It is construction time again on the Trans Mountain Pipeline Expansion (TMX) and the activists are out in force. Interestingly, I saw that Dr. Tim Takaro was back in the news. This time he is up in a tree to try and stop the the building of the pipeline. While Dr. Takaro is variously described in the media as a “Vancouver Physician” or an “SFU Professor“, in my mind he will always be “Dr Butadiene”.
The reason I think of him as Dr. Butadiene is a report he submitted to the Canada Energy Regulator (the CER formerly the National Energy Board or NEB) during the TMX consultation process. The report was: Major Human Health Impacts of the Kinder Morgan Trans Mountain Pipeline Expansion (by Takaro et al., 2015). I use this report as an object lesson on why it is recommended that you consult a chemist before you present a paper involving significant chemistry content. I do so because this report represents a case study in how a lack of chemical knowledge can metastasize to result in bad public policy recommendations.
Now to be absolutely clear, Dr. Takaro is indeed an expert in Occupational & Environmental Health. Just look at his Curriculum Vitae. No seriously, look at that document he submitted to the CER. It has 51 pages. But if you look carefully you will notice the keywords that are missing in that C.V. There are zero instances of keywords like: “hydrocarbons” “gasoline” or “crude oil”. It begs the question, what specific expertise did he bring to the table when he decided to accept the job of writing a regulatory submission on the topic of the toxicity of diluted bitumen? As I will show in the following text, he clearly brought very little.
For the TL;DR crowd – as I will detail below the report is rife with out-of-date references and bad information. It gets the concentration of benzene in diluted bitumen so wrong as to make its arguments about benzene invalid and more amusingly, it gets the chemistry of diluted bitumen so wrong that most of the report is simply moot. Almost half the text is dedicated to a component (1,3-Butadiene) that isn’t found in detectable concentrations in diluted bitumen [hence the moniker Dr. Butadiene].
Now that I have provided that spoiler, let’s start with the stuff they get almost right. The report does establish that benzene is found in detectable concentrations in diluted bitumen. The problem is they get the concentrations (and thus the relative risk) all wrong. Here is what the report says:
Benzene is an important component of gasoline (1‐4%) due to its high octane number, which gives the high compression rates for the fuel to prevent knocking (Kirk et al, 1983). On average, benzene content in premium and regular unleaded gasoline is 2.15% by weight or 1.76% by volume (Madé, 1991). The quantities of benzene in diluent are similar.
Here is the issue: in a scientific document you really shouldn’t be relying on references from the 1980’s unless you are absolutely sure that nothing has changed in the intervening decades. This report didn’t do that.
Unfortunately for Dr. Takaro et al., in 1997 the Benzene in Gasoline Regulations came into force. These Regulations restricted the amount of benzene allowed in gasoline in Canada. What this means is the numbers provided by from the 1983 and 1991 references are wrong and should not have be cited in this report. Since 1997, it has been illegal to sell gasoline with concentrations of benzene over 1.5% by volume so the range of 1-4% provided is simply not valid.
What I find particularly odd is that Dr. Takaro et al. appear to know this since they later cite that very regulation:
Government of Canada regulations on benzene have prohibited the sale of gasoline with more than 1.5% benzene by volume (Environment Canada, 2014) [where the EC report is actually the Gasoline in Benzene regulation].
Can someone explain to me how they can, in one paragraph, claim that benzene makes up 1.76% by volume in premium gasoline then follow that statement by saying it can’t legally be sold at more than 1.5% by weight?
Considering that this submission is supposedly about diluted bitumen, it seems odd that Dr. Takaro et al., fail completely to investigate or report on the actual concentration of benzene in diluted bitumen, instead falsely claiming that diluent has similar concentrations to gasoline.
The truth of the matter is that diluted bitumen has some of the lowest benzene concentrations of all crude oils. The five year average for benzene concentration in Cold Lake Blend is 0.23% +/- 0.03 %. As presented above, in the report they claim that benzene could be as high as 4% in fuels but in diluted bitumen it is over an order of magnitude lower than the concentration presented.
From a chemical perspective this difference is critical. Benzene vapours are generated by all sorts or activities in our modern urban environments and given the negligible benzene concentrations in diluted bitumen, and the design of our pipeline systems, fugitive benzene emissions from these systems would not be detectable. These inconvenient facts totally undermine the entire argument presented in the report.
Now if Dr Takaro et al., were only wrong about benzene then the report might be have been salvageable but the benzene problem isn’t even the biggest issue with this report. As I hinted earlier, the larger issue is the section on 1,3-Butadiene. You see Dr Takaro et al., appear to have missed the really minor point that 1,3-Butadiene is not a detectable component in diluted bitumen. Yes you read that right, half of this report discusses all the human risks posed by the pipeline from emissions of 1.3-Butadiene but 1,3-Butadiene isn’t a detectable component in diluted bitumen.
But you don’t have to trust me on that claim. Pull out your copies of the three primary references used by the activists on the composition of diluted bitumen. Here’s Environment Canada’s technical report:
Here is the National Academies of Science (NAS) report:
And finally here is the Royal Society of Canada (RSC) report:
A search of the three documents won’t even find the the word “1,3-Butadiene”. So one might ask, where did Dr. Takaro et al., get their reference to 1,3-Butadiene in crude oil? Reading the report we find this line:
Anthropogenic sources (i.e., due to human activity) of concern for human exposure to butadiene include the following (Hughes et al, 2001):
– fugitive and combustion emissions from pipelines, pump stations, and storage terminals, during both construction and operations.
Now here is the problem for this report, when you go to that reference (Hughes et al., 1,3-Butadiene: Human Health Aspects) it includes no such claim. A simple text search finds zero references to the words “pipelines”, “pump stations” or “storage terminals”. In the Hughes report we are informed that 1,3-butadiene is sourced from incomplete combustion of hydrocarbons (as vehicle exhaust or from forest fires) or as an emission from a number of industrial processes. The report NEVER SAYS it is found in fugitive emissions from pipelines, pump stations or storage terminals. It doesn’t say that because that is simply not true. In order to be in fugitive emissions it would have to be observed in detectable concentrations in the source material and as the reports above make clear 1,3-Butdiene is not found in detectable concentrations in diluted bitumen.
Admittedly the Hughes report does include a proviso that
As well, very low levels of butadiene itself may be present in gasoline and in liquefied petroleum gas.
and later they write:
Based on data in NPRI, it was estimated that the total release of butadiene from fuel distribution in 1994 was 24 tonnes (Environment Canada, 1996a), although gasoline and diesel fuel contain little or no butadiene (US EPA, 1989).
Remember earlier when I mentioned that it is imperative that you check old sources to make sure they are current. Well here is another example of the importance of that rule.
Historically there was a lot of confusion about the presence of 1,3-Butadiene in fuel mixtures. In 1996 they cleared up the confusion. As detailed in the article (1,3-Butadiene in Gasoline: An Analytical Confusion by Rolf et al., 1996) the original claim that 1,3-Butadiene was in gasoline was based on a misinterpreted chemical analysis. This explains why the EPA does not include any petroleum sources of 1,3-Butadiene (outside of combustion) in their report on the topic. Rather the EPA says this:
Levels of butadiene in gasoline and diesel fuel are expected to be insignificant because butadiene tends to readily form a varnish that can be harmful to engines; therefore, refiners try to minimize the butadiene content. As a result, it was assumed that butadiene is not present in evaporative, refueling, or resting emissions.
Let’s summarize our findings about the Takaro et al., report. A report that has been cited repeatedly by activists and which is cited in over a dozen regulatory documents submitted to the Canada Energy Regulator:
- almost half of the report’s contents are inapplicable as they address 1,3-Butadiene which is not even found in diluted bitumen; and
- the remainder regarding benzene is predicated on a massive misstatement of the absolute concentration of benzene in diluted bitumen. That massive overstatement implies that benzene will be observed in detectable concentrations in the fugitive emissions from the TMX system, when benzene is barely detectable in diluted bitumen samples and the emissions in urban settings would not be detectable given the elevated background concentration of benzene in our urban environments.
Put another way, the Takaro et al., report is fatally flawed and should be given no weight in public policy debates about the TMX. That no one has highlighted these flaws before me is simply a testament to the fact that not enough experienced chemists have allowed themselves to be drawn into these regulatory and policy discussions.
That being said, maybe it is time for journalists and regulators to consult with a chemist or two before printing statements or making policy decisions involving significant chemistry content. It is time to stop imagining that expertise only matters in field like engineering and medicine and acknowledge that when the topic of your piece is Chemistry it doesn’t hurt to pass the information by a chemist.