WEBVTT 00:02.600 --> 00:04.300 align:left position:10% line:89% size:80% It was the worst air pollution 00:04.300 --> 00:07.033 align:left position:12.5% line:83% size:77.5% attack in the United States history. 00:07.033 --> 00:08.766 align:left position:10% line:89% size:80% [Announcer voice] “A death bring 00:08.766 --> 00:11.800 align:left position:12.5% line:83% size:77.5% over Pennsylvania's bustling industrial town of Donora. 00:11.800 --> 00:14.300 align:left position:17.5% line:83% size:72.5% Residents have difficulty in breathing the murky air 00:14.300 --> 00:16.266 align:left position:35% line:83% size:55% as the town is plunged into darkness.” 00:17.000 --> 00:19.233 align:left position:25% line:89% size:65% Twenty people died. 00:19.233 --> 00:21.166 align:left position:12.5% line:89% size:77.5% It was almost instantaneous. 00:21.166 --> 00:23.800 align:left position:22.5% line:83% size:67.5% People were choking in the streets. 00:23.800 --> 00:25.766 align:left position:25% line:65% size:65% Newspapers grabbed hold of the story 00:25.766 --> 00:28.833 align:left position:25% line:65% size:65% and it began to run wild across the country. 00:29.233 --> 00:30.833 align:left position:30% line:89% size:60% Donora prompted 00:30.833 --> 00:32.300 align:left position:17.5% line:89% size:72.5% scientific investigation 00:32.300 --> 00:34.833 align:left position:22.5% line:83% size:67.5% to try to figure out what was going on. 00:34.833 --> 00:38.966 align:left position:10% line:83% size:80% And the major breakthrough came from a surprising place. 00:42.433 --> 00:45.933 align:left position:25% line:83% size:65% In the 1950s, the Dole Fruit Company 00:46.366 --> 00:49.333 align:left position:30% line:83% size:60% was the world's largest producer of pineapples, 00:49.333 --> 00:54.266 align:left position:17.5% line:83% size:72.5% and it had an interest in using a new chemical technique 00:54.266 --> 00:57.966 align:left position:22.5% line:83% size:67.5% to better understand its big moneymaking product. 00:58.333 --> 01:00.166 align:left position:10% line:89% size:80% Could you replicate the flavors? 01:00.166 --> 01:03.366 align:left position:30% line:83% size:60% Could you make artificial flavors? 01:03.366 --> 01:06.833 align:left position:10% line:83% size:80% One of the most promising plant chemists at the time was 01:06.833 --> 01:10.933 align:left position:22.5% line:83% size:67.5% Dr. Ari Haagen Smit at Caltech in Pasadena. 01:12.566 --> 01:15.566 align:left position:12.5% line:83% size:77.5% And he's funded by pineapple growers. 01:16.166 --> 01:19.433 align:left position:15% line:83% size:75% His specialty was isolating plant proteins, 01:19.666 --> 01:24.066 align:left position:20% line:83% size:70% basically to figure out all of the chemical explanations 01:24.066 --> 01:26.666 align:left position:25% line:83% size:65% for why pineapples smell like pineapples. 01:29.066 --> 01:30.566 align:left position:27.5% line:89% size:62.5% It turns out that 01:30.566 --> 01:33.266 align:left position:35% line:83% size:55% agriculture is really affected by smog. 01:33.266 --> 01:36.266 align:left position:22.5% line:83% size:67.5% And one of the things that gets him into studying 01:36.566 --> 01:40.233 align:left position:10% line:83% size:80% what is happening to air quality in Southern California 01:40.233 --> 01:41.733 align:left position:17.5% line:89% size:72.5% is that crops are dying, 01:41.733 --> 01:44.933 align:left position:20% line:83% size:70% and they are desperate to figure out why. 01:45.366 --> 01:50.333 align:left position:22.5% line:83% size:67.5% What Haagen Smit did was to take actual air 01:50.333 --> 01:54.933 align:left position:15% line:83% size:75% and deconstruct it, to show what was making up the substance 01:54.933 --> 01:58.400 align:left position:27.5% line:83% size:62.5% that was damaging leaves and plants. 01:58.766 --> 01:59.966 align:left position:22.5% line:89% size:67.5% His initial approach 01:59.966 --> 02:04.066 align:left position:15% line:83% size:75% to figuring out what was in the air was to use exactly 02:04.066 --> 02:07.166 align:left position:25% line:83% size:65% the same processes that he'd used for pineapples. 02:07.433 --> 02:11.733 align:left position:10% line:83% size:80% He drew in about 500 cubic feet of air, about the amount 02:11.733 --> 02:14.466 align:left position:22.5% line:83% size:67.5% that a typical person would breathe in a day. 02:14.466 --> 02:17.066 align:left position:22.5% line:83% size:67.5% And when all of that got distilled down 02:17.066 --> 02:21.466 align:left position:22.5% line:83% size:67.5% into just a few drops of really terrible 02:21.466 --> 02:25.366 align:left position:20% line:83% size:70% smelling brown liquid: distilled smog. 02:28.400 --> 02:29.166 align:left position:35% line:89% size:55% Haagen Smit 02:29.366 --> 02:33.633 align:left position:22.5% line:83% size:67.5% was able to study it at a molecular level. 02:33.633 --> 02:36.900 align:left position:17.5% line:83% size:72.5% And one of the important findings was that 02:36.900 --> 02:41.333 align:left position:10% line:83% size:80% this was not a sulfur problem, which was what had happened 02:41.333 --> 02:44.600 align:left position:17.5% line:83% size:72.5% in Donora, Pennsylvania, in other industrial cities. 02:44.966 --> 02:47.966 align:left position:37.5% line:83% size:52.5% Actually, what he was finding was 02:48.333 --> 02:51.333 align:left position:10% line:89% size:80% large concentrations of ozone. 02:51.833 --> 02:54.633 align:left position:12.5% line:89% size:77.5% But it was a bit of a mystery 02:54.633 --> 02:58.500 align:left position:12.5% line:83% size:77.5% because there were no sources of ozone in Los Angeles. 02:58.500 --> 03:02.400 align:left position:15% line:83% size:75% This is not something that industrial factories just emit. 03:03.733 --> 03:06.800 align:left position:10% line:89% size:80% So something else is going on. 03:06.800 --> 03:09.400 align:left position:30% line:83% size:60% The other thing Doctor Haagen Smit discovers 03:09.400 --> 03:13.266 align:left position:15% line:83% size:75% when he analyzes the air is that there's a component in it 03:13.266 --> 03:15.900 align:left position:15% line:89% size:75% that comes from petroleum 03:15.900 --> 03:18.566 align:left position:32.5% line:89% size:57.5% hydrocarbons. 03:18.566 --> 03:20.933 align:left position:10% line:89% size:80% Hydrocarbons are actually a part 03:20.933 --> 03:24.100 align:left position:12.5% line:89% size:77.5% of fossil fuelsof gasoline. 03:24.100 --> 03:26.866 align:left position:17.5% line:83% size:72.5% When gasoline evaporates, it releases hydrocarbons 03:26.866 --> 03:30.200 align:left position:27.5% line:83% size:62.5% into the air that combine with other chemicals. 03:31.366 --> 03:33.433 align:left position:15% line:89% size:75% But he discovers that smog 03:33.433 --> 03:35.733 align:left position:20% line:83% size:70% is actually not just about the chemicals 03:35.933 --> 03:38.000 align:left position:17.5% line:89% size:72.5% it's also about the sun. 03:38.000 --> 03:41.166 align:left position:22.5% line:83% size:67.5% It's the interaction of the hydrocarbons 03:41.466 --> 03:46.933 align:left position:10% line:83% size:80% with a mix of chemicals in the air being exposed to the sun 03:46.933 --> 03:49.033 align:left position:25% line:89% size:65% that creates ozone. 03:49.033 --> 03:52.233 align:left position:20% line:83% size:70% And of course, Southern California has sun in abundance. 03:54.233 --> 03:57.766 align:left position:12.5% line:83% size:77.5% So the first thing he decided to do was to try to recreate 03:58.033 --> 03:59.933 align:left position:20% line:89% size:70% smog in the laboratory. 04:00.900 --> 04:03.700 align:left position:10% line:83% size:80% [Interviewer] “This device here recreate smog 04:03.700 --> 04:05.300 align:left position:27.5% line:83% size:62.5% as we breathe it in Los Angeles.” 04:05.766 --> 04:06.866 align:left position:12.5% line:89% size:77.5% [Haagen Smit]: “That's right. 04:06.866 --> 04:10.300 align:left position:10% line:83% size:80% There is an abundance of ozone formed here in the air. 04:10.300 --> 04:13.266 align:left position:10% line:83% size:80% And it reacts with, gasoline.” 04:13.266 --> 04:16.266 align:left position:10% line:83% size:80% [Interviewer]: “And this, this then that you're making will be 04:16.266 --> 04:18.166 align:left position:15% line:83% size:75% what we're breathing today here in Pasadena. 04:18.166 --> 04:20.866 align:left position:10% line:83% size:80% [Haagen Smit: “That is a pretty duplication of it. 04:20.866 --> 04:25.000 align:left position:10% line:83% size:80% The hydrocarbons in the air form ozone in the sunlight. 04:25.800 --> 04:28.233 align:left position:10% line:83% size:80% And that is the beginning of our trouble. 04:28.233 --> 04:33.633 align:left position:15% line:83% size:75% Then we take some gasoline and the vapors of the gasoline. 04:33.633 --> 04:36.433 align:left position:20% line:83% size:70% You will see react now as the ozone. 04:36.433 --> 04:38.066 align:left position:10% line:89% size:80% And we get concentrated smog.” 04:38.066 --> 04:40.800 align:left position:25% line:83% size:65% His great discovery is that the combination 04:40.800 --> 04:44.333 align:left position:10% line:83% size:80% of the ozone, the hydrocarbons, and their exposure 04:44.333 --> 04:47.666 align:left position:25% line:83% size:65% to sunshine creates ozone pollution. 04:48.333 --> 04:51.333 align:left position:25% line:83% size:65% Doctor Haagen Smit calls this photochemical smog. 04:52.666 --> 04:53.933 align:left position:22.5% line:89% size:67.5% To learn more, watch 04:53.933 --> 04:56.133 align:left position:25% line:77% size:65% Clearing the Air: The War on Smog 04:56.133 --> 04:57.733 align:left position:17.5% line:83% size:72.5% from American Experience.