New Zealand’s Air: Why We Shouldn’t 'Breathe Easy'
Our Air 2018, produced by the Ministry for the Environment and Stats NZ, published last year, reports that burning wood and coal for home heating in winter remains the largest single cause of human-generated poor air quality in New Zealand. Transitioning home heating to pellet fires could see a major reduction in the negative health impacts to Kiwis.
Emissions from home heating accounted for about 25% of larger particulate matter and a third of finer particulates recorded in 2015. Measurements show that a majority of sites tested, (30 out of 51), showed pollution exceeding the National Environmental Standards for Air Quality at least once in the last 3 years. This occurs mostly when home-heating emissions are high in the cooler months and weather conditions are favourable for the build-up of pollutants.
According to international studies, the health effects of air pollution can range from shortness of breath, chest pain and coughing to premature death from cardiovascular and respiratory problems, such as heart attack, stroke, or emphysema. It can also cause lung cancer and exacerbate asthma. Recent studies point to possible links with diabetes and atherosclerosis due to an increase in inflammation.
People with pre-existing heart or lung disease, young children, and the elderly are the most likely to suffer adverse health effects. Exposure to air pollution can be especially serious for the very young as it is associated with miscarriage, premature birth, low birth weight, infant bronchiolitis, respiratory infections, autism-spectrum disorder, asthma and chronic reduced rate of lung growth.
Long-term exposure to particulates in air pollution has also being linked to poor neurodevelopment and cognitive function. There is emerging evidence that air pollution may be linked to mental health conditions and degenerative brain diseases such as Alzheimer’s disease, Parkinson’s disease and schizophrenia. A recent Chinese study reported that air pollution was responsible for a “huge” reduction in intelligence, creating oxidative stress which causes neuroinflammation, neurodegeneration and accelerated brain aging.
Our Air 2018 reports improving trends in air quality in some regions, such as Nelson, Clyde and Rotorua where a combination of regulatory and non-regulatory initiatives have proven effective. These include requiring lower emission burners and encouraging switching to cleaner, more efficient forms of heating through education campaigns, funding and subsidies.
The promotion of regulation pellet fires has been instrumental in these regional improvements to air quality. Consumer magazine has rated them the “cleanest and greenest home-heating system available”.
Woodburners, even when designed to be as efficient as possible, struggle to be as environmentally-friendly as pellet fires, given the emissions they produce vary depending on the fuel used, (whether it is dry, seasoned and untreated wood), and how it is burned. Our Air 2018 reports the amount of hazardous emissions is highly dependent on how well the wood burns, (which depends on the woodburner, the temperature of the fire and the moisture content of the wood). Consumer also found that even NES-compliant woodburners are still probably significant polluters, with laboratory testing standards unable to be met in practice.
Pellets are made from 100% virgin wood residue that has a controlled density and moisture level, so they burn with more consistency than logs and cause less air pollution. (Pellets have 5-8 % moisture content in comparison to firewood’s 30-70%). The pellet fire system is a fully enclosed one and is a super-efficient form of heating. In contrast, 90% of the heat from an old-fashioned fireplace can escape up the chimney. Pellet fires’ efficiency rating can be as high as 94%, depending on the model and heat output required.
Our Air 2018 reports woodburners heated 33% of North Island homes and 47% of South Island homes in 2013, with even higher percentages in some rural areas. It notes however, that “many New Zealanders are already making decisions that have a positive impact on the quality of the air we breathe, including using high-efficiency heating options, such as heat pumps, pellet burners, or wood burners designed to have low emissions”.
The Coalition Government’s Warmer Kiwi Homes Programme could incentivise a switch to lower emissions appliances when its grants for heating become available in July 2019. Councils, countrywide, should be emulating those in Nelson and Rotorua by implementing swap schemes and grants to encourage switching to low emissions heating, such as pellet fires. Actions such as these, taken today, will protect and improve the health and wellbeing of their communities into the future and allow all of us to live in an environment with high air quality.