~dGossip
~tPollutants Boost Lead Paint Hazard
~w2009-10-29
According to the findings from a new study, two pollutants associated with transport emissions react with surfaces coated with lead-based paint and increase release of lead pigments. The authors found that this interaction may increase the risk of lead poisoning in children, particularly in urban environments and in the developing world. Ordinary household dust can become contaminated with lead when leaded paint products deteriorate. However, there areonly a limited number of studies that have focused on the factors that facilitate the release of lead pigment granules from the paints. Now, environmental exposure scientist Rufus D. Edwards and colleagues at the University of California, Irvine, School of Medicine have examined the impact of nitrogen dioxide and ozone, two compounds associated with auto emissions, on surfaces containing lead paint. “Typically, paint is composed of pigment granules and an unsaturated polymeric binder that holds them together,” Edwards says. “We know that O3 and NO2 react with unsaturated compounds. We were interested in whether this makes lead pigment granules more available to children’s hands,” he says. During the new study, the research team atIrvine applied a thin, uniform coating of lead paint to stainless steel surfaces. Following the exposure to O3 or No2, the surfaces were evaluated using reflectometry and scanning electron microscopy. In addition, the researchers mechanically wiped each surface and measured the lead concentration on the wipe. The results demonstrated that exposure to NO2 and O3 changed the surfaces’ morphology and significantly increased the amount of lead that can be wiped off them. The study adds another factor to consider in risk assessment, not only in U.S. cities where lead paint remains a problem, but also in developing countries, many of which still sell lead paint and have booming urban centres that contribute to air pollution, Edwards says. This study “highlights the importance of the often underappreciated science of heterogeneous chemistry in indoor environments,” says Richard Reiss, an environmental health scientist at Exponent, a consulting firm. “I suspect there are other connections between environmental contaminants that might be discovered with more study of indoor surface chemistry.
Chemical & Engineering News, 23 October 2009
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~dGossip
~tThree coffees a day may slow liver disease
~w2009-10-29
A new investigation by US hasrevealed another reason to go to the local espresso bar: several coffees a day could halt the progression of liver disease.Sufferers of chronic hepatitis C and advanced liver disease who drank three or more cups of coffee a day slashed their risk of the disease progressing by 53 per cent compared with patients who drank no coffee, the US National Cancer Institute study showed. The study consisted of 766 participants enrolled in the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) trial - all of whom had hepatitis C that had not responded to treatment with anti-viral drugs. During the study the participants were asked to report how many cups of coffee they drank every day. The patients were seen every three months during the 46-month study and liver biopsies were taken at 18 months and 42 months to determine the progression of liver disease. "We observed an inverse association between coffee intake and liver disease progression," the authors of the study wrote. The authors of the new study, published in the journal Hepatology, suggest that there may be several ways in which coffee intake might protect against liver disease, including by reducing the risk of type two diabetes, which has been associated with liver illness; or by reducing inflammation, which is thought to cause fibrosis and cirrhosis of the liver. Caffeine came under the spotlight, having been found in previous studies to inhibit liver cancer in rats. However, drinking black or green tea, which also contain caffeine, had little impact on the progression of liver disease
The Australian, 23 October 2009
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~dGossip
~tContaminants reveal tuna’s origins
~w2009-10-29
Bluefin tuna in the Atlantic Ocean are roughly divided into two populations along either side of the 45° W meridian. Because the relatively recent discovery of this demarcation has implications for managing stocks of the commercially lucrative fish, scientists and fisheries managers want to trace the birthplaces and journeys of the fish. Researchers have used methods such as satellite-tracking tags and isotope signals from the fishes’ ear bones. Now, a new study, published in the journal Environmental Science & Technology, has reported a different tracer to determine geographic origins for bluefin tuna: pesticides and PCBs. In conjunction with two other studies, the new research was funded by the Large Pelagics Research Centre at the University of New Hampshire to examine Atlantic bluefin stock structure. “The studies present a consistent and complementary overview of current mixing rates of eastern and western bluefin tuna,” wrote Molly Lutcavage, director of the centre, in an email.The new findings confirm previous results from satellite tags and otoliths—fish ear bones—on how and where these fish intermingle while feeding: past work has shown that up to nearly two-thirds of the tuna in the Mid-Atlantic Bight could be from the eastern fishery. The new method indicates that 33−83% of juvenile bluefin tuna captured in the Mid-Atlantic Bight has eastern origins and that mixing within a feeding ground varies with time and space. The method, developed by Rebecca Dickhut of the Virginia Institute of Marine Studies (VIMS) and her colleagues, uses ratios of two PCBs (PCB153 and PCB187, both of which are prominent in tuna tissue samples) to two chlordane compounds (trans-nonachlor and cis-nonachlor). The team discovered different ratios of chlordanes-to-PCBs in fish from the Mediterranean and western North Atlantic (where the population is critically endangered). They determined that those ratios changed after about a year if fish migrated, because these animals tend to grow and incorporate contaminants without evacuating them from their bodies.The year-old bluefin tuna provided a “smoking gun” for the team’s method, says co-author John Graves, a geneticist at VIMS. Juvenile fish from the Mediterranean are more likely than adults to travel across the Atlantic, hitting foraging grounds in the western North Atlantic. Because the pesticide chlordane is banned in the EU, finding it in fish spawning in the Mediterranean immediately signals that they have made that cross-Atlantic journey, says Graves.
The team believe that the ratio of compounds in a fish makes the method universal, by removing issues of size and age, says Dickhut. This lets the scientists determine how long the fish have been exposed to these chemical compounds, and it further confirms past findings of a fish’s starting point. For example, the nonachlor-to-PCB ratios of fish from the western North Atlantic are similar to those of fish in the Gulf of Mexico feeding grounds; this indicates that the North Atlantic fish ate their way down the U.S. east coast and did not come from the Mediterranean.Preliminary results from the new method indicate that more fish travel from the Mediterranean to the western North Atlantic to feed than originally thought. “We found that 13% of the eastern fishery travelled west, accounting for 70% of juveniles, on average, in the western North Atlantic,” says Dickhut. “Because the eastern stock is 5−10 times larger than the western stock, movement of only a relatively small portion of the eastern stock to the west has a big influence.”The International Commission for the Conservation of Atlantic Tunas (ICCAT) sets catch limits for tuna and related species and reviews emerging science. In 2007, the organisation created a 15-year recovery plan for Atlantic bluefin tuna, with the aim of stemming the fisheries’ collapse.The European Commission’s fisheries unit noted that the ICCAT recovery plan may be the only hope for the species’ future: on September 21, European Commission member states blocked a temporary halt to international trade of Atlantic bluefin tuna. If that recommendation had passed, the EU would have proposed the fish for endangered status under the Convention on International Trade in Endangered Species of Wild Fauna and Flora in March 2010.
Environmental Science & Technology, 21 October 2009
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~dGossip
~tWhy boys are turning into girls
~w2009-10-29
Denmark’s government recently released official research showing that two-year-old children are at risk from a bewildering array of gender-bending chemicals in such everyday items as waterproof clothes, rubber boots, bed linen, food, nappies, sunscreen lotion and moisturising cream.The 326-page report, published by the environment protection agency, is the latest evidence in a series of increasingly alarming findings. A picture is emerging of ubiquitous chemical contamination driving down sperm counts and feminising male children all over the developed world. In addition, anti-pollution measures and regulations are falling far short of getting to grips with it.Sperm counts are falling so fast that young men are less fertile than their fathers and produce only a third as much, proportionately, as hamsters. Furthermore, gender-bending chemicals are increasingly being blamed for the mystery of the "lost boys": babies who should normally be male who have been born as girls instead. In the new research, the Danish government set out to determine how much contamination from gender-bending chemicals a two-year-old child was exposed to every day. It concluded that a child could be "at critical risk" from just a few exposures to high levels of the substances, such as from rubber clogs, and imperilled by the amount it absorbed from sources ranging from food to sunscreens. The study builds on the findings from earlier studies demonstrating that British children have higher levels of gender-bending chemicals in their blood than their parents or grandparents.
Indeed WWF (formerly the World Wildlife Fund), which commissioned the older research, warned that the chemicals were so widespread that "there is very little, if anything, individuals can do to prevent contamination of themselves and their families." Prominent among them are dioxins, PVC, flame retardants, phthalates (extensively used to soften plastics) and the now largely banned PCBs, one and a half million tons of which were used in countless products from paints to electrical equipment.Young boys, like those in the Danish study, could end up producing less sperm and developing feminised behaviour. Research at Rotterdam's ErasmusUniversity found that boys whose mothers were exposed to PCBs and dioxins were more likely to play with dolls and tea sets and dress up in female clothes. It is in the womb that babies are most vulnerable; a study of umbilical cords from British mothers found that every one contained hazardous chemicals. Scientists at the University of Rochester in New York discovered that boys born to women exposed to phthalates had smaller penises and other feminisation of the genitals. In addition, the contamination may offer a clue to a mysterious shift in the sex of babies. Normally 106 boys are born for every 100 girls: it is thought to be nature's way of making up for the fact that men were more likely to be killed hunting or in conflict. However, the proportion of females is rising, so much so that some 250,000 babies who statistically should have been boys have ended up as girls in Japan and the United States alone. In Britain, the discrepancy amounts to thousands of babies a year.
A Canadian Indian community living on ancestral lands at the eastern tip of Lake Huron, hemmed in by one of the biggest agglomerations of chemical factories on earth, gives birth to twice as many girls as boys. It's the same around Seveso in Italy, contaminated with dioxins from a notorious accident in the 1970s, and among Russian pesticide workers. And there's more evidence from places as far apart as Israel and Taiwan, Brazil and the Arctic.Yet gender-benders are largely exempt from new EU regulations controlling hazardous chemicals. Britain, then under Tony Blair's premiership, was largely responsible for this – restricting their inclusion in the first draft of the legislation, and then causing even what was included to be watered down.Confidential documents show that it did so after pressure from George W Bush's administration, which protested that US exports "could be impacted".Now the Danish government is planning to lobby to have the rules toughened up. It is particularly concerned by other studies which show that gender-bending chemicals acting together have far worse effects than the expected sum of their individual impacts. It wants this to be reflected in the regulations, citing its discovery of the many sources to which the two-year-olds are exposed – modern slings and arrows, as it were, of outrageous fortune.
UK Telegraph, 23 October 2009
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~dGossip
~tEarly BPA exposure linked to behavioural effects in children
~w2009-10-29
A new study has suggested that little girls whose mothers were exposed to bisphenol A (BPA) early in pregnancy may be more aggressive and have learning problems. The new study, published in the journal Environmental Health Perspectives was undertaken by Bruce Lanphear of SimonFraserUniversity (Canada) and colleagues. In addition, the research found thatlittle boys seemingly were not as affected. During the new study, the research team followed 249 women starting early in their pregnancies. The women’s urine was tested for BPA levels at the 16-week and 26-week marks while they were pregnant and again at the birth of their children. After two years, the mothers evaluated their children by filling out a behavioural assessment tool for kids that age.The team found BPA in almost 90% of the women’s urine samples they tested. The chemical monomer remains ubiquitous in products such as polycarbonate plastics (e.g., those found in the hard plastic water bottles recently taken off the shelves in Canada). In addition, BPA is commonly used to make medical tubing soft and in food packaging and can linings.The researchers determined that median BPA concentrations were higher in the women’s urine samples taken earlier in their pregnancies: 1.8 and 1.7 nanograms per millilitre, compared to 1.3 nanograms per millilitre when the children were born. Furthermore they found that the higher BPA levels in the samples taken at 16 weeks were more strongly correlated with the children’s behavioural scores, and the association was stronger for girls than boys.
The results are being reported at about the time that the U.S. Environmental Protection Agency (EPA) has decided to revisit the BPA question, after a controversial review in 2008. Another independent report, the “Chapel Hill bisphenol A expert panel consensus statement” (Reprod. Toxicol. 2007, DOI 10.1016/j.reprotox.2007.07.005), funded by EPA and the National Institutes of Health, concluded that current levels of exposure are enough to affect human health, including “increase in neurobehavioral problems such as attention deficit hyperactivity disorder (ADHD) and autism.” None of the authors on the current Environmental Health Perspectives paper were on the independent panel.The authors comment in a press release that this study is the first “to examine the association between prenatal BPA exposure and a health outcome in childhood” and that their results are “consistent with data from animal studies.” Such work has indicated neurotoxic effects, particularly in female mice, and genetic repercussions for their offspring, among other impacts.Nevertheless, the authors also say that their work only suggests a correlation and that many confounding circumstances—from unidentified ADHD in the parents to selection bias in the choice of mothers—could throw doubt on their results. “It is still unknown whether prenatal BPA exposure causes adverse childhood outcomes,” they conclude.
Environmental Science & Technology, 21 October 2009
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~dGossip
~tScientist looking for cause of breast cancer in household objects
~w2009-10-29
Since beginning her job six years ago, medical researcher, Doctor Perinaaz Wadia, has begun to view all the plastics in her house with suspicion. She’s stopped microwaving leftovers in plastic containers and eats out of glass dishes whenever possible. These actions are a result of the fact that many of the plastics in our homes contain a chemical called Bisphenol A, a substance that is great for sealing the inside of tin cans and making sturdy plastic bottles, but could also be responsible for many otherwise-unexplained cases of breast cancer in the United States.“We need to do a little more work before we are absolutely sure,” said Wadia, a research associate at Tufts University. “But looking at the data, I feel there seems to be a link between this chemical and breast cancer.” Since the late 1980’s researchers have been investigating the possible hazards associated with Bisphenol A, or BPA. At this time, Wadia’s boss, Dr. Ana Soto, and fellow researches noticed that plastic lab equipment was affecting the reproduction of certain cells.In the years since, researchers have unearthed possible links between BPA and the development of the prostate gland and brain, as well as “behavioural effects in foetuses, infants and children,” according to a 2008 report from the National Institute of Environmental Health Sciences. The Food and Drug Administration found last year that the chemical posed no threat to consumers, but has since begun to re-examine its finding.Wadia, who moved from India six years ago to study with Soto, is one of many researchers trying to gain a better understanding of how BPA works and how it could affect human development. In particular, Wadia is examining whether a mother’s exposure to BPA could lead to breast cancer in her children years later.In lab tests, Wadia has discovered that female rodents exposed to BPA and other xenoestrogens — industrial compounds that behave like oestrogen — have given birth to pups that eventually develop cancerous lesions in their mammary glands. Wadia said the amount of BPA the rodents are exposed to is similar to the amount humans encounter in their day-to-day lives.