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00:00Once there was a man who went searching for the true age of the earth.
00:16In his struggles to discover it, he stumbled on a grave threat.
00:25Beautiful spring day, Pasadena, California, 1966.
00:30Business is booming, life's good.
00:33Except for one man, a geochemist named Claire Patterson, known as Pat.
00:40He knows that everyone he sees is in danger from an invisible menace.
00:51And he's determined to put a stop to it, no matter what the cost.
01:00The End
01:03ORCHESTRA PLAYS
01:33ORCHESTRA PLAYS
02:03ORCHESTRA PLAYS
02:33You can't really tell Pat Patterson's story without going all the way back to the time long before the Earth our home was built.
02:47When the stars brought forth its substance, iron for the planet's molten core, oxygen for the rocks and the water and the air, carbon for diamonds and life.
03:07A star is born.
03:37For the first few million years, things ran smoothly as dust grains snowballed into progressively larger objects.
03:49But once these objects grew massive enough to have sufficient gravity...
04:01They began pulling each other into crossing orbits.
04:09This is how our world looked when it was new.
04:20No part of the Earth's surface could survive intact from that time to the present.
04:26So with all its birth and early childhood records erased, how could we ever hope to know with any certainty the true age of our world?
04:39People have been wondering about this since antiquity.
04:46In 1650, Archbishop James Usher of Ireland made a calculation that seemed to settle the question.
04:54Like almost everyone else of his time and his world, he accepted the biblical account of creation as authoritative.
05:00But the Bible does not give exact years, so Usher searched for an event in the Old Testament that corresponded to a known historical date.
05:09He found it in the second book of Kings.
05:12The death of the Babylonian ruler Nebuchadnezzar in 562 BC.
05:16Usher added up the generations of the prophets and the patriarchs, the 139 begats of the Old Testament, between Adam and the time of Nebuchadnezzar.
05:28And discovered that the world began on October 22nd in the year 4004 BC, at 6 p.m.
05:37It was a Saturday.
05:39Archbishop Usher's chronology was taken as gospel in the Western world, until we turned to another book to find the age of the earth, the one that was written in the rocks themselves.
05:51Most of the rock layers in the walls of the Grand Canyon are made of sediments, deposited as fine grains, in a time when this part of the world was a sea.
06:00Over eons, the sediments were compressed into rock under the weight of succeeding layers, the oldest ones at the bottom.
06:21Pick a layer. Any layer.
06:30How about that one?
06:38Once upon a time, there must have been shallow water here.
06:43Back in the Precambrian period, about a billion years ago, there was only one kind of life.
06:52These blue-green bacteria were busy harvesting sunlight and making oxygen.
06:57For them, it was just a waste product.
06:59But for the animals who evolved later, including us, it was the breath of life.
07:08Okay. Pick another layer.
07:11How about that one?
07:14This layer is known as the Bright Angel Shand.
07:17It formed about 530 million years ago.
07:20These tracks were left 260 million years ago.
07:27So you want to know the age of the earth?
07:29Just figure out how long it took to deposit each layer.
07:32Then, instead of counting the begats, add up all the layers.
07:36Easy, right?
07:38Just one problem.
07:39We know from observing this process, because it still happens today in oceans, lakes around the world,
07:45that sediments can be laid down at widely different rates.
07:49It usually happens very slowly.
07:51Say, a foot of sediment per thousand years.
07:54But when there's a rare catastrophic flood, it can happen much faster.
07:58As much as a foot in just a few days.
08:00Many geologists try this method to calculate the age of the earth.
08:16They use the Grand Canyon and other sedimentary sequences around the planet.
08:20But their answers range too widely to be of much use.
08:23Anywhere between 3 million years and 15 billion.
08:30And there were other problems with this method.
08:33Even the deepest layers of rock are not the oldest things on earth.
08:37Why?
08:38Because not even rocks could survive the earth's violent infancy.
08:43In space, it's another story.
09:00Are there any mementos from when the earth was born?
09:05Objects that could possibly tell us its true age?
09:08I know a place where the unused bricks and mortar left over from the creation of our solar system can be found.
09:15It lies between the orbits of Jupiter and Mars.
09:19Here is the stuff of the newborn earth.
09:23Adrift in cold storage.
09:25Unchanged ever since that time.
09:27A million or so years ago, a large asteroid happened to jostle a much smaller one.
09:34Sending it on a new trajectory.
09:37A collision course that ended one night.
09:39Some 50,000 years ago.
09:42It must have shattered the piece of the Grand Canyon as it sailed overhead.
10:09To blast out this crater in what would one day be known as Arizona.
10:22Fragments of the iron asteroid that made this crater have survived intact.
10:39If we just knew how long ago that iron was forged, we'd know the age of the solar system, including the earth.
10:45But how could we know that?
10:48Pick a rock.
10:49Any rock.
10:53How about that one?
10:54Some atoms in this rock could be radioactive, which means they spontaneously disintegrate and become other elements.
11:04A uranium atom first becomes a thorium atom.
11:08On average, it takes a few billion years.
11:11The thorium is much more unstable.
11:13In less than a month, it turns into protactinium.
11:15A minute later, protactinium becomes something else.
11:20The atom undergoes 10 more nuclear transmutations.
11:24Until it reaches the last stop on the decay chain.
11:28A stable atom of lead.
11:32And lead will remain for eternity.
11:35In the 20th century, there was a huge effort lasting decades to measure the time it takes for each radioactive element to transmute into another element.
11:48Physicists discovered that the atoms of each unstable element decay at a constant rate.
11:55The nucleus of an atom is a kind of sanctuary, immune to the shocks and upheavals of its environment.
12:03Hit it with a hammer.
12:04Boil it in oil.
12:17Vaporize it.
12:20The nuclear clock goes on ticking, keeping an absolute standard of time that does not look to the sun and the stars.
12:28What better way to find the true age of the Earth than with the uranium atom?
12:32If you knew what fraction of the uranium in a rock had turned into lead, you could calculate how much time it passed since the rock was formed.
12:41But there's a problem.
12:43The rocks in the Earth that were present when it was formed are no more.
12:47They've all been crushed, melted, remade.
12:53There is a way to calculate the amount of lead that was present from the beginning.
12:57It's a gift from the heavens, meteorites.
13:00This one, a fragment of the one that made this giant crater, was ideal.
13:06The amount of lead deep inside this meteorite is exactly the same as when Earth formed.
13:11Since you know the constant rate of uranium decay, that should give you the age of the meteorite, which was made at the same time as the Earth.
13:20All you had to do was measure the amount of lead in meteorites.
13:24Easy, right?
13:34A scientist named Harrison Brown at the University of Chicago first understood this in 1947.
13:39He chose a young graduate student, Claire Patterson, to do the work.
13:44Patterson couldn't possibly know how this assignment would alter the course of his life, and ours.
13:57What seemed like pure scientific research, turned out to be so much more.
14:27Claire Patterson, son of a letter carrier from Iowa, was rebellious by nature.
14:41Not very good in school.
14:43But he was a natural-born scientist.
14:46A geologist named Harrison Brown gave Patterson what seemed like a straightforward scientific assignment.
14:54First off, Pat, you mind if I call you Pat?
14:58Now I know you're no geologist. Probably couldn't tell granite from feldspar.
15:03But I hear you really know your way around a mass spectrometer, Pat.
15:08Good. You married, Pat?
15:10Yeah, Lori. She's a chemist, too.
15:13We worked on the Manhattan Project together at Oak Ridge.
15:16Good, okay. Well, first thing you need to know, there are these tiny crystals called zircons.
15:22Real small, size of a pinhead, tight as a drum and tough.
15:26Nothing gets in or out of them. And I'm talking for billions of years.
15:30We know how old these grains are because we've already dated the rocks they came from.
15:35Each little zircon has only a few parts per million of uranium inside.
15:40And that uranium is decaying to even tinier amounts of lead.
15:45You figure out how to measure that lead. And you'll know how to do it for a meteorite.
15:50You think you can do that, Pat?
15:52Yeah, yeah. I don't see why not.
15:54Good. Because when you do, you'll be the first man to know the age of the Earth.
15:59And you'll be famous.
16:01And you'll see. It'll be easy. Duck soup.
16:08While Patterson tried to measure the trace amounts of lead in the zircon grains,
16:33another grad student, George Tilton, was measuring the amount of uranium in the same grains.
16:39All Patterson had to do was measure the amount of lead with equal accuracy.
16:45She's all yours, Pat. Measured it six times. Same result. 3.2 parts per million.
16:50Yeah, nice going, George. Thanks.
16:57Tilton's results were always the same.
17:01But Patterson's results on the lead content of the same grains were wildly inconsistent.
17:06This made no sense.
17:20Could the lab have been contaminated by previous experiments with lead?
17:27Maybe it was the naturally high amounts of lead in the environment that were messing up his results.
17:38Patterson did everything he could to cleanse the lab of any lead.
17:42There was still a hundred times too much lead. He'd been at it for more than two years.
18:00Duck soup my ass.
18:02Patterson realized he would have to boil his containers and tools in acid and purify all his chemicals to further reduce the lead in his lab.
18:21Oh, I...
18:22No!
18:23I'm new here.
18:24Where's the men's room?
18:26Damn it.
18:27All of Patterson's obsessive scouring and sterilizing had still not solved the problem.
18:35He would need to design his own lab and build it from scratch.
18:39The opportunity arose when Harrison Brown moved to the California Institute of Technology in Pasadena and invited Patterson to join him.
18:57Okay, Tom, that's enough. We can move through the interlock now.
19:04Patterson had now been at it for six years, doggedly tracking down and eliminating the many sources of lead that were compromising his instruments.
19:13He had built the world's first ultra clean room.
19:18He was finally able to measure how much lead was actually in the rock, one whose age had already been established.
19:26Now, at last, Patterson was ready to tackle the Iron Meteorite to find the true age of the Earth.
19:35He brought his meteorite specimen back to the Argonne National Laboratory, where the world's most accurate mass spectrometer had just become operational.
19:49Doc, this can't wait till tomorrow?
20:05Okay, little buddy, we're gonna have to vaporize you.
20:25A mass spectrometer uses magnets to separate the elements contained in a sample so that the amounts of each element can be quantified.
20:32This would provide the last missing piece of the puzzle of the Earth's true age.
20:43Now, I'm gonna ionize you.
20:46Sounds worse than it is.
20:49What's an electron between friends?
20:52Having isolated the sample from any outside lead contamination,
20:57Patterson was at last ready to measure the amount of lead and uranium in the sample.
21:02And calculate how many years before it had formed.
21:06The true age of the Earth.
21:09Thank you to all the scientists who came before.
21:15Thank you, geologists.
21:17Thank you, Charles Lyell.
21:23Thank you, Michael Faraday.
21:24Michael Faraday.
21:33J.J. Thompson.
21:41Ernest Rutherford.
21:42And thank you, Harrison Brown.
21:43The world is four and a half billion years old.
21:47We did.
21:48The world is four and a half billion years old.
21:50We did.
21:52The world is four and a half billion years old.
21:53We did.
21:54Mom!
21:55Mom!
21:56Mom!
21:57Mom!
21:58Mom!
21:59Patterson wanted his mother to be the first person to know what he had struggled for
22:04so long.
22:05The world is four and a half billion years old.
22:08We did.
22:09Mom!
22:10Mom!
22:11Mom!
22:12Mom!
22:13Mom!
22:14Mom!
22:15Mom!
22:16Mom!
22:17Mom!
22:18Mom!
22:19Mom!
22:20Mom!
22:21Mom!
22:22Mom!
22:23Patterson wanted his mother to be the first person to know what he had struggled for so many
22:24years to discover.
22:25The true age of the Earth.
22:26His reward for this discovery?
22:27A world of trouble.
22:28He didn't know it, but he was on a collision course with some of the most powerful people
22:31on the planet.
22:33Mom!
22:34Mom!
22:35Mom!
22:36Mom!
22:37Mom!
22:38Mom!
22:39Mom!
22:40Mom!
22:41Mom!
22:42Mom!
22:43Mom!
22:44Mom!
22:45Mom!
22:46Mom!
22:47Mom!
22:48Mom!
22:49Mom!
22:50Mom!
22:51Mom!
22:52Mom!
22:53Mom!
22:54Mom!
22:55Mom!
22:56Mom!
22:57Mom!
23:14To the ancient Romans, the majestic reigned planet Saturn was not a real place, not
23:18a world, but a god king, a son of the marriage of Heaven and Earth.
23:25The God of Lead.
23:30These columns are all that remain of this oldest temple in the Roman form,
23:35first consecrated to Saturn 2,500 years ago.
23:39It also served as Rome's treasury and its Bureau of Weights and Measures.
23:46Tonight is Saturnalia, the wild December holiday in Saturn's honor,
23:51and everyday life will be turned upside down.
23:54The masters will serve the slaves, no wars or executions will be allowed,
23:59and gifts will be exchanged.
24:01A couple of hundred years from now,
24:03when the early church fathers look for a way to attract more pagans,
24:06they'll decide to turn Saturnalia into Christmas,
24:10making it the latest in a long line of winter solstice holidays to be repurposed.
24:14This towering statue of Saturn may have looked something like this on the night of Saturnalia.
24:29In ancient Rome, this god had another, darker side.
24:34That other Saturn is a cold and sullen, sluggish ghoul given to irrational bouts of rage.
24:43He committed an unspeakable act of violence against his father and devoured his own children.
24:48Of all the planets visible to the unaided eye of the ancients,
24:54Saturn is the slowest,
24:56which could explain why they named the planet after the god of lead.
25:00But there's no denying that the more negative aspects of Saturn's personality
25:06reflect the age-old knowledge of the symptoms of lead poisoning.
25:10Funny thing about the Romans,
25:12even though they knew that contact with lead inevitably poisoned people,
25:16rendered them sterile and drove them mad,
25:18what metal did they use to make the pipes that carry the water through their legendary aqueducts?
25:23I'll give you a hint.
25:25The word plumbing comes from the Latin word for lead.
25:29Plumbum.
25:42What metal did they use to line their famous baths?
25:46And how did they sweeten their wines when they were too sour?
25:49What did they use to line their vats and cooking pots?
25:53There's some historians who believe that the widespread use of lead
25:57was a major cause in the decline and fall of the Roman Empire.
26:01Why did they continue to use lead long after they knew it was toxic?
26:08It was cheap, very malleable, easy to work with.
26:12And the ones who were exposed to it at its most lethal levels,
26:15the miners and workers who processed the lead,
26:17were considered expendable.
26:20Their lives didn't matter.
26:21They were slaves.
26:22Most of the earth's lead started off at a safe distance from living things,
26:27down below the surface.
26:29But about 8,500 years ago,
26:31humans began figuring out how to dig into the earth
26:34and extract metals from rock.
26:36By the time this villa was new,
26:38just a couple thousand years ago,
26:40the Romans were producing 80,000 tons of lead a year.
26:44Why is lead so poisonous to us?
26:49Because when it gets into our bodies,
26:52lead mimics other metals like zinc and iron,
26:56the ones our cells actually need to grow and flourish.
26:59Enzymes in the cell are fooled by the lead's masquerade,
27:06and they begin to dance.
27:08But it's a dance of death,
27:10because the lead is an imposter that can't fulfill the cell's vital needs.
27:15Lead also blocks neurotransmitters,
27:18the communication network between the cells.
27:23It interferes with the molecular receptors that are vital to memory and learning.
27:27This is especially damaging to children,
27:31but lead poisoning spares nobody.
27:35Starting at the turn of the 20th century,
27:38the makers of leaded paint hired the fledgling advertising industry
27:41to persuade the consumer that lead was child-friendly.
27:46A little toy lead soldier once to the Dutch boy said,
27:49we have some fine relations who all contain some lead.
27:52Why don't you give a party so folks can meet and see
27:55the other happy members of the great lead family.
27:58The first one at the party was gay electric light.
28:01He said, I'm very brilliant.
28:02I always shine at night.
28:04No little of my brilliance is due to my glass head,
28:07which gives a light much brighter,
28:09because it's made with lead.
28:11A pair of rubbers entered and took the Dutch boy's arm.
28:14They said, we are protectors who keep you dry and warm.
28:18You know, when we were molded,
28:19the man who made us said,
28:21we're strong and tough and lively,
28:23because in us there's lead.
28:25But lead production didn't really shift into high gear
28:28until the early 1920s,
28:30when chemist Thomas Midgley
28:32and inventor Charles Kettering of General Motors
28:34found that tetraethyl lead
28:36could be marketed as an anti-knock additive to gasoline.
28:42They formed a new company called the Ethyl Corporation.
28:47It had once been considered for use as a poison gas
28:51by the U.S. War Department.
28:52Unlike the lead in paint,
28:55tetraethyl lead was fat-soluble.
28:57A half a cup of it on your skin could kill you.
29:01The manufacturers calculated
29:02that they could sell 60 million tons of it a year.
29:05Only problem was some of the workers
29:08who processed the stuff in factories
29:10in Delaware and New Jersey
29:12were going insane,
29:14hallucinating,
29:15jumping out of windows.
29:18They died screaming.
29:20This was a selling job that would require a lot more
29:24than dancing light bulbs.
29:26What was needed was a man of science
29:37to calm the public's fears
29:38and improve lead's image.
29:41They found the right man for the job.
29:44This was one of the first times
29:46that the authority of science was used
29:48to cloak a threat to public health
29:50and the environment.
29:51Robert Kehoe,
29:53a young doctor from Cincinnati,
29:55was hired by GM.
29:57He raised scientific doubts
29:59in the public mind
30:00about the dangers of lead.
30:03Lead was naturally occurring
30:04in the environment, he said.
30:07Yes, there might be occupational hazards
30:09for the people who worked with lead,
30:11but that could be best handled
30:12by industry self-regulation.
30:15And there was no evidence to suggest
30:17that lead posed any threat to the consumer.
30:19For decades,
30:22no one challenged him.
30:26Until Claire Patterson
30:27went searching for the age of the Earth.
30:34Claire Patterson's research
30:35on the age of the Earth
30:36had made him the world's leading expert
30:38on measuring trace amounts of lead.
30:41And like everyone else at the time,
30:43he assumed the prevalence of lead
30:44occurred naturally.
30:45True scientist that he was,
30:51he set out to discover
30:52everything he could
30:53about how lead circulates
30:55through the environment.
30:57On a grant from
30:58the American Petroleum Institute,
31:00he carefully measured
31:01the concentrations of lead
31:03in deep and shallow sea water.
31:06Once again,
31:06Patterson found that his initial data
31:09made no sense.
31:10There were only minuscule concentrations
31:12of lead in the deep ocean water,
31:14but in shallow waters
31:15and at the surface,
31:17the concentrations of lead
31:18were hundreds of times greater.
31:20In any ocean,
31:21it takes a few hundred years
31:23for the shallow waters
31:24to mix with the deep.
31:25This told Patterson
31:26that the large amount of lead
31:28in the surface waters
31:29had arrived recently.
31:31Otherwise,
31:32it would have been
31:32more evenly distributed.
31:34Knowing the quantity of lead
31:36in the shallow seas
31:37and the time needed
31:38to mix it
31:38into the deeper layers,
31:40he was able to estimate
31:41the rate of lead contamination
31:43at the surface.
31:46Patterson asked himself,
31:47what could possibly supply lead
31:49to the world's ocean
31:50at such a rate?
31:51Where's all that lead coming from?
32:16I think I know, Harrison.
32:18It's from leaded gasoline.
32:20Well, then,
32:21we've got a problem, Pat.
32:24Because that's the same place
32:25the money comes from.
32:29But Patterson would not give in.
32:31He went right to work
32:32on publishing
32:33the scientific paper
32:34that would make the case
32:35against leaded gasoline.
32:39When he sent the paper
32:40to the prestigious
32:41scientific journal Nature,
32:43Patterson put his own name second.
32:45He often did that
32:46with his students
32:47to advance their reputations.
32:48he made a lifelong point
32:50of shunning the limelight,
32:52the privileges that come with it.
32:57Only three days
32:58after publication,
33:00the pushback began.
33:03Hello, Dr. Patterson.
33:16Pleasure to meet you.
33:16I'm very impressed
33:17by your work.
33:19Your work
33:19is of great interest
33:21to us
33:21in the petroleum
33:22and chemical industries.
33:24It wouldn't have been possible
33:26without your funding.
33:27Precisely.
33:28And there's so much more
33:30we'd like to do for you.
33:31Well, I've been thinking
33:32about measuring lead
33:34in polar ice
33:35to see if it shows
33:36the same kind of pattern
33:37as the oceans.
33:38Lead?
33:39But you've already done that.
33:41We're thinking
33:42it's time you move on
33:43to other trace elements.
33:45In fact, Dr. Patterson,
33:47our ability to fund you
33:48in any other line of research
33:50is virtually limitless.
33:55Lead is a neurotoxin.
33:57When you ship
33:58your tetraethyl lead
34:00from the factory,
34:01before you add it
34:02to the gasoline,
34:03it's handled
34:03just like a chemical weapon.
34:05There's a reason for that.
34:07Where do you suppose
34:08all that lead goes
34:09after it leaves the tailpipe?
34:11Think about what it might
34:12be doing to us
34:13and our kids.
34:16Dr. Kehoe has shown
34:17that the level of lead
34:19in the environment
34:20is as natural
34:21as snow in December.
34:22Then why doesn't it show up
34:25in the deep water?
34:26Here, let me just show you.
34:30Thanks for your time.
34:32What do you do?
34:32You're just gonna keep on
34:33putting millions of tons
34:34of poison into the air
34:35we breathe?
34:37If my research
34:38doesn't put you
34:39out of business,
34:40some future scientist will.
34:42Patterson's funding
34:43from the oil industry
34:44vanished overnight.
34:46In fact,
34:46they tried to get him fired.
34:49But the U.S. government,
34:51the Army,
34:53the Navy,
34:54the Atomic Energy Commission,
34:55the Public Health Service,
34:57and the National Science Foundation
34:58stood by him
35:00supporting his research
35:01on lead pollution.
35:03His investigations
35:03took him from Greenland
35:05in the far north
35:06to Antarctica
35:07in the far south
35:08and to rivers,
35:10mountains,
35:10and valleys in between.
35:15In even the most
35:16hostile conditions,
35:17Patterson and his team
35:18worked to replicate
35:20the immaculate environment
35:21of the clean room.
35:22Their plastic suits
35:23were replaced daily.
35:26Working 10 to 12-hour days
35:28in sub-zero weather,
35:29they dug a 200-foot-long shaft
35:31into the ice of Antarctica.
35:34It was a form of time travel
35:36to recover snow
35:37that had fallen
35:38three centuries ago
35:39before the start
35:40of the Industrial Revolution.
35:43Nose!
35:44Wipe your nose,
35:46damn it!
35:47There's a thousand times
35:49more lead in you
35:50than in this ice!
35:51You want to contaminate
35:52the whole damn sample?
35:58After four grueling weeks
36:00of painstaking sample collection,
36:03Patterson was ready
36:03to go back to the land.
36:07As with the oceans,
36:09he found that the amount
36:10of lead was much lower
36:12in the snow
36:12of a few hundred years before.
36:15No matter where
36:15he searched on Earth,
36:17no matter how far
36:18he traveled back in time,
36:20the results always told
36:21the same story.
36:23The naturally occurring levels
36:24in the air and water
36:25in the past
36:26were far lower.
36:33For thousands of years,
36:34lead had been known
36:36to cause brain damage,
36:37developmental impairment,
36:38violent behavior,
36:40and even death.
36:42In searching
36:43for the age of the Earth,
36:44Patterson had stumbled
36:46on the evidence
36:47for a mass poisoning
36:48on an unprecedented scale.
36:54But Kehoe
36:56and the other scientists
36:57employed by the lead industry
36:58persuaded the public
37:00they had nothing
37:00to worry about.
37:02Everyone thought
37:03Patterson was a crank
37:04until one man
37:06started to pay attention.
37:08Patterson went public
37:14with his discoveries
37:15about lead
37:15in a big way.
37:17He published his findings
37:18in a major
37:18environmental health journal
37:20and sent copies
37:21to various government leaders,
37:22including
37:23one highly influential senator.
37:31Edmund Muskie of Maine
37:32was the chairman
37:33of the Senate subcommittee
37:34on air and water pollution.
37:35In 1966,
37:39he held hearings
37:40on the lead question.
37:42The first witness
37:43was Dr. Robert Kehoe,
37:45longtime scientific advocate
37:47for leaded gasoline.
37:49Is it your conclusion
37:51that in 1937
37:52to the present time
37:54there has been
37:55no increase
37:56in the amount of lead
37:57taken in
37:58from the atmosphere
37:58by the average
38:00traffic policeman
38:01and service station
38:02attendant
38:03or motorist?
38:05There is not
38:05the slightest evidence
38:07that there has been
38:08a change in this picture
38:09during this period of time.
38:11Not the slightest.
38:13The hearings
38:14were scheduled
38:15to take place
38:16when their fiercest critic,
38:17Claire Patterson,
38:19was off in Antarctica.
38:20but he unexpectedly
38:22appeared
38:23on the fifth day
38:24of testimony.
38:26Looks like there seems
38:27to be an increase
38:29in the concentration
38:30of lead in people
38:31as a result
38:33of exposure
38:34to the environment.
38:35Is that correct?
38:36That is correct.
38:38In identifying
38:39typical lead levels,
38:41you use actual measurements
38:43you've taken
38:44in the field.
38:45Yes.
38:46Are these observations
38:48different from the ones
38:50we've been hearing about
38:51from other witnesses?
38:53No.
38:53They're the same observations.
38:57You've testified
38:58that there has been
38:59no change
39:00in natural lead levels.
39:02Is that correct?
39:03That is correct.
39:04You're sure about that?
39:06Absolutely.
39:07The levels we see
39:08in people today
39:09may be typical,
39:10but they are not
39:11by any means natural.
39:13So,
39:14you don't disagree
39:14with Dr. Kehoe's numbers?
39:16No, no.
39:18You're saying
39:18that the same numbers
39:20are leading
39:20to different conclusions?
39:23Yes.
39:24You know,
39:25this is the kind of thing
39:26we expect to hear
39:27from lawyers,
39:29not scientists.
39:32I would agree
39:33with that, yes.
39:35You seem to be
39:36very sure
39:36of your conclusions,
39:38Dr. Kehoe.
39:39It so happens
39:40that I have
39:40more experience
39:41in this field
39:42than anyone else alive.
39:44at these levels,
39:46lead is a severe
39:48chronic insult
39:49to the human body.
39:50There is no
39:51medical evidence
39:52that lead
39:53has introduced
39:54a danger
39:54to public health.
39:56It's irresponsible
39:57to mine millions
39:59of tons
39:59of toxic material
40:01and disperse it
40:02into the environment.
40:03If there was proof
40:04of harm,
40:05we would have found it.
40:06Not if your purpose
40:07is to sell lead.
40:08Patterson fought
40:11the industry
40:11for another 20 years
40:13before lead
40:14was finally banned
40:15in U.S. consumer products.
40:17The man
40:17who figured out
40:18the age of the earth
40:19was also responsible
40:21for one of the greatest
40:22public health victories
40:23of the 20th century.
40:26In just a few years,
40:27average lead levels
40:28in the blood of children
40:29plummeted
40:30by some 75%.
40:32Today,
40:33the medical consensus
40:34is unanimous.
40:35there is no such thing
40:37as a non-toxic level
40:38of lead in humans,
40:40however small.
40:41Today,
40:42scientists sound the alarm
40:43on other environmental dangers.
40:46Vested interests
40:47still hire their own scientists
40:48to confuse the issue.
40:50But in the end,
40:52nature will not be fooled.
41:05First in her class
41:16is Ms. Pesta,
41:17our Cosmos Star
41:18Science Teacher of the Week.
41:20Next Sunday,
41:21explore the vastness of space.
41:23Travel to the most mysterious
41:24corner of the cosmos.
41:26A place where gravity
41:27is so strong,
41:28not even light
41:29can escape.
41:30And,
41:31is this the way
41:31the world will end?
41:33An explosion so powerful,
41:34it'll make a supernova
41:36seem like a firecracker.
41:40Are we safe?
41:41All new Cosmos,
41:42a space-time odyssey
41:43next Sunday.