An actual chemist looks at claims made about "toxic foods" in a recent Buzzfeed linkbait post and calmly explains
why the whole thing is ridiculous. Of the 8 foods (actually, mostly food additives) mentioned, one is hardly used anymore, another was withdrawn from the market two years ago, two only sound scary if you failed chemistry, and four have had their risks vastly overstated. It's the sort of situation where some studies show a risk, some studies don't, and there's good reasons to think the risk — if it exists — isn't that big, to begin with. Read the rest
Last week, Mother Jones published a really fascinating article arguing that the crime wave that swept through America between the 1960s and 1980s can largely be blamed on leaded gasoline
— and the subsequent lead poisoning of an entire generation of Americans. For more background on the dangers of leaded gas, I suggest reading this post by Deborah Blum. Essentially, it's an excerpt from her fantastic book, The Poisoner's Handbook
. In it, she tells the story of the history of leaded gas
— a substance that was known to be dangerous even in the 1920s — and the conspiracy to sweep that danger under the rug. Read the rest
Scientists are amassing evidence that suggests exposure to tetraethyl lead — the additive once used in almost all the gasoline sold in the United States — could account for the dramatic increase in crime that happened in this country between the 1960s and 1980s. As leaded gasoline was phased out, they say, children were exposed to less lead, leading to the decline in crime that began to really kick in in the 1990s.
This is the same curve of crime statistics that economist Steven Levitt, of Freakonomics fame, attributed to the legalization of abortion. Levitt's theory was that, after Roe v. Wade, there were fewer unwanted babies born into dire circumstances and, thus, fewer people to grow up on the path to criminal behavior. Levitt matched the rise in abortion rates to the decrease in crime, but frankly, there are a lot of things that you can correlate to the decrease in crime.
What makes the lead theory interesting is that correlations match not just at the national level, but at regional, and even neighborhood levels. Increases in lead relate to increases in crime — usually a couple of decades later. Likewise decreases in lead relate to later decreases in crime. What's more the same correlations exist in countries all over the world. Meanwhile, we know that lead has big impacts on growing bodies — it affects brain function, it's linked to hyperactivity, difficulty managing aggression, and lowered IQ.
Correlation isn't causation. But in this case they definitely seem to be winking suggestively at one another. Read the rest
On Christmas Day, I watched a documentary about the terra cotta warriors — thousands of clay soldiers built as funerary objects for the tomb of Qin Shi Huang, China's first emperor. One crazy fact I learned: Unlike the type of lacquer we call shellac today (which comes from crushed beetles), ancient Chinese artists used a lacquer derived from the sap of the lacquer tree, a relative of poison ivy. Anybody tasked with the job of applying that lacquer can end up with
a serious allergic reaction
. Another fun fact: We've still never seen the inside of Qin Shi Huang's tomb. Partly, this is a bureaucratic issue. But the larger problem is the mercury-laden soil on top, possibly contaminated by Qin Shi Huang's tomb, itself, which was supposed to contain a scale model of his empire
, complete with rivers and oceans flowing with (you guessed it) mercury. Read the rest