The History of Human Pollution

By Wayne Persky

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What, exactly, is the definition of pollution?

Pollution is defined as the introduction of substances, energy, or agents into the environment in quantities or forms that cause harm or discomfort to living organisms, degrade natural ecosystems, or disrupt natural processes.​

To put things into perspective, note that humans are not the only species that are polluting this planet. But interestingly, we give all other species a free pass. By definition, we consider pollution generated by other species as "natural, and part of normal ecological cycles". Presumably, because the impact of other species' "pollution" is relatively insignificant, compared with the levels of pollution attributed to humans. By contrast, we don't cut humans any slack. We consider any effects on the environment that can be attributed to humans, as unnatural.

This biased attitude is presumably further supported by the fact that we don't consider other species capable of even recognizing pollution, anyway, let alone capable of restricting it.

Despite this bias, there are many examples of pollution by other species.

1. Ruminants like cows, sheep, and wild ungulates release methane through digestion (enteric fermentation). But of course when these emissions are associated with domesticated animals, they're considered to be associated with human activities.
2. Termites also produce methane as they digest cellulose.
3. Animals, such as seabirds, or bats, deposit large amounts of guano (feces) in specific areas, enriching soil with nutrients like nitrogen and phosphorus. This can lead to localized "eutrophication" of nearby water bodies.
4. Beavers create dams that alter water flow and ecosystems, potentially causing local flooding or changes in water quality.
5. Certain animals and plants can become invasive when they spread to new ecosystems (for example, zebra mussels in North America), leading to habitat disruption and changes in biodiversity. But note that invasive species are usually transferred to new locations by human activity, rather than by natural forces.
6. ​Large herbivores, like elephants, can significantly alter forests by uprooting trees and creating clearings, impacting the ecosystem's structure.

In contrast to most human sources of pollution, the pollution events that can be attributed to other species do not involve the addition of synthetic materials or chemicals that persist for hundreds of years. The effects of their pollution typically degrade rather rapidly. Ecosystems tend to recover or adapt over time without long-term degradation.

Human pollution has developed in phases.

Human pollution is closely tied to the development of human societies, from early hunter gatherer lifestyles to the rise of agriculture, industrialization, and modern consumption patterns.

During early human evolution (2 million to 10,000 BCE),

Hunter gatherer societies had minimal impact on the environment. Small nomadic populations left behind localized waste such as bones and fire residues. Campfires released smoke and soot, marking the earliest form of air pollution, and stone tool production generated small amounts of localized debris.

As the old saying goes, one man's trash is another man's treasure.

Interestingly, early evidence of trash left behind by our evolving ancestors is treasured by archaeologists, and considered to be valuable artifacts. By contrast, it's rather unlikely that the mountains of trash we're generating today will be viewed by future generations as "valuable artifacts".

As agriculture began to be developed (about 10,000 BCE),

deforestation began in order to accommodate farming and settlements. Livestock farming added to methane emissions from animals. Overuse of land eventually led to soil degradation, and early irrigation systems introduced water pollution as waste and sediment flowed into existing bodies of water.

Early civilizations (10,000 BCE to about 500 CE),

brought the development of early cities such as those in Mesopotamia, the Indus Valley, and ancient Egypt, resulting in the concentrated production of waste. The use of metals such as copper, bronze, and iron increased as tools and weapons were produced. Water pollution increased due to poor sanitation and untreated sewage. Air pollution increased from metal smelting and open fires. And soil pollution increased from waste accumulation and mining activities.

During the tenure of the Roman and Greek empires (800 BCE to 500CE),

​the expansion of mining and metalworking, and increased trade spread pollution across regions. Lead contamination from mining and smelting was so extensive that evidence can still be found in ice cores and soil samples. Research suggests that exposure to lead from mining in the Roman Empire probably lowered I.Q. levels. In the cities, urban waste led to disease outbreaks that contributed to population decreases in some regions

During the medieval period (500 to 1500 CE),

deforestation intensified as land was cleared for farming and fuel, and the growth of towns and trade routes lead to increases in waste production. Air pollution increased from widespread use of wood and coal for heating and industrial production. Water pollution increased from tanning, dyeing, and similar early industries. Increased land degradation and soil erosion resulted from farming.​

As mining for silver, gold, and other metals increased in Europe and Asia, toxic runoff into rivers and lakes increased. Localized deforestation and habitat destruction occurred in the vicinity of mines.

During the early modern period (1500 to 1750),

global exploration and colonization introduced intensive agriculture and resource extraction to new areas. New colonies added to soil degradation and deforestation. And the introduction of invasive species disrupted ecosystems. The use of coal expanded for early industries, particularly in Europe, and air pollution from coal smoke became a significant problem in urban centers. Water pollution from early mills and factories increased.

The Industrial Revolution (1750 to 1900),

was fueled by the widespread use of fossil fuels such as coal, as the invention of the steam engine brought a big boost to the construction of factories. Severe air pollution from coal combustion brought urban smog. Waterways became heavily polluted with industrial waste and chemicals. The increased need for raw materials brought increased deforestation and habitat destruction. As cities grew rapidly, so did waste production and sanitation problems. Sewage and waste dumped into rivers caused public health crises such as cholera outbreaks.

The 20th century brought the modern industrial and technological Era.

With the post-World War II boom, advances were made in technology, transportation, and agriculture. Plastics and synthetic chemicals were developed. Air pollution and industrial emissions increased significantly. Plastic waste became widespread, accumulating in oceans, and soil chemical pollution from pesticides such as DDT and fertilizer became a long-term problem.

Nuclear weapons testing and energy production led to long-lasting radioactive contamination in ecosystems, which was compounded from accidents like the 1986 Chernobyl incident.​

The 21st century Anthropocene

brought globalization and mass consumption, which intensified industrial activities and global trade. The proliferation of single-use plastics led to microplastics in oceans, drinking water and human bodies. Air pollution remains a major health crisis with hot spots in India and China, and discarded electronics contributes to heavy metals in the environment.​

Greenhouse gases and climate change become a major problem due primarily to the burning of fossil fuels, and methane emissions from livestock and landfills add to the greenhouse effect. Rising CO2 levels have disrupted global climate patterns, and ocean acidification is negatively affecting marine ecosystems.

The cumulative impacts of human pollution are worrisome.

Air and water pollution contribute to millions of deaths annually due to respiratory, cardiovascular, and infectious diseases. Pollution has led to the extinction or population declines of many species. Agricultural runoff and industrial chemicals have rendered vast areas unsuitable for farming or drinking water. Human activities have accelerated global warming, causing rising sea levels, extreme weather, and ecosystem collapse.​

Throughout their evolution, humans have transitioned from minimal environmental impact to becoming the dominant force altering Earth's ecosystems. While early pollution was localized and relatively small-scale, industrialization and modern consumption have led to global challenges that threaten the planet's health and sustainability.

And now were polluting space.

Apparently we haven't learned much about preventing pollution during our evolution, because now we appear to be well on our way to polluting the universe. As of 2024, humans have left a staggering amount of space debris, commonly known as "space junk," in Earth's orbit. There are approximately 36,000 pieces of debris larger than 10 cm (4 inches) currently being tracked by global space surveillance networks, such as the U.S. Space Surveillance Network. There are an estimated 1 million pieces of debris between 1 cm and 10 cm (0.4–4 inches). Scientists estimate there are more than 100 million pieces smaller than 1 cm, including fragments from collisions, paint flecks, and particles from rocket fuel.

Most space junk consists of:

1. Satellites that no longer operate but are left in orbit after their mission
2. Spent upper stages of rockets that remain in orbit after launching payloads
3. Fragments resulting from satellite collisions, explosions, or impacts with other debris
4. Bolts, clamps, and lens caps unintentionally discarded during spacecraft operations
5. Satellite destruction tests that result in thousands of fragments (China 2007, India 2019)

​Because objects in orbit tend to travel at speeds of up to 28,000 km/h (17,500 mph), even small particles can cause catastrophic collision damage. A mathematical analysis known as the "Kessler Syndrome" describes a scenario where cascading collisions exponentially increase debris, making space operations impossible.

We're rapidly trashing space.

Despite the relatively limited amount of time that we've spent exploring space, we've already filled it with so much debris that collisions are becoming an increasing problem. The International Space Station, for example regularly has to perform collision avoidance maneuvers. And although much of this debris in low Earth orbit may eventually burn up upon reentry into our atmosphere, debris in higher orbits can persist for centuries.​

The United Nations Office for Outerspace Affairs (UNOOSA) has issued guidelines for mitigating space debris. And technologies such as nets, harpoons, and robotic arms are being developed and tested to remove debris. Satellites are increasingly being designed to deorbit themselves at the end of their lifecycle. And space agencies and private organizations are enhancing debris tracking capabilities to prevent collisions.

It's worth noting that:

• In 2007, China's anti-satellite test created over 3000 pieces of debris.
• In 2009 a collision between an inactive Russian satellite (Cosmos 2251) and sn active US satellite (Iridium 33), generated thousands of fragments.
• In 2021, Russia's anti-satellite test destroyed a satellite, generating debris that posed immediate risks to the International Space Station crew.

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We've even polluted much of the universe within reach of our space travels.

On our moon:

we've left a significant amount of debris from decades of lunar explorations that began in 1969 with the Apollo mission. We've left behind numerous lunar lander stages, rovers, scientific instruments, and personal items such as tools, flags, and cameras. Unmanned missions have also left debris where probes were deliberately crashed into the surface of the moon for the purpose of gathering scientific information.

Mars:

is littered with the remains of rovers, landers, and entry, descent, and landing hardware such as parachutes, and heat shields. Several unsuccessful missions left debris from incomplete landings.

Venus:

has debris such as atmospheric probes left from early Soviet and US exploration missions.

Jupiter:

contains the remains of the Galileo spacecraft which was deliberately crashed into Jupiter to avoid contaminating Europa (a moon of Jupiter).

Saturn:

contains the remains of the Cassini spacecraft which was deliberately deorbited into Saturn in order to protect its moons from contamination.

Titan, Saturn's largest moon:

contains the remains of the Huygens probe, left as part of the Cassini mission.

Even certain comets and asteroids have been affected.

NASA's Deep Impact mission in 2005 left an impactor on comet Tempel. Other spacecraft (such as Hayabusa and OSIRIS-REx) left components or spent materials during sample collection from asteroids.

The Outer Space Treaty (UNOOSA, 1967)

mentioned above was enacted to prevent harmful contamination. This was intended to be a treaty on principles governing the activities of states in the exploration and use of outer space, including the moon and other celestial bodies.​

Unfortunately the treaty has notable shortcomings in several critical areas (Roberds, 2016).1 One such issue is the development of anti-satellite (ASAT) technology, which undermines the principle that all nations have equal rights to explore space without discrimination. The destructive capabilities of ASAT, controlled by a limited number of nations, pose a potential threat to the space programs of countries lacking such technology. In the current geopolitical climate, a nation equipped with ASAT capabilities could significantly impair another nation's ability to conduct space exploration.

Another area of concern is the treaty's inability to prevent the weaponization of space. While Section A, Article IV explicitly prohibits the placement of nuclear weapons and weapons of mass destruction in outer space, it provides no restrictions on the deployment of conventional or future technological weapons. This oversight creates a situation where only nations with advanced capabilities may dominate space militarization, further hindering the principle of equal access to space exploration.

Additionally, the treaty has failed to address the growing problem of space debris. The lack of measures to prevent outer space from becoming cluttered with debris exacerbates challenges for exploration, including the threat of collisions, increased repair costs, and the financial burden of tracking debris.

​Most cities treat wastewater and place nonrecyclable trash in landfills.

Wastewater treatment benefits us by reducing disease potential and obviously benefits the environment by reducing the pollution that would otherwise flow into rivers lakes and oceans. And although landfills are mostly used to concentrate (and hopefully decompose) nonrecyclable items (many of which may last thousands of years before deteriorating), at least it gets the trash out of our immediate environment so that we're not smothered in trash everywhere else. The downside is that some items may never deteriorate.

For some items, we're able to reduce landfill accumulations by recycling.

• Recycling has a long history that dates back thousands of years. Evidence suggests that recycling practices were present in ancient civilizations. The earliest known recycling efforts can be traced back to around 400 BC in ancient Greece, where materials like metal and glass were melted down and reused. During the Middle Ages in Europe, people would collect and reuse materials such as rags and metal scraps. In some regions, it was common to collect used glass and metal for remelting.
• Recycling gained significant momentum during World War II as countries sought to conserve resources for the war effort. Governments encouraged citizens to recycle materials like paper, rubber, and metals. The modern recycling movement began in the 1960s and 1970s, driven by growing environmental awareness and the establishment of formal recycling programs.
• The first curbside recycling program in the United States was initiated in 1973 in Berkeley, California. Overall, while recycling has been practiced in various forms for centuries, the organized and widespread recycling efforts we see today began to take shape in the mid-20th century.
• Recycling remains a practical and essential component of waste management in many parts of the world, but its effectiveness and implementation vary widely depending on location, infrastructure, and economic factors. The recycling rates of aluminum, copper, paper, and cardboard, for example, remain relatively high, because the materials are economically viable to recycle. Plastics are our biggest problem. Globally, only about 9% of plastics have ever been recycled.

Consider what isn't recycled.

This is by no means a complete list, but items that cannot be recycled typically include plastic bags and wraps, styrofoam (polystyrene), mixed plastics, plastic utensils and straws, plastic with food residue, grease, or other contamination, coated or contaminated paper (such as paper cups), shredded paper, pizza boxes, contaminated paper (such as paper towels, tissues, napkins), ceramics, heat resistant glass, mirrors, window glass, paint cans, aerosol cans, metal with nonmetal attachments, electronics, household batteries, synthetic fabrics, mixed fabrics (such as cotton polyester blends), medical waste, chemically treated items, household hazardous wastes, bottle caps, rubber, disposable diapers, wax coated cartons, for example

We seem to be inclined to pollute. Is that characteristic part of our DNA?

We've managed to pollute not only the planet that supports us, but we're even polluting the universe around us, as far as we can reach. Human exploration has left a legacy of debris across the solar system, from the Moon to distant asteroids. While this debris serves as historical artifacts of exploration, it also raises concerns about planetary protection and space ethics.

Will we ever change? Maybe, but the jury is still out on that. Fortunately, it's rather likely that the tendency to pollute everything around us is a negative side effect associated with our rapid rise in technology, rather than being a part of our DNA. So we aren't born to pollute, but on the other hand, we don't seem to be able to to prevent it from happening, either.

Reference

1. Roberds, E. H. J. (2016). FAILURE OF THE OUTER SPACE TREATY. Canadian Forces College, Retrieved from https://www.cfc.forces.gc.ca/259/290/301/305/roberds.pdf&ved=2ahUKEwjsu8z42NmKAxW1IEQIHYtpGkEQFnoECAYQDQ&usg=AOvVaw3hvsaUtUJpQ7hm5RTl7dl9