Estimated annual health costs, Armidale, a city of 22,000 people
Similar costs in Christchurch - $4,000 per woodheater per year
Comparison of Sydney Pollution (1999) with the much higher levels of pollution in Armidale (1999)
Armidale Air Pollution Statistics 2009 - 2012
from Council's submission to the Senate Inquiry on the health effects of Air Pollution
Health costs of a new woodheater in Armidale
The NSW DECC Advice to Councils concerning the intstallation of new woodheaters states: "In considering an application for approval under s68 a council must take into account the protection of the environment and of public health, safety and convenience (s89(3) LGA)". Councils should heed this advice. Permitting new heaters with health costs of $2,000 per year is not consistent with council's obligation protect the health of the community. Until new standards have been developed to ensure that public health will be protected, there should therefore be a moratorium on the installation of woodheaters in new houses.
Like older woodheaters, emissions from new woodheaters depend mainly on the way the heater is operated. An AS4013 heater, rated 3.2 g/kg, can smoke like this. Councils do not have the resources to respond promptly to complaints about woodsmoke. The estimated health costs of the average heater in Armidale was $3,500 per year. Even if the average new heater is half as polluting as the average old one, the health costs would be close to $2,000 per year.
Woodsmoke associated with many other health problems, e.g. mouth and throat cancers, middle ear infections and bronchiolitis in children. Exposure to woodsmoke was noted to produce a higher increase in the risk of bronchiolitis (8%) than living within 50 metres of a major highway. PM2.5 pollution in general is associated with cot deaths; exposure to PM2.5 in childhood is associated with increased risk of chronic obstructive pulmonary disease in adulthood. Woodsmoke also increases the risk of heart disease and people living in areas of high particle pollution also have higher blood pressure - by 1.7 mmHg for an increase of 2.4 μg/m³ PM2.5 exposure. These costs have not been quantified.
A UNE study published in 2007 reported that winter woodsmoke causes 8.8 additional visits per day to GPs in Armidale for respiratory complaints, i.e about 750 additional visits per year. The estimated cost was $189.35 per visit, i.e. about $142,000 per year. This study did not consider more serious ailments, such as hospital admissions, although this will undoubtedly add to the cost.
Christchurch, NZ - highest woodsmoke areas have up to 16% more deaths (and 68% more respiratory deaths)
Analyses published in 2007 show that (after adjusting for other factors such as age, sex, ethnicity, socio-economic status and tobacco smoking habits) death rates in Christchure were related to smoke levels - Christchurch woodsmoke map
Estimates for each increase of 10µg/m3 of PM10 exposure were:
• 34% increase in respiratory deaths
• 11% increase in circulatory deaths
• 8% increase in all deaths
If woodsmoke has similar effects on health in NZ and Australia, it will increase Armidale’s death rate by about 9.2%, i.e. residents will live on average almost 1 year less than if we had clean air, a loss of about 150 healthy life years annually.
Use of averages is however, confusing. Some people will get a respiratory infection, heart attack, lung, mouth or throat cancer 5-10 years before their time, others will not be affected. Overall, if we value a healthy life-year at $50,000, the estimated cost of premature mortality from woodheaters in Armidale is 150 x $50,000 = $7.5 million.
Polycyclic aromatic hydrocarbons (PAH) are the main toxins in woodsmoke. Two studies - A US study published in 2009 and study of Polish mothers published in April 2010 have found that exposure to PAH during pregnancy is associated with reduced IQ when children start school at age 5.
The US study measured exposure to PAHs in women’s home environment during the third trimester of pregnancy. Measured exposure was used to split the mothers into two groups – those with PAH over 2.26 ng/m3 (high exposure) and those with PAH less than this (low exposure group).
After adjusting for the mother's intelligence, quality of the home environment, exposures to other PAH and other relevant factors, children whose mothers were in the high exposure group scored about 5 points lower on average on several measures of IQ than those whose mothers were in the low PAH group.
The second study of pregnant Caucasian women in Poland confirmed the
results. “The effect on intelligence was comparable to that seen in NYC children
exposed prenatally to the same air pollutants,” explained Frederica Perera,
professor of Environmental Health Sciences.
The Polish study measured the pregnant mothers’ exposure to 8 of the most toxic PAH - benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, ibenz[a,h]anthracene, benzo[g,h,i]perylene, indeno[1,2,3-cd]pyrene. Four of these chemicals have the highest-listed carcinogenic potential. Two of the four are in cigarette and wood smoke - burning 1 kg firewood produces as many PAH as in the smoke from 16,000 cigarettes. The other two highest-carcinogenic potential PAH are in woodsmoke, but not cigarette smoke.
A Norwegian study compared DNA damage in human cell lines exposed to woodsmoke and traffic particles: "In conclusion, woodsmoke particulate matter (WSPM) generated more DNA damage than traffic-generated PM per unit mass in human cell lines, possibly due to the high level of polycyclic aromatic hydrocarbons in WSPM."
According to the NSW Department of Environment, Climate Change and water "If you can see or smell smoke from your wood heater then you are causing a problem for yourself, your family and your neighbours".
Now that the findings of the US study have been confirmed by another study, in addition to tests showing genetic damage in the newborn babies associated with exposure to benzo[a]pyrene, the prudent option is to reduce exposure to PAH, including woodsmoke. If there is a problem in your area, ask the local council for help. Councils have an obligation to protect residents' health and the environment. Concerned families should make sure that they fulfil this obligation.
Wintertime PAH measurements in Armidale averaged 8.62 ng/m3 (max 24.0 ng/m3) - about 4 times higher than what was considered high PAH exposure in the US IQ study.
There are about 270 births per year in the Armidale Dumaresq LGA. Given that Armidale’s winter average PAH was four times greater than what was considered high in the US study, both city residents, and people in country areas with wood heaters and some of their neighbours, are likely to be affected. The wood heating season lasts for over 4 months, so a third of the 270 births (i.e. 90) are likely to be exposed to more than 2.26 ng/m3 of PAH pollution during the third trimester. If a 5 point loss of IQ leads to a $1,250 per year reduction in income, or $50,000 over a child’s lifetime, the estimated cost is $4.5 million per year.