CT scans may affect children’s learning

A group of Swedish scientists at the Karoliska Institute and Harvard School of Public Health have found that CT scanning in children could affect their later learning abilities. The British Medical Journal presents the study thus:

Receiving low doses of ionising radiation to the head in infancy may impair the developing brain and affect intellectual development. Hall and colleagues (p 19) studied 3094 men from Sweden who had received radiotherapy for cutaneous hemangioma before the age of 18 months. They analysed military records reporting the men’s intellectual capacity at age 18 or 19 and found that exposure to doses of radiation greater than 100 mGy, the equivalent of a computed tomography scan, was negatively correlated with high school attendance and learning ability assessed by cognitive tests. The authors call for re-evaluating the use of computed tomography for minor head injuries in infants.

The full text of the article Per Hall, Hans-Olov Adami, Dimitrios Trichopoulos, Nancy L Pedersen, Pagona Lagiou, Anders Ekbom, Martin Ingvar, Marie Lundell & Fredrik Granath, ”Effect of low doses of ionising radiation in infancy on cognitive function in adulthood: Swedish population based cohort study”, BMJ 2004;328:19 (3 January) is available at the BMJ web site. The study has already received some criticism at the Rapid Responses section.

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Microwave ovens and wireless networks

Jim Geier reports in an article at Wi-Fi Planet, Dueling with Microwave Ovens, about his experiments, which show how radiation from microwave ovens might interfere with wireless local computer networks, so-called WLAN’s. From a health point of view this seems to indicate that our microwave permeated environment not only includes radiation from cordless phones, cell phones, burgler alarms etc., but also leakage from microwave ovens, short in duration maybe but still adding to the total exposure. A quotation from the article:

A more realistic distance from the microwave is from one of the break tables, which is about eight feet away from the microwave. At this range, I reran the throughput tests, resulting in 178pps. This still equates to around a 75 percent decrease, something that would likely make users unhappy. […]
I also repeated the tests down the hall about 20 feet away with the microwave running and still experienced fairly sluggish responses. In fact, throughput from there was still only 260pps. Obviously, the microwave was making the WLAN crawl at surprisingly great distances from the microwave.

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