Deadly Airborne Particulates: We Must Stop Burning Things

Those of us old enough to remember the smog and haze of the 1950s-1970s tend to believe that because the air looks so much cleaner, air pollution is much less a problem today.  As scientists have learned more about how our bodies respond to pollutants, they are concluding that air quality cannot be ensured by current regulations and more severe constraints must be imposed if significant numbers of fatal health problems are to be avoided.  Jonathan Mingle addressed the current state of knowledge in the New York Review of Books in an article titled Our Lethal Air.  Mingle reviewed three recent books on the subject as well as some of the machinations occurring in our federal establishment.

In 1970, the Environmental Protection Agency (EPA) was formed and the Clean Air Act was passed.  Gradually, scientists and regulators imposed constraints on the emission of pollutants and the skies became bluer and the air fresher.  Mingle provides this perspective.

“Gradually, overall levels of particulate matter, ozone, and other pollutants in the air began to decline. By the 1990s, many people in the US and other wealthy countries thought that sun-blotting soot and smog were hazards safely surmounted in the onward march of progress, concerns of a past era like polio or cholera.”

“It turns out the threat had simply become less visible. Nearly half a century after the Clean Air Act instituted the world’s most stringent emissions controls, the problem of air pollution is far from being solved in the US or anywhere else. Pollution has proved much more persistent, and exposure to it much more damaging, than anyone expected. Today, 91 percent of people worldwide live in areas where air pollution levels exceed the World Health Organization’s recommended limits.”

One of the landmark studies that clarified the issues was referred to as the Six Cities Study.  It was led by the Harvard epidemiologist Douglas Dockery.

“Starting in 1974, researchers followed over eight thousand people randomly selected from three more polluted and three less polluted US cities. They gathered information on height, weight, and health conditions via questionnaires and periodic interviews and tracked deaths over the years. When they analyzed the mountain of data, applying statistical methods to control for other variables, they found that adult residents of the dirtiest cities (e.g., Steubenville, Ohio) were dying two to three years earlier on average than those in the cleanest (e.g., Portage, Wisconsin). Among all the pollutants they studied, the relationship with premature death was most clear and pronounced for particulate matter less than 2.5 microns in diameter (PM2.5), a category that encompasses soot (black carbon), dust, sulphates and nitrates, and a wide range of other substances suspended in the air.”

These mortality results were published in 1993; they indicated that people living in cities with pollutants that met air quality standards were still dying in large numbers.  Tighter limits on PM2.5 concentrations were put in place in 1997 but the problem has not disappeared.  These small particulates are so dangerous because at the 2.5 micron (micrometer) size or less they can penetrate the body’s defenses and lodge in the lungs.  The smaller they are the easier it is to penetrate the lung itself and be transported to other organs where they can do damage.  And these small particles are being produced everywhere, both inside and outside our homes.  The exterior sources are well known; less familiar are the levels that can be reached in a home while cooking, particularly with gas.  The rule that anything that burns produces particulates holds in the kitchen as well as on the highway.  It is interesting to note that tobacco smoking produces particles below 2.5 microns in size, which may explain why smoking can produce so many different ways to die.

“Most of these fine particles are a byproduct of our civilizational dependence on burning stuff: coal, gasoline, diesel, wood, trash, you name it. These particles can get past the defenses of our upper airways to penetrate deep into our lungs and reach the alveoli, the tiny air-filled sacs where oxygen is exchanged for carbon dioxide. From there, they cross into the bloodstream and spread throughout the body. They can travel through the nose, up the olfactory nerve, and lodge themselves in the brain. They can form deposits on the lining of arteries, constricting blood vessels and raising the likelihood of blockages that lead to strokes and heart attacks. For decades, scientists have understood that they exacerbate respiratory illnesses like asthma and chronic obstructive pulmonary disease, but—as with tobacco smoking—the biological mechanisms have been elusive. It is now thought that much of the havoc PM2.5 wreaks is through systemic inflammation, caused by an overreaction by the immune system.”

“Scientists keep learning that there is no part of the body that these particles cannot reach, and no phase of life, from gestation to advanced age, they do not touch. Last year, researchers found inhaled soot particles in the placentas of five women who gave birth in London hospitals.”

“These studies have also yielded another bedrock finding: there is no safe level of exposure to fine particulate matter. Any amount of these tiny particles can harm you.”

Mingle states that we are in the throes of a “global health emergency” due to air pollution.

“Air pollution cuts short the lives of far more people in the US each year—estimates range from 107,500 to over 200,000—than do traffic accidents. Together, indoor and outdoor air pollution caused one in every nine deaths globally in 2016—far more than the number felled by malnutrition, alcohol use, or malaria.”

Whether or not one believes that the term “crisis” is appropriate in the US, clearly, up to 200,000 annual preventable deaths is something the EPA should be addressing.  Rather, the Trump administration seems determined to attack the science of air pollution in the same way it attacks the science of climate change.  Mingle devotes much of his article to this assault on our safety.

“…polluting industries simply do not accept any limit on how much waste they can pour into the air without a vicious fight. In 1952, the same year of London’s killer smog, the chemist Arie Haagen-Smit published his research solving the mystery of another infamous species of smog: the yellow-brown haze that regularly blanketed Los Angeles. The culprit was ozone, produced by hydrocarbons from cars and the region’s refineries reacting in the California sun. He was immediately attacked and ridiculed by the oil and automobile industries, and by scientists they funded. Haagen-Smit prevailed, but that battle created the playbook by which influential industry lobbies have sought to forestall pollution limits, and discredit the peer-reviewed science underpinning them, over the past half-century. When the EPA relaxed ozone standards in 1979 in response to relentless industry pressure, the American Petroleum Institute (API) thanked it by suing to overturn the entire standard, saying it was “far more stringent than medical evidence shows is necessary to protect public health.” After President Obama’s EPA proposed a modest tightening of the ozone standard in 2014, the API, along with other industry groups, sued again. Just last month, the D.C. Circuit issued its ruling, rejecting the API’s arguments. This pattern plays out over and over in these pollution tales.”

EPA regulations limiting pollution levels have saved many lives over the years, and studies have shown that the economy as a whole benefits as new techniques and new technologies are developed to combat pollution.  This entire process is now at risk because Trump has allowed lobbyists and industry insiders to gain control of it.

“Republicans in Congress have repeatedly introduced bills to limit the EPA’s use of studies that rely on subjects’ confidential medical and health data, in the name of ‘transparency.’ These ‘secret science’ bills had never gone anywhere until the disgraced former EPA administrator Scott Pruitt took the plan and refashioned it into a proposed new agency rule…intended to put many of the most important findings on air pollution’s effects out of bounds.”

In spite of the harm Trump’s takeover of the EPA will do, we really must stop burning things.  Cigarettes should be banned, and everything else should be electrified.  Any combustion should take place only in an environment where the particulates can be captured.