 What do you do when you can measure everything? Modern technology is great and one of the things it's great at is enabling us to detect vanishingly small quantities of chemicals in stuff. This is fantastic news for scientists who love nothing better than to measure things. But what does it mean for everyone else? Especially if those chemicals might be toxic. This is the measurement conundrum that was introduced in last week's Risk Bites. The trouble is, once you know something, you can't just un-know it. Just like learning your cell phone probably contains small amounts of fecal matter, new information has a habit of burrowing into your brain and demanding action. But what kind of action? When it comes to mind-bogglingly small yet measurable quantities of chemicals in the things around us, there are a number of possibilities here. One, panic. Probably not the most rational option, as just because we can measure something doesn't necessarily mean it's dangerous. And there's the added problem that panicking could cause more harm than it avoids. Two, do nothing. Possibly the default option for most people and a pretty good one if you know that someone else is looking out for your safety. Three, ask how much of the chemical is dangerous. For most substances, being exposed to vanishingly small amounts means vanishingly small risks. And as long as the exposure is low enough, you're most likely OK. Four, ask more questions. Just because we can measure something doesn't mean that it's dangerous. But it does mean that we can do more research into finding out how infinitesimally small quantities of the stuff behave in our bodies. Measuring small amounts of chemicals in stuff used to be the privilege of scientists stuck in fancy labs, but sophisticated measurement technology is becoming increasingly accessible to anyone with a smartphone. And that puts another interesting spin on the measurement conundrum. What do you do when anyone with an iPhone can measure what you are being exposed to? It's going to happen and when it does, it's going to be pretty important that we know what to do with the information we're given. There'll be more on the measurement conundrum in future risk bites. But in the meantime, look out for next week's video and stay safe.