Environmental Health

Sound level meter with a foam microphone on a desk beside earmuffs, an analog clock, and an open notebook, with translucent sound-wave graphics in front of an industrial window view.

Noise Exposure Data: Decibels, Time Weighting, and Why 3 dB Is a Big Change

by Max Data
November 3, 2026

A 3 dB increase roughly doubles sound energy, but interpreting noise exposure also requires duration, weighting, measurement method and the applicable exposure model.

White tabletop air-quality monitor with colored indicator lights beside a green-to-red color scale, overlooking a hazy city skyline through a large window.

PM2.5 vs AQI: The Measurement and the Communication Scale Are Not the Same Thing

by Max Data
October 13, 2026

PM2.5 is a pollutant concentration, while AQI is a health-communication index calculated from pollution data. Here is how the U.S. system connects them.