Environmental & Social Impacts of Waste (DP IB Environmental Systems & Societies (ESS)): Revision Note

Environmental & social impacts of waste

Environmental impacts of waste

• The production, treatment and disposal of waste can have severe environmental consequences, both locally and globally

Pollution

• Air pollution: burning waste, especially in open landfills, can release harmful gases like methane and carbon dioxide

  • These gases contribute to climate change

  • Decomposing organic waste in landfills also produces methane (a potent greenhouse gas)

• Water pollution: improper waste disposal can lead to chemicals and hazardous materials leaching into rivers, lakes and oceans

  • This harms aquatic life and contaminates drinking water sources

• Soil pollution: hazardous waste, chemicals and heavy metals from landfills or improper waste disposal can seep into the soil

  • These pollutants contaminate soils and harm plant growth, as well as enter food chains through plants and crops

Habitat destruction

• Landfills and waste dumps take up large areas of land

  • This often leads to the destruction of natural habitats and loss of biodiversity

  • For example, in Ghana, the Agbogbloshie e-waste dump has not only polluted local water sources but also destroyed large areas of natural land

Social impacts of waste

• Waste management also has important social consequences

  • These particularly affect low-income communities and countries

Health risks

• Exposure to waste, especially e-waste and biohazardous materials, can lead to serious health issues

  • This can include respiratory diseases, skin infections and cancers

• Low-income countries that receive waste from high-income nations often lack proper facilities to safely handle and treat waste

  • This can result in dangerous living and working conditions for local people

Environmental injustice

• Waste exports: high-income countries often export their waste to low-income countries, which struggle to manage it safely

  • This leads to environmental injustice

  • This occurs when the negative impacts of waste are disproportionately experienced by poorer countries

• The Basel Convention was introduced by the United Nations Environment Programme (UNEP) in 1992

  • It is an international treaty designed to:

    • Regulate the movement of hazardous waste between countries

    • Prevent the export of such waste from high-income to low-income nations

    • Protect human health and the environment from the dangers of improper waste disposal

  • However, illegal waste exporting and dumping still occurs

Impact on local communities

• The presence of landfills or waste processing plants near communities can decrease the quality of life for local people due to:

  • Bad smells

  • Noise

  • Potential contamination of local water and soil

• Communities near waste sites often suffer from:

  • Lower property values

  • Reduced economic opportunities

  • Poor health outcomes

Ecosystems & pollution

• Pollution occurs when harmful substances are added to the environment at a rate faster than ecosystems can process or transform them into harmless substances

  • Ecosystems naturally have the ability to absorb and manage a certain amount of waste and pollution

  • They achieve this through processes like photosynthesis and nutrient cycling

  • However, when the amount of waste exceeds their capacity, pollution builds up

  • At this point, it causes harm to the environment

Ability of ecosystems to absorb waste

• Ecosystems as natural filters: many ecosystems can absorb and transform pollutants into less harmful substances

• Some examples include:

  • Forests: trees absorb carbon dioxide during photosynthesis

    • They convert it into oxygen, reducing the amount of CO2 in the atmosphere

  • Wetlands: ecosystems like salt marshes and mangroves can absorb nitrogen, phosphorus and other pollutants from water

    • They act as natural filters, trapping these substances and using them for plant growth

  • Grasslands and farmlands: plants can take up nitrogen and phosphorus from the soil as nutrients for their growth

    • This can help reduce the impact of agricultural runoff

• Ecosystem services: ecosystems provide services that help manage pollution, such as:

  • Carbon sequestration: plants absorb CO2 from the atmosphere and store it in their tissues, reducing greenhouse gases

  • Water filtration: wetlands and forests filter pollutants from water before they enter rivers, lakes, or oceans, improving water quality

    • For example, salt marshes along coastlines can absorb pollutants like heavy metals and excess nutrients

    • This reduces the flow of these substances into the ocean, protecting marine ecosystems

Limits to ecosystem absorption

• Overloading ecosystems: when pollutants are added at a faster rate than ecosystems can process them, pollution occurs

• For example:

  • Excess CO2: while forests can absorb CO2, human activities like deforestation reduce the number of trees

    • This limits their ability to manage rising CO2 levels

  • Eutrophication: wetlands can absorb nutrients, but when agricultural runoff contains too much nitrogen and phosphorus, these ecosystems become overloaded

    • This leads to water pollution and eutrophication

Biodegradability and half-lives

• The term biodegradability refers to how quickly natural processes can break down a substance into harmless components

  • Biodegradable materials: substances like paper and food waste decompose quickly

    • This is because bacteria and other organisms break them down into harmless materials

  • Non-biodegradable materials: substances like plastic, glass or synthetic chemicals do not break down easily

    • They can remain in the environment for hundreds or thousands of years

• Half-lives: this concept refers to the time it takes for half of a substance to decay or break down

• Some pollutants, especially chemicals or radioactive materials, have long half-lives, meaning they remain dangerous in the environment for extended periods

  • Long half-lives: pollutants like pesticides (e.g. DDT) or radioactive waste have long half-lives

    • They persist in ecosystems for years or decades

    • For example, DDT has a half-life of around 15 years, meaning it can stay in the soil and water for decades, affecting wildlife, food chains and whole ecosystems

  • Short half-lives: substances like organic waste decompose quickly

    • This reduces their environmental impact