Diesel, cancer and how (not) to report about risk

The BBC reports that diesel exhausts have been declared as causing cancer. That could very well be, but the way the results are reported leaves a lot to be desired. First, look at this bit:

Dr Kurt Straif, also from IARC, said: “For most of the carcinogens when there is high exposure the risk is higher, when there is lower exposure the risk is lower.”

Hmm, so lower exposure to diesel lowers the risk of cancer?! Lower than what? Than no exposure at all? I presume that this is just an awkward way of saying that the risk increases with the amount of exposure. But then at what point does the risk become ‘significantly’ higher than the risk if not being exposed? When you pass behind a diesel car once a day? When you work behind fuming diesel engines all day long? When you get a single overdose once in your life? Without answers to all these questions, the information that some level of exposure to diesel is related to an increase in cancer risk is pretty useless to me.

What is also missing is a crucial comparison to petrol. How does the risk of exposure to diesel compare to the risk of exposure to petrol? Is petrol carcinogenic as well, to a smaller degree, or not at all? Part of the scientific evidence for the carcinogenic effects of diesel is apparently based on observing truck drivers. No details or links to this research are provided, but I wonder how these truck drivers have been isolated from the effects of petrol fumes and exposed to the effects of diesel fumes only…

The most disturbing part comes with the statement that ‘Diesel exhausts are now in the same group as carcinogens ranging from wood chippings to plutonium and sunlight to alcohol.’ Plutonium and alcohol! So is inhaling diesel fumes carcinogenic to the same extent that drinking a glass of wine once a week is, or to the extent that ingesting plutonium is?

I certainly understand the scientific rationale to classify diesel fumes as carcinogenic. What I don’t understand the journalistic rationale to report this without the necessary context to make the information understandable and useful for the ordinary readers. After all, shall we all sell our diesel cars now? I mean, diesel fumes do cause cancer, as it says in the title, no?

Climate science wars: The Lysenko move

The Wall Street Journal (WSJ) has published a letter entitled ‘No need to panic about global warming’ which opines that “There is no compelling scientific argument for drastic action to “decarbonize” the world’s economy” and “Alarmism also offers an excuse for governments to raise taxes, taxpayer-funded subsidies for businesses that understand how to work the political system, and a lure for big donations to charitable foundations promising to save the planet.

The letter is signed by 2 meteorologists and 14 other scientists.

Here is another letter signed by 255 scientists making the case for human-induced global warming and published in Science in 2010. This letter allegedly has been submitted to, but rejected by the WSJ. Boing Boing claims that it has also been drafted in response to the WSJ piece but this is obviously wrong since the Science letter has been around since 2010.

The 16 scientists who got their letter published by the WSJ accuse the “international warming establishment ” of pushing science into ‘the frightening period when Trofim Lysenko hijacked biology in the Soviet Union’. Wow!

This rhetorical trick is so incredibly audacious that it deserves to be immortalized as the “Lysenko move” and included into the standard weaponry for academic spats, next to reductio ad absurdum and skeletons in the closet. Who is gonna be the next victim?

Texas vs. Science

This is from the Guardian:

Officials in Rick Perry’s home state of Texas have set off a scientists’ revolt after purging mentions of climate change and sea-level rise from what was supposed to be a landmark environmental report. The scientists said they were disowning the report on the state of Galveston Bay because of political interference and censorship from Perry appointees at the state’s environmental agency.

More details here. The public officials changed any reference to climate change, sea level rises, human influence and global warming form the draft report. In response, all scientists associated with the report withdrew their names from it. I guess that last bit is the good news. The bad news is that politicisation of science is no news anymore.