Ethanol and the environment

I finally know more than Mark about a psychotropic drug! At least if you don’t drink it. Ethanol, the characteristic solvent for social distance and shellac, is also a motor fuel with attractive characteristics: it’s made of sunshine and exactly the CO2 we like to take out of the atmosphere, it increases gasoline octane as an additive, it’s environmentally quite benign in spills and such, and it’s not imported from places with fractious and prickly governments.

However, it doesn’t just dribble out of corn plants: to get ethanol requires growing plants (fertilizer, tractor fuel…), hauling corn to a distillery, smooshing it up with yeast and keeping it warm (more fuel), distilling the alcohol out of the mush (more fuel), and various other industrial operations all of which use energy. A debate has been burbling for several years about whether we really wind up ahead in various important ways by substituting ethanol for gasoline in cars, and the issue has been confused by the patchwork of subsidies and regulations that distort market prices for fuels of all kinds.

A gang at the Energy and Resources Group and the Goldman School at UC Berkeley, who invited me to play with them over the summer and fall while we did the project, have clarified things greatly. In my view our most important finding is that the “net energy” measure, which looks only at the fossil fuel energy consumed to make a unit of energy in the form of ethanol, asks the wrong question. For example, if ethanol provided a means to take 100 joules of energy from coal and obtain 50 joules worth of ethanol, it would not necessarily be a bad idea. Coal is abundant and cheap; the problem with it is that when burned, it releases the “greenhouse gas” CO2. So one would want to ask about the greenhouse gases released (and other costs, of course), not the net energy, and if the CO2 from burning the coal were captured and sequestered, this notional technology would be a prima facie policy winner, allowing us to run cars cleanly on domestic abundant coal rather than imported, scarce petroleum.

Our article in Science (Farrell et al) is behind a paywall (today’s issue, if you have access to it) but also posted here, with the analysis behind it. This LA Times story is a pretty good report. What we found, adjusting six studies of ethanol input demands so they could be compared is that ethanol from corn (maize) as we make it today is a big petroleum saver, and offers modest gains in global warming, compared to gasoline. The specific technology used to make it matters a lot, but what matters more is the crop you start with: ethanol from grass or wood will be a very attractive fuel on energy, global warming, and petroleum displacement grounds.

We are beginning a research initiative that will give us a better look at other considerations like cropland fertilizer runoff, soil protection, and forest conversion to farms. The larger policy debate will be much occupied with conflict between the farm community already in the corn business and quite enamored of the subsidies and regulations that favor it, and the nascent industry of cellulosic ethanol; watch this space for updates.

Lead and PVC

Lead, which is every bit as bad as Mark says it is in your body, is still the standard stabilizer for PVC (polyvinyl chloride), especially in electric cable insulation, though alternatives with somewhat inferior properties are entering the market. I hope Mark doesn’t throw away all his power cords, or his computer will stop and he won’t be able to blog any more.

The stabilizer in essence mops up hydrochloric acid, released by the plastic as it ages, that would otherwise accelerate the degradation of the insulation. Lead exposure from plastic has to do with the surface area of the plastic exposed, exposure to sunlight and solvent environments that cause the plastic to degrade and leave lead dust on the surface, and ingestion paths. Lead in vinyl window blinds was a concern a few years ago because of the large exposed surface area and sunlight degradation, plus the constant exposure of the blinds to children touching them with moist fingers and licking the fingers or even the blinds, and dust being blown off the surface and into the room air. Plastic toys kids could chew or lick, or a large surface-area item exposed to sun and water like a raincoat, are especially bad sorts of things to use lead stabilizer in.

While acute lead poisoning cases related to plastic have occurred, including an electrician with the habit of constantly chewing on his stripped-off insulation bits and workers in vinyl mixing plants where the stabilizer was carelessly handled, I cannot find a single case of lead poisoning, even at very low levels, traceable to normal use of electric cable. Kids need to keep electric cords out of their mouths for many reasons in any case. (The lead in this insulation does present an environmental disposal problem, which is one reason the industry is looking for alternatives.)

Note that long-term performance in electric insulation is a safety-related quality, and it would be a pity if reducing tiny lead exposures from cable resulted in increased cases of amperage overdose (200 fatal electrocutions in 1998), or of fatal heat or smoke intake in houses ignited by wiring failures (about 70,000 such fires per year).

The most important reduction in lead exposure was accomplished when we got the lead out of gasoline (how it got in is one of the most appalling stories of continuing profit-driven corporate callousness in industrial history). The next was managing exposure to lead in paint (no longer sold or used, but still powdering off the outside and inside of older houses) that will need to be pursued for decades to come. Some isolated situations like the Mexican snacks sold in Latino neighborhoods that are still poisoning children remain.

My problem with the Prop. 65 notice on my DVD drive is that such legislation causes us to strain at gnats and conceals the important differences between them and the real camels in the environmental risk arena. Lead toxicity from plastic electric wires is not an important life or health risk, and plastic cable toxicity is not an important element in lead health damage. Even safer stabilizers will be better, but I’m pretty sure the displacement of rubber/fabric and the other old-fashioned types of cable insulation by pvc has been a big net gain in safety, cost, and convenience.

The language of the initiative is:

No person in the course of doing business shall knowingly and intentionally expose any individual to a chemical known to the state to cause cancer or reproductive toxicity without first giving clear and reasonable warning to such individual, except as provided in Section 25249.10


This has no recognition of toxicity level, carcinogenicity, concentration, dosage, or path, all of which are what matter in risk, and this kind of legislation and policy is what leads to warnings that are merely silly and dilute the important warnings of real risk that we need to pay attention to. Your automobile battery, for example, is a really big hunk of lead. It’s very dangerous in at least three ways: the lead sits in a pot of acid, the battery is quite heavy and could break your toe if your drop it, and it can explode if you create a spark near it when its charging. The lead, though there’s lots of it there, is a disposal/pollution concern, not a use risk in this case. Like the two-odd pounds of lead in the glass in your CRT computer monitor that kept it from giving you cancer (radiation!) all those hours you looked at it.

WTF? Lead in a power cord?

Is there really a significant amount of lead in the power cord of a DVD drive? There shouldn’t be.

Lead is hideously nasty stuff. The dose that will measurably lower a child’s IQ is measured in micrograms. Now maybe the lead that Toshiba warns about in the customer instructions Mike had such a good time making fun of is in nanograms, and is mentioned only because of California’s silly toxic substances law (another intitiative special).

But if not, then what’s lead doing in an ordinary power cord? “Wash hands after handling?” No, if there’s enough lead to matter in the power cord, throw the DVD drive away and never buy anything from that manufacturer again.

Update Duhhhhhh…A reader points out the obvious answer: solder. “Until very recently,” he reports, most electrical and electronic assemblies had milligrams, even grams, of lead in the form of solder.” But see Mike’s reply above for an alternative and more convincing answer: lead is used to stabliize the polyvinyl chloride — PVC used as insulation. A reader points out that most garden hoses are made of PVC, and a garden hose recently purchased from Sears carried a warning not to drink from it: a warning I would guess few children know about, let alone heed.

Mike is entirely right: the practice of throwing warnings about indiscriminately is bad for the public health. One the other hand, I’d like to know more than I do now about the quantitative relationships here: are we dealing with micrograms or nanograms? If it’s micrograms, then I’m not sure Mike is right that fire-safety considerations trump the toxic risk of lead

Second update Edited to get the units right; the relevant dosage is in the microgram range (single digits of micrograms per deciliter of blood) not the nanogram range. Perhaps if the lead had been taken out of gasoline in the 1930s rather than the 1980s I’d make fewer mistakes.

Third update Another reader points out that garden hoses are now made of PVC [Yup, but not all, and not all lead-stabilized. Good advice here. —mo’h]


This is very bad news, except maybe for Chinese extreme outdoor down clothing factories. London is at the same latitude as southern Hudson’s Bay; Rome and Madrid are about as far north as New York. Without the Gulf Stream pumped-hot-water heating system, Europe would be a very different place. The world may be getting warmer generally, but if (a fair number of scientists are starting to say when) the Atlantic circulation stops, some important parts of it will go the other way, and dramatically so. Just to offer one example, all of France could easily find itself above the practical limit of cultivation of Vitis vinifera, the wine grape.

Of course the habitability of a small continent isn’t something we should have to bear any economic cost to prevent, certainly we wouldn’t betray our most fundamental national principles of big houses and cars for a bunch of foreigners. Anyway, they’ve been taking all that heat right from Florida for centuries and not paying us a cent for it. Defeatist talk about a carbon tax just encourages…encourages somebody bad, certainly, I’m sure it’s treasonous.

But you might want to take your kids to Europe sooner rather than later to be sure they don’t miss it.