After a discussion about the reliability of a story about tea leaves being dried in a Chinese factory by driving leaded-gasoline-fueled trucks over them, thus contaminating them with lead, I decided to find out the source of the information. I easily found the same quotation of a statement made by William Hubbard, the former deputy commissioner of the FDA, repeated in many places:
“To speed up the drying process, they would lay the tea leaves out on a huge warehouse floor and drive trucks over them so that the exhaust would more rapidly dry the leaves out,” Hubbard says. “And the problem there is that the Chinese use leaded gasoline, so they were essentially spewing the lead over all these leaves.”
In most cases this information was presented absent any additional details, even such important details as where in China the factory was or what kind of tea was being produced. The quote was frequently used to bolster the claim that drinking Chinese tea AT ALL was categorically unsafe.
Eventually I found the source article, an NPR piece from May of 2007 by Richard Knox called “As Imports Increase, a Tense Dependence on China.” In this case the importance of getting as close to the original piece of information as possible was made clear in the paragraph preceding the oft-quoted passage, which reveals that this incident was not observed by Hubbard himself, but was relayed to him by the direct observer, and more importantly, that the factory in question was an herbal tea factory, not a factory producing tea from the camellia sinensis plant. It was unclear from the article how long ago this practice had been observed, but it was while Hubbard was still with the FDA, prior to the story. The additional important paragraph of this story reads:
When Hubbard was at the FDA, he heard all kinds of stories about foreign food processors, like the one a staffer told him after visiting a Chinese factory that makes herbal tea.
The impact and importance of this detail to tea drinkers is obvious. The practice of truck exhaust drying of plant materials may or may not be common, but I could find no evidence that it was used for drying actual tea leaves. This would, in fact, not be advantageous for any producer of pure leaf, high-end tea since it would impart an awful taste to the tea leaf. It seems a safe assumption that none of the people accustomed to drinking high quality tea would appreciate the aromatic “nose of gasoline” that would be prominent.
Chinese medicinal teas, on the other hand, which I assume were the end product of this “herbal tea factory,” have a greater amount of flexibility in taste, particularly when a large number of ingredients are present, which is often the case with such drinks. The story, while still very sketchy on the details, might be incentive enough to recommend avoiding consumption of those low-cost boxes of tea-bagged multiple herbal ingredient teas from China, but I don’t see an indication that this story should be extrapolated into a caution against Chinese teas in general, and particularly not against higher quality whole leaf pure teas.
One thing that I find interesting about the whole thing is the number of sources who picked up the same part of the story and repeated it verbatim, without additional citations or research. I wasn’t able to find a single reference to tea drying in China using truck exhaust outside of references to the original statement by Hubbard. Of course this conclusion does not point towards an assumption that all food products in or coming out of China (or anywhere else) should always be trusted to be safe for consumption, but the story is not giving me cause to worry about the possible presence of exhaust fumes in the Chinese teas I drink.