Controlled burns have always bothered me conceptually, but the recent burns that have blanketed the city have been affecting my immediate health (and I'm in reasonably good health otherwise). So, I started poking around on the internet about the health effects of wood smoke. Of course, what you find immediately is not a discussion of the actual effects, but discussions of what you should do, like don't breathe the smoke, stay indoors, etc. These sites are government or medical industry sites. The government, of course, is responsible for the controlled burns, so they don't really want people to know too much. The medical industry (I'm using "industry" rather than "profession') is closely connected to the government, so they don't want to "burn" any bridges either. What you do find if you dig a little deeper, is that we really don't know the full extent of the effects of smoke. However, the research does suggest that the smoke particles are a health risk, such as contributing to lung cancer and other cardiopulmonary diseases. In addition, the smoke contains carbon monoxide, carbon dioxide, and a number of toxic chemicals. We know that both carbon monoxide and carbon dioxide (in large amounts) are dangerous and can lead to death. The troubling part that no one talks about is the toxic substances in the smoke. We don't know what effects, which may not show up for years.
These issues should be of extreme personal concern for everyone. However, from a larger view, the burning of forest wood is environmentally unsound at this point in time where we're already putting way too much carbon into the atmosphere. The issue here is that our biosphere stores carbon in several places, like deep inside the Earth (what we call fossil fuels), in the atmosphere, in living things, etc. Each of the storage sites have different time scales for the storage of carbon. The deep Earth storage sites are for very longterm periods of time. They are released into the atmosphere naturally during various volcanic or tectonic activities. On the other hand, soil and atmospheric stores are shorter term. However, the natural process of decay from dead trees is a relatively slow process that adds carbon to soils for use in various life processes with some carbon released slowly into the atmosphere. When we burn these trees, we skip most of the soil storage and put most of the carbon (along with toxic substances) into the atmosphere very quickly. As we all know, the atmospheric carbon content is much higher than it should be, and is leading to global warming and all of its effects.
Of course, forest fires in the southwest have been a part of the natural functioning of the ecosystems. However, that was before humankind started saturating the atmosphere with carbon. We screwed up that process and now we're stuck with trying to prevent fires. What we need to think about are alternatives to controlled burns. We could use the dead wood for mulch, compost, and various other products, especially for local use so that carbon emissions can be minimized.
We need to stop controlled burns for our own and our children's health and for the health of our home planet.