional Office for Europe, May 8, 2013)
Today we review an experts’ report that identified 22 key questions that need to be answered with respect to revisions of current World Health Organization and EU standards for the three major air pollutants: PM, O3 and NO2, following a review of new evidence on the impacts of these pollutants on human health. The recommendations point to the need for shorter term limit standards for PM 2.5, evidence of new impacts of O3 on brain development, and the need to look beyond NO2 for roadside emissions.
"Health effects of particulate matter:
- There is increasing, though as yet limited, epidemiological evidence on the association between short-term exposures to ultrafine (<0.1 μm) particles and cardiorespiratory health as well as the central nervous system…..
- The data clearly suggest the absence of a threshold below which no one would be affected. Likewise long-term studies give no evidence of a threshold…."
"Proximity to roads, NO2, other air pollutants and their mixtures
- Exhaust emissions are an important source of traffic related pollution and several epidemiological and toxicological studies have linked such emissions to adverse health effects. Road abrasion, tire wear and brake wear are non-exhaust traffic emissions which become relatively more important with progressive reductions in exhaust emissions…
- some epidemiological studies do suggest associations of long term NO2 exposures with respiratory and cardiovascular mortality, and with children’s respiratory symptoms and lung function,…
- The most relevant exposure period based on existing evidence is one hour
- commuting can increase exposures to particulate matter, NO2, CO and benzene, and is a major contributor to the exposure to ultrafine particles, black carbon and some metals, most importantly Fe, Ni and Cu in underground rail transport systems."
- there is a strong need to re-evaluate and lower at least the limit value stage 2 for PM2.5 of 20 g/m3 (annual average, to be met by 2020)..
- There is a need to revisit the evidence base for setting the WHO AQG for SO2 (very short-term and short-term)…"