Some scholars compare the dismantling of air-pollution evidence to tobacco companies’ efforts to obscure the association between cigarette smoking and cancer.

According to a cache of internal records obtained by the Guardian, the energy industry realized at least 50 years earlier that environmental emissions from burning fossil fuels faced significant health hazards, but still spent decades actively campaigning against clean air rules.

The records, which contain internal memos and surveys, reveal that the industry was long conscious that it was causing massive levels of air emissions. Toxins could lodge deep in the lungs and be “true villains of health consequences,” and that its own employees’ children could be suffering from birth defects.

However, these issues did nothing to prevent oil and gas corporations and their proxies from promoting myths regarding the increasing body of evidence connecting the usage of fossil fuels to a range of health conditions that destroy millions of people worldwide each year. Oil and gas interests launched a barrage of content aimed at increasing doubt about the damage caused by air emissions and using this to prevent US policymakers from imposing further controls on contaminants, echoing the fossil-fuel industry’s history undermining climate science.

“The answer from fossil-fuel interests has followed the same script – first they know, then they plan, then they refute, and then they delay,” said Geoffrey Supran, a Harvard University researcher. He has researched the past of fossil-fuel corporations and climate change. “They’ve resorted to a postponement, covert means of propaganda, and regulatory undermining.”

The consequences of vast quantities of pollution, gasoline, and gas from mills, vehicles, and other sources have long been apparent, with major cities in the United States and Europe often coated in smog before implementing new clean-air regulations.

However, a mass of published papers from industrial repositories at libraries in the United States and Canada, research articles, and records issued in court proceedings indicate that the oil companies started to recognize the harm created by the combustion of fossil fuels in the 1960s.

In internal memos and analyses, Imperial Oil, an Exxon company, admitted in 1967 that the petroleum industry is a “significant contributor to many of the main sources of emissions” and performed polling of “mothers who were anxious about potential smog impacts.”

Shell went much further in a 1968 internal technical paper, advising that air pollution “may, in serious cases, be deleterious to health” and admitting that the oil industry “reluctantly” would agree that cars “are by far the greatest sources of air pollution.” According to the study, sulfur dioxide produced through gasoline combustion will trigger “difficulty in breathing.” In contrast, nitrogen dioxide, which is often emitted by cars and power plants, can cause lung harm and therefore, “there would be a clamor to limit [nitrogen dioxide] pollution, most definitely focused on alleged long-term chronic effects.”

Small particles emitted by fossil fuels, on the other hand, are the “true heroes of health effects,” according to the Shell study since they can transport chemicals, like carcinogens, “deep into the lungs that would normally be absorbed in the throat.”

Particulate matter is the tiny specks of soot and liquid expelled as fuels are burnt and inhaled by humans. Esso, a forerunner of Exxon, sampled particles in New York City in 1971 and discovered, for the first time, that the environment was rife with tiny bits of aluminum, magnesium, and other metals. Esso scientists noticed that gases from industrial smokestacks were “hot, filthy, and involve high concentrations of pollutants” and that additional monitoring was needed for symptoms such as “eye discomfort, persistent coughing, or bronchial effects.”

Imperial Oil had proposed proposals by 1980 to study cancer incidences and “birth defects in industry worker offspring.” Meanwhile, Esso experts raised the “possibility of enhanced particulate control” in modern car designs to minimize toxic pollution emissions.

“We have been increasingly mindful of the possible effects our activities can have on protection and health,” reported an internal Exxon study ten years later. Around this stage, independent academic scientists were amassing their own knowledge of the effects of air emissions.

“The fossil-fuel sector was sowing chaos to retain business as normal, and they were more likely partnering with other parties, such as the cigarette industry,” said Carroll Muffett, CEO of the Center for International Environmental Law.

“When these past records are interpreted in-depth, it is evident that the oil and gas sector has a playbook that they have employed regularly with a number of contaminants. They used that in relation to climate change, but we definitely see that in relation to PM2.5. It follows the same pattern.”

The EPA did implement the first PM2.5 quality regulations in 1997, and scientists have subsequently discovered more about air pollution’s attack on the human body. Particles in the bloodstream can induce harmful inflammation, weaken the immune system, damage women’s fertility, raise the likelihood of stroke, heart disease, Alzheimer’s, and pneumonia, and even injure people’s eyesight.

A team of US and UK researchers estimated last month that particulate contamination triggers approximately one-fifth of all deaths worldwide per year, a shocking death toll greater than that induced by HIV/Aids, malaria, and tuberculosis combined. In the United States, almost 350,000 of these fatalities occur per year. Although aggregate air quality rates in the United States have changed in recent decades, pockets of stubborn pollution persist, primarily clustered in disadvantaged neighborhoods, among people of color, and in the Rust Belt.

“There is now quite clear and strong proof over several countries of the connection between fine particulate matter and health harm,” said Francesca Dominici, a biostatistics professor at Harvard. “There is still a lot of proof that more people are dying in the United States with exposures that are much lower than the current limits. This emission is extremely dangerous, and tougher regulations are required.”

Undaunted, oil and gas lobbyists have worked to stymie stricter air quality controls, thus mobilizing an attempt to cast doubt on this science. A gathering on clean-air regulations called by the Heartland Institute, a conservative think tank, in 2006 helped set the trend – two speakers were from Exxon, and one session was titled “Uncertainty of NAAQS (National Ambient Air Quality Standards) Health Science.”

Industry-funded consultants conducted reports that disputed the association between pollution and poor health or clearly disparaged the findings of other researchers. “Their aim is to discredit the empirical process and research itself,” Thurston clarified.

Even as the major oil corporations openly acknowledged the reality of climate change and pledged to fix it, they have continued to deny mounting evidence of direct air pollution damage. Exxon also told the EPA that calculating the likelihood of death from particulate matter is “unreliable and misleading.” In 2017, API requested that the regulator loosen regulations for nitrogen dioxide – a pollutant related to asthma in children and higher mortality from heart failure and cancer in adults – arguing that there was no established correlation with harm and that current guidelines were “more strict than necessary.”

The industry’s strategy paid off during Donald Trump’s presidency, as top executives from Exxon, Chevron, Occidental Petroleum, and API met with the then-US president in the White House. A slew of clean air rules, such as those restricting emissions from vehicles and vans, were cut down. Simultaneously, a so-called “transparency” law for scientists threatened to invalidate experiments focused on classified medical evidence, which is crucial for bedrock air pollution analysis.

Tony Cox, a researcher who obtained funds from API and enabled the lobby group to edit his reports, was appointed chairman of a significant EPA clean air advisory board under Trump. Cox, whose prior research called into doubt the dangers of particulates, accused EPA scientists of poor science and subjectivity after discovering that contaminants can be lethal even at low concentrations.

Last year, in the wake of a historic respiratory illness pandemic, Trump’s EPA chose not to tighten regulations for fine soot particles. According to a Harvard report, air quality is related to worse results for people with Covid-19. API said that the Harvard paper had included “preliminary results,” which had resulted in “scare stories and inaccurate media coverage.”

According to Dominici, one of the paper’s reporters, the assaults on the Harvard thesis were “tough and very frustrating.” “If you breathe ozone for a long time and get Covid, you would have worse effects; this is rather unsurprising,” said the study, who has since confirmed that more than 60 studies from around the world link air pollution to bad Covid outcomes.

API spokeswoman Bethany Aronhalt said in a quote, “Our industry’s main concern is advancing public health and safety while providing accessible, efficient, and cleaner electricity.”

“Largely as a result of increased usage of natural gas in the electricity sector and renewable motor fuels, the United States has witnessed substantial environmental gains over the years, including better air quality, with average PM2.5 emissions falling 43 percent since 2000.”

                     Oil firms knew decades ago fossil fuels posed grave health risks files