Yes, it's true. Even our Christmas lights are toxic. They contain lead. And sadly, so does every other appliance which uses a UL approved cord. Some lights actually contain lead in the solder (in addition to the cord) and therefore have lead on the bulb. These lights are manufactured in China and make up the majority of light sets you can buy for a few bucks at any chain store.
We've been using these holiday lights for years and yes, they've always contained lead. But today, our environment is overrun with toxic substances and heavy metals - in our food, air, pj's, vaccines, and sadly, even in our Christmas lights.