When the smog plaguing Los Angeles reached distressing levels in the early 1950s, the city hired Arie Haagen-Smit to study the cause. Not only was Haagen-Smit a scientist specializing in airborne microscopic chemicals, he was also angry about the state of the city's air. His work swiftly determined that the culprit was oil.

Following a hunch, Haagen-Smit built an unorthodox laboratory that accurately demonstrated how nitrogen oxide and uncombusted hydrocarbons from tailpipes and refineries react in sunlight to produce smog. His findings unnerved oil companies, which feared onerous regulation would follow. So when another scientist, Harold Johnston, challenged Haagen-Smit's findings, the industry's main consulting group hired him.

"They said terrible things about Haagen-Smit...I was given the job of overthrowing his theory entirely," Johnston recalled in an oral history years later. "I rapidly concluded that Haagen-Smit was a genius!"

That wasn't what the oil industry wanted to hear. It shelved Johnston's work and let his contract lapse. Then it conducted its own research to discredit Haagen-Smit's conclusions and manufacture doubt around the link between oil and smog.

But that link soon became irrefutable and smog became a pressing concern for regulators—first for California officials in the 1950s and 60s, then for the federal government. As Washington began to pass modern clean air laws in the 1970s, oil companies lobbied against regulation. They argued that federal standards would be so expensive they would harm the economy.

Industry's response to smog and its fight against clean air standards unfolds like a rough draft of the muscular strategy it deployed 40 years later to deny climate science and the need for an urgent policy response, as documented in ICN's series "Exxon: The Road Not Taken."

"How the oil industry handled smog is a template for how it handled a bunch of issues, the most significant being climate change. There's a DNA here that's palpable," said Carroll Muffett, an attorney who is the president of the watchdog group, Center for International Environmental Law (CIEL). "Through it all, you see the creation of an echo chamber of doubt that takes the small unknowns and uncertainties and magnifies it until all we have is unknowns, when in fact the actual science isn't that way at all."

The American Petroleum Institute, the oil industry's chief lobby, did not respond to questions about its work on smog.

Smog blankets L.A. on Jan. 5, 1948. Credit: UCLA Library

The story of how the oil industry has battled smog regulation is based on hundreds of industry speeches, articles, reports and oral histories that span the last 70 years. Many were gathered by CIEL and dozens were unearthed by InsideClimate News in the Library of Congress and other archives.

"Why have we generally failed in our efforts to control air pollution?" asked Louis McCabe, the first Los Angeles smog regulator at a conference in 1949. "We have failed because industry believed that air pollution control cost too much. Smoke and dusts were the wages of a prosperous industrial community...There were 'cooperative' programs with the dual objectives of delay and defeat."

API continues to fight attempts to tighten the standard for ground-level ozone, or smog, with considerable success. The Obama administration delayed adoption of a tighter smog standard in 2011 under pressure from API and other business groups. The EPA recently proposed a stronger ozone rule, which the API is battling through ad campaigns, its Congressional allies and in the courts.

Regulations Begin to Pit Public Health vs. the Oil Industry

The federal Clean Air Act has proven a powerful and cost-effective policy tool since it came into force in 1970, providing trillions of dollars in health and economic benefits that far exceed the cost of the regulations. One recent Environmental Protection Agency study calculated that the benefits of the 1990 amendments to the law would amount to $2 trillion a year by 2020.

Smog can irritate respiratory tracts, exacerbate asthma and over time, damage lungs and boost the chances of early death. Despite progress, it continues to be a major problem. About 44 percent of the country, nearly 138 million people, live in areas where smog levels are dangerous to human health for at least part of the year.

Annually, about 200,000 people in the United States die prematurely because of air pollution, including smog, according to a 2013 study by the Massachusetts Institute of Technology.

Los Angeles' smog began to rise to alarming levels in the early 1940s and swiftly became an economic and public health threat. On December 11, 1946, the Los Angeles Times ran a front-page article identifying a local refinery as the source. That afternoon, oil executives organized a group to determine the causes of smog, the responsibility the oil industry bore for it and what it needed to do to curtail the pollution. It became known as the Smoke and Fumes committee.

In 1947, California became the first state to grant counties the authority to regulate smog, and Los Angeles set up its Air Pollution Control District. Desperate for a solution, city authorities skipped time-consuming research and brought in experts from cities such as Pittsburgh and St. Louis. In their haste, the officials erroneously blamed sulfur dioxide, another common pollutant. Oil refineries were big emitters, and under regulatory pressure, they spent millions of dollars to reduce sulfur dioxide.

Smog in L.A. on Dec. 24, 1948. Credit: USC Libraries Special Collections

But the smog persisted because sulfur dioxide was only a minor contributor to the problem. This mistake stoked the oil industry's mistrust of regulators and their experts.

Local academics eventually prevailed upon Los Angeles officials to research smog. The city hired Haagen-Smit, a rising star in plant biochemistry at the California Institute of Technology. Haagen-Smit was bothered physically by the acrid air and intellectually by the city's haphazard approach in dealing with it, according to Smogtown, a book by Chip Jacobs and William Kelly.

Haagen-Smit's initial chemical analysis of smog homed in on aerosolized compounds of hydrocarbons that irritated the eyes.

"The volatile material released into the air consists of hydrocarbons, saturated and unsaturated, originating from products derived from the petroleum industry," Haagen-Smit wrote in 1950. "This includes all the material lost at the oil fields, refineries, filling stations, automobiles, etc."

His findings drew swift criticism from the oil industry and automakers. In an air pollution lecture at Caltech, a scientist from the Stanford Research Institute, the industry's main smog consultant, publicly disparaged the work of Haagen-Smit.

The consultant said, "Haagy's research was not consistent with the SRI's findings, and expressed regret that a respected scientist such as Dr. Haagen-Smit could make such a serious mistake," recalled Arnold Beckman, a Caltech chemist who was in the audience with Haagen-Smit. "Well, I could almost feel Haagy's blood pressure rise. He was furious," Beckman recounted. "The validity of his work was being questioned! 'I'll show them who's right and who's wrong,' he muttered as we left the room.

"That was the turning point in his career," Beckman said in a Caltech oral history. "He decided to take a leave of absence to do more work on air pollution, to squelch his critics and to prove beyond doubt the authenticity" of his findings.

Amid Gloomy Skies, the Industry Organizes

To research smog, the Smoke and Fumes committee had hired the Stanford Research Institute, established in 1946 by Stanford University, to manage the experiments. (SRI split from Stanford in 1970.)

"The prime responsibility of Stanford Research Institute is to serve Industry," said the first sentence of a booklet about SRI published in 1952.

Several oil executives served on its board of directors, including W.L. Stewart, Jr., senior vice president of Union Oil Co. and an early chairman of the Smoke and Fumes committee.

Stewart's inclination was to lead earnest research on smog. "We would win the gratitude of the community and, at the same time, warn ourselves in advance if there was something in our operations which contributed to smog so that we could correct it before the authorities and the newspapers were at our throats again," he said in a speech at the 1951 API convention.

Members of the Highland Park Optimist Club in L.A. are seen here wearing smog-gas masks at a banquet, circa 1954. Credit: Los Angeles Times photographic archive, UCLA Library

In closing, he underscored the moral need for industry to act: "I am not kidding myself or you. It will be expensive, and I am thinking in terms of lots of money—millions of dollars for the oil industry...To me, it is also smart to be leaders, to be good neighbors, to play fair, to practice the golden rule; but, above all, to be the sort of Americans we should like America to be made of."

Stewart's appeal would be echoed 35 years later by Exxon scientists Jim Black, Henry Shaw and Harold Weinberg as they called upon their company to research carbon dioxide from oil consumption and to prepare itself for a possible transition to other fuels. "What would be more appropriate than for the world's leading energy company and leading oil company [to] take the lead in trying to define whether a long-term CO2 problem really exists, and if so, what counter measures would be appropriate," Weinberg, a manager at Exxon Research & Engineering wrote in a memo to a colleague in March 1978.

"This may be the kind of opportunity that we are looking for to have Exxon technology, management and leadership resources put into the context of a project aimed at benefitting mankind."

But just as Exxon later pivoted from that impulse and worked to sow doubt about climate science, decades earlier oil companies faced a similar choice on smog and rejected taking responsibility.

In 1952, the American Petroleum Institute took over the Smoke and Fumes committee from the West coast companies. It funded research into smog, by groups such as the Franklin Institute in Pennsylvania, the Armour Research Foundation in Illinois and the Kettering Lab at the University of Cincinnati. Around that time, less than a year after Stewart's recommendation, API's stance on smog became more defensive as the science grew more definitive, showing refineries and auto exhaust were likely to blame for smog.

SRI scientists and the Smoke and Fumes committee's new executive secretary, Vance Jenkins, pushed back against Haagen-Smit's findings.

In a paper "Smog: Fact and Fiction," SRI scientists maintained that many substances were responsible for smog, not just hydrocarbons. In another paper, "The Policeman is Coming!" Jenkins wrote, "This new idea is still merely a theory—a plausible but entirely unproved speculation or guess."

But Haagen-Smit's work was taking hold in the wider community. In August 1954, Los Angeles' top air pollution regulator, Gordon Larson, told the county's governing Board of Supervisors that auto exhaust was behind smog, according to the Los Angeles Times. Larson based his statement, the first targeting an exact cause, on Haagen-Smit's work.

In 1955, the industry-backed Air Pollution Foundation asked an Illinois research chemist named Arnold Miller to come to California to resolve the issue.

Miller spent time with Haagen-Smit in his lab. He also went to SRI's lab in Pasadena, which had been unable to replicate Haagen-Smit's results despite their state-of-the-art facilities. The enmity between the two camps was palpable, and they did not exchange information, despite being five miles apart. Miller recalled in 2009 that he saw the "overt disdain" SRI felt toward the Caltech smog scientist.

When he closely copied Haagen-Smit's methodology, Miller achieved the same results and independently validated his work.

Arnold Miller in 1957 conducting a high temperature arc-air systems study. Courtesy of Arnold Miller

Nevertheless, industry continued to pursue alternative theories. One industry-funded study in 1955 examined 10 other American cities and found that they did not have the same eye-watering levels of ozone. The implication was that smog was a particular problem for L.A., and did not need to be addressed with urgency elsewhere.

A 1957 study at the University of California at Riverside investigated damage caused on smoggy days to the leaves of plants. It found that one form of damage was caused merely by ultraviolet light, whether or not smog-forming chemicals were introduced. This would suggest that the sun, not chemical pollution, was to blame.

"The worst thing that can happen, in many instances, is the hasty passage of a law or laws for the control of a given air pollution situation," Jenkins wrote in a 1954 paper. "For many such cases their passage results from a panicky feeling that 'there ought to be a law' and laws drawn for such reasons are likely to be poorly drawn and based on either insufficient or erroneous data."

A New Approach to Defensiveness

Eventually, Haagen-Smit's theory prevailed. The Franklin Institute, which conducted research for the Smoke and Fumes committee, built a 30-foot long spectrometer in 1956 called "Silent Sam" that confirmed his results. With the science now more certain, the oil industry shifted its public posture. It no longer denied hydrocarbons were the main ingredient in smog. Instead, industry executives blamed the auto industry.

At an air pollution conference in Los Angeles in 1955, Philip S. Magruder, chairman of the Western Oil and Gas Association's Air Pollution Control Committee acknowledged that smog "involves our product." However, he then said that daily hydrocarbon emissions from refineries and other industry sources amounted to 120 tons, while the 2.5 million vehicles in Los Angeles County accounted for more than 10 times that amount.

He suggested that once fuel left the oil refineries, the industry was not responsible for emissions from vehicles. The industry could refine gasoline to emit less, but that gas wouldn't work in current car engines, he said.

"We study the requirements of the automotive engines that the automotive industry designs and builds," Magruder said. "Then we make the fuel to meet those needs as best we can."

Smoggy L.A. day in 1955. Credit: Los Angeles Public Library Photo Collection

"If anyone ever tells you he can lick all of the smog problems by changing gasoline, be sure to ask him if the gasoline mixture he's proposing will also perform that other vital function, namely making your modern car run the way you want it to."

By the 1960s, the industry was in the crosshairs of regulators. Federal rules addressing pollution had become stricter since the Air Pollution Control Act of 1955 allocated funding for research. The Clean Air Act of 1963 and the Air Quality Act of 1967 set nationwide emissions standards.

The industry worked harder to sway public opinion.

Mobil Oil began a campaign that warned smog controls would be costly. "Just wishing for it won't make the air cleaner," according to a booklet published by the Mobil Oil Corp., which merged with Exxon in 1999 to form ExxonMobil. "It will cost a lot of money. And sooner or later the cost will fall on the people. All the people."

API promoted the same concept in a 16-page booklet in 1967 titled "Clearing the Air: A Layman's Guide to Atmospheric Purity." It read: "It is obvious that the control of pollution has cost a great deal of money and is going to cost even more in the future."

Fighting Regulation to the Present Day

Throughout the 1960s, the oil industry offered voluntary steps as an alternative to federal rules, which they said would cripple the economy.

The federal Department of Health, Education and Welfare proposed new air quality guidelines for sulfur oxide in 1967. Spokesmen for the coal and oil industries denounced them. They said the guidelines were "'economically unrealistic, scientifically indefensible and technologically impossible,'" wrote Jeanne Logsdon, professor emerita of management at University of New Mexico, in a 1985 paper.

"Industry was largely successful in weakening the stronger proposals in 1967," she added.

Threats of litigation from API and other business groups convinced the Carter administration in 1979 to relax the ozone standard from 80 parts per billion to 120 parts per billion, a 50 percent increase. That was not enough for API, which filed a lawsuit to overturn the standard completely, according to The Washington Post.

Another major tightening of the rules for smog came during the Clinton administration, again over vigorous opposition from industry.

When President Obama took office, his administration vowed to heed the EPA's science advisers, who said a standard between 60 and 70 parts per billion would best protect public health.

Jack Gerard, CEO & president of the American Petroleum Institute. Credit: energy.gov

But Obama surprised the EPA by delaying the more stringent limit in September 2011. A few weeks earlier, API president Jack Gerard, and other lobbyists had met with top White House officials and drove home the argument that the economies of several battleground states in the 2012 election might suffer because of the tougher standard, according to The New York Times.

In 2014, after years of inaction, the EPA proposed a new ozone standard of 70 parts per billion, the weakest limit recommended by its science advisers. API has filed suit to halt adoption of the new limit and API's allies in Congress have proposed legislation to overturn it.

"New ozone rules could be the most expensive ever," according to the API website. "Tightening ozone standards could increase costs to the American public, reduce America's ability to compete internationally, and threaten American jobs."

API's position on the ozone rule differs little from its assessment of EPA's Clean Power Plan, instituted in 2015 to address the carbon pollution that causes global warming.

"Meeting climate challenges must go hand-in-hand with ensuring that Americans have the affordable and reliable energy necessary to grow our economy and create jobs. Instead, the EPA rule could impose the greatest costs on those who can least afford it," said Howard J. Feldman, API senior director of regulatory affairs, on the lobby's website.

He added: "We can continue that progress without costly new regulations that could hurt consumers and stifle economic growth."

ICN's managing editor, John H. Cushman, Jr., contributed to this report.