Last year, the Ministry for the Environment and the Government Statistician produced a report purporting to show how reducing concentrations of fine particles (PM 10) in the air had improved public health. In March this year the Parliamentary Commissioner for the Environment commented on this report.
Basically what the Parliamentary Commissioner for the Environment said was fair enough, but it left unasked the vital question “What do the New Zealand data tell us about the actual health effects”
Neither the Ministry for the Environment nor the Government Statistician nor the Parliamentary Commissioner for the Environment consulted the official Health Department statistics to find out.
The Domain Report from the Ministry for the Environment and the Government Statistician claimed improvements in health consequent on decreases in concentrations of fine particles (PM10) in the air. For PM10 you can read wood smoke from home fires. But it did not provide any evidence of such improvements in health. It did not give any statistics of the claimed reductions in deaths from pulmonary disease, or of reductions in hospital admissions. This seems a very strange omission in a report from the Government Statistician.
That is, it seemed strange to me until I began to look at the deaths from
Chronic Obstructive Pulmonary Disease in the District Health Boards throughout New Zealand over the last ten years, as recorded in official vital statistics from the Department of Health.
I have no expertise in epidemiology, but it is quite plain that the claims in Health and Air Pollution in New Zealand reports of great differences between districts in death rates caused by PM10 are quite wrong. For instance, according to these reports, which are the base for the Ministry for the Environment claims, only three in a hundred deaths in Taranaki are supposedly caused by the toxic PM10, compared with ten in a hundred in Canterbury . The official statistics show that about six in a hundred deaths in both places are certified as from Chronic Obstructive Pulmonary Disease. Only in Westland is the death rate higher than the New Zealand average.
In Christchurch, over the past 15 or so years, by putting out log burners, the Canterbury Regional Council has reduced the concentrations of PM10 in the air from about 30 to less than 20. Calculating in the same way as the Ministry for the Environment, Canterbury Regional Council science advisers claimed that this has resulted in about 65 fewer deaths each year, a reduction of about 20%. The official statistics show that the deaths from Chronic Obstructive Pulmonary Disease have not decreased. They have remained stubbornly the same. Putting out log-burners has not improved our health.
As Freddie Truman asked the umpire when his ball sent Garry Sober’s middle stump over the Old Trafford boundary “Is that still in?”. Garry walked. It is time for the Ministry for the Environment PM10 standard to walk too.
This has been a very expensive experiment for Canterbury people, probably costing us, upwards of half a billion dollars. It has denied us, and is still denying us, the comfort of sitting by our own home fire and being economically warmed. If the Ministry for the Environment has its way, worse is to come.
Neither the Domain Report, nor the Parliamentary Commissioner for the Environment considered these local data in their reports. Even so, the Parliamentary Commissioner for the Environment could conclude that the concentration of PM10 was not a good standard of the healthiness or toxicity of the air. It is not fit for this purpose.
The Parliamentary Commissioner for the Environment is to be commended for her report, which goes some way towards countering the Ministry for the Environment claims based on smoke and mirror evidence.
For more information by Pat Palmer, see the article written for the NZCPR last year:
Air quality PM10 standards and health in Christchurch.