Agricultural abandoned lands as emission sources of dust containing metals and pesticides in the Sonora-Arizona Desert

This investigation examines the transport of metal- and pesticide-polluted dust emitted by one of the most relevant agricultural areas of Northwestern Mexico. In the contaminated area, an excessive water extraction of the aquifer and seawater intrusion caused the abandonment of fields, which are pollutant-loaded dust emitters. We used air mass forward trajectories (HYSPLIT) model to obtain particle trajectories in the wind and the use of banned pesticides as geochemical tracers for dust transported by wind. Fifty dust samples from 10 agriculture fields and 26 roof dust of a city close to the agricultural area were analyzed for their contents of zirconium, lead, arsenic, zinc, copper, iron, manganese, vanadium, and titanium, by portable X-ray fluorescence. Nine pesticides were analyzed in the roof dust and agricultural soil samples by gas chromatography. Results show that the distribution of metals was significantly different between active and abandoned fields. Arsenic-lead-copper was mainly concentrated in abandoned fields, while zinc-iron-manganese-titanium was dominant in active fields. Two potential sources of metal contamination were found by principal component analysis (PCA): (I) a mixture of traffic and agricultural sources and (II) a group related to agricultural activities. The occurrence of banned pesticides in dust deposited on roofs collected at nearby cities confirms the atmospheric transport from the agricultural area. The HYSPLIT results indicated that the dust emitted from agricultural fields can reach up to the neighboring states of Sonora, Mexico, and the USA. The impacts that these emissions can have on human health should be studied in future research.

Characterization and Polydispersity of Volcanic Ash Nanoparticles in Synthetic Lung Fluid

The inhalation of natural nanoparticles (NPs) emitted from volcanic activity may be a risk to human health. However, the literature rarely reports the fate and response of NPs once in contact with lung fluids. In this work, we studied the particle size distribution of ashfall from Popocatépetl volcano, Mexico. The collected ashes (n = 5) were analyzed with scanning electron microscopy (SEM) to obtain the elemental composition and morphology, and to determine the size of the ash particles using ParticleMetric software (PMS). The PMS reported most of the ash to have submicrometric size (<1 μm) and an average equivalent circle of 2.72 μm. Moreover, to our knowledge, this study investigated for the first time the behavior of ash NPs at different times (0 to 24 h) while in contact with in vitro lung fluid, Gamble Solution (GS) and Artificial Lysosomal Fluid (ALF) using dynamic light scattering (DLS). We found a large variability in the hydrodynamic diameter, with values less than 1 nm and greater than 5 μm. Furthermore, aggregation and disaggregation processes were recognized in GS and ALF, respectively. The results of this study increase the knowledge of the interaction between NPs and lung fluids, particularly within the alveolar macrophage region.

Oxidative potential of metal-polluted urban dust as a potential environmental stressor for chronic diseases

Oxidative stress (OS) associated with metals in urban dust has become a public health concern. Chronic diseases linked to general inflammation are particularly affected by OS. This research analyzes the spatial distribution of metals associated with OS, the urban dust´s oxidative potential (OP), and the occurrence of diseases whose treatments are affected by OS. We collected 70 urban dust samples during pre- and post-monsoon seasons to achieve this. We analyzed particle size distribution and morphology by scanning electron microscopy, as well as metal(loid)s by portable X-ray fluorescence, and OP of dust in artificial lysosomal fluid by using an ascorbic acid depletion assay. Our results show that the mean concentration of Fe, Pb, As, Cr, Cu, and V in pre-monsoon was 83,984.6, 98.4, 23.5, 165.8, 301.3, and 141.9 mg kg^-1, while during post-monsoon was 50,638.8, 73.9, 16.7, 124.3, 178.9, and 133.5 mg kg^-1, respectively. Impoverished areas with the highest presence of cardiovascular, cancer, diabetes, and respiratory diseases coincide with contaminated areas where young adults live. We identified significant differences in the OP between seasons. OP increases during the pre-monsoon (from 7.8 to 237.5 nmol AA min^-1) compared to the post-monsoon season (from 1.6 to 163.2 nmol AA min^-1). OP values are much higher than measured standards corresponding to contaminated soil and urban particulate matter, which means that additional sources beside metals cause the elevated OP. The results show no risk from chronic exposure to metals; however, our results highlight the importance of studying dust as an environmental factor that may potentially increase oxidative stress.

Health risk assessment of gaseous elemental mercury (GEM) in Mexico City

Emissions of gaseous elemental mercury (GEM or Hg⁰) from different sources in urban areas are important subjects for environmental investigations. In this study, atmospheric Hg measurements were conducted to investigate air pollution in the urban environment by carrying out several mobile surveys in Mexico City. This work presents atmospheric concentrations of GEM in terms of diurnal variation trends and comparisons with criteria for pollutant concentrations such as CO, SO₂, NO₂, PM_2.5, and PM₁₀. The concentration of GEM was measured during the pre-rainy period by using a high-resolution active air sampler, the Lumex RA 915 M mercury analyzer. In comparison with those for other cities worldwide, the GEM concentrations were similar or slightly elevated, and they ranged from 0.20 to 30.23 ng m^-3. However, the GEM concentration was significantly lower than those in contaminated areas, such as fluorescent lamp factory locations and gold mining zones. The GEM concentrations recorded in Mexico City did not exceed the WHO atmospheric limit of 200 ng m^-3. We performed statistical correlation analysis which suggests equivalent sources between Hg and other atmospheric pollutants, mainly NO₂ and SO₂, emitted from urban combustion and industrial plants. The atmospheric Hg emissions are basically controlled by sunlight radiation, as well as having a direct relationship with meteorological parameters. The area of the city studied herein is characterized by high traffic density, cement production, and municipal solid waste (MSW) treatment, which constantly release GEM into the atmosphere. In this study, we included the simulation with the HYSPLIT dispersion model from three potential areas of GEM release. Emissions from industrial corridors and volcanic plumes localized outside the urban area contribute to the pollution of Mexico City and mainly affect the northern area during specific periods and climate conditions. Using the USEPA model, we assessed the human health risk resulting from exposure to inhaled GEM among residents of Mexico City. The results of the health risk assessment indicated no significant noncarcinogenic risk (hazard quotient (HQ) < 1) or consequent adverse effects for children and adults living in the sampling area over the study period. GEM emissions inventory data is necessary to improve our knowledge about the Hg contribution and effect in urban megacity areas with the objective to develop public safe policy and implementing the Minamata Convention.

Gaseous Elemental Mercury (GEM) in the Mexico City Metropolitan Area

This paper presents atmospheric gaseous elemental mercury (GEM) data recorded during two short-term monitoring surveys in the Mexico City Metropolitan Area (MCMA) at 12th May 2019 and at 22nd May 2020, during conditions of low and high human activity respectively. Results, although they are limited, can be considered as the representative range of exposure to GEM of the inhabitants of MCMA; differences in results reveal the impact of human activities on GEM background levels (2.53 and 3.76 ng m^-3, respectively). GEM concentrations and their spatial distribution does not allow for the identification of important industrial sources and do not reach intervention pollution levels. The activity of the Popocatépetl volcano is not likely to have an effect on GEM in the MCMA. In spite the evident decrease in GEM concentrations compared with data previously reported, monitoring must be carried out routinely given Mexico's participation in the Minamata Convention on Mercury.

Study of energetic properties of different tree organs in six Olea europaea L. cultivars

Pruning is an important horticultural practice for the management of olive orchards (Olea europaea L.) that generates a considerable amount of residues every year. Olive orchards are increasingly expanding beyond the Mediterranean Basin to new growing Countries (Australia, California, Argentina, Chile and Uruguay) and this will certainly lead to larger availability of pruning material. Currently, the interest in use of olive tree pruning residues for energy purposes is increasing but unfortunately, the information on the differences among organs of the tree, in terms of calorific value and ash content, is scarce. Another unknown aspect is the effect of cultivar vigour on dry matter partition among different tree organs, these are important traits to establish the energetic quality of pruning residues. The aim of this research was to study energetic aspects of six olive cultivars, largely grown in the Sicilian olive industry and characterized by different vigour. The trees taken into consideration in the study were selected in an experimental orchard to avoid any effect due to differences in environmental conditions and management. The energetic characteristics, calorific value and ash content, were evaluated for the various tree organs particularly shoots, leaves and branches; also root system was evaluated, although the roots can only be used once the trees are uprooted. Significant differences were observed in the calorific values among the different tree organs and the cultivars. Regarding the ash, shoots and leaves showed the highest content with respect to the other organs, thus causing a possible tendency in slagging with fouling and corrosion of boiler components.

Association of airborne particulate matter with pollen, fungal spores, and allergic symptoms in an arid urbanized area

Studies focused on the seasonal distribution of pollen and spores in semiarid cities are scarce. At these sites, climate change potentiates the emission and transport of fine (PM₁₀) to ultrafine particles (PM_2.5), easily attached to pollen surfaces, causing allergen's release. This study examines the potential correlation of seasonal variations of pollen, fungal spores, PM₁₀, and meteorological parameters with allergic reactions of 150 people living in a Sonoran desert city. We collected PM₁₀, airborne pollen, and spores during a year. We also studied topsoil and road dust samples as potential PM-emission sources. We obtained dust-mineralogy, chemistry, and particle size attached to pollen by X-ray diffraction and scanning electron microscope. Results show that seasonal high PM-loading in the urban atmosphere coincides with aeroallergens promoting micro- to nanoparticles' attachment to pollen's surface. A collapsed membrane was observed in several samples after individual grains show the following maximum wall coverage: Poaceae 28%, Asteraceae 40%, Chenopodiaceae-Amaranthacea 29%, Fabaceae 18%. Most of the particles covering pollen's surface have a geogenic origin mixed with metals linked to traffic (bromide, chlorine, and antimony). Mineralogical, granulometric analysis, and main wind-direction show that two local soil-types are the main contributors to PM. A high frequency of positive sensitization to pollen with high particle loading was detected. These results suggest that climate-driven dust emissions may alter pollen and spore surfaces' physicochemical characteristics with the further consequences in their allergenic potential.

Identification of refractory zirconia from catalytic converters in dust: An emerging pollutant in urban environments

Using catalytic converters is one of the most effective methods to control vehicle emissions. A washcoat of cerium oxide-zirconia (CeO₂-ZrO₂) has been used to enhance the performance of the catalytic converter device. To date, the prevalence of this material in the environment has not been assessed. In this study, we present evidence of the existence of inhalable zirconia in urban dust. Samples of the washcoat, exhaust pipe, topsoil, and road dust were analyzed by X-ray fluorescence, X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, photoluminescence (PL) spectroscopy, and thermally stimulated luminescence (TSL). The results showed a CeO₂-ZrO₂ phase separation after sintering. This causes the emission of ZrO₂, CeO₂, and CeZrO_x particles smaller than 1 μm, which can likely reach the alveolar macrophages in the lungs. The Ce-Zr content in road dust exceeds geogenic levels, and a significant correlation of 0.87 (p < 0.05) reflects a common anthropic source. Chronic exposure to such refractory particles may result in the development of non-occupational respiratory diseases. The inhalable crystalline compounds emitted by vehicles are a significant environmental health hazard, revealing the need for further investigation and assessment of zirconia levels generated by automobiles in urban areas worldwide.

Evaluation of possible impact on human health of atmospheric mercury emanations from the Popocatépetl volcano

The contribution of Hg from volcanic emanations is decisive for assessing global mercury emissions given the impact of this highly toxic contaminant on human health and ecosystems. Atmospheric Hg emissions from Popocatépetl volcano and their dispersion were evaluated carrying out two gaseous elemental mercury (GEM) surveys during a period of intense volcanic activity. Continuous GEM measurements were taken for 24 h using a portable mercury vapor analyzer (Lumex RA-915M) at the Altzomoni Atmospheric Observatory (AAO), 11 km from the crater. In addition, a long-distance survey to measure GEM was conducted during an automobile transect around the volcano, covering a distance of 129 km. The evaluation of the GEM data registered in the fixed location showed that heightened volcanic activity clearly intensifies the concentration of atmospheric Hg, extreme values around 5 ng m^-3. Highest concentrations of GEM recorded during the mobile survey were about 10 ng m^-3. In both surveys, the recorded concentrations during most of the measurement time were below 2 ng m^-3, but measurements were taken at a considerable distance from the crater, and GEM is subject to dilution processes. During both surveys, recorded GEM did not exceed the 200 ng m^-3 concentration recommended by the WHO (Air quality guidelines for Europe, 2000) as the regulatory limits for Hg in the atmospheric environment for long-term inhalation. Because this study was carried out in inhabited areas around the volcano during a period of intense volcanic activity, it can be concluded that the Popocatépetl does not represent a risk to human health in terms of Hg.

Robust Mesoporous CoMo/γ-Al2O3 Catalysts from Cyclodextrin-Based Supramolecular Assemblies for Hydrothermal Processing of Microalgae: Effect of the Preparation Method

Hydrothermal liquefaction (HTL) is a promising technology for the production of biocrude oil from microalgae. Although this catalyst-free technology is efficient under high-temperature and high-pressure conditions, the biocrude yield and quality can be further improved by using heterogeneous catalysts. The design of robust catalysts that preserve their performance under hydrothermal conditions will be therefore very important in the development of biorefinery technologies. In this work, we describe two different synthetic routes (i.e., impregnation and cyclodextrin-assisted one-pot colloidal approach), for the preparation in aqueous phase of six high surface area CoMo/γ-Al₂O₃ catalysts. Catalytic tests performed on the HTL of Nannochloropsis gaditana microalga indicate that solids prepared by the one-pot colloidal approach show higher hydrothermal stability and enhanced biocrude yield with respect to the catalyst-free test. The positive effect of the substitution of the block copolymer Tetronic T90R4 for Pluronic F127 in the preparation procedure was evidenced by diffuse reflectance UV-visible spectroscopy, X-ray diffraction, N₂-adsorption-desorption, and H₂-temperature-programmed reduction measurements and confirmed by the higher quality of the obtained biocrude, which exhibited lower oxygen content and higher-energy recovery equal to 62.5% of the initial biomass.

Distinctive clinical features of pediatric systemic lupus erythematosus in three different age classes

It is estimated that around 20% of patients with systemic lupus erythematosus (SLE) have their onset in childhood but there have been conflicting data about the prevalence and severity of the clinical features in different age classes. We conducted this study to analyse the clinical features of patients with pediatric SLE (pSLE) with onset in infancy, prepubertal and postpubertal age.The charts of patients followed at the Department of Pediatrics, University of Padua, who met the criteria for SLE diagnosis, were reviewed. Patients were divided into three groups based on age at disease onset: group A, patients ≤2 years old, group B patients aged between 2 and 10 years, group C patients between 11 and 16 years of age. The clinical and laboratory characteristics of each group were compared. Forty-two patients with pSLE entered the study: 2 were diagnosed before the age of 2 years, 11 between 2 and 10 years and 29 between 10 and 16 years. Eleven more patients with infantile (onset <2 years) SLE (iSLE) were found by a systematic literature search on PubMed and EmBASE and added for analysis to the group A. The female preponderance was significant only in postpubertal patients (F:M = 6.3: 1) whereas the other two groups presented a similar F:M ratio (1.2: 1). In comparison with the other two groups, iSLE showed a significantly higher prevalence of cardiovascular and pulmonary involvement, anemia and thrombocytopenia and a shorter disease duration at time of diagnosis. The postpubertal group showed a higher frequency of musculoskeletal involvement and leukopenia. In prepubertal patients there was no female preponderance and the frequency of clinical features was intermediate between infantile and postpubertal patients. Complement fractions level, antinuclear antibodies (ANA), anti-dsDNA, anti-cardiolipin antibodies and lupus anti-coagulant autoantibodies were not significantly different in the three groups. In general, the prevalence of internal organs involvement in pSLE seems to decrease with age. In infants, SLE is more severe than in the following ages. Postpubertal patients have a strong female preponderance and more specific signs of disease at onset. Prepubertal patients have an intermediate disease severity and no gender predilection. Lupus (2007) 16, 550—555.

Autohydrolysis pretreatment of Arundo donax: a comparison between microwave-assisted batch and fast heating rate flow-through reaction systems

BACKGROUND

Autohydrolysis of lignocellulosic biomass in liquid hot water has been widely studied owing to its high efficiency and relatively low cost. In the perspective of industrial applications, continuous or semi-continuous processes are more interesting than batch systems. Moreover, microwave heating of pretreatment systems has been proposed to intensify the kinetics of the process. In this study, the autohydrolysis of Arundo donax was performed in pure liquid hot water using a microwave-heated batch reactor and a semi-continuous flow-through reaction system with fast heating rate at the same operating conditions with the aim of performing a systematic comparison between the two different experimental apparatuses.

RESULTS

The effect of process temperature and time, biomass to water mass to volume ratio and water flow rate on the concentration and yield of hydrolysis products was investigated. The flow-through set-up allowed us to reach biomass solubilization up to 44.5 wt% on dry basis, while the batch system stopped at 34.5 wt% suggesting that the mass transfer could be the rate-determining step in the solubilization of the constituting biopolymers. For example, in the flow-through layout, using a flow rate of 3.5 mL/min at 200 °C with 20 min of processing time, quantitative recovery of hemicellulose was obtained with limited formation of degradation products. Interestingly, higher cellulose/hemicellulose extraction ratios were found using the microwave-assisted batch reactor. FTIR analyses of the solid residues recovered after the pretreatment offered independent information on the fractions of liquefied biopolymers complementary to those derived from HPLC and UV-Vis spectroscopy.

CONCLUSIONS

Collected experimental results indicated that the flow-through system can be adopted to obtain complete solubilization of the hemicellulose fraction of Arundo donax addressing the product distribution in soluble compounds towards fermentable sugars with limited formation of sugar degradation products and with limited penalty in terms of dilution of the hydrolysate solution. It was also found that microwaves can promote cellulose depolymerization and solubilization, thus allowing a more comprehensive utilization of the biomass and that infrared spectroscopy can be a useful technique to estimate the effect of the pretreatment.

Brain auditory activation measured by near-infrared spectroscopy (NIRS) in neonates

This study presents a new measure of the hemodynamic changes to an auditory stimulus in newborns. Nineteen newborns born at 28-41 wk and aged 1 to 49 d were studied in waking and/or sleeping state, for a median time of 4 min 40 s before, 2 min 40 s during, and 3 min 5 s after an acustic stimulus (tonal sweep of frequency increasing from 2 to 4 kHz, intensity 90 dB SPL) originating 5 cm from the external auditory meatus. The emitter and detector optodes were placed over the left or right temporal region, corresponding to T3 or T4 EEG electrodes. The concentration changes in cerebral chromophores Delta[HbO2], Delta[Hb] and Deltaoxidized-reduced cytochrome aa(3) were recorded every 5 s. Changes in cerebral blood volume were calculated from the changes in total Hb x 0.89/large vessel Hb concentration. Increased oxyhemoglobin, Delta[HbO2], total Hb, Delta[Hb (sum)], and cerebral blood volume, DeltaCBV, were found in 13/19 neonates, with the exception of a neonate who only had increased in Delta[Hb], Delta[Hb (sum)] and DeltaCBV. During the stimulation phase there was a significant increase in DeltaCBV (t test, p = 0.00006) in the responsive newborns from a mean value of 0.006 (+/-0.02) mL/100 g in the pretest phase to 0.09 (+/-0.06) mL/100 g during the auditory stimulus. After the test DeltaCBV decreased to 0.04 (+/-0.07) mL/100 g (t test, p = 0.01), so did Delta[Hb (sum)] (p = 0.02). Hemodynamic responses of the subjects who showed increases in Delta[Hb (sum)] and Delta[HbO(2)] were analyzed to study the Delta[Hb]. The responder subjects could be classified into two groups according to Delta[Hb] changes: 8/13 (61.5%) showed an increase of Delta[Hb] (pattern A), while 5/13 (38.4%) showed a decrease (pattern B) (t test, p = 0.03). These two patterns did not show differences related to Delta[HbO(2)] and Delta[Hb (sum)]. The DeltaCBV changes in nonresponders presented a decrease during the test phase (t test, p = 0.04). CBV did not return to pretest values, suggesting a fronto-temporal brain pathway for storing unusual sounds. The increase in CBV followed the local increase in oxyhemoglobin and total Hb concentrations due to a greater use of oxygen in the homolateral temporal cortex of the newborns.

[Improvement of postinfarct left myocardial contractile function after administration of diltiazem]

BACKGROUND

The impairment of intracellular calcium homeostasis is an important biochemical alteration in stunned and hibernating myocardium. These different forms of viable myocardium frequently occur after myocardial infarction and their recognition may modify the therapeutic program and prognosis. Experimental studies and experiences on male subjects have demonstrated that calcium-channel blockers exert a protective action on myocardial reperfusion injury and reduce infarct size.

OBJECTIVES

The aim of the present study was to evaluate the efficacy of i.v. diltiazem (i.e. a calcium-channel blocker with negative inotropic effect) in enhancing the contractility of viable akinetic myocardium in patients after myocardial infarction.

METHODS

Sixty patients (52 males and 8 females, age 57 +/- 10 years) with the first acute myocardial infarction were evaluated with dobutamine-echocardiography 9 +/- 2 days after admission and on the following day with diltiazem-echocardiography. Diltiazem was administered i.v. using repeated boluses of 0.25 mg/kg up to the maximum dose of 1 mg/kg. Before and during the infusion, left ventricular regional function was scored and the Wall Motion Score Index (WMSI) was calculated; ECG and arterial blood pressure were also monitored. Results were compared with low-dose dobutamine-echocardiography. In a subset of 13 patients who underwent myocardial revascularization (7 coronary artery by-pass graftings and 6 percutaneous transluminal angioplasties), post-procedure echocardiograms were performed to evaluate whether regional left ventricular function had improved.

RESULTS

Low-dose dobutamine and diltiazem enhanced regional left ventricular contractility in 28 and 31 patients, respectively; both tests were positive in 26 cases. Conversely, dobutamine-test was negative in 32 patients and diltiazem in 29, with concordance in 27. A good correlation was found between diltiazem and dobutamine WMSI at the basal evaluation (r = 0.91; p < 0.000) as well as during the pharmacological test (r = 0.86; p < 0.000). In patients who underwent myocardial revascularization, the same good correlation was found between diltiazem-WMSI and WMSI evaluated after the procedure (r = 0.91; p < 0.000).

CONCLUSIONS

Acute i.v. administration of diltiazem about ten days after myocardial infarction may enhance the contractility of viable akinetic ventricular wall segments, as evaluated with echocardiography. The results of this study may have some physiopathological and therapeutical implications that could lead to reconsidering the use of calcium-channel blockers, particularly diltiazem, in selected patients after myocardial infarction.

[Pindolol in the treatment of arrhythmias caused by exertion]

In this study the anti-arrhythmic effectiveness of pindolol has been tested on ventricular effort arrhythmias in a group of 22 cardiopathic patients. The drug, administered for a week at the dose of 5 mg three times a day, obtained positive results due to its beta-blocking action and its intrinsic sympathomimetic activity.

Effects of training and of verapamil on exercise capacity in patients recovering from myocardial infarction. A double-blind study

Physical training causes an increase of aerobic capacity in normal and cardiac patients. The influences of training plus placebo and training plus verapamil have been studied in a double-blind randomized trial on 40 patients recovering from actue myocardial infarction. The two groups were comparable as to clinical characteristics, initial work capacity, and amount of stress tolerated during the training sessions. The training produced a significant increase of total work capacity and maximum VO2, in both groups; the difference between the means of the two groups was not significant. The variation of heart rate, rate pressure product at different work loads and cardiac volume after training were significantly lower in the verapamil group. The anginal threshold did not change in the placebo group and showed a trend to increase in patients treated with verapamil. These results suggest that carefully observed rehabilitation markedly improves the physical capacity of the patients after acute myocardial infarction. Such improvement is enhanced by treatment with verapamil.