Samplers made with different materials were tested for the quantitative collection and recovery of mercury halides from the atmospheric air. The tested adsorbent materials included zirconia (ZrO2), titania (TiO2), melted SiO2 (quartz wool) and potassium chloride (KCl). Different processes affecting the sampler efficiency were investigated specifically: breakthrough during sampling because of the surface passivation and loss of already collected mercury halides due to spontaneous reduction or due to the reaction with ozone. Reduction of mercury because of reaction with the atmospheric ozone appeared to be the major cause of the sample loss and it was inherent in all tested materials at a comparable extent. We hypothesized the zirconia layer covered on a ceramic substrate (patented) to be less sensitive to the ozone-caused reduction, inert to gaseous elemental mercury and completely insensitive to atmospheric humidity. In addition, zirconia samplers were highly resistant to heating and they could be used for multiple adsorption/desorption cycles avoiding degradation in the atmospheric air. Key results of the zirconia sampler tests with mercury halides were: the collection efficiency of >98%; reduction with 50 ppb ozone in the first 4 min of exposition to the atmospheric air ─ 6% ±1%; spontaneous reduction at 50 °C in the first 4 min after spiking ─ <0.6%. Along with the above experimental results, some insights into the possible mechanism of interaction of ozone with mercury halides have been provided.

Deltas provide many worthy ecosystem services. Yet, delta basins are quite vulnerable, especially in the face of climate change, which can affect the outcome of both agriculture and biodiversity. Moreover, rice paddy cultivation is well known to contribute with strong emissions of greenhouse gases (GHGs), such as methane (CH4). Thus, knowing the atmospheric variability of CH4 in relation to the different stages of the rice culture cycle could help to improve GHGs' mitigation strategies in deltas.The Ebro River Delta, in the northwestern Mediterranean basin, forms part of the largest Spanish river basin and is mainly covered by rice fields. In this study, for the first time, ground level (40 cm a.g.l.) atmospheric CH4 concentrations have been monitored in this area, through twenty-seven car mobile transects, over the course of one year. Seasonal, diurnal and spatial variability of CH4 concentrations were studied to identify its relationship with rice cultivation, meteorological conditions and land-use distribution.With regard to seasonal variability, autumn transects showed the highest mean values for atmospheric CH4 (2.466 ppm) when dead rice straw is mixed with the sediment, and weed growth is prevented. Spring and summer measurements gave the highest mean CH4 values at dawn (1.897–3.544 ppm), whereas autumn and winter produced the mean values after sunset (2.148–2.930 ppm). Spatial differences were accounted for by proximity to urban areas, presence of shallow water storage structures, and distance to seawater.

Levels of polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NFRs) were measured in ambient outdoor air, indoor air and indoor dust collected in homes and offices at urban, semi-urban and rural locations in Istanbul, Turkey. Indoor air levels of Σ12PBDEs in homes and offices ranged from 36 to 730 pg/m3 and 160 to 10 100 pg/m3, respectively, while levels of Σ12NFRs ranged from 180 to 7600 pg/m3 and 180 to 42 400 pg/m3, respectively. Outdoor air levels ranged from 110 to 620 pg/m3 for Σ12PBDEs and 750 to 2800 pg/m3 for Σ12NFRs. I/O ratios that are greater than 1 suggest that air concentrations detected in indoor environments are mainly from indoor sources. Indoor dust levels in homes and offices of Σ12PBDEs ranged from 400 to 12 500 ng/g and 330 to 32 200 ng/g respectively and levels of Σ12NFRs ranged from 320 to 31 400 ng/g and 910 to 97 900 ng/g, respectively. The I/O ratios >1 for PBDEs and NFRs may indicate that emissions of these chemicals detected in homes and offices are mainly from indoor sources. Due to childrens' frequent hand-to-mouth behaviour, lower body weight and increased dust ingestion rate compared to adults, exposure rates to target chemicals for children were greater than those of adults. Based on median concentrations of chemicals of interest in dust and air samples from Istanbul, we estimate that exposure rates of children to PBDEs and NFRs are up to 160 times higher compared to adults but none of the estimated exposure rates results for children or adults were than the recommended daily oral reference dose values of certain analytes.

As nitrogen entering coastal waters continues to be an issue, much attention has been generated to identify potential options that may help alleviate this stressor to estuaries, including the propagation of bivalves to remove excess nitrogen. Oysters (Crassostrea virginica) and quahogs (Mercenaria mercenaria) from numerous Cape Cod, MA, (USA) sources were analyzed for nitrogen content stored in tissues that would represent a net removal of nitrogen from a water body if harvested. Results showed local oysters average 0.69% nitrogen by total dry weight (mean 0.28gN/animal) and quahogs average 0.67% nitrogen by total dry weight (mean 0.22gN/animal); however, these values did vary by season and to a lesser extent by location or grow-out method. The differences in nitrogen content were largely related to the mass of shell or soft tissue. Nitrogen isotope data indicate shellfish from certain water bodies in the region are incorporating significant amounts of nitrogen from anthropogenic sources.

This paper deals with the analysis of the global and per capita NOx and VOC emissions in the U.S. and the evaluation of the effectiveness of a number of environmental policies conducted by the government during the last 50 years. For this purpose we have employed fractional integration techniques, which are more flexible than other standard approaches based on the dichotomy between stationary I(0) and nonstationary I(1) behavior. Using the I(d) class of models, our results indicate first that the two NOx series display orders of integration substantially higher than 1, and though the VOC series display smaller orders, the unit root hypothesis cannot be rejected, indicating lack of mean reversion in the four series examined. Including dummy variables for each of the breaks referring to the environmental policies, the results show that the five policies investigated (at 1965, 1967, 1970, 1977 and 1990) were effective in reducing the number of emissions, being particularly important the one that was adopted in 1970.

Reductions of zooplankton biomasses and grazing pressures were observed during overfishing-induced trophic cascades and concurrent oil spills at global scales. Recent phytoplankton increments followed, once Fe-, P-, and N-nutrient limitations of commensal diazotrophs and dinoflagellates were also eliminated by respective human desertification, deforestation, and eutrophication during climate changes. Si-limitation of diatoms instead ensued during these last anthropogenic perturbations of agricultural effluents and sewage loadings. Consequently, ~15% of total world-wide annual asthma trigger responses, i.e. amounting to ~45 million adjacent humans during 2004, resulted from brevetoxin and palytoxin poisons in aerosol forms of western boundary current origins. They were denoted by greater global harmful algal bloom [HAB] abundances and breathing attacks among sea-side children during prior decadal surveys of asthma prevalence, compiled here in ten paired shelf ecosystems of western and eutrophied boundary currents. Since 1965, such inferred onshore fluxes of aerosolized DOC poisons of HABs may have served as additional wind-borne organic carriers of toxic marine MeHg, phthalate, and DDT/DDE vectors, traced by radio-iodine isotopes to potentially elicit carcinomas. During these exchanges, as much as 40% of mercury poisonings may instead have been effected by inhalation of collateral HAB-carried marine neurotoxic aerosols of MeHg, not just from eating marine fish. Health impacts in some areas were additional asthma and pneumonia episodes, as well as endocrine disruptions among the same adjacent humans, with known large local rates of thyroid cancers, physician-diagnosed pulmonary problems, and ubiquitous high indices of mercury in hair, pesticides in breast milk, and phthalates in urine.

In this work, Erythromycin A(EA)- degrading bacteria was isolated from the contaminated soil obtained from a pharmaceutical factory in China. The isolate designated as strain WX-J1 was identified as Ochrobactrum sp. by sequence analysis of its 16S rDNA gene. It can grow in a medium containing EA as the sole source of carbon and its optimal growth pH and temperature were 6.5 and 32°C, respectively. Under these conditions, when the initial Erythromycin A concentration was 100mg·L−1, 97% of Erythromycin A has been degraded. HPLC–MS analyses indicated that Erythromycin A degradation produced intermediates contained the following three substances: 3-depyranosyloxy erythromycin A, 7,12-dyhydroxy-6-deoxyerythronolide B, 6-deoxyerythronolide B and propionaldehyde. Since Erythromycin A-degrading Ochrobactrum sp. strain rapidly degraded Erythromycin A, this strain might be useful for bioremediation purposes.

Based on the remote sensing retrieval of PM2.5 concentration data in the long-time series, both the linear regression and grey system correlation analysis methods were employed to analyze the spatial and temporal pattern, variation trend and the main influencing factors of PM2.5 concentration in China from 1998 to 2014. The results showed that only 16.21%–24.67% of the land area in China PM2.5 concentrations reached the annual average criterion value of 10 μg/m3 set by the World Health Organization (WHO) in 1998–2014; the PM2.5 concentrations were greater than 95 μg/m3 mainly in Xinjiang Taklimakan Desert, west of Tianjin and the central region of Hebei. PM2.5 concentration was less than 10 μg/m3 mainly in Tibet, western Sichuan, northeastern Yunnan, Taiwan, northern Xinjiang, northern Inner Mongolia and northwest of Heilongjiang. High PM2.5 concentration in the northwest of China was mainly affected by sand and dust, while it was mainly caused by human activities in the eastern region. Except for Taiwan, low PM2.5 concentration areas were mainly located in the economically backward regions. The positive indicators in highly correlation with PM2.5 concentration include the average temperature, the proportion of primary and secondary industry to GDP, industrial consumption, the proportion of fulfilled amount of investment in real estate development to GDP, SO2 emissions and population density. The negative indicators in highly correlation with PM2.5 concentration include the average precipitation, the average wind velocity, the proportion of the tertiary industry to GDP, and the greening coverage rate of the built-up areas.

Road traffic emission factors (EFs) are important parameters in managing air quality. Estimation typically requires data from advanced (and expensive) monitoring systems which remain unavailable in some regions (e.g. in developing countries). In this context, the use of simpler (lower-cost) systems may be more appropriate, but it is essential to guarantee the robustness of EF estimations. This article describes a methodology designed to estimate vehicle EFs from street canyon measurements of traffic fluxes, wind speed and direction, and pollutant concentration levels by using low-cost devices, all samples at a one-minute interval. We use different moving window filters (time periods) to average the raw measurements. Applying standard multiple linear regressions (MRL) and principal component regressions (PCR), we show that there is an optimal smoothing level that best relates traffic episodes and pollutant concentration measurements. An application for PM10's EFs on four vehicle categories of Havana's fleet shows a preference for PCR over MLR techniques since it reduced the collinearity effects that appear when traffic fluxes are naturally correlated between vehicle categories. The best regression fits (R > 0.5 and standard deviation of estimates < 15%) were obtained by averaging data between 40′ and 60’; within the boundaries of 95% confidence interval motorcycles have an EF = 111.1 ± 2.7 mg km−1 veh−1; modern, light vehicles have an EF = 90.6 ± 11.2 mg km−1 veh−1; old, light vehicles have an EF = 125.4 ± 18.5 mg km−1 veh−1 and heavy vehicles have an EF = 415.1 ± 31.2 mg km−1 veh−1. We showed that upgrading old light vehicles is a promising scenario for reducing PM10 air pollution in Havana by between 10 and 17%.

Corexit, an EPA-approved chemical dispersant, was intensively used during the 2010 Deepwater Horizon Oil Spill in the Gulf of Mexico. Current studies surrounding Corexit have mainly focused on its toxicity and oil removal capacity. The potential impact of Corexit on the surface ocean carbon dynamics has remained largely unknown. The spontaneous assembly of DOM (dissolved organic matter) polymers into microgels (POM, particulate organic matter) was demonstrated previously that it can influence various critical processes, such as colloidal pump, microbial loops, and nutrition availability in the surface ocean. Here, we report that Corexit alone can significantly inhibit DOM microgel formation and reduce the stability of pre-existing microgels. However, Corexit and oil, Chemically Enhanced Water Accommodated Fraction (CEWAF), could effectively facilitate DOM microgel formation. The unanticipated disturbance of Corexit and oil spills on the critical DOM-POM continuum warrant particular caution and thus should be considered for future application of Corexit during oil spills.