Wood heating: a public health issue for the Montréal region
- The air quality in Montreal has deteriorated in the last few years.
- There are many sources of atmospheric pollution. Road transportation, wood heating and industries are responsible for a large part of this pollution.
- Montreal has, on average, 65 days of poor quality air annually, or one day out of six.
- In the past few years, the Montreal region has been subject to winter smog episodes.
- Since last November, the Montreal region has endured 32 episodes of smog, a much higher level than the previous record for smog episodes (19, in 2005).
- These winter smog episodes are due to the significant presence of fine particles in the air.
- In Quebec, wood heating is responsible for 61% of fine particle emanations.
The issue of wood heating in Montreal
- The number of wood heating systems currently in use on the island of Montreal is estimated at more than 85,241, of which 50,550 are on the territory of the City of Montreal. (City of Montreal, Wood heating)
- The sectors in which wood heating is most heavily used are in the municipalities of Pierrefonds and Dollard-des-Ormeaux, as well as in the boroughs of LaSalle, Ahuntsic, Pointe-aux-Trembles and Rivière-des-Prairies.
- In some Montreal neighbourhoods, the density of wood heating units can reach 1,000 units / km2 (Mémoire de la Ville de Montréal, 2008).
- The number of wood heating installations is increasing in Quebec. Data from Statistics Canada demonstrate that the number of apartments in which wood heating was used increased by approximately 60% between 1987 and 2000, at a time when the increase in the number of apartments was less than 20%.
Environmental consequences of such a practice
- When wood burns, more than a hundred toxic compounds are released into the atmosphere, joining those released by the combustion of gasoline, diesel and heating oil, as well as those produced by many industries.
- The main pollutants are fine particles, carbon monoxide, volatile organic compounds, polycyclic aromatic hydrocarbons, nitrogen oxides and numerous irritants. (Source: DSP, Oct. 2007).
- According to the MDDEP, in Quebec, 61% of fine particles released result from wood heating, compared to 22% from industries and 14% from transportation.
- A non-certified wood heating system releases as high a quantity of fine particles in nine hours as a car does over one year (18,000 km).
- During the winter of 2007, in the Rivière-des-Prairies neighbourhood in the East of Montreal, the number of days when the air quality was poor due to fine particles associated with wood combustion were up to five times more frequent than those observed downtown. (Réseau de surveillance de la qualité de l'air, 2007).
Impact on health
- The particulate matter PM2.5 is the most-studied of the contaminants released into the atmosphere by wood heating. It has been the object of scrutiny because of its impact on the public health.
- Health Canada estimates that every year, 1,540 premature deaths are caused by atmospheric pollution in Montreal.
- Bouchard and Smargiassi (2007) have looked at other health impacts caused specifically by PM2.5:
- 6,028 cases of infantile bronchitis in Montreal per year (9,505 cases in Quebec)
- 40,449 days of asthma symptoms in Montreal (62,707 days in Quebec)
- 1.4 million people suffering from respiratory problems in Quebec
- Children are the group most vulnerable to the impact of atmospheric pollution. In addition to exacerbate asthma, chronic exposure to PM2.5 can cause a reduction of lung growth in children (Gauderman and colleagues, 2004).
- In a study conducted by the Direction de la santé publique de Montréal-Centre, it was demonstrated that people using a wood stove have a higher concentration of contaminants in their urine than those who do not have a wood stove. The combustion of wood is therefore an additional source of exposure to toxic substances inside houses.
- A study published in January 2009 comparing 51 American cities clearly showed that a reduction of the exposure to these fine particles significantly contributed to the improvement of the life expectancy of the population.
EPA-certified wood stoves are not the solution for Montreal
- Wood combustion, even in approved EPA-certified units, still produces pollutants that contribute to the deterioration of air quality. (Réseau de surveillance de la qualité de l'air, 2007). The emanation standards are as follows: EPA phase 1 (8.5g/hour), EPA phase 2 (7.5/hour), Washington (4.5g/hour).
- The efficiency of these stoves diminishes over time and depends on many parameters: the size of the logs, the type of wood used, the moisture level in the wood, the state of the chimney... Even though certified stoves are less polluting than other models, when in use, they still have difficulties meeting the established standard.
- In comparison, pellet-burning stoves respect the 1g/hour standard.
- The prevalence of wood stoves in our urban environment leads to an alarming accumulation of released pollutants that is very dangerous for the health of the residents.
Forbidding the installation of new wood heating systems is not enough
- Such a bylaw will only stop the current situation from becoming worse. It does nothing to reduce the existing high level of pollution.
- The 85,000 units already in use will continue to release pollutants into the atmosphere and will thus continue to have a negative impact on air quality.
In Montreal, improving air quality depends on the adoption of a bylaw requiring the replacement of polluting wood heating systems.
- The City of Montreal must adopt a bylaw not only to forbid the installation of new wood heating systems except for natural gas, propane or pellet-burning systems (less than 1g/hour), but must also impose a seven-year time limit to replace, remove or condemn existing wood heating systems.
- Other municipalities of the Montreal community must also adopt such a bylaw.
- Municipalities in the greater Montreal area, especially cities such as Laval and Longueuil, must evaluate the situation on their territories and adopt a bylaw accordingly.