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Childhood asthma linked to lack of ventilation for gas stoves

Unknown 0 Asthma, children, Educational, Science 08:56

Parents with children at home should use ventilation when cooking with a gas stove, researchers from Oregon State University are recommending, after a new study showed an association between gas kitchen stove ventilation and asthma, asthma symptoms and chronic bronchitis.“In homes where a gas stove was used without venting, the prevalence of asthma and wheezing is higher than in homes where a gas stove was used with ventilation,” said Ellen Smit, an associate professor in the College of Public Health and Human Sciences at OSU and one of the study’s authors. “Parents of all children should use ventilation while using a gas stove.”Researchers can’t say that gas stove use without ventilation causes respiratory issues, but the new study clearly shows an association between having asthma and use of ventilation, Smit said. More study is needed to understand that relationship, including whether emissions from gas stoves could cause or exacerbate asthma in children, the researchers said.Asthma is a common chronic childhood disease and an estimated 48 percent of American homes have a gas stove that is used. Gas stoves are known to affect indoor air pollution levels and researchers wanted to better understand the links between air pollution from gas stoves, parents’ behavior when operating gas stoves and respiratory issues, said Eric Coker, a doctoral student in public health and a co-author of the study.The study showed that children who lived in homes where ventilation such as an exhaust fan was used when cooking with gas stoves were 32 percent less likely to have asthma than children who lived in homes where ventilation was not used. Children in homes where ventilation was used while cooking with a gas stove were 38 percent less likely to have bronchitis and 39 percent less likely to have wheezing. The study also showed that lung function, an important biological marker of asthma, was significantly better among girls from homes that used ventilation when operating their gas stove.Many people in the study also reported using their gas stoves for heating, researchers found. That was also related to poorer respiratory health in children, particularly when ventilation was not used. In homes where the gas kitchen stove was used for heating, children were 44 percent less likely to have asthma and 43 percent less likely to have bronchitis if ventilation was used. The results did not change even when asthma risk factors such as pets or cigarette smoking inside the home were taken into account, Coker said.“Asthma is one of the most common diseases in children living in the United States,” said Molly Kile, the study’s lead author. Kile is an environmental epidemiologist and assistant professor at OSU. “Reducing exposure to environmental factors that can exacerbate asthma can help improve the quality of life for people with this condition.”The findings were published recently in the journal “Environmental Health.” Co-authors included John Molitor and Anna Harding of the College of Public Health and Human Sciences and Daniel Sudakin of the College of Agricultural Sciences. The research was supported by OSU.Researchers used data from the Third National Health and Nutrition Examination Survey, or NHANES, conducted by the National Center for Health Statistics from 1988-1994. Data collected for NHANES is a nationally representative sample of the U.S. population.The third edition of the survey is the only one in which questions about use of gas stoves were asked, Coker said. Participants were interviewed in their homes and also underwent physical exams and lab tests.Researchers examined data from about 7,300 children ages 2-16 who has asthma, wheezing or bronchitis and whose parents reported using a gas stove in the home. Of those who reported using no ventilation, 90 percent indicated they did not have an exhaust system or other ventilation in their homes, Coker said.Even though the study relies on older data, the findings remain relevant because many people still use gas stoves for cooking, and in some cases, for heat in the winter, the researchers said.“Lots of older homes lack exhaust or other ventilation,” Coker said. “We know this is still a problem. We don’t know if it is as prevalent as it was when the data was collected.”Researchers suggest that future health surveys include questions about gas stove and ventilation use. That would allow them to see if there have been any changes in ventilation use since the original data was collected. “More research is definitely needed,” Coker said. “But we know using an effective ventilation system will reduce air pollution levels in a home, so we can definitely recommend that.” SOURCE:SCIENCE BLOG

Childhood asthma linked to lack of ventilation for gas stoves

Parents with children at home should use ventilation when cooking with a gas stove, researchers from Oregon State University are recommendin...

Cancer during pregnancy: Chemo, radiotherapy safe for babies

Unknown 0 Babies, Chemotherapy, children, Educational, Mothers, Radiation, Science 08:54

Presentations at ESMO 2014 examine the impact of in-utero exposure to chemotherapy and radiotherapy, the safety of lymph node biopsy in pregnancy, and the outcomes of unplanned pregnancy during cancer treatmentChildren who are exposed to chemotherapy or radiotherapy while in the womb suffer no negative impacts on mental or cardiac development, international studies presented at the ESMO 2014 Congress in Madrid have shown.“When chemotherapy is administered after the first trimester of pregnancy, we cannot discern any problems in the children,” says lead author Dr Frederic Amant, KU Leuven and University Hospitals Leuven in Belgium. “Fear about the risks of chemotherapy administration should not be a reason to terminate a pregnancy, delay cancer treatment for the mother, or to deliver a baby prematurely.”Concerns about the potential impact of cancer treatment on unborn children has until recently left some oncologists hesitant to administer treatments to pregnant cancer patients, says Amant. To address these concerns, his group has led three new studies presented at ESMO 2014.In the first study, 38 children prenatally exposed to chemotherapy were recruited from the International Network for Cancer, Infertility and Pregnancy (INCIP) registry and assessed for mental development and cardiac health. Their outcomes were compared to 38 control children who were not exposed to chemotherapy.At a median age of almost two years of age, mental development as measured by the Mental Development Index was in the normal range for both groups of children, and were not significantly different. Cardiac dimensions and functions were within normal ranges for both groups.This is the first case control study on the developmental outcome of children exposed in utero to chemotherapy. It shows that chemotherapy during pregnancy can be considered safe for mental development and cardiac functioning of the child, the authors say.Commenting on the results, Dr Fedro Alessandro Peccatori, Director of the Fertility & Procreation Unit at the European Institute of Oncology’s Division of Gynaecologic Oncology, who was not involved in the study, said that these results confirm that chemotherapy administration during pregnancy does not alter neurodevelopment after birth, nor cause cardiac alterations.“This paper points to the very important issue of long-term safety of prenatal exposure to chemotherapy and reinforces the notion that chemotherapy during gestation does not endanger the fetus and her or his subsequent development. To further ameliorate neonatal outcome, a special effort should be made to prolong pregnancy duration, and stringent long-term follow-up should be pursued to confirm these findings. Meanwhile, specific measures to support prematurely delivered babies and their families should be implemented.Future studies will explore the effects of specific chemotherapy types in detail, and longer term follow-up, to fine tune the findings.In a second study, Amant and colleagues explored the impact of radiotherapy on the children of women with cancer.The study included 16 children and 10 adults who had been exposed to radiotherapy in utero. This is the first long-term follow-up study of children prenatally exposed to medical radiation, and the study showed that neuropsychological, behavioral and general health outcomes for those exposed to radiotherapy were within normal ranges. One child revealed a severe cognitive delay, however other pregnancy-related complications are confounding factors, they report.Amant hopes the new results will provide clinicians with the evidence they need to ensure pregnant women with cancer receive the best quality care. “It’s a good feeling to know that research data can be implemented immediately into the clinic. Our data will inform physicians and patients and help them to take decisions in a difficult situation.”Commenting, Peccatori noted that the long-term follow-up of children and adults whose mothers have been treated with radiation therapy during gestation is an important topic.“The main message is that neuropsychological, behavioral and general health outcomes were within the normal range in all, but 3 of the 16 children studied. This is the first long-term follow-up study of children and adults exposed to radiotherapy in utero. Pregnancy, particularly advanced pregnancy, has been traditionally considered a contra-indication to radiotherapy. New radiation techniques and more sophisticated simulations of the received fetal dose may change this scenario, but caution remains mandatory when giving radiotherapy to a pregnant woman, particularly in the third trimester.”Sentinel node biopsy safe for pregnant women with cancerIt is safe and effective to check for the spread of early breast cancer in pregnant women using sentinel node biopsy rather than completely dissecting the node, researchers from the International Network of Cancer, Infertility and Pregnancy and the German Breast Group have shown in another study presented at ESMO 2014 in Madrid.Sentinel lymph node biopsies have been the topic of intensive research over the last 2 decades, and have replaced the older and more invasive method of axillary lymph node dissection for women patients without clinically suspicious axillary lymph nodes.This method removes the first (or ‘sentinel’) lymph node receiving lymphatic drainage from the tumour, therefore most likely to contain metastatic cells. If the SLN does not contain metastatic disease, the remainder of the lymph nodes do not have to be removed, thereby sparing the patient the associated side-effects such as lymphedema and reduced movement.The latest guidelines for doctors still advise that they perform axillary lymph node dissection and avoid sentinel lymph node biopsy during pregnancy, due to lack of safety data, explains Sileny Han of University Hospitals Leuven, Belgium, who is presenting the results of a new study at ESMO 2014. “We aim to add to the body of evidence that sentinel node biopsy is feasible during pregnancy and should be considered an option.”This study is the largest series to date to assess this question. The researchers studied 97 women with breast cancer who underwent sentinel node biopsy. Their aim was to assess whether the sentinel lymph node procedure is safe from an oncologic point of view for the mother.After a median follow-up of 35 months, eight patients had experienced a loco-regional relapse, meaning their cancer recurred in the same or other breast, the chest wall, including two who developed tumours in their lymph nodes. Four patients developed distant metastases, of whom three died of breast cancer.These results show that sentinel lymph node biopsy during pregnancy has a low axillary recurrence rate, they write. “This staging method can be considered during pregnancy instead of standard axillary lymph node dissection for early stage, clinically node negative breast cancer.”Adds Peccatori, co-author on this study: “Axillary staging in early breast cancer is a changing paradigm. Data from different institutions in Europe and US have demonstrated that in non-pregnant patients, sentinel node biopsy is an effective staging procedure that holds equivalent results to axillary lymph node dissection even in patients with up to three positive sentinel nodes, if post operative systemic treatment is adequate. Furthermore, hand sentinel node biopsy is associated with improved arm motility, decreased armpit pain and numbness and shorter hospital stay. Why should we deny this procedure to pregnant breast cancer patients?”Unplanned pregnancy during cancer treatmentAnother study from Amant’s group shows the importance of thinking about contraception during cancer diagnosis and cancer treatment. Sarah van Peer and colleagues checked the database of the International Network for Cancer Infertility and Pregnancy for women who became pregnant during cancer diagnosis or during treatment.The INCIP database currently includes 1011 patients from 21 countries (at the time it included 897 patients).Overall, 3.23% (29/897) of the patients in the database became pregnant after cancer diagnosis or during treatment. Of those 29 patients, three pregnancies were identified during diagnostic examinations for suspected malignancy but before definite diagnosis, 18 during treatment, and seven after cancer diagnosis but before treatment was started.“The core message from our results is that it is vital for doctors and patients to discuss contraception during cancer diagnosis and cancer treatment. Although fertility issues are not the focus of attention at this time, it is necessary to provide advice about contraception. And although we know it’s possible to treat patients with chemotherapy/radiotherapy during pregnancy when necessary, it’s still better to avoid this situation, if possible.” Says Peccatori, “Discussion about effective contraception remains a high priority for oncologists dealing with young patients with cancer. The incidence of unplanned pregnancy during cancer treatment probably remains a rare event. Nonetheless, the high emotional impact of an unplanned pregnancy and the possible maternal consequences in terms of treatment modification should prompt more effective. SOURCE: SCIENCE BLOG

Cancer during pregnancy: Chemo, radiotherapy safe for babies

Presentations at ESMO 2014 examine the impact of in-utero exposure to chemotherapy and radiotherapy, the safety of lymph node biopsy in preg...

Cancer during pregnancy: Chemo, radiotherapy safe for babies

Unknown 0 Babies, Chemotherapy, children, Educational, Mothers, Radiation, Science 03:18

Cancer during pregnancy: Chemo, radiotherapy safe for babies

Presentations at ESMO 2014 examine the impact of in-utero exposure to chemotherapy and radiotherapy, the safety of lymph node biopsy in preg...

How to make a solar absorber

Unknown 0 Educational, Science, Solar 03:14

Now researchers at MIT say they have accomplished the development of a material that comes very close to the “ideal” for solar absorption. The material is a two-dimensional metallic dielectric photonic crystal, and has the additional benefits of absorbing sunlight from a wide range of angles and withstanding extremely high temperatures. Perhaps most importantly, the material can also be made cheaply at large scales.The creation of this material is described in a paper published in the journal Advanced Materials, co-authored by MIT postdoc Jeffrey Chou, professors Marin Soljacic, Nicholas Fang, Evelyn Wang, and Sang-Gook Kim, and five others.The material works as part of a solar-thermophotovoltaic (STPV) device: The sunlight’s energy is first converted to heat, which then causes the material to glow, emitting light that can, in turn, be converted to an electric current.Some members of the team worked on an earlier STPV device that took the form of hollow cavities, explains Chou, of MIT’s Department of Mechanical Engineering, who is the paper’s lead author. “They were empty, there was air inside,” he says. “No one had tried putting a dielectric material inside, so we tried that and saw some interesting properties.”When harnessing solar energy, “you want to trap it and keep it there,” Chou says; getting just the right spectrum of both absorption and emission is essential to efficient STPV performance.Most of the sun’s energy reaches us within a specific band of wavelengths, Chou explains, ranging from the ultraviolet through visible light and into the near-infrared. “It’s a very specific window that you want to absorb in,” he says. “We built this structure, and found that it had a very good absorption spectrum, just what we wanted.”In addition, the absorption characteristics can be controlled with great precision: The material is made from a collection of nanocavities, and “you can tune the absorption just by changing the size of the nanocavities,” Chou says.Another key characteristic of the new material, Chou says, is that it is well matched to existing manufacturing technology. “This is the first-ever device of this kind that can be fabricated with a method based on current … techniques, which means it’s able to be manufactured on silicon wafer scales,” Chou says — up to 12 inches on a side. Earlier lab demonstrations of similar systems could only produce devices a few centimeters on a side with expensive metal substrates, so were not suitable for scaling up to commercial production, he says.In order to take maximum advantage of systems that concentrate sunlight using mirrors, the material must be capable of surviving unscathed under very high temperatures, Chou says. The new material has already demonstrated that it can endure a temperature of 1,000 degrees Celsius (1,832 degrees Fahrenheit) for a period of 24 hours without severe degradation.And since the new material can absorb sunlight efficiently from a wide range of angles, Chou says, “we don’t really need solar trackers” — which would add greatly to the complexity and expense of a solar power system.“This is the first device that is able to do all these things at the same time,” Chou says. “It has all these ideal properties.”While the team has demonstrated working devices using a formulation that includes a relatively expensive metal, ruthenium, “we’re very flexible about materials,” Chou says. “In theory, you could use any metal that can survive these high temperatures.”“This work shows the potential of both photonic engineering and materials science to advance solar energy harvesting,” says Paul Braun, a professor of materials science and engineering at the University of Illinois at Urbana-Champaign, who was not involved in this research. “In this paper, the authors demonstrated, in a system designed to withstand high temperatures, the engineering of the optical properties of a potential solar thermophotovoltaic absorber to match the sun’s spectrum. Of course much work remains to realize a practical solar cell, however, the work here is one of the most important steps in that process.”The group is now working to optimize the system with alternative metals. Chou expects the system could be developed into a commercially viable product within five years. He is working with Kim on applications from this project. The team also included MIT research scientist Ivan Celanovic and former graduate students Yi Yeng, Yoonkyung Lee, Andrej Lenert, and Veronika Rinnerbauer. The work was supported by the Solid-State Solar Thermal Energy Conversion Center and the U.S. Department of Energy. SOURCE:SCIENCE BLOG

How to make a solar absorber

Now researchers at MIT say they have accomplished the development of a material that comes very close to the “ideal” for solar absorption. T...

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Childhood asthma linked to lack of ventilation for gas stoves

Cancer during pregnancy: Chemo, radiotherapy safe for babies

Cancer during pregnancy: Chemo, radiotherapy safe for babies

How to make a solar absorber

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