Thursday, June 14, 2012

soil contamination in Tokyo

 Leading magazines started reporting the contamination in Tokyo.

From 'Aera' 11th of June

 

Ward/place         Bq/kg

Kita            10,704

Kita                          36,523

Kita            48,595

Kita                88,885

Bunkyou           47,808

Bunkyou          14,060

The University of Tokyo, Bunkyou    60,581

The University of Tokyo, Hospital, Bunkyou     52,007

The University of Tokyo, Yasuda Hall, Bunkyou 4,306

Chiyoda                               25,159

Chiyoda                                        91,790

Imperial Palace, Chiyoda                                   77,547

Imperial Palace, Chiyoda                                84,611

Imperial Palace, Chiyoda                                34,667

Imperial Palace, Chiyoda                                49,393

Minato                             71,133

Okutama                              16,825

 

50,000 Bq/kg is equivalent to 3,250,000 Bq/m2, falls on the red part below in Chernobyl.

Four months ago 20,000 Bq/kg was the highest.

 

3 comments:

  1. These publishing Ca137 samplings, or just radiological activity? Be good to know what the pre-accident background radiation was for those areas. Were NYC Grand Central Station a nuke plant, they would shut it down - way to much uranium in the granite. Finding man-made material in Tokyo would be disquieting.

    How true are the official metrics, btw? Anyone getting calibrated secondary readings that are backing up the formal released data? I'd be wondering if the published numbers were low, if others are getting higher results.

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  2. Those surveys were conducted by groups such as city authorities, cooperatives, members of assembly at an official party and counters were not simple geiger, but expensive scintillation type.

    Background radiation was almost nothing in those area.

    So suppose those figures were correct, what would they do next? No one can relocate 30 million people to somewhere outside Tokyo, so it seems they are waiting for people's willingness to move.

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  3. 10,000 pCi/kg (370 Bq/kg) was the level the FDA said don't eat this. Got a pointer to the data? Wondering about the numbers. The isotopes matter, btw, as do when the measurements were taken. I-131 has a very short half life.

    It is worth comparing the numbers to Europe after Chernobyl. Germany and Sweden were not evacuated with similar numbers. (Forsmark, Sweeden was 120,000 Bq/m2) Also worth looking at the impact that it had on similar levels of contamination. That said, I might import my mushrooms from areas outside of the contamination zone.

    http://www.davistownmuseum.org/cbm/Rad7.html

    Anyhow... Chernobyl does provide some reasonable data points on the health side. Compare like radiological numbers, compare the mid term (26 years) of medical data. I want to say Fukushima released about a tenth of what Chernobyl did, so the European data, adjusted for distance, might be a reasonable approximation of Tokyo.

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