Changes in thyroid peroxidase activity in response to various chemicals

Thyroperoxidase (TPO) is a large heme-containing glycoprotein that catalyzes the transfer of iodine to thyroglobulin during thyroid hormone (TH) synthesis. Previously, we established an in vitro assay for TPO activity based on human recombinant TPO (hrTPO) stably transfected into human follicular thyroid carcinoma (FTC-238) cells. It is important to determine whether environmental chemicals can disrupt TPO activity because it is an important factor in the TH axis. In this study, we used our assay to examine the changes in TPO activity in response to various chemicals, including benzophenones (BPs), polycyclic aromatic hydrocarbons (PAHs), and persistent organic pollutants (POPs). Overall, BPs, PAHs, and POPs slightly altered TPO activity at low doses, as compared with the positive controls methimazole (MMI), genistein, and 2,2',4,4'-tetrahydroxy BP. Benzophenone, benzhydrol, 3-methylchloranthracene, pyrene, benzo(k)fluoranthene, benzo(e)pyrene, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and heptachlor decreased TPO activity, while 2,4-dihydroxy BP, 2,2'-dihydroxy-4-methoxy BP, and dibenzo(a,h)anthracene increased TPO activity. From these data, we can predict the disruption of TPO activity by various chemicals as a sensitive TH end point. TPO activity should be considered when enacting measures to regulate environmental exposure to thyroid-disrupting chemicals.     

Speciation of mercury in the strongly polluted sediments of the Deûle River (France)

The De?le River in Northern France experienced serious contamination from the metallurgical industry, especially from the smelter Metaleurop prior to 2003. In 2002 the surface sediments were collected from the bed of the river around 10 km above and 10 km below the smelter. Total mercury (HgT) and methylmercury (MeHg) concentrations exceeded the background value of 0.1 mg kg(-1). The average concentrations were 19.67 ± 1.02 mg kg(-1) and 10.88 ± 1.08 μg kg(-1), respectively. In 2003 the sediment core samples were collected at two different sites near the factory for survey depth profiles of Hg contamination. The concentrations of HgT and MeHg in sediment cores varied from 10.47 to 259.44 mg kg(-1) and from 3.24 to 82.61 μg kg(-1), respectively. The concentration of total mercury was significantly correlated with the methylmercury concentration in the sediment below a depth of 23.5 cm (R(2) = 0.81, p < 0.01). This may suggest that the production of MeHg is directly related to the HgT concentration. Nevertheless the MeHg/HgT ratio in the upper part of the sediment core was higher than that in the lower part. This suggests that HgT and MeHg may have been co-deposited together. However, the methylmercury production takes place in the surface sediment by microorganisms. The strong correlation observed between MeHg and acid volatile sulfides (AVS) suggests that MeHg variability is associated with the bacterial activity (presence of AVS).     

Prioritizing GM crop monitoring sites in the dynamics of cultivation systems and their environment

EU legislation stipulates that GM crops have to be monitored for potential adverse environmental effects. Monitoring preferably should take place in the most exposed areas-the cultivated fields and their neighbouring environment. Current monitoring designs do not give detailed consideration to the different exposure intensities in agricultural practice. At the same time, the selection of specific, more exposed sites is difficult considering the dynamic and diversity of crop cultivation and rotation systems and their environments. We developed an approach for prioritising the monitoring of on-farm and neighbouring sites based on differing exposure levels using a minimum dataset of cultivation and land use information. Applying a Bt-maize cultivation scenario to Brandenburg, Germany, where presently no GM crops are cultivated, we systemised and categorised areas with different spatio-temporal exposure intensities including 50 m, 200 m and 1000 m buffers. These categories correspond to different suitabilities to serve as monitoring sites. Sites are prioritised using a sequential scheme. This yields an improved and objective spatial monitoring design providing detailed exposure information. This methodology is flexible and transferable to any agricultural setting, therefore enabling superior statistical comparisons between locations and regions and thus enhancing monitoring data quality.     

Monitoring of ozone effects on the vitality and increment of Norway spruce and European beech in the Central European forests

The ozone effect on Norway spruce (Picea abies (L) Karst.) and European beech (Fagus sylvatica L.) was studied on 48 monitoring plots in 2005-2008. These plots represent two major forest tree species stands of different ages in eight regions of the Czech Republic. The forest conditions were represented by defoliation and the annual radial increment of individual trees. The ozone exposure was assessed by using modeled values of mean annual O(3) concentration and the AOT40 index. The malondialdehyde (MDA) content of the foliage was analysed and used as an indicator of oxidative stress. The correlation analysis showed a significant relation of Norway spruce defoliation to the AOT40 exposure index, and European beech defoliation to the MDA level. The radial increment response to ozone was significant only for the European beech: (a) the correlation analysis showed its decrease with increasing AOT40; (b) the regression model showed its decrease with increasing mean annual ozone concentration only at lower altitudes (<700 m a.s.l.).     

Utilizing pyrosequencing and quantitative PCR to characterize fungal populations among house dust samples

Molecular techniques are an alternative to culturing and counting methods in quantifying indoor fungal contamination. Pyrosequencing offers the possibility of identifying unexpected indoor fungi. In this study, 50 house dust samples were collected from homes in the Yakima Valley, WA. Each sample was analyzed by quantitative PCR (QPCR) for 36 common fungi and by fungal tag-encoded flexible (FLX) amplicon pyrosequencing (fTEFAP) for these and additional fungi. Only 24 of the samples yielded amplified results using fTEFAP but QPCR successfully amplified all 50 samples. Over 450 fungal species were detected by fTEFAP but most were rare. Twenty-two fungi were found by fTEFAP to occur with at least an average of ≥0.5% relative occurrence. Many of these fungi seem to be associated with plants, soil or human skin. Combining fTEFAP and QPCR can enhance studies of fungal contamination in homes.     

A simple linear model for estimating ozone AOT40 at forest sites from raw passive sampling data

A rapid, empirical method is described for estimating weekly AOT40 from ozone concentrations measured with passive samplers at forest sites. The method is based on linear regression and was developed after three years of measurements in Trentino (northern Italy). It was tested against an independent set of data from passive sampler sites across Italy. It provides good weekly estimates compared with those measured by conventional monitors (0.85 ≤R(2)≤ 0.970; 97 ≤ RMSE ≤ 302). Estimates obtained using passive sampling at forest sites are comparable to those obtained by another estimation method based on modelling hourly concentrations (R(2) = 0.94; 131 ≤ RMSE ≤ 351). Regression coefficients of passive sampling are similar to those obtained with conventional monitors at forest sites. Testing against an independent dataset generated by passive sampling provided similar results (0.86 ≤R(2)≤ 0.99; 65 ≤ RMSE ≤ 478). Errors tend to accumulate when weekly AOT40 estimates are summed to obtain the total AOT40 over the May-July period, and the median deviation between the two estimation methods based on passive sampling is 11%. The method proposed does not require any assumptions, complex calculation or modelling technique, and can be useful when other estimation methods are not feasible, either in principle or in practice. However, the method is not useful when estimates of hourly concentrations are of interest.     

牛骨炭对水溶液中Hg（Ⅱ）吸附性的研究

以牛骨为原料,氯化锌为活化剂制备牛骨基炭,通过静态吸附试验研究了牛骨炭对水中Hg（Ⅱ）的吸附效果并确定了影响吸附性能的因素。研究结果表明：牛骨炭对Hg（Ⅱ）的最佳吸附时间约为2h、吸附温度为25℃、pH值为1、投加量为0．1g、吸附溶液的最大初始浓度为600mg／L,其最大吸附容量Q^0为43．1mg／g,吸附行为符合Freundl—ich吸附等温模型;通过BET分析和扫描电镜（SEM）等手段表征了牛骨炭的孔结构参数及形貌特征,经分析,所制备牛骨炭的孔径分布为中孔。     

Relevance of the economic crisis in chemical PM10 changes in a semi-arid industrial environment

This paper shows the changes in PM(10) levels and chemical composition in a region in southeast Spain between two periods: September 2005-August 2006 and June 2008-May 2009. PM(10) levels in this arid region, with a great number of cement, ceramic and related industries, have decreased in the second period in concordance with the reduction of industrial production due to the economic crisis and the closure of a cement plant. Annual average levels of PM(10) decreased from 41?μg?m(-3) in 2005 to 30?μg?m(-3) in 2008 (27%) and to 23?μg?m(-3) in 2009 (23%). The relative contribution of the different sources has not changed in the area in the latter period and the elements with mineral origin are the main components of the PM(10) composition. There is a reduction in the concentration of the components that have soil-related industries and crustal material resuspension as their main sources, mainly in the case of CO(3) (2-), Ca, Sr, Tl and Pb, but the seasonal patterns were the same in both periods. As a particular case, there is an uncoupling between the seasonal evolution of SO(2) and sulphates in the two study periods, which remarks the existence of a sulphate regional background that does not depend on SO(2) local emissions. The decrease of V, Ni and Tl levels reflects the reduction of the industrial activity during the crisis period, affecting mainly the ceramic sector characterised by a great decrease of Tl levels.     

Baseline values for metals in soils on Fildes Peninsula, King George Island, Antarctica: the extent of anthropogenic pollution

Metal contents (Al, Ca, Cd, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Ti, and Zn) have been measured in 30 surface soils on Fildes Peninsula, King George Island, Antarctica, yielding values (in milligrams kilogram(-1)) of 41.57-80.65 (Zn), 2.76-60.52 (Pb), 0.04-0.34 (Cd), 7.18-25.03 (Ni), 43,255-70,534 (Fe), 449-1,401 (Mn), 17.10-64.90 (Cr), 1,440-25,684 (Mg), 10,941-49,354 (Ca), 51.10-176.50 (Cu), 4,388-12,707 (Ti), 28,038-83,849 (Al), and for Hg (in nanograms gram(-1)) 0.01-0.06. Relative cumulative frequency analysis was used to determine the baseline values for the 13 metals. Compared with adjacent areas in Antarctica, Mg and Ni are significantly lower, but Cu is significantly higher than that of McMurdo Station. Enrichment factor analysis and the geo-accumulation index method were applied in order to determine the extent of anthropogenic contamination, and both show that Pb, Cd, and Hg have been significantly increased by human activities. Principal component analysis was used to identify the sources of metals in these soil samples.     

Characteristic, composition, and sources of TSP investigated by HRTEM/EDS and ESEM/EDS

Total suspended particle (TSP) collected at the fifth floor of House Dust in Hunan University, China, was analyzed in terms of microscopic morphology and chemical composition. The fine particles (50?nm-2?μm) in the TSP were analyzed by a high-resolution transmission electron microscope equipped with an energy-dispersive X-ray analyzer (HRTEM/EDS). Results showed that the particles were in shapes of plate, irregular and agglomerate. Based on EDS results, these fine particulate matter was primarily composed of Fe-rich (35.82-61.29%), Ca-rich (30.18-36.77%) and Si-rich (18.95-32.28%) particles. Other elements mainly including Mg (0.47-4.97%), Al (0.45-14.57%), S (0.45-4.73%), K (1.13-2.13%) and Zn (0.67-3.85%) were also observed. The sources analysis indicated that the HRTEM particles mainly originated from coal combustion, traffic emission, vehicles exhaust emission and fugitive soil or cement particulate matter. The coarse particles (4-50?μm) were detected by environmental scanning electron microscopy coupled with energy-dispersive X-ray detector (ESEM/EDS). Based on a simple algorithm, ESEM particles were categorized into five groups: C-bearing (46.15%, 67% and 86.98%), Si + Ca-bearing (21.48?+?11.80%, 16.51?+?10.81% and 16.32?+?10.62%), Si + Al-bearing (20.06?+?12.40%, 20.16?+?11.22% and 15.31?+?11.25%), Si-bearing (34.40%, 26.92% and 27.15%) particles and aggregates, most of which exhibit obvious crystalline structure, and these ESEM particles mainly derived from vehicles exhaust emission, coal combustion, soil, and biomass burning, while the aggregates are indicative of atmospheric reaction progress. HRTEM/EDS and ESEM/EDS are mutual complementary in analyzing the characteristic and determining the sources of TSP.