Last summer, I was writing a story on big agriculture. In the circuitous way reporting goes, I ended up on the phone with Bruce Blumberg, a scientist at UC Irvine who discovered “obesogens,” foreign chemicals that appear in the body as a result of exposure to, among other things, BPA (a chemical used in some plastics and the liners of canned and baby foods), vinyl, a few kinds of paint, and some antidepressants — all of which disrupt the endocrine system enough that they can lead to obesity and probably a whole host of other disorders. The scariest thing about some of these chemicals, his research shows, is that they can actually change the expression, or patterns, of our genes — and that these changes will be inherited by our offspring.

Blumberg walked me through the science of his work in terms that I could understand. For instance, he informed me that vinyl (used to make, among many other common household items, plastic bins used for storage, linoleum flooring, shower curtains, and children’s toys) actually creates a microscopic dust that we end up consuming when we get it on our hands and breathe it in. Kids, he told me, are the most susceptible because they’re on the floor so much, touching the dust and then putting their hands in their mouths.

I thought of my three-year-old son sleeping at the other end of our apartment. For a second I felt relief: because I had known, by the time my son was born in early 2009, that BPA was dangerous for babies and young children, I made a considered effort to stay on top of the news from various environmental groups working to get BPA out of baby products. I did what I could with the little I understood: I used glass bottles for milk and tried to make most of his baby food (which I stored in glass Ball jars). Of course, we hadn’t thought much about our plastic storage bins, which held years’ worth of hand-me-downs from my friend Vanessa; becoming new parents was a crazy enough time that just getting through the day felt like a survival exercise. So we trusted labels that said “BPA-free” and didn’t look too closely at some fine print. Scrutinizing every single corner of our world for chemicals didn’t feel feasible.

“What about the initiatives so many groups are working on to get BPA out of baby foods and toys?” I asked Blumberg. Flashing through my mind were the e-mails I get — almost daily, it seems — from the Environmental Working Group, MomsRising, MoveOn.org, and many others, that inform me of groups of mothers and concerned citizens working hard and courageously against BPA. Victory has seemed right around the corner for months (and, indeed, in the state of Maine, where I live, a watchdog group called Environment Maine has garnered national attention for successfully leading the charge to ban BPA in infant formula and baby foods).

“I hate to tell you this,” Blumberg said, perhaps sensing how this information might come across to me, as a mother (forget the reporter!), “but it’s virtually impossible to ban a chemical in this country. The standard of proof [for proving a chemical is dangerous] is so high it’s almost impossible to ever reach it. Also, when people start scrutinizing a chemical like BPA, the companies look for the closest one they can use. And so they’re using BPS now, which is almost the exact same chemical.”

Under the Toxic Substances Control Act of 1976, the EPA can’t order a company to test a substance unless there’s already evidence that it’s dangerous. And many chemicals that were created before that date have been grandfathered into the system, meaning they are free from scrutiny. Senator Frank Lautenberg, a Democrat from New Jersey, has introduced legislation that would transfer the burden of proof to the companies for new chemicals, making it mandatory that they test them before releasing them — but the bill hasn’t made it past the committee stage. According to Lautenberg’s office, the EPA has only been able to order testing on 200 of the more than eighty thousand chemicals in circulation. Only five have ever been banned.

After hearing Blumberg’s news, it was hard for me not to feel defeated. I only have one child and it’s hard enough to keep him fed and his winter boots on the right feet; do I now have to worry about eighty thousand chemicals I’ve never heard of, too?

I squeaked out a final question, one that was almost intuitive, it was so simple: “What can I do?”

“Do the best you can,” he said. “Whatever you can do to minimize your exposure to plastics — whether you get wooden or metal bins for your storage, use your own steel water bottles, filter your water, eat organic or fresh food — you’re better off if you can at least do that.”

When I hung up the phone, I looked around our apartment. Despite many natural cloth, glass, and wooden items throughout our home, I saw plastic everywhere I turned: the linoleum flooring in the bathroom; the coatings on the screw tops of those Ball jars I’d piously bought to store my homemade baby food; the Ziploc bags we reuse to help the environment; the piles of plastic tractors and trucks, balls, and barn animals strewn throughout the playroom.

My mind went back to a conversation I’d had one afternoon, standing in my friend Jodi’s kitchen. We were talking about food and our children. Jodi has a big old house with a cast-iron wood stove and a long wooden dining table on a residential street in Portland. She organizes a bulk food-buying group that sources local fruits, vegetables, meats, grains, and dairy products. That day, as her dog and cats sniffed around, we were sorting chicken breasts, oats, flour, and heirloom apples into a box for me to take home. As we loaded up the vacuum-packed chicken breasts and poured oats into huge Ziploc bags, I said, “Isn’t it weird how we’re buying local and yet we can’t get away from plastic? Even when it seems like we’re doing the right, wholesome thing?”

“I know,” she said. “It makes me feel like I’m suffocating all the time.”

I didn’t realize until she said it, but hers is the exact same sense I often get: that purity — something I (perhaps foolishly) believe my child has a right to — is increasingly elusive, no matter what I do. When I let myself notice it, I often feel that our world is increasingly toxic and dangerous and that protecting ourselves, our kids, and the small plots of ground we call home is a Sisyphean task.

But it helped me to know, in that moment, that someone else felt the same way I did. If there’s anything harder than fear, it’s being alone with one’s fear.