- New statistical analyses show health effects of fine particle air pollution are worse than previously thought
- NZ woodsmoke costs half a billion dollars per year
- New 197-page UK report on the long-term health effects of air pollution. "air pollution has a greater effect on mortality in the UK than previously thought, with a 10 µg/m3 increase in fine particles being associated with a 6% increase in risk of death from all causes"
- New spatial analyses: 8% increase in mortality for each 10ug/m3 increase in annual PM10 exposure (Christchurch) and 6% (Auckland)
- New time series analyses of air pollution (mainly woodsmoke) in Christchurch
- Australian Standards Committee - considering a health warning on woodheaters, most Committee members wanted immediate reduction in emissions to 2 g/kg, but strong opposition by industry
- Review of literature suggests woodsmoke as bad as other forms of particulate pollution
New statistical analyses show the health effects of fine particle air pollution worse than previously thought
Evidence that current methods under-estimate the hazards of air pollution continues to grow. Until recently, estimates of the effects of air pollution were obtained by assuming that everyone in the same city experienced the same pollution. However, pollution can vary tremendously from one part of a city to another. New, more accurate analyses (that estimate personal exposure from the nearest pollution monitors) show that the effect is greater than previously thought. For example, a comprehensive study published in 2007 of 65,893 post-menopausal women found a 76% increase in the risk of death from cardiovascular disease (and a 24% increase in strokes, heart attacks onset of coronary or cerebrovasular disease) for an increase of 10 μg/m3 of PM2.5 pollution (see here).
June 07 saw the release of the main 'Health and Air Pollution in NZ' report. Estimated health costs:
- effects associated with domestic (woodsmoke) emissions cost half a billion dollars per year - $186 per person per year
- effects associated with vehicle emissions: $165 per person per year
- effects associated with industrial emissions: $70 per person per year.
A comprehensive evaluation was published by the UK COMEAP, an advisory committee of independent experts that provides advice to the Chief Medical Officer (England) on all matters concerning the potential toxicity and effects on health of air pollutants. COMEAP released a draft report “Long-term Exposure to Air Pollution: Effect on Mortality” in 2007. The UK Health Protection Agency explains: “The report suggests that air pollution has a greater effect on mortality in the UK than previously thought, with a 10 µg/m3 increase in fine particles being associated with a 6% increase in risk of death from all causes.” (see here)
New spatial analyses: 8% increase in mortality per 10ug/m3 increase in annual PM10 exposure (Christchurch) and 6% (Auckland)
Christchuch’s air pollution is dominated by winter woodsmoke. The fact that there areas with high pollution have higher mortality than less polluted areas, the estimate being an increase of 8% in mortality for an increase of 10 μg/m3 in PM10, is very significant. (See here )
The effects of fine particle pollution are believed to be cumulative so that exposure to high levels of pollution over several weeks has more serious consequences than a single daily one-off exposure. Time series results in both Christchurch and Auckland confirm this. The HAPINZ report discusses the results of distributed lag time series analysis which attempt to estimate the effect on daily mortality of each preceding day’s air pollution level, adding these daily effects into an estimate of the total impact. For Christchurch, the HAPINZ report states: “The distributed lag analysis showed that the combined effect on daily mortality of up to 40 preceding days’ exposure may be much greater (on average 13−23% increase in mortality per 10 μg/m3 increase of PM10) than the single-day effect.” (See here)
Most Committee members wanted immediate reduction in emissions to 2 g/kg, but strong opposition by AHHA Standards Australia sent an email about the most recent meeting on woodheater standards, saying amongst other things: Discussion centred on the lack of change to the standard since 1999 in light of multiple submissions from members and the general public calling for a reduction in the particle emission factor. The committee agreed that this was overdue given the that any change as a result of work being progressed by the sub-committee on real life emissions would realistically require another five years before adoption. The committee agreed to a reduction to 3.0 g/kg with the majority further in agreement that 2.0 g/kg was more appropriate.
Several submissions were also considered on the need for a health warning. The first few were rejected by the Committee. But after hearing the submission by the Australian Lung Foundation, opinions seemed to change. The Vic EPA representative agreed to ask the Deptof Health was asked to verify how this “health warning" could be drafted in order to included in the Standard. Unflued gas heaters already carry a warning, so there is a precedent.
Standards Australia aims to reach consensus, so it's not clear what will happen. The manufacturers (except those in NZ) are strongly opposing a reduction in the limit to 2 g/kg and say they haven't even agreed to 3 g/kg. There was talk about abandoning the emissions standard altogether and just retaining AS4013 as a test method. This would put the onus on the EPAs to decide what limit was appropriate. The next meeting is likely to be in late October or early November 2007.
Boman et al (2003) reviewed the literature relating to adverse health effects of ambient exposure to woodsmoke stating: “comparing the results of studies of acute exposure to those done in areas without much woodsmoke, concluded that there was no reason to think that the adverse impacts of acute woodsmoke exposure would be less than those associated with other sources of ambient particulate matter”.
More news in a few months