What Does This Chart Do? Radon Exposure

Eli Holder
2 min readJan 8, 2024
A chart from Joshua Gold’s 2018 study: “The unintended impact of smoking-risk information on concerns about radon: A randomized controlled trial”

This chart, based on a brochure from the Idaho Department of Health and Human Welfare, is meant to raise awareness about radon exposure for smokers. Specifically, it’s meant to nudge them to get their homes tested for radon.

But what effect does this chart actually have?! In their 2018 study, Joshua Gold and other University of Iowa researchers showed that…

  • For smokers (the intended audience): The chart had no real effect on risk perception or testing intent. So at best the chart is ineffective.
  • For non-smokers (the majority audience): The chart actually backfires, convincing them they’re invincible to radon.

The study highlights an interesting contrast effect for charts like these. Non-smokers anchored their risk to smokers’ relatively high risk, mistaking their lower relative risk for low absolute risk. This invincibility effect matters because lower perceived risk invites more risky behavior.

These contrast effects are a big deal for equity-related dataviz. Disaggregating health risks by race, age, and other social groups might backfire similarly. Consider early news reports during the Covid-19 pandemic. Contrast effects like Gold’s suggest that coverage highlighting risk disparities for essential workers or older people may have convinced everyone else that the pandemic…