KEY POINTS:
The idea of sitting in front of an open fire on a winter's night is a romantic notion for many New Zealanders.
But it's also one that is a slow killer - for the bank balance, the environment and you.
Analysis carried out by the government-owned research institute GNS Science for councils throughout the country have revealed worrying levels of fine particulates - the noxious by-products of inefficient burning that can aggravate or cause respiratory problems.
Fine particles less than 2.5 micrometres, which are typically produced by car exhausts and wood fires, can travel into the bloodstream without being filtered by the lungs.
Over a typical Auckland winter, domestic fires will contribute 64 per cent of fine particulate emissions, far overshadowing the contributions of the region's 750,000 vehicles (27 per cent).
Last year, six breaches of the New Zealand air quality standard were recorded in Auckland - five of those over the winter months.
But more worryingly, the World Health Organisation says the effects of long-term exposure to high levels of fine particulates is between 10 and 15 times worse than one-off exposures.
And the long-standing tradition of an open fire in many homes - while stoking the primeval instincts of many a New Zealander - is the least efficient and dirtiest of home heating methods, according to the Energy Efficiency and Conservation Authority.
For every unit of energy that is put in, only five to 15 per cent of it is translated into heat. As warm air from the room is sucked up the chimney, cold air is dragged in behind it.
While it is regarded as cheap to run, especially if the firewood is free, its inefficiency means you would need to burn more fuel than an electric or gas heater to get a comparable amount of heat.
