Jordan - Regarding your TB article, , I agree that fit-testing is important and an N-95 respirator is much better than a boulder-catching surgical mask. A full-face respirator with HEPA filters would be even better, but my bet is that hospitals are using half-faced respirators. When I did respirator fit-testing in one USEPA course, none of the three half-faced respirators that I tried worked when I talked or moved my head from side-to-side. The movement broke the seal. Needless to say, hospital staff do talk and move their heads.
When I did that respirator fit testing, only a properly fitted full-faced respirator worked, and only 2 out of 3 full-faced respirators that I tried passed the fit test. People with glasses (like me) can get eyeglass inserts. Also, a beard will prevent an adequate fit. Don't ask me how many times I've seen people with beards wearing respirators that they bought at a hardware store. Between not being properly fit-tested and the bypass created by the beard, they're worthless. Personally, I wouldn't trust a respirator that isn't fit-tested, period, with absolutely no exceptions whatsoever (am I perfectly clear?). The U.S. representative who is trying to stop fit-testing for hospital workers is totally ignoring the science, and if passed, I predict increased infections of all sorts. Also, God help us if this passes and some terrorist releases large quantities of Anthrax or the like. They'll take out the hospitals along with everything else. What we had in the mail was "bionuissance" compared to what someone really could do, I'm afraid.
Regarding linking cancer and pollution in China, having gone there in 2000 to adopt a little girl (who's doing great), I can attest that the pollution is incredible there. The pollution covers the cities and countryside in a thick haze. While there, we felt constant eye, nose, and throat irritation. I'm sure that the air pollution contributes to increased mortality from respiratory and cardiovascular diseases, including lung cancer.
However, that's not the whole story. One other item of note is that many Chinese males smoke (almost half), which would compound their (and their family's) risk. In fact, I wouldn't be surprised if the risk from smoking (first- and second-hand smoke) is the larger cancer risk. Of course, adding air pollutants could add or synergize the risks. No one (I hope) would call for less stringent asbestos standards for non-smokers (maybe we shouldn't give GW any ideas, though).
Another item of note is that most Chinese heat and cook with a coal-burning or charcoal-burning stove, which isn't vented too well. They generally don't have separate furnaces for their homes. I remember reading an article a while back about arsenic poisoning in one Chinese provence where the people burned high-arsenic coal in their homes. The inhalation of arsenic has been associated with lung cancer (and ingestion with skin and bladder cancer - unsure if their water was also contaminated with arsenic, but boiling to make the water "safe" would concentrate the arsenic). Consequently, the Chinese also exposed to exhaust from the coal/charcoal burning in their home stoves, which also likely contributes to their problems.
We toured a jade factory where workers lacked eye and hearing protection, which certainly would have been required in the U.S. If, as I assume, their general industrial respiratory and skin protection standards are as lax, that also could contribute to the problem.
General santition is very poor in China. The rivers smell like open sewers, and you can't drink the water without boiling it. We wondered if we were cleaner before or after we took a shower (probably before). An estimated 25% to 35% of the Chinese people are infected with hepatitis, which is spread by sewage. It can survive on surfaces for up to a week and still remain infective. The virus that causes hepatitis B also is a primary cause of liver cancer, which is very prevalent in China.
Industrial chemicals dumped into water supplies, while not good, probably do not cause a large enough increase in cancers to be readily noticed without a sophisticated epidemiologic study. You might get a 1/10,000 or so increased risk, but probably not of the magnitude you observe from smoking, air pollution, or hepatitis. I'm certainly not defending the industries, and I certainly think that the pollution should be reduced; I'm just trying to put things into perspective.Finally, we get many calls from people concerned about "cancer clusters." In almost all cases, epidemiologic studies show that the cancer rates are no greater than background levels. Many people don't realize how common cancer is, affecting about 1/3 of all people at some point in their lives. It's important to do a scientific study to determine if a perceived cancer cluster is real. In the case of China, I'd be surprised if lung cancer rates in particular weren't elevated.
Wednesday, September 15, 2004
Mail: Respirators and China
I get mail. Sometimes long, sometimes short. Sometimes supportive and sometimes so profane, it would make Dick Cheney blush. Some of it I keep to myself, but I though all of you might enjoy this not from an anonymous state government employee: