Rethinking “Better Safe Than Sorry”

Friends,

For more than 100 years, our health and environmental policies have been driven by fear—cleaning up waste sites until the dirt is "safe to eat," warning people away from medical X-rays, and raising alarms over trace pesticide residues.

These efforts are often grounded in a flawed idea known as the linear no-threshold (LNT) theory, which assumes that if something is dangerous at high doses, it’s also dangerous at any dose—no matter how small.

That’s like saying jumping off a five-story building is deadly, so jumping off a curb must be a little bit deadly, too. But our biology doesn’t work that way.

Our bodies have evolved to handle intermittent low doses of radiation and chemicals. We even use radiation in medicine—at low levels, it’s therapeutic. Water can kill you if you drink too much, and it can also kill you if you don’t drink enough. Context matters.

Pesticides, too, have helped feed the world, and the tiny residues left behind are easily handled by our bodies. Yet we continue to spend massive sums chasing phantom risks while overlooking far more serious problems like crime, depression, or food insecurity. Worse, these misplaced fears can lead to higher risks. For example, avoiding fish because of minute traces of methylmercury may lead people to eat less healthy alternatives.

The precautionary principle—“better safe than sorry”—sounds reasonable. But in practice, it can be dangerous. When we lower exposures without considering biology or trade-offs, we’re not being cautious—we’re ignoring science and real-world consequences.

That’s the argument my colleague Edward Calabrese and I make in a new open-access article. It’s time to update our understanding of risk and let science, not fear, guide our policies.

Read the full article here.

Have a great week.

—Richard