An Open Letter to Rio Tinto Alcan Shareholders

I am addressing this letter to you rather than to RTA itself in order to avoid reinforcing the idea that a corporation is a “person”

An Open Letter to Rio Tinto Alcan Shareholders

(I am addressing this letter to you as the people who own the company rather than to RTA itself in order to avoid reinforcing the idea that a corporation is a “person”. )

As the former Chief Medical Health Officer with Northern Health and a resident within the air shed RTA is planning to use as a repository for the waste Sulphur Dioxide (SO2) its updated smelter in Kitimat will produce, I have watched the company’s management of this issue with great interest.

RTA has been given a permit to emit up to 42 metric tonnes of SO2 into the air shed on a daily basis, up from the current permitted level of 27 metric tonnes per day. That’s a lot of sulphur dioxide! SO2 is toxic to humans at high doses but the jury is out as to the harm it does at lower ambient levels. Everyone agrees that SO2 air pollution can cause airway spasm, induce asthma attacks, worsen chronic bronchitis among people with pre-existing respiratory problems, and lower the threshold for exercise induced asthma. But it may be significantly more serious than that.

Although the Permit is currently the subject of an appeal, RTA was able to convince the BC Ministry of Environment that simply raising the height of its stacks would ensure that current permissible levels are seldom exceeded using a computer model of air dispersion based on data gathered mostly in 2008. Using the model, RTA consultants have created scenarios predicting likely peak exposure levels on the ground at a variety of sites in and around Kitimat and extending down the valley to Terrace. They have even attempted to predict the expected number of episodes of airway spasm based on crude population data in each of these sites of interest.

As part of the permitting process, RTA was required to consult with the public and in doing so they painted a reassuring picture suggesting that any human health effects from the increased SO2 emissions would be minimal and transient at worst.

I believe I understand the epidemiology of the health effects of SO2 at least as well as the RTA consultants but I am far from reassured. I also understand that an air dispersion model is just a model: every conclusion based on the model, including projected SO2 levels and health effects no matter how many charts and graphs are created, is speculative and only as good as the model itself.

Here are some of my concerns:

1. The air dispersion model does not factor in or consider the possible and probable impacts of Climate Change which is an ongoing scientifically established reality in 2015. Will the foreseeable future include hotter dryer summers with more frequent inversions and less wind dispersion than in 2008? Will there be more forest fires in the Northwest with ambient smoke pollution interacting with and changing the characteristics and behaviour of emitted SO2 with respect to humans and the environment? At the very least, consideration of these possibilities could have expanded the range of predicted effects and improved the quality of the data by being more realistic about its uncertainty.

2. The RTA consultants have summarized the evolving science of SO2 toxicity according to the principle that “the absence of proof of an effect constitutes proof of no effect” and have confined the discussion to monitoring the relatively minor effects where causation is certain. However the US EPA Advisory Committee which is extensively referred to in the Sulphur Dioxide Technical Assessment Report (STAR) prepared by the RTA consultants (p50, vol.2) states clearly that the evidence is insufficient to infer the presence or absence of a causal relationship between short term exposure to ambient SO2 and cardiovascular mortality as well as between long term exposure and respiratory disease mortality, non respiratory morbidity, and overall mortality. To proceed as if these very worrisome associations had been disproven simply because the complex and difficult studies needed to either rule them in or out have not yet been done flies in the face of what I have come to see as prudent public health practice, particularly in the presence of technology (scrubbers) which would substantially reduce these potential risks to people who live in the air shed. It occurs to me that a corporation wishing to promote tobacco use in the late 1940s would have likely produced a very similar scientific assessment acknowledging the relatively minor effects of throat irritation and cough while pointing to the lack of hard evidence in relation to the scourges of heart disease and lung cancer that took decades of research to confirm; even for a straightforward and easily documented exposure like tobacco smoke.

3. The consultants have neglected to consider the variability among the human receptors (people) who will be exposed to the SO2 emissions. It is well known that populations with different demographics, social and economic status, and preexisting health status respond differently to the same levels of stress whether the stress is a toxin, a pollutant or a virus. While the STAR report acknowledges this there is no consideration of these important variables in their final analysis or in their health impact projections.

The technology exists to reduce SO2 emissions from your company’s smelter to well below what they are currently. Installing scrubbers may be a cost the company would rather avoid, but if it wishes to retain a reputation as a good corporate citizen based on prudence and genuine concern for its neighbours that is what it should do. There is much uncertainty in the current understanding of the health effects of long term exposure to ambient SO2 and there are good reasons to think that they may be more severe than the RTA consultants have predicted. It will be virtually impossible to adequately document or respond to these more serious and/or long term impacts given the small size of the population at risk. The effects are likely to be cumulative and the damage done long before it can be detected in a conclusive way.

I am writing this based on many years of experience in Public Health in Northern BC, and with a profound sense of the importance of clean air as a fundamental underpinning of good population health. While scrupulous attention to the bottom line is an understandable corporate priority, human health is, or should be, an even more fundamental priority for all of us. I urge you to ensure that the company you own takes this into consideration by installing the scrubbers that are needed to reliably protect the public’s health in relation to SO2 generated by the RTA smelter operation in Kitimat.


David Bowering MD MHSc.