Tuesday, April 29, 2008

Some thoughts on hybrid cars

Does this press release indicate an unintended consequence? Hybrid Cars May Require Hundreds Of New Power Plants To Be Built, If Owners Charge Up During Peak Hours

On another note, this NYT article:
ALMOST without exception, scientists and policy makers agree that hybrid vehicles are good for the planet. To a small but insistent group of skeptics, however, there is another, more immediate question: Are hybrids healthy for drivers?

There is a legitimate scientific reason for raising the issue. The flow of electrical current to the motor that moves a hybrid vehicle at low speeds (and assists the gasoline engine on the highway) produces magnetic fields, which some studies have associated with serious health matters, including a possible risk of leukemia among children.

With the batteries and power cables in hybrids often placed close to the driver and passengers, some exposure to electromagnetic fields is unavoidable. Moreover, the exposure will be prolonged — unlike, say, using a hair dryer or electric shaver — for drivers who spend hours each day at the wheel.

CNN Money April 21, 2008 notes (using an AP release):
U.S. registrations of new hybrid vehicles rose 38% in 2007 to a record 350,289, according to data to be released Monday by R.L. Polk & Co., a Southfield-based automotive marketing and research company.
Link: http://money.cnn.com/2008/04/21/autos/hybrid.ap/index.htm?section=money_latest

Here is a chance for a data collection effort (not as good as a randomized trial):
With a population of 350,000 and a random sample of about 8,000 - 10,000 (I'm not sure what's a good sample size here but 8-10K is probably more than enough) and with controls (non-hybrid) and treatment (hybrid drivers) equally divided this would make a good experiment.
1. It is possible that hybrid drivers and somehow different (in terms of health) than gasoline car drivers but I'm thinking not.
2. There is probably going to be some need to stratify in terms of region, race and age groups but again not being sampling statistician I would not know for sure.
3. Car manufacturers would pay for the health exam (perhaps with some subsidy from the government). I would think that they might be self interested enough to fund this.
4. The exam would probably require blood draws.
5. The exam will probably take place when drivers bring in their cars for routine maintenance.
6. Drivers may be amenable since they get a free checkup.
7. I'm thinking of this as a national survey across all manufacturers but even with just Toyota it might be sufficient. (We would then have a smaller sample.)
8. This study is probably going to be longitudinal - perhaps 2-3 years.

How does it sound? Not bloody likely. Perhaps NHANES investigators will tack on hybrid car ownership and driving habits onto its next wave of data collection.

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