c*****n
发帖数: 601 | 1 http://www.epa.gov/japan2011/japan-faqs.html#precip-dw-milk
Do the levels found in rainwater exceed EPA drinking water MCLs? If so, why
shouldn't people be concerned?
•While the levels in the rainwater exceed the applicable MCL of 3piC/L
for drinking water, it is important to note that the corresponding MCL for
iodine-131 was calculated based on long-term chronic exposures over the
course of a lifetime 70 years. The levels seen in rainwater are expected to
be relatively short in duration.
这个信不信由你。不过我觉得配方奶最好还是上买蒸馏水/nursery water之类的，便宜又方便。
还有各国饮水 I-131的limit怎么差那么多？
美国： 3piC/L， 大约0.1Bq/L
加拿大：6 Bq/L
http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/radiological_par
日本：Infant 100Bq/L, others 300Bq/L | s********n
发帖数: 2939 | 2 这个蒸馏水没用吧，I-131超容易蒸发的。估计得用反渗透。
why
/L
for
to
宜又方便。
【在 c*****n 的大作中提到】
: http://www.epa.gov/japan2011/japan-faqs.html#precip-dw-milk
: Do the levels found in rainwater exceed EPA drinking water MCLs? If so, why
: shouldn't people be concerned?
: •While the levels in the rainwater exceed the applicable MCL of 3piC/L
: for drinking water, it is important to note that the corresponding MCL for
: iodine-131 was calculated based on long-term chronic exposures over the
: course of a lifetime 70 years. The levels seen in rainwater are expected to
: be relatively short in duration.
: 这个信不信由你。不过我觉得配方奶最好还是上买蒸馏水/nursery water之类的，便宜又方便。
: 还有各国饮水 I-131的limit怎么差那么多？
| j*****n
发帖数: 3617 | 3 加拿大是美国的60倍，日本是美国的3000倍？this is ridiculous
why
/L
for
to
宜又方便。
【在 c*****n 的大作中提到】
: http://www.epa.gov/japan2011/japan-faqs.html#precip-dw-milk
: Do the levels found in rainwater exceed EPA drinking water MCLs? If so, why
: shouldn't people be concerned?
: •While the levels in the rainwater exceed the applicable MCL of 3piC/L
: for drinking water, it is important to note that the corresponding MCL for
: iodine-131 was calculated based on long-term chronic exposures over the
: course of a lifetime 70 years. The levels seen in rainwater are expected to
: be relatively short in duration.
: 这个信不信由你。不过我觉得配方奶最好还是上买蒸馏水/nursery water之类的，便宜又方便。
: 还有各国饮水 I-131的limit怎么差那么多？
| c*****n
发帖数: 601 | 4 瓶装水的保质期很长，i131早放没了
【在 s********n 的大作中提到】
: 这个蒸馏水没用吧，I-131超容易蒸发的。估计得用反渗透。
:
: why
: /L
: for
: to
: 宜又方便。
| f*********l
发帖数: 176 | 5 这个回复的意思很明显啊： 我们知道现在这个雨水很不好， 不过是短时间的， 有劳
各位当当小白鼠好不？ ----好让俺们知道一下以前根据70年辐射期计算的标准到底需
要调整多少----知道了也不会告诉你。
更重要的一点是： 所谓70年的辐射期情况下的安全值，是怎么算出来的？ 哪位查查
资料？ 95%以上可能是基于所谓线性关系，即伤害与时间成正比。
可是其实人类对辐射的种种伤害的了解远远没有普通大众以为的那么周详！ 这个70年
，EPA和相关单位根本还没有这么长时间进行可靠的样本研究！ 线性关系真的对70年
长的I131（以及其他放射性核素）有效么？
下面这个PetKau effect所揭示的不过是冰山一角--- 当然，会有人要求我证明这真的
是冰山一角， 否则要告我妖言惑众。 其实最困难的是：证明这不是冰山一角。 或者
更困难的是： 证明政府决策层已经告知了大众他们政府知道的一切。
注：几个出来发言的政府人员不能代表政府决策层。
Petkau effect
From Wikipedia, the free encyclopedia
The Petkau effect is an early counterexample to linear-effect assumptions
usually made about radiation exposure. It was found by Dr. Abram Petkau at
the Atomic Energy of Canada Whiteshell Nuclear Research Establishment,
Manitoba and published in Health Physics March 1972.
Petkau had been measuring, in the usual way, the dose that would rupture a
particular cell membrane. He found that 3500 rads delivered in 2¼ hours
(26 rad/min) would do it. Then, almost by chance, he tried again with much
weaker radiation and found that 0.7 rads delivered in 11½ hours (1
millirad/min) would also destroy the membrane. This was counter to the
prevailing assumption of a linear relationship between total dose or dose
rate and the consequences.[1]
The radiation was of ionising nature, and produced negative oxygen ions.
Those ions were more damaging to the membrane in lower concentrations than
higher (a somewhat counterintuitive result in itself) because in the latter,
they more readily recombine with each other instead of interfering with the
membrane. The ion concentration directly correlated with the radiation dose
rate and the composition had nonmonotonic consequences.
why
/L
for
to
宜又方便。
【在 c*****n 的大作中提到】
: http://www.epa.gov/japan2011/japan-faqs.html#precip-dw-milk
: Do the levels found in rainwater exceed EPA drinking water MCLs? If so, why
: shouldn't people be concerned?
: •While the levels in the rainwater exceed the applicable MCL of 3piC/L
: for drinking water, it is important to note that the corresponding MCL for
: iodine-131 was calculated based on long-term chronic exposures over the
: course of a lifetime 70 years. The levels seen in rainwater are expected to
: be relatively short in duration.
: 这个信不信由你。不过我觉得配方奶最好还是上买蒸馏水/nursery water之类的，便宜又方便。
: 还有各国饮水 I-131的limit怎么差那么多？
| b*****g
发帖数: 983 | 6 直说不做小白鼠的办法吧
【在 f*********l 的大作中提到】
: 这个回复的意思很明显啊： 我们知道现在这个雨水很不好， 不过是短时间的， 有劳
: 各位当当小白鼠好不？ ----好让俺们知道一下以前根据70年辐射期计算的标准到底需
: 要调整多少----知道了也不会告诉你。
: 更重要的一点是： 所谓70年的辐射期情况下的安全值，是怎么算出来的？ 哪位查查
: 资料？ 95%以上可能是基于所谓线性关系，即伤害与时间成正比。
: 可是其实人类对辐射的种种伤害的了解远远没有普通大众以为的那么周详！ 这个70年
: ，EPA和相关单位根本还没有这么长时间进行可靠的样本研究！ 线性关系真的对70年
: 长的I131（以及其他放射性核素）有效么？
: 下面这个PetKau effect所揭示的不过是冰山一角--- 当然，会有人要求我证明这真的
: 是冰山一角， 否则要告我妖言惑众。 其实最困难的是：证明这不是冰山一角。 或者
| i***h
发帖数: 12655 | 7 我也想问这个
也许他海归了
【在 b*****g 的大作中提到】
: 直说不做小白鼠的办法吧
| s********n
发帖数: 2939 | 8 海归也没用，现在哪没有啊，估计南半球好点。
【在 i***h 的大作中提到】
: 我也想问这个
: 也许他海归了
| R******d
发帖数: 5739 | 9
most of these kind of study are based on animal studies. in general, the
government would set a much lower limit than the level that found to be
harmful in animal models. as far as I know, ionizing radiations damage
cells by damaging DNA. in general, if one or two cells are damaged, those
cells would go thru apoptosis. if one hundred cells are damage, some might
go thru apoptosis right away, some might stay longer. if one thousand are
damaged, some probably turn into cancer cells but take out by immune system.
if ten thousand, then some cancer cells might survive and start
proliferate. this is a therefore a linear relationship. however, if in a
short time someone is exposed to a huge amount of radiation, then other than
cells being damaged, other biochemistry in the body might be affected as
well. If there is no evidence that this is a PetKau effect, then believing
it is a Petkau effect is groundless. coming back to this I 131 level, the
level set by U.S. government is probably much stricter than other places.
In general, EU sets stricter limits on these things than the U.S.. If you
don't worry about taking second hand smoke over a long period of time, then
you shouldn't be alarm by the current situation. But if you really want to
make it a big deal, then you should and figure out a way to avoid drinking
tap water. Unfortunately, many don't believe in expert opinion, but when
they try to avoid such dangers, they have to sort to expert opinions how to
avoid.
【在 f*********l 的大作中提到】
: 这个回复的意思很明显啊： 我们知道现在这个雨水很不好， 不过是短时间的， 有劳
: 各位当当小白鼠好不？ ----好让俺们知道一下以前根据70年辐射期计算的标准到底需
: 要调整多少----知道了也不会告诉你。
: 更重要的一点是： 所谓70年的辐射期情况下的安全值，是怎么算出来的？ 哪位查查
: 资料？ 95%以上可能是基于所谓线性关系，即伤害与时间成正比。
: 可是其实人类对辐射的种种伤害的了解远远没有普通大众以为的那么周详！ 这个70年
: ，EPA和相关单位根本还没有这么长时间进行可靠的样本研究！ 线性关系真的对70年
: 长的I131（以及其他放射性核素）有效么？
: 下面这个PetKau effect所揭示的不过是冰山一角--- 当然，会有人要求我证明这真的
: 是冰山一角， 否则要告我妖言惑众。 其实最困难的是：证明这不是冰山一角。 或者
|
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