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Wood Smoke Exposure Multiplies Damage from Smoking, Increases Risk of COPD
Smokers who are exposed to wood smoke, either through home heating and cooking or through ambient neighbourhood pollution, are not only at increased risk of COPD, but are also more likely to have epigenetic changes in the DNA that further increase their risk of COPD and related pulmonary problems. Together, smoking, wood smoke exposure and these epigenetic changes can increase an individual’s risk of COPD fourfold. “When cigarette smokers are exposed to wood smoke their risk of having reduced lung function increases,” explained lead author Yohannes Tesfaigzi, Ph.D. senior scientist and director of COPD Program at the Lovelace Respiratory Research Institute, where the research was completed. “Cigarette smokers who have both changes in sputum DNA and are exposed to wood smoke have a synergistically increased risk of having reduced lung function and other indicators of COPD such as chronic mucous hypersecretion.” The new study was published online in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine. During the new study, Dr. Tesfaigzi and colleagues administered questionnaires to more than 1800 current and former smokers between 40 and 75 years old, and obtained demographic and smoke exposure information, as well as sputum samples which were analysed for epigenetic changes to eight genes known to be associated with lung cancer. The researchers detected that wood smoke exposure was significantly and independently associated with an increased risk of respiratory disease, especially among current smokers, non-Hispanic whites and men. Furthermore, wood smoke exposure was associated with specific COPD outcomes in people who had aberrantly methylated p16 or GATA4 genes, and both factors together increased the risk more than the additive of the two risk factors together.
Furthermore, they found that people with more than two of the eight genes analysed showing methylation were also significantly more likely to have a lower than predicted FEV1 than those with fewer than two methylated genes. “Because exposure to wood smoke appears to increase the risk of reducing lung function, cigarette smokers should try to avoid heating their homes or cooking with wood stoves and try to avoid environments where wood smoke is likely (for example, neighborhoods where wood smoke is common),” said Dr. Tesfaigzi. “Because the same gene changes were associated with increased risk for lung cancer one would assume that wood smoke exposure also increases the risk of developing lung cancer. Future studies may show that it would be appropriate to screen patients for lung cancer if these exposures were present for prolonged periods.” Based on these findings, Dr. Tesfaigzi and colleagues established an animal model that will be able to further test whether exposure to both wood and tobacco smoke cause more damage to the lung than either one of the exposures alone. “We observed increased inflammatory response in mice that were exposed to both cigarette smoke and low concentrations of wood smoke compared to those exposed to cigarette smoke only. We would like to use this animal model to determine the mechanisms underlying this exacerbation,” said Dr. Tesfaigzi. Because wood smoke exposure was documented by self-report and was not quantified in this study, in the future Dr. Tesfaigzi also intends to characterise the type and amount of wood smoke the participants were exposed to. Such studies will help to further refine the analysis and provide intervention strategies.
Science Daily, 16 July 2010 http://www.sciencedaily.com
Mercury poisoning, the dark side of Colombia’s gold boom
Recently U.N experts reported that there was a dark side to Colombia’s gold bonanza: mercury poisoning spreading from miners to the population of a northwest state where they use mercury to extract the precious metal, U.N. experts said. Colombia is one of the world’s top mercury polluters, as 50 to 100 metric tons of mercury are lost annually in the process of capturing gold while soaring prices push miners and artisans to extract ever more of the yellow metal, analysts say. “As prices of gold have been increasing, more artisanal miners are mining and processing gold using mercury which is accessible, easier and cheaper to use,” said Marcello Veiga, an adviser to the U.N. industrial development arm. The Andean nation is the world’s No. 1 mercury polluter per capita from artisanal (small-scale) mining, Veiga said. “The number of artisanal miners in Colombia is also increasing.” For decades, miners have used mercury to separate gold, but part of it is lost in the process, contaminating rivers and soils. Currently, the environment ministry allows mercury but may soon forbid it, with a few exceptions. In northwest Antioquia state, they use the most damaging process, adding around 120 grams (4.2 ounces) of mercury to 60 kilograms (132 pounds) of ore, without condensing or capturing the mercury, Veiga said. As a result, mercury levels in some urban areas of Remedios, Segovia and Zaragosa can be 1,000 times higher than the levels accepted by the World Health Organization, he said. “Around 15 kidney transplants are carried out in Remedios every year ... because mercury vapor stays in the kidneys, damaging them,” Veiga said, citing data from the Remedios department of health.
According to the energy ministry, Antioquia -- the country’s largest gold producer -- has about 15,000 to 30,000 artisanal miners producing between 10 and 20 metric tons of gold per year. But the miners are releasing 50 metric tons of mercury annually in the municipalities of Remedios, Segovia, Zaragosa, El Bagre and Nice, where 90 percent of the population depends on gold mining or jewellery for their livelihood, Veiga said. Colombia is experiencing a gold boom with more than 40 companies exploring for the metal and production likely to grow over the next two years to around 3 million troy ounces (93.3 kilograms) of gold, the mining regulator says. The United Nations calls for a gradual elimination of mercury in mining as miners switch over to use of centrifuges, which allow for greater gold extraction than mercury. “With the centrifuge, small miners can produce twice as much gold than using mercury without affecting their health or the environment,” said Monica Roeser, who leads the Global Mercury Project in Colombia for the United Nations. Studies of children have detected attention deficit disorders, memory and language problems in Segovia and Remedios, the project has reported. Among miners, mercury exposure can be linked to memory loss, language issues and chronic headaches, researchers say. “We don’t know how many people may have died from mercury pollution because neither doctors nor nurses have instruments to analyse whether mercury is in the urine,” Veiga said.
Reuters Health, 13 July 2010 http://www.reuters.com/news/health
Another reason not of landfill: composting can help reduce green gas emissions
The North East Biosolids and Residuals Association analysed the energy consumption and greenhouse gas emissions associated with two biosolids management options, i.e., composting and landfilling. Results indicate that the difference in annual greenhouse gas emissions from composting operations and landfills is equal to that of nearly 500 passenger cars. Composting has lower greenhouse gas emissions. The results suggest that highly controllable systems, such as composters and anaerobic digesters, manage solids more efficiently than landfills. Although research continues on bioreactor landfills and their potential to generate and capture methane efficiently, anaerobic digestion and composting currently are far more controllable processes. Also, even the best landfills do not take advantage of the soil-building nutrients and organic matter in biosolids.
Authors: Beecher, Ned; Kuter, Geoff A.; Petroff, Barbara A.
Full Source: Water Environment & Technology 2009, 21(4), 36-41 (Eng)
Method for assessing transgenic drought resistant soybean on soil environment safety using functional and pathogenic microbes
The method comprises homogenising the roots from transgenic drought-resistant soybean and wild-type soybean of the same variety 100g each, filtering, centrifuging to collect supernatant, preparing selective media individually suitable for functional microbes and pathogenic microbes, adding the root extracts from the above-mentioned soybeans into the selective media at 0, 1%, 0.1%, 0.01%, 0.001% and 0.0001% and providing five parallel samples each, preparing culture plates, inoculating the culture plates individually with functional microbes such as Azotobacter, silicate bacteria, Trichoderma, Bacillus megaterium, and Bacillus subtilis and pathogenic microbes such as Phytophthora sojae, culturing the microbes at 28-30°C for 5-7d, comparing the diameters of the colonies in the culture media containing the root extract from transgenic drought-resistant soybean with those of corresponding colonies in the culture media containing the root extract from wild-type soybean so as to ascertain whether the transgenic drought resistant soybean influences the functional microbes and the pathogenic microbes, continuing microbial culture at 28-30°C to reach 10d, drying at 28-30°C, grinding, and testing the activities of corresponding enzymes such as urease, phosphatase and cellulase in the functional microbes.
Authors: Ding, Wei; Li, Wenbin; Yan, Chunxiu; Wang, Zhenhua
Full Source: Faming Zhuanli Shenqing Gongkai Shuomingshu CN 101,665,819 (Cl. C12Q1/18), 10 Mar 2010, Appl. 10,072,986, 28 Sep 2009; 4pp.(Ch).
Biological effects of nano-nickel in rat lungs after administration by inhalation and by intratracheal instillation
Wistar male rats were exposed to nickel oxide (NiO) nanoparticles (nNiOs) for 4 wk (6 h/day). The nNiOs were black-coloured NiO (99.8%) and average particle size (APS) was 20 nm. The geometric mean diameter of the particles in the chamber and the daily average exposure concentration were 139 ( 12 nm and 1.0 ( 0.5 x 105 particles/cc, respectively. The deposited amount of nNiOs in the rat lungs at 4 days after the inhalation exposure ended was 29 ( 4 íg. Although nNiOs exposure group showed temporal significant increase in the number of total cells in brochoalveolar lavage fluid (BALF) at 4 days after the exposure end, the difference were not seen at one month after an exposure end compared with control group. The histopathological change was not severe just after the inhalation nor throughout the observation time. Elemental mappings of nickel showed that nickel particles were located in agglomeration at the pulmonary macrophages.
Authors: Ogami,A.; Morimoto,Y.; Murakami, M.; Myojo,T.; Oyabu,T.; Tanaka,I.
Full Source: Journal of Physics: Conference Series [online computer file] 2009, 151, No pp. given (Eng)
Male reproductive system parameters in a two generation reproduction study of ammonium perfluorooc- tanoate in rats, and human relevance
Ammonium perfluorooctanoate (ammonium PFOA) is an industrial surfactant that has been used primarily as a processing aid in the manufacture of fluoropolymers. The environmental and metabolic stability of PFOA together with its presence in human blood and long elimination half-life have led to extensive toxicological studies in laboratory animals. Two recent publications based on observations from the Danish general population have reported: (1) a negative association between serum concentrations of PFOA in young adult males and their sperm counts and (2) a positive association among women with time to pregnancy. A two generation reproduction study in rats was previously published (2004) in which no effects on functional reproduction were observed at doses up to 30 mg ammonium PFOA/kg body wt. The article contained the simple statement: “In males, fertility was normal as were all sperm parameters”. In order to place the recent human epidemiological data in perspective, detailed male reproductive parameters are provided from that study, including sperm quality and testicular histopathology. Sperm parameters in rats from the two-generation study in all ammonium PFOA treatment groups were unaffected by treatment with ammonium PFOA. These observations reflected the normal fertility observations in these males. No evidence of altered testicular and sperm structure and function was observed in ammonium PFOA-treated rats whose mean group serum PFOA concentrations ranged up to approximately 50,000 ng/mL. Given that median serum PFOA in the Danish cohorts was approximately 5 ng/mL, it seems unlikely that concentrations observed in the general population, including those recently reported in Danish general population, could be associated causally with a real decrement in sperm number and quality.
Authors: York, Raymond G.; Kennedy, Gerald L.; Olsen, Geary W.; Butenhoff, John L.
Full Source: Toxicology 2010, 271(1-2), 64-72 (English)
Evaluation of silver nanoparticle toxicity in skin in vivo and keratinocytes in vitro
Products using the antimicrobial properties of silver nanoparticles (Ag-nps) may be found in health and consumer products that routinely contact skin. This study was designed to assess the potential cytotoxicity of Ag-nps in human epidermal keratinocytes (HEKs) and their inflammatory and penetrating potential into porcine skin in vivo. Eight different Ag-nps were used in this study [unwashed/uncoated (20, 50, and 80 nm particle diameter), washed/uncoated (20, 50, and 80 nm), and carbon-coated (25 and 35 nm)]. Skin was dosed topically for 14 consecutive days. HEK viability was assessed by MTT, alamarBlue (aB), and CellTiter 96 Aq. One (96AQ). Release of the proinflammatory mediators interleukin (IL)-1â, IL-6, IL-8, IL-10, and tumour necrosis factor-R (TNF-R) were measured. The effect of the unwashed Ag-nps on HEK viability after a 24-h exposure indicated a significant dose-dependent decrease (p < 0.05) at 0.34 íg/mL with aB and 96AQ and at 1.7 íg/mL with MTT. However, both the washed Ag-nps and carbon-coated Ag-nps showed no significant decrease in viability at any concentration assessed by any of the three assays. For each of the unwashed Ag-nps, a significant increase (p < 0.05) in IL-1â, IL-6, IL-8, and TNF-R concentrations was noted. Localisation of all Ag-nps was observed in cytoplasmic vacuoles of HEKs. Macroscopic observations showed no gross irritation in porcine skin, whereas microscopic and ultrastructural observations showed areas of focal inflammation and localisation of Ag-nps on the surface and in the upper stratum corneum layers of the skin. This study provides a better understanding Ag-nps safety in vitro as well as in vivo and a basis for occupational and risk assessment. Ag-nps are nontoxic when dosed in washed Ag-nps solutions or carbon coated.
Authors: Samberg, Meghan E.; Oldenburg, Steven J.; Monteiro-Riviere, Nancy A.
Full Source: Environmental Health Perspectives 2010, 118(3), 407-413 (English)
In utero and in vitro effects of benzene and its metabolites on erythroid differentiation and the role of reactive oxygen species
Exposures to benzene both prenatally and during adulthood are associated with the development of disorders such as aplastic anaemia and leukaemia. Mechanisms of benzene toxicity are unknown; however, generation of reactive oxygen species (ROS) by benzene metabolites may play a role. Little is known regarding the effects of benzene metabolites on erythropoiesis. Therefore, to determine the effects of in utero exposure to benzene on the growth and differentiation of foetal erythroid progenitor cells (CFUE), pregnant CD-1 mice were exposed to benzene and CFU-E numbers were assessed in foetal liver (hematopoietic) tissue. In addition, to determine the effect of benzene metabolite-induced ROS generation on erythropoiesis, HD3 chicken erythroblast cells were exposed to benzene, phenol, or hydroquinone followed by stimulation of erythrocyte differentiation. Results show that in utero exposure to benzene caused significant alterations in female offspring CFU-E numbers. In addition, exposure to hydroquinone, but not benzene or phenol, significantly reduced the percentage of differentiated HD3 cells, which was associated with an increase in ROS. Pretreatment of HD3 cells with polyethylene glycol-conjugated superoxide dismutase (PEG-SOD) prevented hydroquinone-induced inhibition of erythropoiesis, supporting the hypothesis that ROS generation is involved in the development of benzene erythrotoxicity. In conclusion, this study provided evidence that ROS generated as a result of benzene metabolism may significantly alter erythroid differentiation, potentially leading to the development of blood disorders.
Authors: Badham, Helen J.; Winn, Louise M.
Full Source: Toxicology and Applied Pharmacology 2010, 244(3), 273-279 (English)