27 research outputs found
Recent Advances for Polycyclic Aromatic Analysis in Airborne Particulate Matter
Polycyclic aromatic hydrocarbons (PAHs) are formed in natural processes during combustion of biomass (e.g., forest fires) and by anthropogenic activities at high temperatures. In according with the suggestion the major sources of PAHs in the environment. The main sources of PAHs come basically from heat and power generation (e.g., coal, gas, wood, and oil), industrial processes (e.g., coke production), refuse burning and vehicle emissions. Human exposure to airborne PAHs can result from these processes, as well as from emissions from other sources, such as cooking, smoking, and materials containing PAHs (e.g., petroleum products and fuels). The potential serious health effects resulting from acute and chronic human exposure to PAHs are of concern. For this reason, the identification and quantification of PAHs in airborne particles have been a real challenge, given the multiple impacts that these substances represent for human health. In the last decade, multiple technological developments have been implemented, ranging from sampling systems, extraction and analysis of these compounds with the aim of obtaining more accurate and reliable results. This chapter was prepared to describe and to assess the state of the art about the evolution and application of sampling, extraction and analysis methodologies for the determination of PAHs in airborne particles
Emerging Compounds in Mexico: Challenges for Their Identification and Elimination in Wastewater
In recent years, the presence of organic pollutants has received great attention due to their effects on public health and biota. Within this set of compounds, a new range of compounds that are characterized by their high persistence and low degradation have been identified, called Emerging Compounds. Emerging pollutants include a wide variety of products for daily use of different structures, domestic and industrial applications, such as: pesticides, industrial and personal hygiene products, hormones, and drugs, most of which are toxic, persistent and bioaccumulative. A characteristic of these types of pollutants is that current wastewater treatment plants are unable to remove them; they are designed to remove organic matter and nutrients in higher concentrations. In Mexico there is little information on the concentration levels of these compounds, due to the lack of public policies aimed at providing resources to institutions and researchers trained to carry out this type of study. On the other hand, the technological infrastructure of the wastewater treatment plants is insufficient for the country’s demand. This situation represents one of the greatest challenges for the authorities responsible for the management of water resources, in the immediate time if it is intended to preserve said resource and therefore take care of the health of the population
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Potential Sources of Trace Metals and Ionic Species in PM2.5 in Guadalajara, Mexico: A Case Study during Dry Season
This study was conducted from May 25 to June 6, 2009 at a downtown location (Centro) and an urban sector (Miravalle) site in the Metropolitan Zone of Guadalajara (MZG) in Mexico. The atmospheric concentrations of PM2.5 and its elemental and inorganic components were analyzed to identify their potential sources during the warm dry season. The daily measurements of PM2.5 (24 h) exceeded the WHO (World Health Organization) air quality guidelines (25 μg·m−3). The most abundant element was found to be Fe, accounting for 59.8% and 72.2% of total metals mass in Centro and Miravalle, respectively. The enrichment factor (EF) analysis showed a more significant contribution of non-crustal sources to the elements in ambient PM2.5 in Centro than in the Miravalle site. Particularly, the highest enrichment of Cu suggested motor vehicle-related emissions in Centro. The most abundant secondary ionic species (NO3−; SO42− and NH4+) and the ratio NO3−/SO42− corroborated the important impact of mobile sources to fine particles at the sampling sites. In addition, the ion balance indicated that particles collected in Miravalle experienced neutralization processes likely due to a higher contribution of geological material. Other important contributors to PM2.5 included biomass burning by emissions transported from the forest into the city
Optimization and Application of a GC-MS Method for the Determination of Endocrine Disruptor Compounds in Natural Water
Bisphenol A (BPA), 4-nonylphenol (4NP), estradiol (E2), and ethinylestradiol (EE2) are considered as endocrine disruptors or mutagens. These compounds are commonly called endocrine disrupter chemicals (EDCs). BPA and 4NP are widely used as plastic additives, lacquers, resins, or surfactants, while E2 is one of the predominant female sex hormones during the reproductive years, and EE2 is an estrogen derived from estradiol, used in the production of contraceptive pills. All of these can be usually found in wastewater. In Mexico, it is common for water from rivers, lakes, and canyons to be reused for different purposes. Unfortunately, there is little information on the concentration of many of the pollutants present in such bodies of water. To determine the presence of these compounds in samples of wastewater in the Apatlaco River, an accurate and reproducible method was developed by coupling gas chromatography to mass spectrometry (GC-MS). A solid-phase extraction with Chromabond RP-18 cartridges was carried out, and the elution was performed with an acetone/methanol mixture. After isolation, the solvent was removed and a silylation step was carried out using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). Recoveries for spiked samples were between 71.8% and 111.0%. The instrumental limits of detection (IDL) ranged between 24.7 and 37.0 ng mL−1. In total, 16 samples were taken in 2015 at the microbasin of the Apatlaco River, located in the state of Morelos. The maximum concentrations found were 4NP (85.5 ng mL−1), BPA (174.6 ng mL−1), E2 103.6 (ng mL−1), and EE2 (624.3 ng mL−1)
Polycyclic Aromatic Hydrocarbons (PAHs) Associated with PM2.5 in Guadalajara, Mexico: Environmental Levels, Health Risks and Possible Sources
PM2.5 samples were collected from January 2009 to January 2010 at two sampling sites located in the downtown (Centro) and toward the southwest (Miravalle) in the city of Guadalajara, Mexico. The environmental concentrations of 14 selected polycyclic aromatic hydrocarbons (PAHs) in PM2.5 were identified and quantified. The most abundant PAHs in PM2.5 samples were benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, benzo[b]fluoranthene, benzo[a]pyrene and benzo[k]fluoranthene, accounting for approximately 75% of the total PAHs. The total PAH concentrations at the two sampling sites ranged from 0.65 to 19.62 ng·m−3. Spatial variations were found during the dry-warm season, which were attributed mainly to differing intensities of local traffic and less dispersion of air pollutants in Miravalle. Seasonal variations were associated with increases in rainfall (June-September) and differences in temperature (January–May and October–January). The benzo(a)pyrene-equivalent (BaPE) and BaP results suggest that exposure to PM2.5-containing carcinogenic PAHs (C-PAHs) in Miravalle during the warm-dry and cold-dry seasons can be seen as representing a serious risk to human health. The contributions from potential sources to PAHs in PM2.5 were evaluated by the diagnostic ratios between PAHs and principal component analysis (PCA). In the whole sampling period, vehicular emission activity, probably related to light and heavy traffic, was found to be the predominant contributor to PM2.5-bound PAHs
Assessment of the kinetics of oxidation of some steroids and pharmaceutical compounds in water using ozone
[EN] Emerging contaminants are present in surface and ground water, generating a potential risk for the
public health of surrounding populations that consume contaminated water. However, their elimination
using conventional treatment methods has not been an easy task. The aim of this research was the
assessment of the kinetics of oxidation of four emerging contaminants in water two steroids: estradiol
(E2) and ethynilestradiol (EE2) and two pharmaceutical drugs: naproxen (NPX) and ibuprofen (IBP) ¿ by
using an ozonation process. The stoichiometry and the second order rate constants for the four
compounds were obtained. The method of competitive kinetics was established to assess the kinetics of
oxidation of steroids and NPX and the absolute rate constant under pseudo-first-order conditions
method for IBP. The second order rate constants for E2, EE2, NPX were in the order of 104 to 105 L/(mol s)
and for IBP the value was 101 L/(mol s). An oxidation kinetic model for the steroids and pharmaceutical
drugs at different doses of ozone was obtained from the rate constants, and validated with the
experimental values. In addition, the half-life of the selected compounds for each experimental ozone
dose was obtained, which serves to predict the behavior of oxidation of emerging contaminants,
knowing the initial concentration of ozone. This research is focused toward a project for water treatment
with the presence of emerging contaminants on a semi-pilot scale in continuous operation.
2014 Elsevier Ltd. All rights reserved.Vallejo Rodríguez, R.; Murillo Tovar, M.; Navarro-Laboulais, J.; León Becerril, E.; López López, A. (2014). Assessment of the kinetics of oxidation of some steroids and pharmaceutical compounds in water using ozone. Journal of Environmental Chemical Engineering. 2:316-323. doi:10.1016/j.jece.2013.12.024S316323
Compuestos emergentes: implementación de métodos analíticos para extraer y cuantificar 17β-estradiol, 17⍺-etinilestradiol, ibuprofeno y naproxeno en agua
Los métodos implementados permitieron la cuantificación de dos esteroides (17β-estradiol y 17⍺-etinilestradiol) y dos fármacos (ibuprofeno y naproxeno) utilizando extracción en fase sólida (EFS) y cromatografía de líquidos de alta resolución con detector de arreglo de diodos (CLAR-DAD). Las condiciones de EFS con cartuchos C18 se evaluaron variando los tipos y las cantidades de disolvente de elución, condiciones de pH y la masa de muestra en el cartucho. La eficiencia se evaluó mediante la fortificación de muestras de agua con cantidades conocidas de los analitos en tres niveles de concentración distintos. Las recuperaciones encontradas indican que la eficiencia de los métodos es independiente de la cantidad de analito tratada en el rango de ensayo (p > 0.05) con recobros (promedio ± desviación estándar) para 17β-estradiol (86.9% ± 4.2), 17⍺-etinilestradiol (87.1% ± 6.1), ibuprofeno (89.4% ± 5.3) y naproxeno (85.9% ± 15), que reúnen criterios de aceptación suficientes para el control de calidad de futuras aplicaciones. Por lo tanto, los métodos propuestos son confiables para ser aplicados a muestras acuosas. Sin embargo será necesario probar su desempeño y ajustar sus condiciones cuando se analicen muestras más complejas
Composition and mutagenicity of PAHs associated with urban airborne particles in Córdoba, Argentina
The comet assay and micronucleous test were used to assess the genotoxicity of organic compounds associated with particulate material collected in the city of Córdoba, Argentina. Samples were collected on fiber glass filters and their organic extracts were analyzed by GC-MS. These extracts were used for the comet assay on human lymphocytes and for the MCN test with Tradescantia pallida. The concentrations of polycyclic aromatic hydrocarbons as well as some of their nitro derivates were higher during winter. Their composition suggested that their main emission sources were gasoline and diesel vehicles. We observed genotoxic effects of these organic extracts due to the presence of both direct and indirect acting mutagens. We found a good agreement between the two test systems employed, which encourages the further use of plant bioassays for air pollution monitoring, especially in developing countries, due to their flexibility, low cost and efficiency.Fil: Carreras, Hebe Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Calderon Segura, María Elena. Universidad Nacional Autónoma de México; MéxicoFil: Gomez Arroyo, Sandra. Universidad Nacional Autónoma de México; MéxicoFil: Murillo Tovar, Mario A.. Universidad Nacional Autónoma de México; MéxicoFil: Amador Munoz, Omar. Universidad Nacional Autónoma de México; Méxic