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Research Notes: Environmental HealthSee also: (09/06/07 - London Guardian) Danger to children from food and drink additives is exposed Parents are to be warned of the dangers of giving their young children drinks, sweets and cakes containing specified artificial additives, as a result of new findings being made public for the first time today which confirm their link with hyperactivity and disruptive behaviour. The government's Food Standards Agency is taking the significant step of issuing revised guidance to consumers recommending that they steer clear of products containing certain E-numbers if their children are showing signs of hyperactivity or attention deficit hyperactivity disorder (ADHD). The release of the new public health advice follows the results of the biggest UK study into the links between hyper-activity and chemical food additives, which was commissioned by the government and published today in the medical journal the Lancet. But the move has confounded experts and health campaigners, who say the government had missed an opportunity to take a tougher line by banning the additives completely instead of placing a huge burden on parents. Adults are being advised to check for additives by scrutinising labels, yet many sweets and cakes are sold loose without labels, as is ice cream. The FSA also said it would not be issuing any formal advice about the findings to headteachers about the content of school meals via the School Food Trust. The agency said yesterday it was passing them to the European Food Safety Authority for it to make a decision about a ban as part of re-evaluation of the safety of all food colours. Hyperactivity is a behaviour officially indicated by increased movement, impulsiveness and inattention, and can impair learning. It is unclear how many people in the UK are affected by hyperactivity conditions. In its more severe form ADHD is believed to affect between 2.4% and 5% of the population. For their research, scientists from Southampton University recorded the responses of 153 three-year-olds and 144 eight to nine year-olds to mixes of additives placed in different drinks; they found that artificial food colour and additives were having "deleterious effects". The children drank mixtures of additives, which included artificial colourings and the preservative sodium benzoate, which is commonly used in soft drinks. The mixtures were designed to reflect what a typical child might eat in the course of a normal day. The results of the Southampton study show that when the children were given the drinks containing the test mixtures there was an increase in hyperactivity. However, the responses were not consistent; some children reacted significantly, others not at all. The study found that the deterioration in behaviour after consuming the additives occurred in children in the general population, not just in those identified as suffering from hyperactivity. Professor Jim Stevenson, who headed the Southampton study, said: "We now have clear evidence that mixtures of certain food colours and benzoate preservative can adversely influence the behaviour of children. There is some previous evidence that some children with behavioural disorders could benefit from the removal of certain food colours from their diet." He said it was his "personal view" that the government could easily have taken a tougher line and banned the colours, although he admitted the issue of sodium benzoate was more complex. Dr Andrew Wadge, the FSA's chief scientist, said: "We have revised our advice to consumers: if a child shows signs of hyperactivity or ADHD then eliminating the colours used in the Southampton study from their diet might have some beneficial effects." He went on: "If parents are concerned about any additives they should remember that, by law, food additives must be listed on the label so they can make the choice to avoid the product if they want to." A spokesman for the Hyperactive Children's Support Group said: "This research confirms what many of us have known for 30 years. But we seriously question the implementation of the new advice. Is it practical to expect parents to quiz headteachers about additives in school meals, or to ask parents about the contents of party bags?" Popular drinks and sweets that still contain one or more of the named additives include Diet Coke, Irn-Bru, Orangina, Refreshers and Skittles. Richard Watts, coordinator of the Children's Food Campaign, said: "The junk food diet turns out to be bad for children's mental health, as well as their physical health. We need to go further to make parents aware of the potential health problems created by additives, as well as do more to persuade children to eat less E-number-riddled junk food by restricting its marketing and labelling it clearly." ... (09/06/07 - Japan Times) PCB-like toxin in breast milk, scientists warn A toxic substance similar to the pollutant polychlorinated biphenyl, or PCB, has been found in the breast milk of Japanese women, according to a group of Japan-based scientists. On Tuesday, the group announced at a session of the ongoing international conference Dioxin 2007 in Tokyo its discovery of polychlorinated/brominated coplanar biphenyls, or Co-PXBs, in mothers' milk. The contaminants are thought linked to the eating of fish. The group is urging authorities to add Co-PXBs to a list of toxic substances being monitored under a law aimed at controlling dioxin. The toxicity level of Co-PXBs is apparently similar to that of PCBs. The group warned that the adverse effects of Co-PXBs on babies have possibly been underestimated. "It was the first discovery of the contamination of humans by these materials," said Soichi Ota, associate professor of medicine at Setsunan University in Osaka Prefecture, who led the group. "One of the causes of the human contamination is believed to be the intake of fish, as it has been confirmed Co-PXBs contaminated fish in many regions in the world," Ota said. "It will be an urgent task to assess the effect on human beings and determine the origin," Ota said, referring to the possibility that Co-PXBs may also originate from incinerated garbage or factory wastewater. The group of scientists said they detected 0.42-1.41 picograms of Co-PXBs per gram of fat in the breast milk of seven women in Japan aged 21-33. Co-PXBs were also found in meat and fish from regions around Japan as well as minke whales in the Antarctic Ocean. (09/06/07 - The Province/Canada.com) Report buttresses argument against power lines A scientific report released late last week joins others in raising serious public-health concerns over long-term exposure to electromagnetic fields from high-voltage power lines. This one was compiled by international scientists, researchers and public-health professionals from the University at Albany in New York state, and concludes that existing limits are inadequate for public health. Such emissions are linked to increased cases of childhood leukemia and adult cancers later in life. That got the attention of the Tsawwassen Residents Against Higher Voltage Overhead Lines, a group trying to block the B.C. Transmission Corp.'s plan to replace two existing 138-kilovolt transmission lines that run through their back yards, parks and the local high school with 40-metre towers carrying 230-kilovolt power lines to Vancouver Island. Evidence at last year's B.C. Utilities Commission hearing, which gave the project a green light, was that the new high-voltage lines will emit 149 milligauss - or almost 150 times the report's recommended EMF levels. The problem here is that the linkage of EMF exposure to cancer has not been proven absolutely, unlike tobacco use or exposure to asbestos. But increasingly, studies conclude such links exist, and the Tsawwassen residents' group has turned to the Supreme Court of Canada, where it seeks leave to appeal on the grounds that if an EMF health risk is even suspected, the project shouldn't be built. This is called the "precautionary principle," and it's been adopted by some governments and jurisdictions, including the United Nations. But the residents' group says concerns reach beyond caution. During the utilities commission hearing, the group introduced affidavits from 58 households showing an above-average rate of cancer among family members - and among household pets - along the power-line route. However, despite the residents offering a viable route or construction alternatives to reduce or eliminate these risks, the provincial Crown corporation and Gordon Campbell's government have refused to back down on the proposed routing. The residents' group thinks it knows why. "If we're successful in court, it'll set a huge precedent for the government and the BCTC because much more due diligence will have to be applied to these projects," says group co-chairman Cec Dunn. Adds director Bernadette Kudzin: "Because the B.C. transmission grid is so old, the Tsawwassen project is only the start of a lot of upgrading - this is all about money." Kudzin is particularly concerned about the lines crossing South Delta Senior Secondary School's grounds. "Most of the high-school kids in our neighbourhood go to that school, so they live under these power lines 24/7," she says. Group members also point out that the existing 28-year-old limit of 833 milligauss, which the transmission corporation often cites, is only for short-term exposure. They say there are no EMF limits in Canada for long-term exposure. For its part, the transmission corporation is fully aware of the studies but says it's sticking with the current EMF guidelines even though this latest report say they're not good enough. Clearly, only the country's highest court will be able to decide this issue. (09/05/07 - Environmental Science & Technology) Swimming in chlorine byproducts When athletes at this year's U.S. national swimming championships found themselves gasping for breath while competing at the indoor pool at Indianapolis University, event organizers said the culprit most likely was the disinfection byproducts (DBPs) from the chlorine meant to keep the pool clean. Swimmers' lung troubles—and other possible long-term health effects—generally have been attributed to breathing chloroform, trihalomethanes, and trichloramines, which form in such settings and volatilize at the water's surface. But new research published in ES&T indicates that other byproducts hidden in the watery mix also might be to blame. At the water's surface, swimmers breathe in a mix of volatilized disinfection byproducts, including some recently discovered to form in chlorinated swimming pools.As people have increasingly turned to swimming for its health benefits, a flurry of research relating swimming-pool-water treatment to potentially hazardous byproducts has come down the pike in the past year. Alfred Bernard of the Catholic University of Louvain (Belgium) and colleagues have published data in the past several years that connect early childhood exposures to indoor swimming pools with the development of asthma later in life. Higher chloramine levels in indoor-swimming-pool air have been correlated with upper respiratory complaints from pool workers and swimmers, and chloroform and bromodichloromethane levels in swimmers' and workers' urine have been suggested as markers of trihalomethane exposures. Trihalomethanes or trichloramine typically are blamed, says Thomas Lachocki, head of the National Swimming Pool Foundation. But in the new work (funded partly by the foundation), Jing Li and Ernest "Chip" Blatchley, III, of Purdue University find a fuller spectrum of DBPs with a technique called membrane introduction mass spectrometry (MIMS). From laboratory experiments and assessments of four indoor swimming pools, an outdoor pool, and a recreational water park, the researchers teased out evidence of several compounds, including trichloramine, dichloromethylamine, cyanogen chloride, and dichloroacetonitrile. The authors are the first to report the formation of organic chloramines in pools, in addition to the inorganic chloramines and haloforms already known to be there. "Dichloroacetonitrile has been identified as a respiratory irritant, so it is possible that some of these newly identified volatile pool DBPs may also contribute to asthma observed in swimmers," says Susan Richardson of the U.S. EPA. She hypothesizes that the presence of dichloromethylamine — which is not a known DBP in drinking water — may be particularly significant. "I think this is a very important study, taking us beyond the inorganic chloramines and THMs," or trihalomethanes. Although MIMS has the potential advantage of being portable, Richardson would like to see the spectra confirmed by gas chromatography/mass spectrometry. Christian Zwiener, who studies the effects of trichloramine on lung cells among other water-quality issues at the University of Karlsruhe (Germany), notes that it would be difficult to identify some of these compounds with either method. Blatchley says that he and his colleagues plan to sample more swimming pools with a newly developed portable MIMS device that has real-time, sequential, and multiple sampling capabilities. "The reality is that not a lot of research is done in the arena of public swimming exposures and health," says Lachocki. "The question [the new study] leads to really is, is this of toxicological significance?" Swimming has health benefits that need to be weighed against the risks of chemical exposures, he emphasizes. Treatments to reduce DBP loads include circulating water through traditional sand filters and implementing UV light, a newer method that could reduce the precursors that would react with chlorine. The pools in Germany, which tend to use much less chlorine compared with the U.S., according to Zwiener, use flocculation methods or regularly replace pool water to avoid extreme DBP production. Many researchers who are focused on the DBP–asthma connection met in Belgium last month for a workshop to discuss the state of the science and where to go next. (08/16/07 - Los Angeles Times) Cat thyroid disease linked to chemicals An epidemic of thyroid disease among pet cats could be caused by toxic flame retardants that are widely found in household dust and some pet food, government scientists reported Wednesday. The often-lethal disease was rare in cats until the 1980s, when it began appearing widely, particularly in California cats. That was at the same time industry started using large volumes of brominated flame retardants in consumer products, including furniture cushions, electronics, mattresses and carpet padding. Scientists from the Environmental Protection Agency noted a possible connection between hyperthyroidism and flame retardants. The chemicals - known as polybrominated diphenyl ethers, or PBDEs - mimic thyroid hormones, so experts have theorized that high exposure in cats could cause overactive thyroids. Cats that remain indoors and eat fish-flavored canned food were found to be the most highly contaminated. "We know there is an association between indoor living for cats and hyperthyroidism," said Linda Birnbaum, a senior author of the study and the EPA's director of experimental toxicology. "Our paper does show cats are highly exposed and hyperthyroidism may be due to the high PBDEs. More studies are needed to fully determine this." A major unanswered question is whether cats are the proverbial canaries in the coal mine, signaling health dangers for their owners. Cats and human beings are the only mammals with a high rate of hyperthyroidism. So far, no link has been established between human endocrine disorders and exposure to flame retardants. However, "there is growing concern," the scientists wrote. "It is clear that house cats may be able to serve as sentinels for indoor exposure to PBDEs for humans who share their houses," said Birnbaum, one of the world's leading experts on hormone-altering chemicals. Brominated flame retardants are ubiquitous outdoors and inside homes. The chemicals have been building up in people and wildlife over the last two decades, particularly in the United States, where human concentrations have doubled every few years. People in the United States have the highest PBDE levels in humans worldwide, but U.S. cats are even more exposed - some with levels 100 times greater, according to the study. Twenty-three cats were tested in the EPA's study, including 11 with hyperthyroidism. The researchers found that the cats with hyperthyroidism had substantially higher levels of a PBDE compound. Symptoms of the disease, which is a leading cause of cat death, include weight loss, rapid heartbeat and irritability. "Our results demonstrated that cats are being consistently exposed to PBDEs, an endocrine-disrupting environmental contaminant," the research team, led by Janice Dye and Marta Venier of the EPA's National Health and Environmental Effects Research Laboratory in North Carolina, wrote in their study published in the journal Environmental Science & Technology. Because of this exposure, "cats may be at increased risk for developing thyroid hyperplastic changes." Myrto Petreas, branch chief of environmental chemistry at the California Department of Toxic Substances Control, said that the cat study was small but that it reaffirmed health concerns not only for cats but humans too, "especially children, anyone exposed to high levels." "PBDEs are in consumer products, so we get exposed while we use the products in homes and during the lifetime of the products. We inhale or ingest dust, mostly from hand-to-mouth transfer," said Petreas, who did not participate in the study. The risk to cats that eat dry food and live in homes with average contamination is minimal, the study said, while "at the other extreme, maximal PBDE exposure" occurs in cats that eat fish-flavored canned food and live in houses with highly contaminated dust. Cats that eat canned food containing whitefish, salmon and other seafood are exposed to PBDE levels up to 12 times higher than cats that eat dry food, and five times more than cats that eat poultry or beef canned foods, the study said. The chemicals build up in oceans and other water bodies and magnify in food chains. However, much of the exposure - for cats as well as people - comes from dust, not food. Cats, while sleeping, often come in direct and prolonged contact with upholstery, carpeting and mattress materials that contain flame retardants. In addition, they often sit on electronic equipment. "Because of their meticulous grooming behavior, cats would effectively ingest any volatilized PBDEs or PBDE-laden dust that deposited on their fur during such activities," the scientists wrote. Scientists say toddlers who crawl on floors and put objects in their mouths also can be highly exposed to the chemical-tainted dust, which has been found in most U.S. homes. In people and cats with the highest levels, Petreas said, "it's explained not by diet, but more contact with contaminated sofas, computers and other consumer products." Two pervasive PBDEs, used mostly in foam cushions, mattresses and carpet padding, have been banned in the United States since 2004. The ban was spurred by a California law. However, other brominated flame retardants remain in widespread use. In June, the California Assembly passed AB 706, written by Assemblyman Mark Leno (D-San Francisco), which would prohibit brominated and chlorinated flame retardants in furniture and bedding. The bill, which now goes to the Senate Appropriations Committee, does not ban their use in electronics. California has the nation's strictest fire-retardant standards for furnishings, so PBDE exposure is generally higher than elsewhere. The cat epidemic showed up first in California and the Great Lakes region - the areas with the highest environmental levels of the chemicals. (08/16/07 - Oakland Tribune) Flame retardants linked to thyroid disease in cats A mysterious epidemic of thyroid disease in cats may be linked to flame retardants common in carpets, foam furniture and mattresses, according to U.S. Environmental Protection Agency researchers, who suggest that scientists have underestimated the damaging health risk the chemicals pose to humans. The research, published Wednesday in the journal Environmental Science and Technology, does not prove these compounds, known as PBDEs, caused the rash of hyperthyroidism in the nation's household cats over the past 30 years. Rather, it lays out a hypothesis, showing that cats are heavily contaminated by these compounds, which leach from household products and are found everywhere, particularly household dust. Cats, meticulous cleaners, ingest PBDE-contaminated dust daily. The rise of feline hyperthyroidism - a rare disorder prior to 1980 that today is a leading cause of death in older cats -- matches the increasing sales of PBDEs, or polybrominated diphenyl ethers. The study was conducted jointly by researchers at the EPA's National Health and Environmental Effects Laboratory and Indiana University. These cats, they note, are the proverbial canaries for humans, who spend upward of 90 percent of the day indoors, according to some estimates. Pound for pound, a 2-year-old ingests nearly as much dust as a cat, based on EPA estimates. And while the blood of everyone living in the developed world is thought to be contaminated with PBDEs, Americans have by far the highest levels - 10 to 100 times higher than residents of Japan and Europe. The spike in hyperthyroidism in cats suggests long-term, low-dose exposure to these compounds is far more endocrine disrupting than laboratory experiments indicate. "Cats are in the right place to be exposed. They're in our homes, they're on our carpets, sometimes they're on our appliances and furniture," said Janice Dye, an EPA veterinarian and research biologist who was one of the paper's lead authors. "We know they're being exposed. We know these (PBDEs) have the potential to be endocrine disrupting compounds. We know they can bind to the thyroid hormone." The epidemic of hyperthyroidism in older cats, Dye added, is likely a result of the thyroid gland responding to chronic disruption over a very long period of time. John Kyte, a spokesman for the Bromine Science and Environment Forum, an industry group, noted the study was small and that other research attributes the epidemic to increased awareness and longer feline life spans. "In other words, the increase in the number of cases diagnosed is not at all surprising, and it is speculation to try to link it to flame retardants," he said in a statement. "This is an issue that bears watching, and we will see what additional research indicates, but people should not be making broad conclusions based on this single, very limited study" Millions of pounds of PBDEs known as Penta and Octa were added annually to foam in furniture until 2004, when California and Europe banned them and the nation's sole manufacturer voluntarily agreed to cease production. A third PBDE known as Deca continues to be mixed with hard plastic and is today found in various household appliances, with the United States making up more than half the global market. The thyroid gland is the body's regulator, controlling how quickly the body burns energy, makes proteins and responds to other hormones. Before 1980, hyperthyroidism in cats was unheard of; today it is one of the most prevalent health problems in older cats and a leading cause of death. Hyperthyroidism accelerates the body's metabolism. Typical symptoms in cats are increased appetite, weight loss, irritability, lethargy and diarrhea. "It's quite astounding," said Michael Sozanski, a veterinarian at VCA Albany Animal Hospital. "For us it's become somewhat of a routine diagnosis and treatment. But to see something that's become an epidemic in that time frame is quite scary." Sozanski easily recalls the day in vet school in 1979 when he gathered in the ward with classmates and heard a professor say they'd likely never see another cat with hyperthyroidism in their careers. Today he averages a case a day. But it's the human effects that have researchers concerned. PBDEs, or polybrominated diphenyl ethers, contaminate virtually every house dust sample ever analyzed. Young children, with their smaller size and tendency to mouth objects, are likely as highly contaminated as cats, the EPA researchers estimated. Though children quickly outgrow such tendencies, they're exposed at a critical developmental window to a far higher load of endocrine-disrupting compounds than adults. "People are just beginning to look to see if we can find anything in the human population," said Linda Birnbaum, research director of the EPA's Health Effects Laboratory and a paper co-author. "Nobody's done any long-term studies with these." The findings also lend a sense of urgency to a bill, working its way through the Legislature, to ban these chemicals from commerce, said Arlene Blum, a Berkeley chemist and one of the bill's backers. The bill, AB 706, would ban any brominated or chlorinated flame retardants from bedding, mattresses and furniture sold in California. It's no small irony to Blum that her 15-year-old cat, Midnight, suffers from hyperthyroidism. She's had her house dust tested for PBDEs. It's off the charts. She learned earlier this year that the foam in her furniture -- a J.C. Penney-brand sofa, easy chair and recliner bought in a thrift store in 1987 - is saturated with PBDEs. "Can you believe 5 percent of the foam, by weight, in the chair I bought to nurse my daughter is PBDEs?" she asked. "I wish someone would look at people. If it's happening to Midnight, the rest of us can't be too far behind." (08/14/07 - USA Today) Hospitals move to phase out chemical Newborns in hospital intensive care units are vulnerable in so many ways. Their paper-thin skin can be torn by medical tape. Their lungs may not be developed enough to supply their tiny bodies with oxygen. Their immature immune systems leave them susceptible to a wide world of germs. Now, a growing number of hospitals are trying to protect babies like these from a newly recognized threat — the medical equipment that provides them with lifesaving blood, medicine or nutrition. The plastic used in intravenous tubing, blood bags and other products — DEHP, or di(2-ethylhexyl) phthalate — can leach a hormone-like chemical linked to reproductive problems, says Richard Grady, interim chief of pediatric urology at Seattle's Children's Hospital & Regional Medical Center. While doctors agree that the benefits of specialized care for newborns outweigh the potential risks from plastic devices, leading medical organizations now say that hospitals should find safer substitutes whenever possible. Grady notes that even minute amounts of hormones could cause problems for infants whose organs are still developing, especially newborn boys who spends weeks in neonatal intensive care units, or NICUs. Manufacturers say their products are safe and note that there are only a few human studies of DEHP. Many doctors and nurses say they're concerned, however, about animal studies that suggest the chemical can suppress testosterone, impair fertility and alter the development of reproductive organs. The Seattle hospital and more than 100 others across the USA have pledged to begin phasing out DEHP. Influential groups such as the American Medical Association and American Nurses Association in recent months also have urged hospitals to find safer substitutes. Officials at hospitals such as Lucile Packard Children's Hospital at Stanford and John Muir Medical Center in Walnut Creek, Calif., say they've saved money since making the switch. While some DEHP-free products are cheaper, others are lighter, which saves money on waste disposal. Jolene Farris of San Jose, Calif. had never heard of DEHP before giving birth last week. But she says she's glad that he's in a hospital using safer plastics to treat her son, Jameson, who was born about 8 weeks early. "They're already so small, why take the chance?" Farris asks. "It absolutely makes me feel safer." But Grady says avoiding DEHP — which he calls "the everywhere chemical" — is no easy task. Beyond IV tubes, DEHP — which adds flexibility to polyvinyl chloride plastic, or PVC — is also found in a variety of consumer products, including flooring, wallpaper, auto upholstery, food packaging and toys. Plastics often have no labels listing their ingredients, says Kathy Gerwig, vice president of workplace safety at Kaiser Permanente, the country's largest non-profit health system. "There's no way to know just by looking," says Gerwig, who says Kaiser now has phased out all DEHP in its neonatal intensive care units, except where substitutes are unavailable. "It was a hunt and guess process." Manufacturers often refused to reveal the ingredients in their products, noting that ingredients are trade secrets, Gerwig says. "Even given our enormous size and buying power, we have had relatively little power getting this information," she says. "It really puts the burden on the user." That's why Kaiser, the AMA and others support a petition, filed by a coalition of medical groups called Health Care Without Harm, asking the Food and Drug Administration to require manufacturers to label plastics that could expose patients to DEHP. Although the FDA rejected the group's petitions in 1999 and 2001, the agency did advise hospitals in 2002 to find alternatives to DEHP, especially for the most vulnerable patients: male newborns, pregnant women carrying boys and boys near puberty. Concern about DEHP — which belongs to a class of chemicals called phthalates — has grown steadily since. Government studies have found the chemical in about 80% of Americans tested. In December, the government's highly respected National Toxicology Program concluded there is "serious" concern — its highest level — that DEHP could harm critically ill baby boys. The program also found reason for "concern" — its second-highest level — in boys younger than 12 months and those born to pregnant women undergoing certain medical treatments. Marian Stanley of the American Chemistry Council describes those risks as "theoretical," because of the scarcity of human studies. She said the federal report was "erring on the precautionary side, because you can't really get exposure information from these tiny infants." Researchers say that the few available human studies add to worries about DEHP. A 2005 study in Environmental Health Perspectives found that more intensive medical care increased the amount of DEHP in the bodies of newborn boys. In another study that year, Shanna Swan of the University of Rochester School of Medicine found differences in the reproductive organs of boys whose mothers were exposed to higher levels of several phthalates. More highly exposed boys had a shorter distance between their anus and the base of their penis, a measurement that is usually longer in boys than in girls. Boys in whom this distance was shorter were also more likely to have incompletely descended testes. The FDA hasn't yet answered the petition on DEHP, filed in late July. But the agency is working with international agencies to assess DEHP's risks and find a safe exposure level for hospitalized patients, says spokeswoman Karen Riley. That will help the FDA decide on labeling or further recommendations. Some manufacturers say they're already seeing a boom in DEHP-free goods. B. Braun Medical Inc., a Pennsylvania-based manufacturer, is even building a new facility to help keep up with demand. With a burgeoning range of consumers choices, Allen Blakey, a spokesman for a trade group called the Vinyl Institute, says there's no need for FDA labeling. But others are forging ahead. Catholic Healthcare West, a network of 40 hospitals in California, Arizona and Nevada, is making many environmental improvements, says Sister Mary Ellen Leciejewski, ecology program coordinator. Beyond using only DEHP-free IV bags and tubing, the network has eliminated most mercury and hopes to replace vinyl-backed carpeting. Robert Felicelli of Hospira, Inc., an Illinois-based manufacturer, notes that hospitals are attracted to DEHP substitutes for many reasons. For example, Hospira's DEHP-free plastics create 40% to 70% less waste, he says. Avoiding PVC plastics helps the environment in many ways, Leciejewski says. Producing and incinerating PVC plastic releases dioxins, a class of potent carcinogen. Blakey notes that PVC plastics product a very small amount of all the dioxins released. "They're not going to get rid of dioxin by getting rid of PVC devices," Blakey says. "The Hippocratic Oath says to do no harm," Leciejewski says. "We should be going to these alternatives if at all possible." More information about DEHP — and a list of hospitals phasing out the chemical — can be found at Health Care Without Harm, which advocates "environmentally responsible healthcare," at www.noharm.org/us. Information also is available at the American Chemistry Council's Phthalate Information Center, which provides the plastics industry's perspective, at www.phthalates.org. (07/30/207 - Los Angeles Times) Pesticide link to autism suspected Women who live near California farm fields sprayed with organochlorine pesticides may be more likely to give birth to children with autism, according to a study by state health officials to be published today. The rate of autism among the children of 29 women who lived near the fields was extremely high, suggesting that exposure to the insecticides in the womb might have played a role. The study is the first to report a link between pesticides and the neurological disorder, which affects one in every 150 children. But the state scientists cautioned that their finding is highly preliminary because of the small number of women and children involved and lack of evidence from other studies. "We want to emphasize that this is exploratory research," said Dr. Mark Horton, director of the California Department of Public Health. "We have found very preliminary data that there may be an association. We are in no way concluding that there is a causal relationship between pesticide exposure of pregnant women and autism." The two pesticides implicated are older-generation compounds developed in the 1950s and used to kill mites, primarily on cotton as well as some vegetables and other crops. Their volumes have declined substantially in recent years. Examining three years of birth records and pesticide data, scientists from the Public Health Department determined that the Central Valley women lived within 500 meters, or 547 yards, of fields sprayed with organochlorine pesticides during their first trimester of pregnancy. Eight of them, or 28%, had children with autism. Their rate of autism was six times greater than for mothers who did not live near the fields, the study said. Susan Kegley, senior scientist of Pesticide Action Network North America, a San Francisco-based advocacy group, said the report adds to an existing body of evidence that endosulfan and dicofol, already banned in some countries, are harmful. "This is one of the first papers that links use of pesticide to incidence of a disease, and autism in particular," she said. "The findings are very strong. This is a sixfold risk factor in comparison to someone who is not exposed. There aren't too many studies that come out like that." Even though small numbers of children were involved, "it is still one of those things that make you sit up and pay attention," she said. The findings suggest that 7% of autism cases in the Central Valley during the years studied — 1996 through 1998 — might have been connected to exposure to the insecticides drifting off fields into residential areas. Births during those years were analyzed because children born later might not yet be diagnosed with autism. Children with autism spectrum disorders have impaired social and communication skills. The causes are unknown, but because diagnoses have been increasing, scientists have been exploring various environmental factors, including children's vaccines and chemical pollutants. "The good news is we've used a new research technology to generate hypotheses and possible associations, so we are making progress in the battle to get more information" about the cause of autism, Horton said. The goal of the study was to "systematically explore the general hypothesis that residential proximity to agricultural pesticide applications during pregnancy could be associated with autism spectrum disorders in offspring," the authors wrote in their study, published online today in the scientific journal Environmental Health Perspectives. The scientists collected records of nearly 300,000 children born in the 19 counties of the Sacramento and San Joaquin river valleys. Of those children, 465 had autism. The scientists then compared the addresses during pregnancy to state records that detailed the location of fields sprayed with several hundred pesticides. For most pesticides, no unusual numbers of autism cases were found, but the exception was a class of compounds called organochlorines. Most, including DDT, were banned in the United States several decades ago because they were building up in the environment. Only dicofol and endosulfan remain. The autism rate was highest for children of those mothers who lived the closest to the fields and it declined as the distance from the fields increased. There is no other human or animal evidence that the two chemicals can cause autism. But both affect nerves and the brain — and cause reproductive effects and alter hormones in animal tests. In addition, dicofol is a possible human carcinogen. The scientists concluded that "the possibility of a connection between gestational exposure to organochlorine pesticides and autism spectrum disorders requires further study." A July report by the state Department of Pesticide Regulation said endosulfan can spread far from fields via the air and expose the public, based on air monitoring in Fresno, Monterey and Tulare counties. The agency is likely to designate endosulfan as a toxic air contaminant soon, and dicofol could follow. That designation triggers a review by the agency to see whether steps should be taken to minimize the chemicals drifting off fields into nearby communities. Glenn Brank, spokesman for the pesticide agency, said officials there are "very interested" in the new autism data but say that "more work" on the potential link is needed before it can carry much weight in assessments of the chemicals' risks. The two insecticides are now used much less often than in the years in which the possible connection to autism was found. As a result, there is less likelihood that pregnant women are exposed today. Nearly 774,000 pounds were applied in 1996, compared with 277,000 pounds in 2005, down nearly 64%, according to state records. "In the past couple years, the bottom has dropped out of these two," Brank said. Insects have built up resistance and cotton farmers have switched to new compounds. The two chemicals are not found in household or yard pesticides. Traces are found in food, but the study looked only at possible exposure from the air. The chemicals are used most extensively in Fresno, Kings, Imperial and Tulare counties. Dicofol is mostly used on cotton, oranges, beans and walnuts. Endosulfan is used primarily in tomato processing and on lettuce, alfalfa and cotton crops. (07/25/07 - Environmental Safety & Technology) Dioxins linked with behavioral disorders Two clinically significant behavioral disorders, namely learning disabilities and attention deficit disorder, have been linked with low or average blood serum concentrations of two dioxins and one furan. Researchers say these are the first indicators of a connection between such levels of persistent organic pollutants and diagnosed behavioral problems in children in the general population. Previous work has shown a correlation between these chemicals and reductions in cognitive function indicators. The findings, by Duk-Hee Lee with Kyungpook National University School of Medicine (South Korea) and colleagues from Spain and the U.S., were published in the Journal of Epidemiology and Community Health (2007, 61, 591–596). The team discovered the link after reviewing 1999–2000 data for seven polychlorinated compounds as well as lead and cadmium from the U.S. Centers for Disease Control and Prevention's (CDC's) National Health and Nutrition Examination Survey. In 278 children aged 12–15, those who had detectable concentrations of three of the polychlorinated compounds were about 2–3 times as likely as those without detectable concentrations to report that they had been diagnosed with a learning disability. The researchers also found that exposure to two of those three compounds was linked with reports of a diagnosis of attention deficit disorder. The affected children tended to be white and to have mothers who were younger and smoked during pregnancy. The tested concentrations of the three implicated compounds — 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HPCDD); 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin(OCDD); and 1,2,3,4,6,7,8-heptachlorodibenzofuran (HPCDF) — were in the middle or lower end of the concentration ranges in the CDC's Third National Report on Human Exposure to Environmental Chemicals. These compounds usually are generated by certain chlorination, manufacturing, or incineration processes. Human exposures largely occur via breast milk or contaminated meat, milk, eggs, or fish. The researchers acknowledge that limitations of the study preclude firm conclusions about the cause–effect relationships of these substances and behavioral disorders. However, they say that their research — including the discovery that these results would not have been predicted by using accepted toxic equivalency factors — adds to the growing knowledge and uncertainties about the neurotoxic effects of dioxins and furans. J Neurol Sci. 2007 Jul 23. The incidence and prevalence of autism have increased during the past two decades. Despite comprehensive genetic studies the cause of autism remains unknown. This review emphasizes the potential importance of environmental factors in its causation. Alterations of cortical neuronal migration and cerebellar Purkinje cells have been observed in autism. Neuronal migration, via reelin regulation, requires triiodothyronine (T3) produced by deiodination of thyroxine (T4) by fetal brain deiodinases. Experimental animal models have shown that transient intrauterine deficits of thyroid hormones (as brief as 3 days) result in permanent alterations of cerebral cortical architecture reminiscent of those observed in brains of patients with autism. I postulate that early maternal hypothyroxinemia resulting in low T3 in the fetal brain during the period of neuronal cell migration (weeks 8-12 of pregnancy) may produce morphological brain changes leading to autism. Insufficient dietary iodine intake and a number of environmental antithyroid and goitrogenic agents can affect maternal thyroid function during pregnancy. The most common causes could include inhibition of deiodinases D2 or D3 from maternal ingestion of dietary flavonoids or from antithyroid environmental contaminants. Some plant isoflavonoids have profound effects on thyroid hormones and on the hypothalamus-pituitary axis. Genistein and daidzein from soy (Glycine max) inhibit thyroperoxidase that catalyzes iodination and thyroid hormone biosynthesis. Other plants with hypothyroid effects include pearl millet (Pennisetum glaucum) and fonio millet (Digitaria exilis); thiocyanate is found in Brassicae plants including cabbage, cauliflower, kale, rutabaga, and kohlrabi, as well as in tropical plants such as cassava, lima beans, linseed, bamboo shoots, and sweet potatoes. Tobacco smoke is also a source of thiocyanate. Environmental contaminants interfere with thyroid function including 60% of all herbicides, in particular 2,4-dichlorophenoxyacetic acid (2,4-D), acetochlor, aminotriazole, amitrole, bromoxynil, pendamethalin, mancozeb, and thioureas. Other antithyroid agents include polychlorinated biphenyls (PCBs), perchlorates, mercury, and coal derivatives such as resorcinol, phthalates, and anthracenes. A leading ecological study in Texas has correlated higher rates of autism in school districts affected by large environmental releases of mercury from industrial sources. Mercury is a well known antithyroid substance causing inhibition of deiodinases and thyroid peroxidase. The current surge of autism could be related to transient maternal hypothyroxinemia resulting from dietary and/or environmental exposure to antithyroid agents. Additional multidisciplinary epidemiological studies will be required to confirm this environmental hypothesis of autism. (06/29/07 - Missoulian) Testing reveals drugs' residue For five miles downstream of the Boulder, Colo., sewage treatment plant there are no male fish. In Pacific currents off the Los Angeles coastline, fish are too lazy to hunt, too laid back to bother with breeding. In south-central Asia, vultures are dying of drug overdoses. All because what goes in must come out. “All domestic sewage, regardless of your location on the globe, will contain pharmaceuticals,” said Kate Miller. “If you can find a human being, you'll probably find pharmaceuticals in the environment.” Miller works for the Montana Department of Environmental Quality as an engineer and a hydrologist, but she sounds more like a chemist - what with all those crazy long compound names in the parts per billion. Recently, Miller was asked to go on a hunt for fecal contamination - sewage, basically - in Helena Valley groundwater. She was to use certain microbial markers, such as E. coli and coliphage, to sniff out the presence or absence of fecal taint. But the more she read about sewage-borne contaminants, the more she became convinced that more modern markers would make for a more interesting study. And so Miller added 28 man-made chemicals to her search target, including pharmaceuticals, endocrine disrupters and personal care products. On Wednesday, she presented her findings to the Flathead Basin Commission, a multi-agency commission charged with protecting water quality in the Flathead River drainage and Flathead Lake. Miller's is a compelling story - 32 of 35 drinking water wells tested positive for the chemicals, and of the 28 compounds she chose to look for a whopping 22 were found. Some were 425 feet down, in rock from the Paleozoic Era, a time when Miller is fairly certain there were no pharmaceuticals. Conclusion: It must be long-term contamination from the surface. “They act like pesticides,” Miller said of the contaminants. “They're big, long-chain molecules.” Which means they're persistent and tend to stick around for a while. “If a cancer patient lives above you and is on chemotherapy drugs, and your neighborhood is on septic, then there's a good chance you're on chemo drugs, too,” she said. Albeit at very, very low doses. Doses, in fact, that probably don't pose much of a health risk. Probably. “The fact is,” Miller said, “no one knows.” Neither does anyone know how low-dose drugs might affect fish and wildlife, or how a cocktail of drugs, even at low doses, might combine to cause some surprising cumulative effects. The pharmaceuticals - both over-the-counter and prescription drugs - make their way into water systems because they are flushed (think leftover or out-of-date prescriptions) or because they pass through us and then are flushed. The endocrine disrupters - mostly hormones and birth-control drugs - pass the same way, and are known to disrupt endocrine systems in fish and birds, just as they do in humans. That's why there are no male fish in the waters below Boulder's sewage treatment plant. They've all been feminized by estrogen, Miller said. The laid-back Pacific fish are happy on Prozac, and the Asian vultures are overdosed on anti-inflammatory drugs, pumped by local farmers into their water buffalo herds before those animals die and become vulture food. The personal care products - musks and perfumes and sunblock - enter the system through shower drains, then continue on through septic systems or municipal treatment plants. “None of these systems have been designed to remove these things,” Miller said. “The possible impacts are very poorly understood.” What will a trace of steroid do to an insect, or to a fish? What will traces of many drugs combined do to those same animals? “We don't have a lot of answers yet,” Miller said. What she does know is that the combined action of several compounds can exceed the sum of the individual parts. And the longer an organism is exposed, the more sensitive it can become to the contaminant. And some compounds - think antibiotics - definitely overlap between species. And most drugs have multiple side effects, both known and unknown. Fish, Miller said, are especially vulnerable because they swim steeped in the stew 24 hours a day, seven days a week. “That's key, because they can't get up out of the river and walk to a new spot,” Miller said. “They're captive.” There's no escape. Even if the compound has a short half-life, it's constantly being replenished into the system, offering no relief. The questions are so far beyond the answers, Miller said, that science often doesn't even know what to ask. She tested just 28 of the 800,000 or so known chemicals that could pass through our systems into ground - and later surface - waters. Antidepressants are affecting shellfish reproduction, she said. Blood-pressure drugs are reducing sperm counts in aquatic organisms. Anti-seizure drugs cause neurodegeneration in fish. Arthritis medicines affect fin growth. “This is something that's only been recently uncovered in the United States,” Miller said, “and as a body of scientists we're still trying to get our arms around it. We may have to start regulating the way our wastewater is treated.” And not just in the Helena Valley, where her study was centered. According to Miller, Missoula-based researcher Bill Woessner found acetaminophen, caffeine, nicotine, codeine and antibiotics in his backyard groundwater. Others have repeated the results around the globe. Miller stresses that the amounts found are astoundingly small - measured in half-parts per billion - and that the effects to human health, if any, are by no means clear. But she also notes that antibiotics were found in 80 percent of her test sites, “and I do worry about antibiotic resistance when I see something like this.” She also worries that breast cancer and prostate cancer could be on the rise in part due to hormones leaching into drinking water. It's just a hunch, but she's not alone. Her immediate prescription is to stop flushing unused drugs, and to stop overusing drugs in general. Miller recommends taking those unused medicines - be careful, though, with narcotics - and zipping them in a plastic baggie with a handful of kitty litter. Then drop it in the local landfill, which is lined to contain contaminants. Canada has an even better solution, requiring drug distributors to collect any unused pharmaceuticals and dispose of them properly, at a facility designed to filter out the contaminants. Another answer might simply be better sewage treatment plants, “but we're still trying to figure out how to do that,” Miller said. That would, she admits, be expensive. “We're very early in the research here,” Miller said, “and there are so many things we still don't know. But we've begun looking, and that's an important start.” (06/08/2007 - Oakland Tribune) Flame retardant may be more toxic than thought. Previous assumptions about the health risks of one of the world's most widely used flame retardants are wrong, scientists say, with new data suggesting the compound is both more toxic and widespread in humans and wildlife than thought. The chemical, known as "Deca," is a close cousin to PCBs and the bigger brother of two flame retardants already banned in Europe and several states, including California. A bill attempting to banish Deca from consumer products in California fell short Thursday evening in the Assembly and appeared doomed. More than 56,000 tons of Deca were infused into consumer goods worldwide last year, chiefly TV sets. Scientists knew Deca leached out into the environment, contaminating house dust and food and, by extension, our blood and breast milk. But they thought it was largely inert, harmless and quickly passed from our bodies. Evidence from California's Department of Toxic Substances Control and the Virginia Institute of Marine Science undermines those assumptions. What was thought to be harmless is likely not, say scientists conducting the research. Deca appears to be quickly absorbed by organisms and quickly broken down into long-lasting and far more toxic compounds. Maine last week passed a bill banning the compound; a similar measure is already on the books in Washington state. Illinois lawmakers are also contemplating a ban. "What's troubling is our assumptions," said Rob Hale, a professor at the Virginia Institute who led some of the research. "We long assumed these products did not leach out of plastics or get into the environment. That was etched in stone. Now out pops data on birds of prey ... that all point to not only does Deca get out and get into organisms, it can also be broken down into (compounds) that have all these toxic effects." The data comes from addled eggs of peregrine falcons and other raptors in California, Washington, the East Coast and China. The two dozen or so eggs tested so far indicate those raptors — including two falcon pairs nesting in the Bay Area — have the highest chemical loads of Deca of any living organism tested, a red flag for a species that only recently rebounded from DDT exposure in the late 1970s. Deca is part of a family of flame retardants known as PBDEs, or polybrominated diphenyl ethers. It's the only PBDE still on the market. Siblings Penta and Octa were banned earlier in the decade in California and Europe after scientists concluded both compounds were bioaccumulative and toxic. The largest domestic manufacturer ceased making the chemicals in 2005. Deca escaped any ban in part because scientists couldn't find evidence of similar effects. (The names come from the number of bromine atoms attached to the molecule: 10 for Deca, eight for Octa, five for Penta. The fewer rings, the smaller the molecule and the more toxic and persistent it is for living organisms.) Industry groups note that the chemical is astoundingly effective at stopping a very real risk — fire — in plastics. Manufacturers say they don't need much Deca to protect products; plastics with Deca can be readily recycled, unlike those with other additives; the amounts contaminating humans remains, so far, fairly minuscule; and much less is known about alternative flame retardants. "What's the right balance?" asked John Kyte, North American director for the Bromine Science and Environmental Forum, representing Deca's manufacturers. "Deca does not pose a threat to human health and the environment. Can I say that definitively? No I can't. But no one can for any compound. "The bottom line is we don't want to produce — and we don't want to have on the market — a product that's not safe," he said. The egg data, in conjunction with other ongoing research, suggests otherwise. The values range from about 0.5 parts per million to 3.5 parts per million and are 10 to 15 times higher than what scientists find in Swedish raptors. One egg from China tested at 12 parts per million, astonishing scientists. The levels are nearly 100 times beyond body burdens found in aquatic species such as harbor seals and terns. It is also 100 times what is commonly found in humans, although data is scant on the latter point and some evidence suggests children are more contaminated than their parents. Such a concentration seems small: A drop or three of Deca into a swimming pool. But the molecules are many. Any drop of water from that pool would contain 31 trillion molecules of Deca. Kim Hooper, a research supervisor in DTSC's Environmental Chemistry lab, believes researchers misread the chemical because they focused initially on aquatic species and thus never noticed a problem. Peregrines in urban areas eat pigeons and sparrows — scavengers of human society. It appears now — and for reasons little understood — that Deca accumulates in such a terrestrial food web but doesn't in the more well-studied aquatic food web. "We haven't thought these things were getting in biota in any amounts," said Kim Hooper, who is supervising the research at DTSC. "Now that it is in biota, you say, 'What are the terrestrial wildlife we've looked at?' Well, the answer is essentially none." Raptor researchers say they doubt Deca endangers the birds the way DDT or PCBs did a generation ago. Thirty years ago, California had only two peregrine nests statewide. Today there are between 200 and 300. There's also a lot of evidence that Deca quickly breaks down in the body and the environment to smaller, more toxic compounds — such as Octa, said Heather Stapleton, an assistant professor at Duke University's Nicholas School of the Environment and Earth Sciences. The science on this is largely settled, she said. But not to industry, which maintains the chemical is largely inert. And that uncertainty has left lawmakers paralyzed. Maine was one of the first states to buck the trend and ban Deca, with a bill clearing the Legislature last week. The state of Washington was earlier, with the governor in April inking into law a bill that would ban Deca once safe and suitable alternatives are found. But in California, a bill by Assemblywoman Sally Lieber, D-San Jose, to ban Deca outright in California could only muster 30 of the 41 votes necessary to clear the Assembly Thursday. A different bill banning a wide class of brominated and chlorinated flame retardants from mattresses, bedding and domestic furniture did clear the Assembly late Wednesday. But while Deca is subject to that ban, manufacturers say they don't use Deca in household furniture or bedding. "We're taking on the manufacturers of all consumer products," Lieber said last week. "This is a big struggle. But we have to push this as hard as we can. There's no doubt in my mind that this is the biggest public health threat we're facing." (06/07/2007 - Scientific American) Strange but True: Antibacterial Products May Do More Harm Than Good. Tuberculosis, food poisoning, cholera, pneumonia, strep throat and meningitis: these are just a few of the unsavory diseases caused by bacteria. Hygiene—keeping both home and body clean—is one of the best ways to curb the spread of bacterial infections, but lately consumers are getting the message that washing with regular soap is insufficient. Antibacterial products have never been so popular. Body soaps, household cleaners, sponges, even mattresses and lip glosses are now packing bacteria-killing ingredients, and scientists question what place, if any, these chemicals have in the daily routines of healthy people. Traditionally, people washed bacteria from their bodies and homes using soap and hot water, alcohol, chlorine bleach or hydrogen peroxide. These substances act nonspecifically, meaning they wipe out almost every type of microbe in sight—fungi, bacteria and some viruses—rather than singling out a particular variety. Soap works by loosening and lifting dirt, oil and microbes from surfaces so they can be easily rinsed away with water, whereas general cleaners such as alcohol inflict sweeping damage to cells by demolishing key structures, then evaporate. "They do their job and are quickly dissipated into the environment," explains microbiologist Stuart Levy of Tufts University School of Medicine. Unlike these traditional cleaners, antibacterial products leave surface residues, creating conditions that may foster the development of resistant bacteria, Levy notes. For example, after spraying and wiping an antibacterial cleaner over a kitchen counter, active chemicals linger behind and continue to kill bacteria, but not necessarily all of them. When a bacterial population is placed under a stressor—such as an antibacterial chemical—a small subpopulation armed with special defense mechanisms can develop. These lineages survive and reproduce as their weaker relatives perish. "What doesn't kill you makes you stronger" is the governing maxim here, as antibacterial chemicals select for bacteria that endure their presence. As bacteria develop a tolerance for these compounds there is potential for also developing a tolerance for certain antibiotics. This phenomenon, called cross-resistance, has already been demonstrated in several laboratory studies using triclosan, one of the most common chemicals found in antibacterial hand cleaners, dishwashing liquids and other wash products. "Triclosan has a specific inhibitory target in bacteria similar to some antibiotics," says epidemiologist Allison Aiello at the University of Michigan School of Public Health. When bacteria are exposed to triclosan for long periods of time, genetic mutations can arise. Some of these mutations endow the bacteria with resistance to isoniazid, an antibiotic used for treating tuberculosis, whereas other microbes can supercharge their efflux pumps—protein machines in the cell membrane that can spit out several types of antibiotics, Aiello explains. These effects have been demonstrated only in the laboratory, not in households and other real world environments, but Aiello believes that the few household studies may not have been long enough. "It's very possible that the emergence of resistant species takes quite some time to occur…; the potential is there," she says. Apart from the potential emergence of drug-resistant bacteria in communities, scientists have other concerns about antibacterial compounds. Both triclosan and its close chemical relative triclocarban (also widely used as an antibacterial), are present in 60 percent of America's streams and rivers, says environmental scientist Rolf Halden, co-founder of the Center for Water and Health at Johns Hopkins Bloomberg School of Public Health. Both chemicals are efficiently removed from wastewater in treatment plants but end up getting sequestered in the municipal sludge, which is used as fertilizer for crops, thereby opening a potential pathway for contamination of the food we eat, Halden explains. "We have to realize that the concentrations in agricultural soil are very high," and this, "along with the presence of pathogens from sewage, could be a recipe for breeding antimicrobial resistance" in the environment, he says. Triclosan has also been found in human breast milk, although not in concentrations considered dangerous to babies, as well as in human blood plasma. There is no evidence showing that current concentrations of triclosan in the human body are harmful, but recent studies suggest that it acts as an endocrine disrupter in bullfrogs and rats. Further, an expert panel convened by the Food and Drug Administration determined that there is insufficient evidence for a benefit from consumer products containing antibacterial additives over similar ones not containing them. "What is this stuff doing in households when we have soaps?" asks molecular biologist John Gustafson of New Mexico State University in Las Cruces. These substances really belong in hospitals and clinics, not in the homes of healthy people, Gustafson says. Of course, antibacterial products do have their place. Millions of Americans suffer from weakened immune systems, including pregnant women and people with immunodeficiency diseases, points out Eugene Cole, an infectious disease specialist at Brigham Young University. For these people, targeted use of antibacterial products, such as triclosan, may be appropriate in the home, he says. In general, however, good, long-term hygiene means using regular soaps rather than new, antibacterial ones, experts say. "The main way to keep from getting sick," Gustafson says, "is to wash your hands three times a day and don't touch mucous membranes." (June, 2007 - Journal of the National Cancer Institute) Environmental Chemicals - Not Just Overeating - May Cause Obesity. Obesity is a known risk factor for many cancers, and it is associated with an increased rate of some malignancies and the likelihood of aggressive disease in others. So new data showing that common environmental chemicals cause obesity in animal models may alarm some oncologists. Until now, most physicians and researchers have thought that an imbalance of food intake and energy output — and a touch of genetics — is the root cause of obesity. But the cause may also link back to several hormone-altering chemicals. "When animals are exposed prenatally to these chemicals, their metabolism is reprogrammed so that even if they are never exposed again in their lives, they gain weight," said Bruce Blumberg, Ph.D., associate professor of developmental and cell biology at the University of California, Irvine. "Even with normal diet and normal exercise, they become obese. "We think that is very relevant to the current epidemic of obesity," he said during a press conference devoted to chemicals and obesity at the American Association for the Advancement of Science meeting in San Francisco earlier this year. The chemicals in question, which disrupt hormone system function in animals, are common in the human environment. Bisphenol A is used in polycarbonate plastics, including baby bottles and hard clear plastic water bottles, and for lining tin cans. Tributyltin has been used in the green paint on the underside of ships, which has led to ongoing seafood contamination with the chemical, and is a component of PVC (polyvinylchloride) plastic, a material sometimes used in household pipes. When Frederick vom Saal, Ph.D., professor of biological sciences at the University of Missouri in Columbia, and colleagues exposed developing mouse embryos in utero to one dose of bisphenol A, the animals were born underweight relative to littermates that were not exposed. By 6 months of age, the exposed animals outweighed their siblings, despite being fed the same amount and type of food and having similar exercise habits. "Not only are the animals getting heavy, they are forming cancers," vom Saal said. Interestingly, the level of chemicals the team used in these experiments is at or below the level found in human tissues, according to data from the Centers for Disease Control and Prevention. Blumberg, vom Saal, and others are working out just how the reprogramming happens. While the details are still unclear, the changes appear to occur at the level of epigenetic alterations during development. Blumberg's team found that the chemicals activate the fat cell differentiation pathway in cells grown in vitro and in animal studies, which leads to both larger fat cells and more of them. Thus far there are only correlative data suggesting that the chemicals are affecting human weight. Vom Saal, for example, cited a small Japanese study in which researchers found that women with a higher level of such chemicals tended to be heavier than those with lower levels. The effect of similar endocrine-disrupting chemicals on adult animal health appears to be less permanent, according to at least some studies. The animals put on excess weight shortly after exposure but lose the weight again if the environmental source is withdrawn. But if the researchers are correct that the chemicals are reprogramming human metabolism to favor weight gain, more cancers are likely to follow. "Unless the obesity from these chemicals is somehow different biologically from obesity as we understand it now, which I doubt, then it will be a concern," said Scott Lippman, M.D., chair of the department of clinical cancer prevention at the University of Texas M. D. Anderson Cancer Center in Houston. |