Jun 10, 2013

Plastic Water Bottles Causing Cancer?

The EWG says that "BPA is associated with a number of health problems and diseases that are on the rise in the U.S. population, including breast and prostate cancer and infertility. Given widespread human exposure to BPA and hundreds of studies showing its adverse effects, the FDA and EPA must act quickly to set safe levels for BPA exposure based on the latest science on the low-dose toxicity of the chemical."
BPA is an industrial chemical whose major use is in the production of polycarbonates and epoxy resins. Polycarbonates are used in various consumer products, including a number that come into contact with food, such as certain plastic beverage containers and baby bottles, plastic dinnerware, and plastic food storage containers. Epoxy resins are part of the protective linings used in food and beverage cans, and it is likely that canned food is the major source of human consumption of BPA (in addition to that from plastic baby bottles). The plastic beverage containers that use BPA in their manufacture are the hard colored plastic bottles with the number 7 on the bottom (as opposed to PET bottles that are clear, softer and have the number 1).
 We'll never forget when Sheryl Crow attributed her breast cancer to the BPA (Bisphenol A, a chemical used in plastics) in re-used water bottles.

 According to Shanaz H. Dairkee, Ph.D., a Senior Scientist of Cancer Research at the California Pacific Medical Center Research Institute and Consulting Professor at the Stanford University School of Medicine, BPA is all around us, everywhere. "We are swimming in it," she says. "In our homes, workplaces, schools, and recreation areas." She points out that it's used to line food cans and paper plates, in beverage bottles, and even in cash register receipts.

Beverly Rubin, Ph.D., Associate Professor of Anatomy & Cellular Biology at Tufts University, says BPA is also in the soil, ground water, and in the dust that collects both indoors and outdoors. And, it's not just around us: a whopping 93% of people in the U.S. have appreciable levels of BPA in their urine, according to Cheryl S. Watson, Ph.D, the editor-in-chief of Endocrine Disruptors (Landes Bioscience Journals) and professor of bio-chemistry and molecular biology at the University of Texas Medical Branch. Dr. Dairkee says that BPA has also been found in human blood, breast milk, and fetal liver - which indicates that BPA can cross the placenta.

 The danger of BPA in our bodies lies in its relationship to estrogen, Dr. Watson says. "BPA resembles (but is not exactly like) natural estrogens, and can mimic or disrupt the actions of the body's own estrogens, for both males and females." When a body has too much estrogen, Dr. Dairkee says, it can initiate cancer and precancerous lesions in estrogen-sensitive tissues. The effect has has been proven in animals, with results that repeat across species. Though this isn't technically direct evidence that BPA causes cancer in humans, humans are indeed animals, and the results of these tests should be taken seriously.
The human papillomavirus (aka HPV) is more or less everywhere, statistically speaking. It’s estimated that 75 to 80 percent of all sexually active adults will have some form of HPV in their lifetime. Some will develop genital warts, while in others, the virus will lead to a life-threatening disease: Nearly 12,000 new cases of HPV-related cervical cancers are diagnosed in the U.S. every year, according to the Centers for Disease Control and Prevention.

“HPV is a skin-to-skin contact infection,” says Diane Harper, M.D., professor at the University of Missouri-Kansas City School of Medicine and a lead researcher of HPV and cervical cancer prevention and treatment.  Condoms can’t shield you from HPV because the virus could be lingering on skin outside of the condom. “There are over 100 types of HPV that invade the human skin, and 40 types invade the soft, wet, mucosa in the mouth, anal, and genital area,” says Harper.

It’s those 40 that have been linked to cervical cancer. “HPV-16 causes the greatest number of cancers,” says Harper. “About 90 percent of the time, HPV infections disappear within two years and never cause any ill effect. Five percent of the time, the HPV infections will turn into a cancer precursor, and about half of those cancer precursors will develop into cancer.”

 Schedule an annual ob/gyn exam to get a Pap test, which will screen for cellular changes that, left untreated, could lead to cervical cancer.

But, cautions Harper, know that a Pap is not a flawless method: “Pap screening programs are very effective but not perfect at early detection for early treatment,” she says. What’s even more frustrating is that once you have HPV (whatever the form) there’s no pill to pop or shot to get rid of it. “No anti-viral exists for it to date,” says Harper. “There is no treatment for HPV infections — the only treatment is for cells already infected with HPV that have changed into a cancer precursor or a cancer.” What that means: surgical removal to cut out the HPV-ridden growths either on the outside, or inside of your body.

 There are two vaccines, Gardasil and Cervarix, which pretty much ward off the most common strains. "Both vaccines protect against some types of HPV that cause cancer and some types that cause genital warts," says Harper, who helped develop both vaccines. "Cervarix provides better protection against cancer-causing types and Gardasil provides better protection against genital warts. But they both only protect against a limited number of HPV types, not all the types that cause cervical cancers.”

Though early detection through Pap smears has made cervical cancer relatively rare in the United States (with an annual death toll of about 4,000), lack of preventive screening and treatment results in the death of some 200,000 women in developing countries each year. In those areas, the manpower and testing laboratories often aren't available to facilitate regular check ups. However, Dr. Surendra Shastri, head of preventive oncology at Tata Memorial Hospital in Mumbai, may have come up with a solution.

Suspicious Pap smears are usually further investigated by dousing cervical cells in acetic acid, which is basically a sterile vinegar solution. This allows even less-trained healthcare workers to examine the cells under a microscope and determine if any cancerous cells are present. After conducting research comparing unscreened women to those screened with the vinegar process only for fifteen years, Dr. Shastri presented his findings yesterday to the American Society for Clinical Oncology — announcing an astounding 31% reduction in death from cervical cancer among the women regularly screened with his new method.

In India alone, implementing this process could save 22,000 women a year — and 73,000 worldwide. And, while Dr. Shastri's study benefited from the high level of organization and diligence of a controlled study, the process is simple and cheap enough that it could work miracles in areas with limited medical access. The issue lies mainly in the follow-up process; it may prove difficult to get women who test positive into hospitals for the necessary treatment. But, this is one case where knowing is quite literally half the battle; and coupled with other low-cost methods currently in development, it could mean major change in the health of women the world over.

As far as HPV leading to throat cancer, Dr. Haddard says the risk is relatively low. However, he explains, many patients with throat cancer are likely to have had HPV - it's present in two out of three cases, according to the American Cancer Society. He likens the phenomenon to smoking: "Not all smokers will develop lung cancer, but of patients who do have lung cancer, many of them are smokers." So, while having HPV does increase the risk of developing throat cancer, it's not an inevitable result. According to Dr. Haddard, smoking and drinking are much more closely linked to throat cancer.

 Additionally, as for the buzz about

 There are some preventative measures one can take. If you get the HPV vaccination, use protection when you have sex, make sure that you and/or your partner get regular Pap smears, and quit smoking.

.Of course, smoking doesn't just increase your own risk of getting cancer, it increases the risk for everyone around you. Secondhand smoke is a well-known carcinogen, but what about thirdhand smoke? Even after cigarette smoke has cleared, toxins can linger, says Dr. Jyothi Marbin, M.D., a pediatrician at Children's Hospital & Research Center Oakland.

 Some of Dr. Marbin's patients have reported that their asthma symptoms flare up in a room where someone has been smoking. ("Even long after the smoker is gone," she notes.) It's no coincidence: Thirdhand smoke contains at least 11 toxic substances, she says, "including arsenic, cyanide, and lead."

Dr. Marbin says that everyone should be concerned, but children are at a greater risk, as they spend more time indoors.

 Non-smoking adults are commonly exposed to thirdhand smoke when they stay in a hotel, ride in a car, or move into a home or a building where smoking is allowed.
It's very easy to detect thirdhand smoke - if you can smell it, it's there. But, Dr. Marbin says, it might be there even if you can't smell it. "Research studies found that even two months after a cigarette is smoked in a room, there are still measurable levels of thirdhand smoke," she says. Unfortunately, there's no publicly available test for it, and it's not easy to get rid of. Dr. Marbin suggests cleaning surfaces or fabrics with an acidic solution like vinegar, and washing walls with hot, soapy water.

 Dr. Marbin says taking a shower and washing your clothes can remove the residue.

throat cancer in straight men in particular, Dr. Haddard says that there's no evidence to indicate whether throat cancer from orally-contracted HPV is more or less likely than cervical cancer from vaginally-contracted HPV. Dr. Haddard says that oral sex is just one of many ways of contracting the virus, and advises taking safer sex precautions with all sexual activity. And, having a partner with HPV-related oral cancer does not mean that you will necessarily develop the virus or the cancer: In a recent study of partners of people with HPV-related throat cancer, the HPV subtype which can lead to throat cancer was present in 2% of female partners and actually none of the male partners.

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