Materiales y Reactivos

2.5.1 Air quality regulation

The primary regulatory instrument for managing outdoor air quality in New Zealand is the Resource Management Act 1991 (RMA). Under section 15 of the RMA, discharge of contaminants to air are subject to provisions of the regional plan which activities are permitted and which require resource consent. These rules are laid down in Regional Plans made under section 30 of the RMA. The current Regional Air Quality

Management Plan for the Wellington region adopts a non-regulatory approach to discharges of contaminants from fires. At the time of writing the draft Natural Resources Plan for the Wellington region specifically prohibits the burning of CCA- timber in domestic fires.

Pursuant to section 43 of the RMA, a national environmental standard for air quality was introduced in 20049_{. This standard prohibits certain activities, sets emission and} design standards for new wood burners and limits for concentrations of PM10, carbon monoxide, nitrogen dioxide, sulphur dioxide and ozone in outdoor air. The intent of this standard is to provide a guaranteed minimum level of health protection for all New Zealanders in terms of air quality (MfE, 2011a).

Regional Councils, in areas of New Zealand that do not meet the limit for PM10 in outdoor air (i.e., no more than one 24-hour average above 50 µg/m3 per year), are required to implement measures that will lead to reduced emissions of PM10 sufficient to ensure their airsheds comply by with the standard by 2016 and 2020 (MfE, 2011b). Regional Council’s policy interventions typically include a suite of measures such as regulation, information, education and incentives principally aimed at reducing the number of wood burners through households switching from solid fuel heating to clean heat or lower emission technology burners (Wilton & Bluett, 2012a). In an attempt to achieve further reductions in emissions, some Regional Councils, notably, Environment Canterbury are adopting behaviour change campaigns based on social marketing to encourage “environmentally-responsible” wood burner operators – for example, fire lighting techniques that reduce the amount of smoke emitted from the chimney10_.

Territorial Authorities who permit the installation of wood burners under the Building Act 1991 also have powers to issue local bylaws under the Local Government Act 2002, for example, that control the type of wood burning appliances allowed to be installed.

2.5.2 Social understanding of air quality management

In the context of air quality management the use of wood for home heating is viewed as an environmental “pressure” as this activity results in emissions to air of PM10 that then result in poor air quality leading to adverse health effects at the population level (MfE, 2014). The use of wood for home heating has a different meaning for those involved in the practice. A qualitative study in Christchurch investigated how residents

9 _{Resource Management (National Environmental Standards for Air Quality) Regulations 2004} 10 _{http://letscleartheair.co.nz/}

made sense of their home heating practices using wood burners in an environment with high levels of winter air pollution (PM10) and where substantial educational campaigns and financial incentives to switch to “clean heat” have occurred (Cupples, Guyatt, & Pearce, 2006). This study found that although Christchurch residents were very aware of the air pollution problem and its causes, they were reluctant to change their heating methods and indeed felt good about burning wood as it was connected with a masculine pioneering spirit (i.e., tough and practical) and thriftiness (Cupples et al., 2006). In a similar vein, residents in an Australian town (Armidale) with high winter air pollution due to use of wood for home heating justified their use by a variety of strategies, including presenting wood heating as a natural, traditional and social activity strongly linked to a shared rural identity (Reeve, Scott, Hine, & Bhullar, 2013). Although it has been established that domestic wood burning is the principal source of emissions leading to degraded air quality (Kuschel et al., 2012), the public perception is that poor air quality is caused by vehicles and transport, and industries (Hughey, Kerr, & Cullen, 2013).

The burning of CCA-treated timber is prohibited through most regional plans enacted under the RMA. The dangers of the practice have been passively publicised through web pages of Ministry for the Environment (MfE), New Zealand Home Heating Association (NZHHA) and BRANZ. Despite the prohibition and the warnings, there is evidence that this practice persists in the domestic setting. A home heating survey in Auckland found that 17% of wood burning households burnt decking or fence posts offcuts on their fires in the previous week (Stones-Havas, 2014). A home heating survey conducted in Masterton found that 16% of wood burners always, often or sometimes decking or fence posts offcuts on their fires (Sridhar & Wickham, 2013). It is highly likely that some component of decking or fence post offcuts reportedly used as firewood was treated with CCA.

No research articles investigating the level of public awareness of the dangers of burning treated timber in the home were found. However, studies showed that personal knowledge about poor air quality or health effects is not an important consideration for home heating choices (Cupples et al., 2006; Smith, McChesney, &

Butcher, 2005). Anecdotal evidence suggests that many people are unaware (or possibly unconvinced) that burning treated timber releases contaminants to air that can be harmful if inhaled. Informal discussions with air quality practitioners and people in the community indicate that there is a widely held perception that treated timber is used as a wood source by “poor” people or those classed as lower-socioeconomic because they can get waste wood for free and they cannot afford to buy clean burning fuel. The basis for this view has not been formally investigated.

A home heating survey in 2006 found that 61% of people who used wood for home heating in Wainuiomata obtained some or all of their wood for free. Information is not available on the nature of self-collected or free wood and this may include waste wood: for example, commercial premises that make pallets available for members of the public to collect (Figure 2.1).

Figure 2.1: Photo showing typical scenario of pallets available for public collection (Petone, July 2013)