By Rayana Godfrey
There’s no place for lead in the human body, plain and simple. Even the smallest amount of exposure to the element is toxic. Scientists estimate that before the Industrial Revolution, most people had about .01 micrograms of lead for every half cup of blood in their bodies. But we’ve put a lot of lead into the environment since then.
“If you’re lucky,” environmental toxicologist Donald Smith told me, “the level of lead in your blood is probably between 1 and 2 micrograms.” That’s a hundred times more than what preindustrial people had. It’s also enough to cause detectable neurological damage, said Smith, who teaches at the University of California at Santa Cruz.
The only thing I knew about lead when I was younger was that it’s the pointy part of a pencil (that’s actually graphite, I’ve since learned). In high school, lead became merely another element on the periodic table (somewhere near the bottom among those heavy metals). But recently, I’ve had the chance to learn how the metal makes its way from the environment into our bodies.
The occasion was one of Youth Radio’s Brains & Beakers events (watch a video of it above). Researchers from the Center for Environmental Health visited Youth Radio’s Oakland headquarters and demonstrated how they use an X-ray gun to test the chemical makeup — and safety — of fashion accessories and household items. Such everyday products pose a serious health hazard if they contain lead. Over time, the metal follows a repeated pathway from the product to your hand to your mouth and into your bloodstream.
“There’s an amazing number of health impacts due to lead,” said Caroline Cox, the Center’s research director. The most severe impacts are the result of exposure in utero and during early childhood when the brain is rapidly developing. According to Cox, a child who is exposed to lead is more likely to be arrested when he’s a teenager. In support of this theory, some economists point to how the U.S. ban on leaded gasoline in the early 1980s resulted in much less lead exposure for infants. And how in the mid 90s, when those infants were teens, the juvenile arrest rate dropped dramatically.
I had no idea these links existed, and I had to learn more about my own exposure. The Center’s researchers told us what to look out for: inexpensive jewelry, vinyl and fake leather, and anything that’s brightly colored, since manufacturers sometimes add lead compounds to paint to give their products a neon glow.
It occurred to me: what if the popular retro trend of dressing in bright colors is increasing our exposure to lead? As someone with a lot of neon in her wardrobe, I felt I had a lot at stake. So I asked Cox and her researchers to test the one fashion accessory I’m always handling — my canary yellow cell phone case.
A researcher placed my phone case in a chamber and fired X-rays at it. The rays bounced off the case and traveled back at different frequencies based on what elements were in the case. A sensor in the gun read these frequencies and after 30 seconds, a screen revealed which elements were present. I looked next to the symbol for lead, Pb, and saw the letters “ND”… not detected. Phew!
My phone case was lead free. In fact since 2009, although Cox and her team say about 5 percent of the jewelry they check still tests positive for trace amounts of lead, they have found fewer and fewer lead-contaminated products on the market.
But my relief was short-lived, because I soon learned something discomfiting from Donald Smith of UC Santa Cruz. He told me the majority of lead poisoning in children doesn’t come from consumer products; it comes from old houses painted with lead-based paints and dust contaminated years ago by leaded gasoline. My worries became less about what’s in stores and more about what’s in the larger environment.
And I asked Smith if teenagers are safe from the effects of lead, since public health efforts focus on preschool lead exposure.
“Not at all,” he said. Smith even studied elderly people who had accumulated a decade worth of lead in their bones. As osteoporosis set in and their bones began to break down, the lead seeped into their bloodstream. “So even though they weren’t being exposed to high levels of lead now,” said Smith, “lead they were exposed to as children and young adults was remobilized and increased their blood lead levels when they were adults.”
There’s no running away from what’s in our environment, and in us.
Editing was contributed by Charlie Foster. Video was produced by Charlotte Buchen with Jenny Bolario and Susana Vuong.
Youth Radio Investigates is an NSF-supported science reporting series in which young journalists collect and analyze original data with professional scientists, and then tell unexpected stories about what they discover. Check out more from Youth Radio’s science desk here.
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