Human beings are great at dealing with obvious, immediate risks; charging wildebeests, carcasses on the side of the road, that sort of thing. When it comes to subtle or long-term risks, though, we fall flat on our faces.

Take radiation. We view it as a killer, and in high doses it can be a nasty one. But we also view it as harmless, maybe even beneficial in small doses. Both sides carry some truth, as the dose makes the poison, but when that poison is invisible we struggle to weigh the costs and benefits.

No one has been killed or sickened by the radiation — a point confirmed last month by the International Atomic Energy Agency. Even among Fukushima workers, the number of additional cancer cases in coming years is expected to be so low as to be undetectable, a blip impossible to discern against the statistical background noise.

But about 1,600 people died from the stress of the evacuation — one that some scientists believe was not justified by the relatively moderate radiation levels at the Japanese nuclear plant.

Because nuclear disasters are rare events, we overestimate their risk. On the opposite end of this is Radon.

Radon is a radioactive gas that is formed naturally by the breakdown of uranium in soil, rock and water. As a gas, radon is slowly released from the ground, water, and some building materials that contain very small amounts of uranium, such as concrete, bricks, tiles and gyproc. Radon gas breaks down further to form additional radioactive particles called radon daughters, or “progeny” that can be breathed into the lungs.

Radon cannot be detected by the senses, i.e., it is colourless, odourless and tasteless; however, it can be detected with special instruments. When radon is released from the ground outside it mixes with fresh air and gets diluted resulting in concentrations too low to be of concern. However, when radon enters an enclosed space, such as a house or basement, it can accumulate to high concentrations and become a health risk.

It’s trivial to test for Radon, yet in the USA it causes about 15,000 lung cancer deaths every year. As Radon is a common occurrence, though, we tend to underestimate it’s risk.

The only good solution for this is to follow the numbers. Let studies and research guide your decisions, no feelings.