Archive for December, 2019
The key to successfully treating cancer is early detection. The problem is that many cancers take years before they show obvious symptoms.
How do dogs sniff out cancer in humans?
Researchers in Canada have demonstrated1 that dogs can be taught to “sniff-out” cancer using human exhaled breath aerosol samples. While the dogs can’t tell us which chemicals they are detecting, they can be trained to reliably sort biological samples into cancer and not-cancer groups. How do the dogs do it? What chemicals are they detecting with their noses that lead them to sniff out cancer, and can we detect those chemicals in the lab? Ultimately, we might learn from the dogs which environmental chemicals and their metabolites are related to human health effects.
In a recent article published in the Journal of Breath Research Exit, EPA investigators analysed a series of samples collected from standard hospital masks that had been previously sorted into the cancer and non-cancer groups by trained dogs. The researchers used gas and liquid chromatography – mass spectrometry (GC- MS and LC-MS), and immunochemistry instrumentation to measure as many chemical compounds as possible in each sample, and then compared the cancer and non-cancer groups to see which chemicals were different.
In this study, EPA found that in the LC-MS analyses, there were distinct differences between mask samples sorted by the dogs, but not as much differentiation in the GC-MS analyses. From this, EPA researchers hypothesized that the dogs were detecting the aerosols (i.e., the tiny liquid droplets) part of breath to make their decisions, rather than the lighter gas-phase molecules (i.e., the gaseous part of breath).
This work needs further research to confirm the conclusion compounds and to achieve better statistical relevance. However, these results indicate that standard hospital masks can be used as a sampling medium for exhaled aerosols, and that LC-MS analyses can find compounds to separate groups similarly to the discrimination practiced by the dogs. This suggests that we may eventually be able to identify cancer at earlier stages.
1 See Rappaport and Smith, Environment and Disease Risk, Science Vol 330, Issue 6003, 460-461.
[Source: US EPA, 10 Dec 2019]
Photograph: Joe Raedle/Getty Images
Hans-Werner Sinn’s opinion piece on whether electric cars are as climate friendly as they seem generated a good deal of controversy. William Todts, executive director of Transport & Environment, gives his response.
Hans-Werner Sinn is quite the character. This German economics professor’s writings range from the Greek crisis to migration, to German energy policy.
Recently he has discovered a new passion: electric vehicles. Back in April Sinn published a paper claiming electric cars were worse than diesel. The study was roundly criticised for being misleading. Even Germany’s largest carmaker VW felt compelled to publicly contradict the report days after its publication, giving a rare glimpse of its own lifecycle analysis based on company-specific data that shows Volkswagen EVs are better than their diesels.
Yet rather than backing down, Sinn’s now back at it in an article published by the Guardian. Rather than forcing carmakers to invest in clean technology – the EU’s current policy – Sinn proposes introducing a big fuel tax on car drivers which he believes would be more effective than forcing German carmakers to go electric.
But this isn’t about Sinn. In fact, whenever you read a newspaper article claiming EVs are worse than diesel or petrol cars, that article will be based on a report that deliberately makes EVs look worse than they are.
Usually the plot is as follows: a smaller petrol or diesel car is compared with a bigger, more powerful electric car; then the fossil fuel car is assumed to be as efficient as the EU’s official tests portray (in reality its fuel economy is always a lot worse); and finally the electric car is driving in a region with a very dirty electricity mix. Then you assume very high emissions for battery production based on outdated studies and finally you pretend electric cars don’t last very long and that its batteries aren’t reused or recycled.
There will always be a new study with some flawed assumptions to keep us all busy and we could rebut these until we all drop. The advantage for the oil and diesel industry is that articles and reports, however poor, keep the controversy alive. Discrediting or distorting science is a political strategy, as Naomi Oreskes chronicles so well in Merchants of Doubt.
So let’s skip the detailed rebuttal and just look at some basic facts. Every year we burn around 275m tonnes of petroleum and diesel in cars, vans and trucks in the EU alone. Petrol and diesel vehicles are hugely inefficient. Around 70% of the energy that goes into a car engine is wasted. Oil that is burned cannot be recovered, reused or recycled. Oil cannot be made clean. Actually, thanks to the rise of unconventional oil, it is getting dirtier.
So if we want to halt global warming we need vehicles that don’t burn stuff. That’s the unique appeal of electric cars, trains and buses. They’re ultra-efficient and have no tailpipe emissions. And yes, of course, we’ll need clean electricity to run the vehicles and to produce the cars and batteries.
But we know how to make power clean and we’re making rapid progress towards exactly that. The UK has almost got rid of coal, Germany is phasing it out, and even in Poland and Trump’s America, coal is in decline. Meanwhile clean wind and solar power are on the rise. By 2030 half of the EU’s electricity will come from renewables driven by renewable electricity mandates and the increasingly robust EU carbon pricing scheme.
The rise of electric cars and green power are some of the biggest climate success stories of the past few years. It is the result of regulators in Europe, California and China doing their job and industry rising to the occasion. It shows what we can achieve if we set industry ambitious goals to clean up its act.
That might not please some but it is fair, effective and, for the climate, unequivocally a good thing. As the Nobel prize committee eloquently put it: “Lithium-ion batteries have revolutionised our lives since they first entered the market in 1991. They have laid the foundation of a wireless, fossil fuel-free society, and are of the greatest benefit to humankind.”
• William Todts is executive director of Transport & Environment, a European research and campaign group
[Source: The Guardian, 26 Nov 2019]