something of a presence in these photographs. and that photograph in particular is an important one to me. >> host: >> host: maurice wallace and here is the cover cover of your book. >> next, jake talks about the history of the drinking water and he says unsafe drinking water is the single largest killer in the world. this is part of our college series. >> host: now joining us is the author of "drinking water: a history" and he is the professor at duke.

in this book, you write that unsafe drinking water is the single largest killer in the world. >> guest: i was surprised to find that. more than warfare and aids. the statistics are somewhat rough, but over half of the population in the developing world is estimated to suffer from a water-borne disease. >> host: why in 2014 don't we have clean drinking water worldwide? is it hard? >> guest: it is hard. and the challenge we are facing in 2014 with drinking water are a different than bc 2014. the water cleaning has been a challenge for each society. and whether it was egypt or rome or togo today or durham, north

carolina today, everyone thinks their water is safe enough. but if we went back a hundred years, we could probably not be paid to drink the water. so the notions of safety have changed over time. >> host: in the united states do we have 100% safe tap water? >> guest: no, and we will not have a 100% and that is probably a good thing. but if you had said risk-free i would have said no, we don't. but for safe, i guess we do. and what i mean is we accept the tradeoffs. it really is quite remarkable that i can go anywhere in the united states whether it is tallahassee or bangor or santa barbara and i don't give a second thought to the drinking

water. and that has happened in a short period of time. for most of history drinking water hasn't been safe. >> host: but you can go anywhere in the united states and drink the water. where else can we do that in the world? nearly everywhere? >> guest: in the richer countries, nearly everywhere. some countries have their own particular microorganisms the body takes time to get used to. but there are other parts of the developing world where you want to avoid drinking the water, if you can, and the reason is twofold. and part of that is water provision and water sanitation. two sides of the same coin, right? the romans were the first great society to have the insight you need water to flush away your

waste to have clean water. and many developing countries don't have the infrastructure to clear away the waste so the water is contaminated. and the most fascinating statistics i heard in years was for the first time in human history more humans live in urban settlements than rural. we are now an urban species. and providing safe drinking water in dense populations is more difficult than in disburse populations because of the sanitation challenge. >> host: is bottled water safer than tap water? >> guest: in the united states the answer briefly is there is no reason to think so. a lot of people drink bottled

water. why do they do it? three reasons. one is convenience. if you go to a grocery store or gas station and you want something to drink that is not soda you reach for the water. i grew up in the '70s and if i went to the station and asked for water then, they would have pointed me to a hose. first is convenience and second is fashion. that is falling more out of flavor. students have the see-through containers now on their desk. and the third is the notion of safety. and the reason why it is unlikely that bottled water is safer than tap water is for strange reasons. bottled water is regulated by the fda as a food stuff and tap water is regulated by the epa and the safe drinking water. tap water is more rigilously

regulated and many more test are done a day. if bottled water doesn't cross state line the federal government isn't involved and it is the state and many states don't regulate the bottled water. so fiji water were in an add campaign saying it is called fiji because it isn't from cleveland and an article came out soon after that that compared cleveland tap water to a lot of bottle water and about roughly a third of the bottled water had more contaminents. in developing countries, it is safer to drink bottled water. >> host: what is the importance

of fluoride in the water? >> guest: it has been put in to stregthen the enamel on teeth and there is a huge talk on whether this is dangerous or not. peer reviewed literature says the biggest concern is in the water that has containing fluoride naturally it can lead to brittle bones. i have not talked about science that talked about links to behavorial disorders or autism, and my own view is i think they fall under the notion of liberty and autonomy and the fact the government is doing something to your body without your consent.

so the concern of big brother. floridation is something people feel about literature but the review literature doesn't press it is a cause of concern. >> host: what do you do here? >> guest: i am a professor and on the school of law and environment. >> host: what do you teach? >> guest: administrative law, and all kinds of law and i sweep halls sometimes. >> host: you teach contracts and environmental law. when it comes to environmental standards where does the u.s. rank? >> guest: it depends on the issue. the united states has been a leader and pioneer in environmental law. the united states developed the first generation of modern environmental law in the sense

of uniform standards across the country that gave citizens the right to enforce the law which was an innovative and aggressive in a sense concept. since then, depending on the particular presence of the administration we have not had a new environmental law since the 1990s and it is a partisan issue and is now caught up in the partisanship we see in washington, d.c. so for instance, you look at climate change. you know, there is a lot going on at the state level. some of the states and some federal level but if you compare that to when you see happening in europe it is hard to see the united states is a leader in that regard. >> host: how important was the safe drinking water act? >> guest: it was important because it provided uniform standards for drinking water across the country. the more important date was 1914

actually. and in 1914 that was when the interstate commerce commission required that buses had to use water that was added with clore rene. and one of wright brothers died of the typhoid. the federal governments in the early 1900's were not willing to dictate to local governments and states that you must put clore rene in your water. they said if you have a train or

bus passing through your town and you will provide them water it better be chlorinated. there were so many depos in town that the transport went through that gave a huge push to put the chlorine in the water. >> host: who discovered chlorine? >> guest: the contract with jersey city said they were required to provide pure and who wholesome water. the technology up to them was sand filtration and you pass the water through the barriers of sand and most of the contaminants are taken out but

the company said we will use chlorine and the judge sided with the company and said i have been persuaded that this will provide pure water as well >> host: what about converting sea water to regular water? is that technology second or third generation? >> it is quite developed. there are different variants of it. you find it along the coast. australia is getting into it. the middle east is getting into it. and people say that is the answer to water scarcity and it can be but there are three challenges. water is heavy and doesn't move

up hill is the first challenge. so unless you are on the coast it could be expensive to move the water inland. the state of california roughly 20% of their electricity is consumed for moving water. 20%! so it isn't the solution for inland communities. and the second thing is it is expensive. there are two types. one you heat the water and the second is reverse osmosis where you force it through filters and take out the salts. and then you have to get rid of the waste water, which is brine water, and you will use naeshlg

as well and the body line is for this to be effective there is going to have to be constraint on where it is used and not use. >> host: what percent of the world today has water shortages? >> guest: i will preface this by say drinking water is only a fraction of the water consumed. most countries it is for agriculture or industry. so in terms of places where there is no drinking water, that is unusual because everyone has to drink. so the last thing that will fall is drinking water. that said, water scarcity is a big issue. their snow pack is 15% of where it would normally be and we are

seeing farmers not growing crops but they will drink. water is the think they preserve always. barcelona, that said, for about 3-4 months they had to bring water in from marseille because they were not getting the drinking water. ...

the second thing is it turns out your body tells you when you're thirsty. people get in trouble when they're in a different climate and they don't know the signs of dehydration. the body is very good at telling us when we actually need water. studies have been done that say a about a liter a day is reasonable. but if you're going to sweat allot you need more. some people are told if you drink a lot of wear, helps your complexion. not that drinking water is a bad thing but people going around unblotted all the time because they think it's good for them are probably uncomfortable for no good reason. >> host: a brief interview with james salzman who has written a history of drinking water. this is booktv on c-span2.

now, clay risen accounts the civil rights act of 1964. recalling the arduous work involved in passing the legs, marked we bun of the longest filibusters in history by opponents who south to defeat the measure. this is an hour and ten minutes. >> host: clay. a terrific book. >> guest: thank you. >> host: a terrific book on an important topic, and you don't