Ninety-four years ago, Calvin Coolidge, Jr., while playing tennis on the White House grounds, got a blister on his toe. One week later, the 16-year-old son of the president of the U.S. lay dead. Bacteria infected the blister and killed young Coolidge.

Four years later, Alexander Fleming invented penicillin, an antibiotic that would have saved the boy’s life.

We now largely take antibiotics for granted. Yet this invention — along with the commercial, financial, and transportation infrastructures that make antibiotics widely available — has saved lives too many to count. Antibiotics cleanse our bodies of one of history’s most noxious and commonplace pollutants: excess bacteria.

In 2018, we don’t think of bacteria as pollutants. But that’s what they are — or were. Bacteria are matter that historically pervaded food, water, and air. And they infiltrated our bodies with remarkable regularity, often with fatal consequences. On this Earth Day, let’s celebrate our victory over this pollutant.

Let’s also recognize that antibiotics are only one of many products of industrial society that abate bacterial pollution. Refrigeration reduces the bacteria in our food. Machine-woven textiles, powerful detergents, and automatic washing machines extract this foul menace from our clothing. And of course there’s no need to spell out the cleansing benefits of indoor plumbing.

That bacteria occur naturally is irrelevant. Once dangerously pervasive in our environment, capitalism has largely solved this pollution problem.

In fact, once you notice that bacterial pollution is abated by the products of free markets, you notice the many other ways in which our lives are cleaned by capitalism.

Consider the roof over your head. It seems mundane, but it’s really a marvel. Most of our ancestors lived beneath thatched roofs, which harbored mice, rats, birds, spiders, and insects. The bodily wastes and carcasses of these creatures rained down on the occupants below. And the floors beneath our ancestors' feet were just as filthy: These were dirt strewn with thresh. (Our word “threshold” is a throwback to pre-industrial times when families put pieces of wood at the entrances to their huts to hold the thresh in.)

In reality, hard roofs and solid floors for the masses were made possible only by industrial capitalism, which greatly reduced the costs of producing these marvels.

Yet capitalism is today incessantly accused of increasing pollution and threatening our environment. This accusation false.

It’s true that the likes of factories, trucks, and cargo ships emit pollutants. But it’s untrue that capitalism makes our environment more polluted. The reason is that industrial pollutants are by-products of production processes that supply us with antibiotics and countless other anti-pollutants.

Among our favorite anti-pollutants is the automobile. Unlike pre-industrial transportation vehicles, automobiles don’t strew spittle, urine, and feces on our streets and sidewalks. And when automobiles die, their carcasses don’t rot in public and attract vermin and flies that then spread filth into our homes, schools, and workplaces.

Environmentalists will protest our celebration of automobiles as devices that reduce pollution. This protest, though, springs from environmentalists’ failure to look at the full picture. Obviously, looking only at the downsides of industrial, global capitalism makes it appear to be a threat to humanity. But when the upsides are brought into view, modern capitalism is revealed to be not only a source of great material abundance, but a cleanser of the human environment.

Consider again the automobile. Of course producing each one creates industrial wastes. Of course the automobile’s operation emits greenhouse gasses — although, because of consumer demands, automobiles’ emissions have been greatly reduced.

Yet against these costs must be weighed the automobile’s great benefits, many of which contribute to the lengthening of our life expectancies. In addition to ridding our streets and sidewalks of toxic animal filth, the automobile enables us to get quickly to hospital emergency rooms when we’re seriously ill or injured. It also enables firefighters to get quickly to our homes — which, by the way, because they are constructed with fire-retardant industrial materials, are far less likely to burn than were homes in the past.

Indeed, our lives today are less polluted and less dangerous than at any time in history. We have capitalism to thank for this remarkable achievement.

And so on this Earth Day, when you’re bemoaning climate change and species extinction, pause to reflect how fortunate you are to have the luxury to bemoan such problems. However serious you believe these environmental issues to be, they are far less serious and hazardous to our health than were the multitudes of pollutants and perils that capitalism has abated.

Donald J. Boudreaux is a professor of economics and a senior fellow at the Mercatus Center at George Mason University. Veronique de Rugy is a senior research fellow at the Mercatus Center.