brenner. have you done any studies regarding to the exposure of the tsa agents, on the typical for a logical applications x-ray technicians are required to wear detection devices to determine their a can of the exposure to the radiation. are we doing anything to protect our agents from radiation that may spell out of these machines? >> the film badge monitor won't protect the tsa agents but will certainly give an estimate for the future use what they are being exposed and it makes no sense to me whether they're wearing fell because film badges to be in any medical setting anybody has any association with ionized radiation. >> i don't know if you are married or not, but i am going to assume you are. would you let your pregnant wife goes through one of these machines? >> i probably would not. >> okay. and you indicate that the backscatter x-ray is more dangerous than the millimeter wave technology. are there any risks associated with the wave technology we are aware of at this point in time? >>

and david brenner, director of the center for radiological research at columbia university. james acton, i'll start with you. what do we know about this new problem of contaminated water outside the reactor and how serious is it? >> it's serious for a couple of reasons. it doesn't actually surprise me that they're finding very large quantities of radioactive water because they've been pumping huge quantities of water into the system. that water has got to go somewhere. the radioactive water there found inside the place is serious because it will complicate the relief effort. the radioactive water they found in the trenches is serious because if they don't pump that quickly into a storage facility there's a chance it will leak out and increase the radiation in the environment. >> brown: just to try to make this complicated equation clear, they now have a process where they have to pump water in to cool off the fuel rods, but they also have to pump out the contaminated water somewhere, to some safe place. >> that's exactly right. i mean, if you think back a couple of weeks to

>> suarez: and we talk to newshour science correspondent miles o'brien and radiation expert david brenner about the state of japan's nuclear reactors. >> ifill: plus, margaret warner examines saudi arabia's military move into neighboring bahrain after a weekend of protests. >> ifill: that's all ahead on tonight's newshour. major funding for the pbs newshour has been provided by: breathe in. breathe out. as volatile as the markets have been lately, having the security of a strong financial partner certainly lets you breathe easier. for more than 140 years, pacific life has helped millions of americans build a secure financial future. wouldn't it be nice to take a deep breath and relax? your financial professional can tell you about pacific life, the power to help you succeed. >> you can't manufacture pride, but pride builds great cars. and you'll find it in the people at toyota, all across america. chevron. we may have more in common than you think. and by bnsf railway. and by the bill and melinda gates foundation. dedicated to the idea that all people deserve the chance to live a healthy,

brenner. have you done any studies regarding to the exposure of the tsa agents, on the typical for a logical applications x-ray technicians are required to wear detection devices to determine their a can of the exposure to the radiation. are we doing anything to protect our agents from radiation that may spell out of these machines? >> the film badge monitor won't protect the tsa agents but will certainly give an estimate for the future use what they are being exposed and it makes no sense to me whether they're wearing fell because film badges to be in any medical setting anybody has any association with ionized radiation. >> i don't know if you are married or not, but i am going to assume you are. would you let your pregnant wife goes through one of these machines? >> i probably would not. >> okay. and you indicate that the backscatter x-ray is more dangerous than the millimeter wave technology. are there any risks associated with the wave technology we are aware of at this point in time? >>

brenner says is the biggest concern. >> the bigger the dose, the bigger the risk.he smaller the dose, the smaller the risk. and it doesn't happen overnight. typically 10, 15, 20, 30 years after the exposure is when a cancer might appear. >> reporter: we're all exposed to low levels of radiation every day. it occurs naturally in the air, soil and water. we get it when we fly or have an x-ray. and all that radiation is cumulative. it adds up in our bodies over time. but researchers do not know if those low levels can actually make us sick. >> that's no question that radiation produces cancer. there are certainly still debates going on that very low doses of radiation, do they produce cancer or not. >> reporter: dr. brenner says so far the radiation released in japan is nowhere near the level of the nuclear disaster at chernobyl almost 25 years ago. as for our risk of exposure, the head of the u.s. nuclear regulatory commission says it is very unlikely that we will feel any harmful effects here in the united states. manuel gallegus, cbs news, new york. >>> we'll be ri

brenner. have you done any studies regarding to the exposure of the tsa agents, on the typical for a logical applications x-ray technicians are required to wear detection devices to determine their a can of the exposure to the radiation. are we doing anything to protect our agents from radiation that may spell out of these machines? >> the film badge monitor won't protect the tsa agents but will certainly give an estimate for the future use what they are being exposed and it makes no sense to me whether they're wearing fell because film badges to be in any medical setting anybody has any association with ionized radiation. >> i don't know if you are married or not, but i am going to assume you are. would you let your pregnant wife goes through one of these machines? >> i probably would not. >> okay. and you indicate that the backscatter x-ray is more dangerous than the millimeter wave technology. are there any risks associated with the wave technology we are aware of at this point in time? >>

the next reader is summer brenner. . >> i'm going it read today an excerpt from anana, queen of heaven and earth. i wanted to say a few words about anana. this is the oldest literary work that we have. these are the cuniform tablets that were excavated in the late 1880's and early 1890's by the university of pennsylvania. tens of thousands of fragments of cuniform fragments. the story of anana starts in her adolescence. it travels through her journey as a queen and a goddess, and much of her story is devoted to the love, a very passionate love, for dimusi, who is a shepherd who she takes as her husband, lover and king. and this is called the return. a lament was raised in the city. my lady weeps bitterly for her young husband. anana weeps bitterly for her young husband. woe for her husband, woe for her young love, woe for her house, woe for her city. dimusi was taken captive in aruk. he will no longer bathe in aradu. he will no longer treat the mother of anana of his mother. he will no longer perform his sweet task among the maidens of the city. he will no longer raise his sword higher

david brenner says is the biggest concern. >> the bigger the dose, the bigger the risk, the smaller the dose the smaller the risk and it doesn't happen overnight. typically 10, 15, 20, 30 years after the exposure is when cancer might appear. >> reporter: as for the radioactive steam it's unclear how far it will travel or the risk to the public. pentagon officials say helicopters flying 60 miles from the crippled plants were coated with radioactive dust. radiation exposure is cumulative, even at very low doses. >> there is no question that radiation produces cancer. there are certainly still debates going on very low doses of radiation. >> reporter: so far, the radiation released in japan is nowhere near the level of the nuclear disaster at chernobyl almost 25 years ago. as for our risk of exposure from what's happening in japan? the head of the u.s. nuclear regular attorney commission says it's very unlikely that we'll feel any harmful effects here in the united states. now, japanese officials are also distributing potassium iodide pills as a precaution. but the benefits of these pills

david brenner is the biggest concern. >> the bigger the risk the bigger the risk. the smaller the dose the smaller the risk. it doesn't happen overnight. 10, 20, 30 years after the exposure is when the cancer can appear. >> reporter: as for the radioactive steam it is unclear how far it will travel or the risk to the public. however the pentagon says helicopters flying 60 miles were coated with radioactive dust. radiation is cumulative even at low doses. >> there is no question that radiation produces cancer. there are debates going on whether low doses of radiation develop cancer or not? >> reporter: japan is nowhere near the disaster of chernobyl. the head of the u.s. regulatory commission says it is very unlikely we will feel any harmful effects from the radiation steam. they are distributing pills as a precaution. but the benefits of these pills are limited and misunderstood. they only help protect against thyroid cancer but block the one type of radioactive iodine. it does not help protect other organs or protect against the potential harm from other radioacti

the-- i always emphasize that those who invented-- watson, brenner, all these great characters-- they focused on how information was managed. dna, the structure of dna, beautiful structure, but actually what's really beautiful about it is when you recognize it's actually a digital memory device. that's what it actually is. you know, the memory of all those nucleotieds, all the chemicals in a particular order, conveys information. it stores information, if & that's how you should view it and that's what's really beautiful. what i suggest is we need to translate that kind of thinking with everything to do in life work. >> rose: i think stephen hawkins is interested-- >> they're interested in how you can combine qaunt mechanics -- >> isn't your daughter worth hyden collider. >> in genev athat's right. and how you combine the thought there and how that works-- quantum mechanics, together with gravity. and is there some way to-- of understanding that? and there's a theory-- i'm well now out of my depth and i may say something stupid-- the theories, the "n" theory that are trying to put thi

the embassy official says chinese quake could games have less overtly current drought but future brenner. --but their future bread winner. high level contact with those of gaddafi the rebels' plight in libya is trying more serious by the hour as gadhafi's forces corp. appeared to be tuning momentum. libyan government took a tremendous honor " tour of recaptured areas. >> reporter: driving east mile upon mile of vehicles discarded weapons, ammunition littering the roadside evidence of a rebel retreat and outgunned come out started by governments forces. the first stop on this organized checked. this has been their police station is not clear what happened but as the first sign of any real bottle as you're driving we saw the occasional to demand by to three dozen are some policemen we have seen most of the stores closed sometimes leaving this list isn't as a real person and as far. azeris massed operas while they've been blown up, shopping fired being fired by soldiers servicer of the impromptu celebration for the cameras. a few days ago this town wasn't rebel hands. this looks like the ta