How Did We Discover Pollution's Toxic Nature?

Pollution has been a problem since the emergence of our earliest ancestors. As populations grew, pollution became a universal problem, with the Industrial Revolution marking the beginning of environmental pollution as we know it today. By the 1800s, people began to understand the link between unsanitary living conditions, water contamination, and disease epidemics. The burning of coal and wood, as well as the presence of many horses in concentrated areas, made cities the primary sources of pollution. In the 19th century, episodes of smog in cities like New York and London resulted in numerous deaths, and air pollution continued to be a significant issue until the middle of the 20th century. Today, pollution continues to have widespread consequences on human and environmental health, causing approximately nine million deaths worldwide annually.

The Industrial Revolution

Waterways were also heavily polluted with oil, debris, sewage, and other waste, leading to water quality issues and the contamination that allowed cholera to flourish. From 1848-1849, around 15,000 people died from cholera in London. The Industrial Revolution also led to environmental degradation, the depletion of natural resources, deforestation, and urban overcrowding.

The technological advances of the Industrial Revolution greatly improved the quality of life for many, but they also had unintended consequences for both the environment and society. These consequences were not always immediately apparent, and many of the negative cycles and trends that began during this period continue to influence society today.

Water contamination

As cities became more populated towards the end of the 19th century, industrialised cities in Europe and the United States faced a new type of pollution: industrial waste. A notable example is the Tawe River in Wales, which was contaminated by "alkali works, copper works, sulfuric acid liquid, sulfate of iron from tin-plate works, and by slag, cinders and small coal". Similarly, in the United States, industrial chemicals and wastes polluted waters in the Northeast.

In the 20th century, water pollution continued to be a significant issue, with the Cuyahoga River in Ohio becoming infamous for catching fire multiple times between 1936 and 1969 due to extreme pollution. The river was heavily contaminated with oil, sludge, and debris, and the fires served as a stark reminder of years of environmental neglect. The 1969 fire catalysed the Clean Water Act and the creation of the Environmental Protection Agency (EPA).

Today, water pollution remains a widespread problem, with agricultural pollution being the leading cause of water degradation worldwide. Fertilisers, pesticides, and animal waste wash into waterways, causing nutrient pollution and harmful algal blooms. Additionally, radioactive waste, uranium mining, and nuclear power plants contribute to water contamination, posing significant threats to both human health and the environment.

Air pollution

Pollutants in the air can take the form of gases, solid particles, or liquid droplets. Some gases, such as sulfur dioxide, are toxic and can have acute effects on health, especially for people with existing respiratory conditions. Particulate matter, which is formed when pollutants break down into smaller particles, can also have harmful effects, with smaller particles being more detrimental as they can enter our lungs, airways, and even our blood.

The health impacts of air pollution are wide-ranging. It can cause respiratory diseases, cardiovascular disease, neurological damage, cancer, and even death. Children are particularly vulnerable, with exposure to high levels of air pollutants increasing the risk of developing bronchitis symptoms in adulthood and cognitive and emotional problems. Prenatal exposure to pollutants has also been linked to an increased risk of cerebral palsy and adverse birth outcomes, such as low birth weight.

To address air pollution, the World Health Organization (WHO) has developed strategies to raise awareness about the risks and promote interventions for healthier sectoral policies, such as energy, transport, and housing. The United States Environmental Protection Agency (EPA) also plays a crucial role in regulating emissions and providing guidance to states and communities to reduce toxic air pollutants.

Reducing air pollution requires a multi-faceted approach, including transitioning to clean and renewable energy sources, improving energy efficiency, promoting sustainable land use, and implementing policies that support cleaner household energy and transport. These efforts not only benefit the environment but also have significant health benefits for people worldwide.

Toxic metal pollution

Pollution has been a problem since the emergence of our earliest ancestors. As human populations grew, so did the risk of disease and bacteria. In the Middle Ages, Europe suffered from cholera and typhoid fever, caused by unsanitary living conditions. By the 1800s, the link between unsanitary conditions, water contamination, and disease was established.

As cities grew in the 19th century, a new kind of pollution emerged: industrial waste. A report from 1897 detailed how the Tawe River in Wales was contaminated by "alkali works, copper works, sulfuric acid liquid, [and] sulfate of iron". Similar pollution was seen in the US, with industrial chemicals and waste contaminating waters in the Northeast. This marked the beginning of toxic metal pollution, which is now a significant global issue.

Toxic heavy metal pollution refers to the presence of harmful metallic elements in the environment, particularly in water. These metals include arsenic, cadmium, chromium, lead, and mercury, which are known to be highly toxic and can induce organ damage and cancer even at low levels of exposure. Mercury, for example, is a neurotoxin, while lead can cause brain damage and impair children's learning abilities.

Heavy metals enter the environment through natural processes and human activities. Natural sources include volcanic activity, metal corrosion, and soil erosion. Human activities that release heavy metals include waste disposal, industrial manufacturing, and mining. For instance, runoff from agricultural fields can carry fertilizers and pesticides containing metal compounds into nearby water sources.

The consequences of heavy metal pollution are severe. It poses risks to both human and animal health, particularly when it contaminates water and soil. Heavy metal poisoning can lead to liver and kidney dysfunction, skin problems, and even cancer. Additionally, these metals can accumulate in the food chain, leading to high quantities of toxins in larger organisms like tuna.

Oil spills

The history of oil spills is a long one, with the Ecuadorian Amazon suffering countless spills over the past 50 years due to the irresponsible practices of oil extraction companies. Between 1972 and 1993, an estimated 714 million barrels (30 billion gallons) of oil and toxic waste were released into the environment in this region.

The toxic chemicals released by oil spills also pose a significant risk to human health. Short-term health symptoms following exposure to an oil spill include headaches, nausea, dizziness, chest pain, and breathing difficulties. There are also potential mental health consequences, such as depression, anxiety, and post-traumatic stress.

Long-term health effects of oil spill exposure are less understood due to a lack of comprehensive studies. However, studies of biomarkers have revealed irreparable harm to humans exposed to oil and gas from spills, including respiratory damage, liver damage, decreased immunity, increased cancer risk, and reproductive damage.

The cleanup process after an oil spill is challenging. Workers use skimmers and sorbents to absorb the oil, or chemicals may be employed to break down large slicks of floating oil, making it less harmful to animals and coastlines. However, the toxic nature of the oil means that cleanup workers are also at risk of health issues.

Frequently asked questions