Explore the vast range of titles available.

Intoxications by chromium (Cr) compounds are very life threatening and often lethal. After oral ingestion of 2 or 3g of hexavalent Cr (CrVI), gastrointestinal injury, but also hepatic and renal failure, often occurs which each leads to a fatal outcome in most patients. Cellular toxicity is associated with mitochondrial and lysosomal injury by biologically CrVI reactive intermediates and reactive oxygen species. After CrVI has been absorbed, there is not much that can be done except to control the main complications as the treatment is only symptomatic. The biotransformation of CrVI to CrIII reduces the toxicity because the trivalent form does not cross cellular membranes as rapidly. In fact, more than 80% of CrVI is cleared in urine as CrIII. We report the case of a 58-year-old male patient who was admitted to hospital after accidental oral ingestion of a 30g/L potassium dichromate (the estimated amount of ingested Cr is about 3g). ICP-MS equipped with a collision/reaction cell (CRC) and validated methods were used to monitor plasma (P), red blood cells (RBCs), urine (U) and hair chromium. For urine the results were expressed per gram of creatinine. After 7days in the intensive care unit, the patient was discharged without renal or liver failure. P, RBC and U were monitored during 49days. During this period Cr decreased respectively from 2088μg/L to 5μg/L, 631μg/L to 129μg/L and 3512μg/g to 10μg/g. The half-life was much shorter in P than in RBC as the poison was more quickly cleared from the P than from the RBC, suggesting a cellular trapping of the metal. Hair was collected 2months after the intoxication. We report a very rare case of survival after accidental Cr poisoning which has an extremely poor prognosis and usually leads to rapid death. For the first time, this toxicokinetic study highlights a sequestration of chromium in the RBC and probably in all the cells.

To compare the inspiratory volume pressure (VP) curves of the respiratory system (rs) produced by static occlusion (OCC) and dynamic low constant flow inflation (LCFI) methods using a new device in acute respiratory distress syndrome (ARDS) patients. A multidisciplinary 24-bed ICU in a tertiary university hospital. Eleven intubated and mechanically ventilated patients with ARDS. OCC and LCFI methods were performed using the same ventilator, which had been specifically implemented for this purpose. LCFI of 5, 10, and 15 l/min and OCC were applied in a random order at zero end-expiratory positive pressure. Airway pressure was measured both proximal (P(ao)) and distal (P(tr)) to the endotracheal tube. Lower inflection point (LIP) and maximal slope (C(max,rs)) were estimated using unbiased iterative linear regressions. LIP(rs) was obtained in all patients under LCFI and in nine patients under OCC. With LCFI of 5, 10, 15 l/min and OCC the average LIP(rs) values were 12.2 +/- 3.9, 12.9 +/- 4, 14.3 +/- 3.4, and 11.9 cm H(2)O for P(ao) and 11.9 +/- 3.9, 11.5 +/- 3.3, 12.5 +/- 3.4 and 11.8 +/- 4.4 for P(tr), respectively. Only the mean values of LIP(rs) for P(ao) with LCFI at 15 l/min were significantly different from those obtained for OCC. The C(max,rs) values found with the two methods were similar. An LCFI less than or equal to 10 l/min seems to be a quick, safe, and reliable method to determine LIP(rs) and C(max,rs) at the bedside.

Approximately, 75,000 people live in areas prone to volcanic hazards and floods in the large city of Arequipa, Peru. We have conducted three different surveys involving c. 280 respondents to appraise the socio-economic characteristics of urban dwellers living in informal settlements along two ravines, the extent to which they know hazards, perceive risk, and how they behave in case of disaster. This study also assesses how local communities consider, and civil authorities implement mitigation procedures in the city. The statistical analysis of the survey datasets included univariate, bivariate, and multivariate techniques together with hierarchical agglomerative clustering. Low-income urban dwellers, with a minimum or without education, represent almost 32% of the vulnerable population living in four districts. Almost 45% of the respondents have a regular to minimum knowledge of hazards, and half of the population is worried or uncertain about volcano and debris flow threats. A large proportion of dwellers trust early warning messages, but almost half of them check them out before evacuating. Overall, between a third and half of people living in the four most exposed districts of Arequipa seem to be quite vulnerable in case of an imminent debris flow. Interviews and focus groups with risk managers aimed to understand why planning emergency operations and risk mitigation are not as efficient as the municipality, and the communities would expect in Arequipa. Several issues hinder an adequate disaster risk management, as the underlying vulnerability factors of the exposed population are not accounted for. Under-investment in disaster risk management has led to diminish accountability among the risk managers and involvement of dwellers.

An eight-year long reanalysis of atmospheric composition data covering the period 2003–2010 was constructed as part of the FP7-funded Monitoring Atmospheric Composition and Climate project by assimilating satellite data into a global model and data assimilation system. This reanalysis provides fields of chemically reactive gases, namely carbon monoxide, ozone, nitrogen oxides, and formaldehyde, as well as aerosols and greenhouse gases globally at a horizontal resolution of about 80 km for both the troposphere and the stratosphere. This paper describes the assimilation system for the reactive gases and presents validation results for the reactive gas analysis fields to document the data set and to give a first indication of its quality. Tropospheric CO values from the MACC reanalysis are on average 10–20% lower than routine observations from commercial aircrafts over airports through most of the troposphere, and have larger negative biases in the boundary layer at urban sites affected by air pollution, possibly due to an underestimation of CO or precursor emissions. Stratospheric ozone fields from the MACC reanalysis agree with ozonesondes and ACE-FTS data to within ±10% in most seasons and regions. In the troposphere the reanalysis shows biases of −5% to +10% with respect to ozonesondes and aircraft data in the extratropics, but has larger negative biases in the tropics. Area-averaged total column ozone agrees with ozone fields from a multi-sensor reanalysis data set to within a few percent. NO2 fields from the reanalysis show the right seasonality over polluted urban areas of the NH and over tropical biomass burning areas, but underestimate wintertime NO2 maxima over anthropogenic pollution regions and overestimate NO2 in northern and southern Africa during the tropical biomass burning seasons. Tropospheric HCHO is well simulated in the MACC reanalysis even though no satellite data are assimilated. It shows good agreement with independent SCIAMACHY retrievals over regions dominated by biogenic emissions with some anthropogenic input, such as the eastern US and China, and also over African regions influenced by biogenic sources and biomass burning.

Arequipa, the second largest city in Peru, is exposed to many natural hazards, most notably earthquakes, volcanic eruptions, landslides, lahars (volcanic debris flows), and flash floods. Of these, lahars and flash floods, triggered by occasional torrential rainfall, pose the most frequently occurring hazards that can affect the city and its environs, in particular the areas containing low-income neighbourhoods. This paper presents and discusses criteria for delineating areas prone to flash flood and lahar hazards, which are localized along the usually dry (except for the rainy season) ravines and channels of the Río Chili and its tributaries that dissect the city. Our risk-evaluation study is based mostly on field surveys and mapping, but we also took into account quality and structural integrity of buildings, available socio-economic data, and information gained from interviews with risk-managers officials. In our evaluation of the vulnerability of various parts of the city, in addition to geological and physical parameters, we also took into account selected socio-economic parameters, such as the educational and poverty level of the population, unemployment figures, and population density. In addition, we utilized a criterion of the \"isolation factor\", based on distances to access emergency resources (hospitals, shelters or safety areas, and water) in each city block. By combining the hazard, vulnerability and exposure criteria, we produced detailed risk-zone maps at the city-block scale, covering the whole city of Arequipa and adjacent suburbs. Not surprisingly, these maps show that the areas at high risk coincide with blocks or districts with populations at low socio-economic levels. Inhabitants at greatest risk are the poor recent immigrants from rural areas who live in unauthorized settlements in the outskirts of the city in the upper parts of the valleys. Such settlements are highly exposed to natural hazards and have little access to vital resources. Our study provides good rationale for the risk zoning of the city, which in turn may be used as an educational tool for better understanding the potential effects of natural hazards and the exposure of the population residing in and around Arequipa. We hope that our work and the risk-zonation maps will provide the impetus and basis for risk-management authorities of the Municipality and the regional government of Arequipa to enforce existing regulations in building in hazardous zones and to adopt an effective long-term strategy to reduce risks from lahar, flash flood, and other natural hazards.

Daily global analyses and 5-day forecasts are generated in the context of the European Monitoring Atmospheric Composition and Climate (MACC) project using an extended version of the Integrated Forecasting System (IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF). The IFS now includes modules for chemistry, deposition and emission of reactive gases, aerosols, and greenhouse gases, and the 4-dimensional variational data assimilation scheme makes use of multiple satellite observations of atmospheric composition in addition to meteorological observations. This paper describes the data assimilation setup of the new Composition-IFS (C-IFS) with respect to reactive gases and validates analysis fields of ozone (O3), carbon monoxide (CO), and nitrogen dioxide (NO2) for the year 2008 against independent observations and a control run without data assimilation. The largest improvement in CO by assimilation of Measurements of Pollution in the Troposphere (MOPITT) CO columns is seen in the lower troposphere of the Northern Hemisphere (NH) extratropics during winter, and during the South African biomass-burning season. The assimilation of several O3 total column and stratospheric profile retrievals greatly improves the total column, stratospheric and upper tropospheric O3 analysis fields relative to the control run. The impact on lower tropospheric ozone, which comes from the residual of the total column and stratospheric profile O3 data, is smaller, but nevertheless there is some improvement particularly in the NH during winter and spring. The impact of the assimilation of tropospheric NO2 columns from the Ozone Monitoring Instrument (OMI) is small because of the short lifetime of NO2, suggesting that NO2 observations would be better used to adjust emissions instead of initial conditions. The results further indicate that the quality of the tropospheric analyses and of the stratospheric ozone analysis obtained with the C-IFS system has improved compared to the previous \"coupled\" model system of MACC.

America's ozone imports Anthropogenic emissions of ozone precursors, chiefly nitrogen oxides and volatile organic compounds, have caused widespread increases in lower-atmosphere concentrations of ozone since the late 1800s. In the lowermost part of the atmosphere ozone is a greenhouse gas that can have detrimental effects on plant and animal life. At present East Asia has the fastest rate of growth in such emissions and much of its pollution is exported towards North America. A compilation of springtime ozone measurements from across western North America now provides evidence for a strong increase in ozone mixing ratios during 1995–2008. The rate of increase in ozone mixing ratio is greatest when measurements are more heavily influenced by direct transport from Asia. This phenomenon, previously suspected but not confirmed, may make it more difficult for the United States to meet its own ozone air quality standard. High concentrations of ozone in the troposphere are toxic and act as a greenhouse gas. Anthropogenic emissions of ozone precursors have caused widespread increases in ozone concentrations since the late 1800s, with the fastest-growing ozone precursor emissions currently coming out of east Asia. Much of the springtime east Asian pollution is exported towards western North America; a strong increase in springtime ozone mixing ratios is now found in the free troposphere over this region. In the lowermost layer of the atmosphere—the troposphere—ozone is an important source of the hydroxyl radical, an oxidant that breaks down most pollutants and some greenhouse gases 1 . High concentrations of tropospheric ozone are toxic, however, and have a detrimental effect on human health and ecosystem productivity 1 . Moreover, tropospheric ozone itself acts as an effective greenhouse gas 2 . Much of the present tropospheric ozone burden is a consequence of anthropogenic emissions of ozone precursors 3 resulting in widespread increases in ozone concentrations since the late 1800s 3 , 4 , 5 , 6 , 7 . At present, east Asia has the fastest-growing ozone precursor emissions 8 . Much of the springtime east Asian pollution is exported eastwards towards western North America 9 . Despite evidence that the exported Asian pollution produces ozone 10 , no previous study has found a significant increase in free tropospheric ozone concentrations above the western USA since measurements began in the late 1970s 5 , 11 , 12 . Here we compile springtime ozone measurements from many different platforms across western North America. We show a strong increase in springtime ozone mixing ratios during 1995–2008 and we have some additional evidence that a similar rate of increase in ozone mixing ratio has occurred since 1984. We find that the rate of increase in ozone mixing ratio is greatest when measurements are more heavily influenced by direct transport from Asia. Our result agrees with previous modelling studies, which indicate that global ozone concentrations should be increasing during the early part of the twenty-first century as a result of increasing precursor emissions, especially at northern mid-latitudes 13 , with western North America being particularly sensitive to rising Asian emissions 14 . We suggest that the observed increase in springtime background ozone mixing ratio may hinder the USA’s compliance with its ozone air quality standard.

The European research infrastructure IAGOS (In-service Aircraft for a Global Observing System) equips commercial aircraft with a system for measuring atmospheric composition. A range of essential climate variables and air quality parameters are measured throughout the flight, from take-off to landing, giving high-resolution information in the vertical in the vicinity of international airports and in the upper troposphere–lower stratosphere during the cruise phase of the flight. Six airlines are currently involved in the programme, achieving a quasi-global coverage under normal circumstances. During the COVID-19 crisis, many airlines were forced to ground their fleets due to a fall in passenger numbers and imposed travel restrictions. Deutsche Lufthansa, a partner in IAGOS since 1994 was able to operate an IAGOS-equipped aircraft during the COVID-19 lockdown, providing regular measurements of ozone and carbon monoxide at Frankfurt Airport. The data form a snapshot of an unprecedented time in the 27-year time series. In May 2020, we see a 32 % increase in ozone near the surface with respect to a recent reference period, a magnitude similar to that of the 2003 heatwave. The anomaly in May is driven by an increase in ozone at nighttime which might be linked to the reduction in NO during the COVID-19 lockdowns. The anomaly diminishes with altitude becoming a slightly negative anomaly in the free troposphere. The ozone precursor carbon monoxide shows an 11 % reduction in MAM (March–April–May) near the surface. There is only a small reduction in CO in the free troposphere due to the impact of long-range transport on the CO from emissions in regions outside Europe. This is confirmed by data from the Infrared Atmospheric Sounding Interferometer (IASI) using retrievals performed by SOftware for a Fast Retrieval of IASI Data (SOFRID), which display a clear drop of CO at 800 hPa over Europe in March but otherwise show little change to the abundance of CO in the free troposphere.