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Phone vs. Official: Which Air Quality Data Should You Trust?

You check your phone’s air quality app—it says the air is hazardous. But the official station nearby reports moderate conditions. Which one is right? This project puts you in the middle of that real-world dilemma. You’ll learn how low-cost sensors like PurpleAir stack up against EPA regulatory monitors. Have you ever wondered why your readings differ from government data? Factors like season, location, and sensor design play a role. Using real data, you’ll analyze accuracy and uncover surprises. By the end, you’ll have your own answer—and maybe change how you check the air.

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  When was the last time you checked an air quality app on your phone? What did it say?

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  Have you ever noticed a difference between what your phone reports and what you see or feel outside?

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  In your neighborhood, where do you think the nearest official air quality monitor is located? Have you seen it?