I read Rachel Carson before I read Thoreau. Silent Spring came out 50 years ago, and I read it for a 7th grade book report. I’m not sure how I got hold of a copy, but it must have been from the library. I remember my mother picking it up and looking through it.

“So this is the book everyone’s talking about,” she said. When I was done, she read it. “It’s an important book,” she said. She went on and wrote a book review for the newspaper she was working at.

It influenced much of my thinking, and much of what I’ve done since. Thoreau, Muir, Aldo Leopold and so many others have all shaped my thinking in their own way.

I was going to write something about Silent Spring and Rachel Carson to commemorate the anniversary. But then I read an article on autism in the New York Times this weekend. I’ve linked to it for anyone who’s interested.

It’s been all over the news that 1 in 88 American children are now diagnosed with some form of autism, and the numbers are growing. Trying to figure out why this is happening has the experts scratching their collective backsides. Some suggest it doesn’t exist at all. Others point to as-yet-undiscovered genetic reasons.

What’s Silent Spring have to do with this? The Times article has an interesting sentence: “The C.D.C. was … holding out the possibility of unknown environmental factors.” They don’t elaborate.

I will.

Consider the following: a 2011 Stanford University study showed that 38 percent of autism cases could be traced to genetic factors, while 62 percent came from environmental factors. The sharp rise in autism cases cannot be blamed on genetic factors, because genes simply don’t mutate that fast.

That would leave environmental factors as the chief culprit.

Consider all the toxic substances we are exposed to: something like 85,000 different chemicals in our food, in our water, in the air, and in the products we use.

The average newborn has more than 200 different chemicals and heavy metals in its blood at the moment of birth, and 158 of them are toxic to the brain. These children experience 100 times more chemical exposures now than children 50 years ago, when Rachel Carson was writing Silent Spring.

I would suggest there is nothing “unknown” or otherwise mysterious about the environmental factors.

One last thought.

“The question is whether any civilization can wage relentless war on life without destroying itself…”– Rachel Carson