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A chemical's environmental life can outlast its product

PFOA is one example of a persistent compound documented in environmental contamination. Persistence asks how readily it breaks down; mobility and accumulation ask different questions about where it goes and where it remains.

3–7 min

Questions you could explore

  • Why would a strong chemical bond alone be insufficient to predict a compound’s route through water and soil?
  • How do persistence and mobility answer different questions about a chemical released into the environment?

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Environment and climate

What can tree rings reveal about past climate?

A tree keeps a record of growth in its wood, but reading that record as climate history takes more than counting rings. Moisture, temperature, and other growing conditions can leave overlapping clues.

4–5 min

What can tree rings reveal about past climate?

Environment and climate4–5 minA tree keeps a record of growth in its wood, but reading that record as climate history takes more than counting rings. Moisture, temperature, and other growing conditions can leave overlapping clues.

Environment and climate

Why can a city be warmer than nearby countryside?

The trip from a leafy edge of town to a dense street can also be a trip between different temperatures. Buildings, pavement, vegetation, and waste heat all affect the balance, and the contrast changes with weather and time of day.

3–5 min

Why can a city be warmer than nearby countryside?

Environment and climate3–5 minThe trip from a leafy edge of town to a dense street can also be a trip between different temperatures. Buildings, pavement, vegetation, and waste heat all affect the balance, and the contrast changes with weather and time of day.

Environment and climate

A trip through a wastewater treatment plant

Water disappearing down a drain begins another journey before it returns to a river or the sea. Inside a wastewater treatment plant, screens, settling tanks, and microbes tackle different kinds of pollution. Conventional sewage treatment produces effluent for controlled discharge; making recycled water suitable for drinking requires additional treatment and safeguards.

4–5 min

A trip through a wastewater treatment plant

Environment and climate4–5 minWater disappearing down a drain begins another journey before it returns to a river or the sea. Inside a wastewater treatment plant, screens, settling tanks, and microbes tackle different kinds of pollution. Conventional sewage treatment produces effluent for controlled discharge; making recycled water suitable for drinking requires additional treatment and safeguards.

A chemical's environmental life can outlast its product | Speech Topic | speaking.app