Monday, 21 July 2014
Forest Fires, Air Quality and Public Health risks and advice
For most Canadians, our interaction with forest fires is through the news. Pictures of candling trees shooting flames high in the sky and jumping from treetop to treetop. For many of us, that reality becomes closer to home with periodic episodes of degraded air from fire smoke generated sometimes thousands of kilometers away.
The actual number of fires nationally is actually fairly constant and may even be decreasing. The area burned seems to fluctuate more widely. Moreover province by province analysis see wide variation in fire activity from year to year justifying the interprovincial movement of fire suppression crews as needs shift in a less than predictable manner (there is minimal correlation to the El Nino:La Nina cycles)
Predicting fires, fire behavior, smoke impacts and health impacts has become a significant Canadian operation. Despite the headlines garnished by fires on the outskirts of communities that impinge on residential areas, the vast majority of Canadian wildfires are located in sparsely or inhabited areas. Great information is available on fire location and activity at Canadian Wildland Fire Information System and the Canadian Interagency Forest Fire Centre
From a public health perspective the key issues relate first and foremost to those in the path of fires and their safety for which the number of deaths and injuries from forest fires annually are counted on fingers and often associated with fire suppression efforts. Secondly are the largescale impacts of smoke dispersion.
BC developed the BlueSky forecasting system based on particulate matter in 2010 and has expanded to Western Canada and more recently to Eastern Canada. More recently Meterological Services of Canada (MSC)have started limited user testing of a Forest Fire Smoke Forecasting system. Both systems rely heavily on remote satellite sensing information combined with meterological forecasting information. The MSC modelling is expected to bring a greater level of sophistication and geographic precision.
Some areas have done better measuring and modelling of predicted health outcomes. A recent comprehensive review by the National Collaborating Centre on Environmental Health provides an international state of the art understanding of the impacts, surveillance and advice to be provided during a forest fire smoke event. The synthesis of which is copied below as found in the general advice synthesis though directed to BC for some reason even though forest fire smoke is a national concern.
Communications advising people to:
• stay indoors: reduce time spent outdoors in order to protect health
• reduce outdoor physical activity: decrease physical exertion outdoors in order to protect health
• wear an N95 respirator: properly use a certified N95 half face respirator to reduce exposure to smoke
• activate asthma/COPD action plans: ensure that plans for self-management of asthma/COPD are in place, up-to-date, and adequate supplies (e.g., medication) is available
• use a home clean air shelter: spend time in a room in your home with cleaner air to reduce smoke exposure
· Cancelling outdoor events: Decision that group activities that occur outside will not take place. Such activities include school activities (e.g., recess, outdoor classes and events), sporting events (e.g., tournaments, practices) and mass gatherings (e.g., arts and cultural events, athletic events).
· Providing community clean air shelter(s): Spend time in a community based facility such as a mall or school that has cleaner air than outdoor air.
· Augmenting air filtration in institutions: The use of in-duct or portable filtration to improve air quality and protect people in institutional settings including hospitals, nursing homes, long term care facilities, day cares, schools, and other institutions.
· Evacuating: The urgent removal of individuals from a community in order to protect them from exposure to wildfire smoke.