Managing pollution and waste practice questions.

From 1 January 2025 an amendment to the Basel Convention brought all electronic waste, including waste that is not classified as hazardous, under the convention's prior informed consent procedure. What does this mean for an exporter of discarded electronic equipment?

• Shipments of used electronic devices across borders are now prohibited outright
• Consent from the importing state is required before the shipment leaves
• Only movements between member states of the OECD now need documentation
• The exporter must pay into an international fund for recycling in the destination country

Answer: Consent from the importing state is required before the shipment leaves

Prior informed consent is a procedural control rather than a ban: the receiving state must be told what is coming and agree in advance, which closes the route of declaring hazardous scrap as ordinary second-hand goods. Whether it reduces harm depends on whether the importing authority can inspect what arrives.

In towns such as Guiyu in Guangdong, China, workers recovered copper and gold from imported circuit boards by burning cable insulation and leaching with acid, and studies published in the 2000s reported raised blood lead levels among local children. Which feature of the practice explains that exposure most directly?

• Circuit boards contain radioactive elements that escape when the boards are cut
• The workers were paid by weight recovered rather than by device processed
• The recovery methods release metals and combustion products into air and soil
• The imported boards were older than the boards discarded in the same region

Answer: The recovery methods release metals and combustion products into air and soil

The harm follows the method rather than the material: open burning and acid baths move lead and flame retardants into the air, soil and water where families live, which is exactly what a certified plant contains. This is why an export control and a health outcome belong to the same argument in this prescribed area.

In 2022 the United States communications regulator adopted a rule requiring most satellites in low Earth orbit to be removed from orbit within five years of the end of their mission, replacing a guideline of 25 years. Which problem is the rule meant to slow?

• Interference between satellite transmissions and ground-based mobile networks
• Accumulation of objects whose collisions generate yet more fragments
• Sunlight reflected from satellites leaving streaks across astronomical images
• Fuel burned by launch vehicles on the way up to low Earth orbit

Answer: Accumulation of objects whose collisions generate yet more fragments

A shorter disposal deadline reduces how long dead hardware stays in the traffic, and dwell time is the input to the collision-and-fragment cycle that Kessler described in 1978. Optical brightness and radio interference are separate problems of the same constellations, with separate remedies.

A large data centre in Odense, Denmark, has delivered the heat from its cooling system into the municipal district heating network since 2020. Which statement about that arrangement is accurate?

• A by-product of computing displaces fuel the network would otherwise burn
• The site becomes a net supplier of electricity to the local grid
• The arrangement removes the site's need to draw water for cooling
• Reusing the heat drives the site's reported power usage effectiveness below one

Answer: A by-product of computing displaces fuel the network would otherwise burn

Servers convert almost all the electricity they draw into low-grade heat, so the only open question is whether that heat is dumped or piped somewhere useful, and where a district network exists it substitutes for combustion. It does not change how much electricity the site itself consumes.

A container of used laptops leaves a European port bound for a port in west Africa. Which single observation would show that the shipment is an export of waste rather than of second-hand goods for reuse?

• The units in the container are more than five years old.
• No record of functionality testing accompanies the units in the container.
• The importing country has no plant certified to a recognised treatment standard.
• The units were bought as a job lot from a public sector office.

Answer: No record of functionality testing accompanies the units in the container.

Reuse and waste are separated by evidence that the goods work: tested, documented and packed to survive the journey. Age, the buyer's identity and the facilities at the destination describe the trade but do not classify the load.

A municipality closes its open dump and opens an engineered landfill with a liner and a leachate collection system, funded by a fee added to the price of new electrical goods. Which group bears a cost of the change without buying any of those goods?

• Households that buy new electrical goods and therefore pay the added fee.
• The manufacturers whose products carry the fee added at the point of sale.
• Waste pickers who earned an income sorting material at the open dump.
• The operator of the new landfill, which must monitor the liner for leaks.

Answer: Waste pickers who earned an income sorting material at the open dump.

The other three groups are inside the transaction and priced into it. Formalising a waste stream removes the livelihood of the people who worked it informally, which is why Brazil's national solid waste policy of 2010 requires their inclusion rather than assuming they will be absorbed.