Search results for "Pollutant"
showing 10 items of 1389 documents
Social factors associated with nitrogen dioxide (NO2) exposure during pregnancy: The INMA-Valencia project in Spain
2011
Numerous studies have focused on the effects of exposure to air pollution on health: however, certain subsets of the population tend to be more exposed to such pollutants depending on their social or demographic characteristics. In addition, exposure to toxicants during pregnancy may play a deleterious role in fetal development as fetuses are especially vulnerable to external insults. The present study was carried out within the framework of the INMA (Infancia y Medio Ambiente or Childhood and the Environment) multicenter cohort study with the objective of identifying the social, demographic, and lifestyle factors associated with nitrogen dioxide (NO2) exposure in the subjects in the cohort…
Preterm birth and exposure to air pollutants during pregnancy.
2010
Background Research has shown that prenatal exposure to air pollutants may have a detrimental effect on fetal development with the strength of the relationship depending on the effect being studied The evidence to date however is insufficient to establish a direct causal link between such exposure and preterm delivery This study evaluates the specific effect of prenatal exposure to NO2 and benzene on preterm births Methods The population under study comprised 785 pregnant women who formed part of the INMA cohort in Valencia Spain (2003-2005) Multiple regression models were used for mapping outdoor nitrogen dioxide (NO2) and benzene levels throughout the area Individual exposure was assigned…
Concentrations, optical properties and sources of humic-like substances (HULIS) in fine particulate matter in Xi'an, Northwest China
2021
Humic-like substances (HULIS) are ubiquitous in the atmospheric environment, which affects both human health and climate. We present here the mass concentration and optical characteristics of HULIS isolated from aerosol samples collected in Xi'an, China. Both mass concentration and absorption coefficient (Abs365) of HULIS show clear seasonal differences, with the highest average in winter (3.91 μgC m-3 and 4.78 M m-1, respectively) and the lowest in summer (0.65 μgC m-3 and 0.55 M m-1, respectively). The sources of HULIS_C and light absorption of HULIS were analyzed by positive matrix factorization (PMF) and four major sources were resolved, including secondary formation, biomass burning, c…
Identification of organic hydroperoxides and hydroperoxy acids in secondary organic aerosol formed during the ozonolysis of different monoterpenes an…
2009
On-line ion trap mass spectrometry (ITMS) enables the real-time characterization of reaction products of secondary organic aerosol (SOA). The analysis was conducted by directly introducing the aerosol particles into the ion source. Positive-ion chemical ionization at atmospheric pressure (APCI(+)) ITMS was used for the characterization of constituents of biogenic SOA produced in reaction-chamber experiments. APCI in the positive-ion mode usually enables the detection of [M+H](+) ions of the individual SOA components. In this paper the identification of organic peroxides from biogenic volatile organic compounds (VOCs) by on-line APCI-ITMS is presented. Organic peroxides containing a hydroper…
Enantioselective transformation of fluoxetine in water and its ecotoxicological relevance
2017
European legislation focusing on water quality is expected to broaden to encompass several pharmaceuticals as priority hazardous substances. This manuscript aims to challenge current regulatory approaches that do not recognize stereochemistry of chiral pharmaceuticals by testing the hypothesis that environmental transformation and effects of chiral pharmaceuticals are stereoselective. Our experiments revealed that, while degradation of chiral fluoxetine (FL) in river water occurs via non-enantioselective photochemical and mildly-enantioselective microbial processes favoring the (R)-enantiomer, a pronounced enantioselectivity favoring (S)-FL (leading to the formation of (S)-NFL (norfluoxetin…
Practical strategies for stable operation of HFF-QCM in continuous air flow
2013
Currently there are a few fields of application using quartz crystal microbalances (QCM). Because of environmental conditions and insufficient resolution of the microbalance, chemical sensing of volatile organic compounds in an open system was as yet not possible. In this study we present strategies on how to use 195 MHz fundamental quartz resonators for a mobile sensor platform to detect airborne analytes. Commonly the use of devices with a resonant frequency of about 10 MHz is standard. By increasing the frequency to 195 MHz the frequency shift increases by a factor of almost 400. Unfortunately, such kinds of quartz crystals tend to exhibit some challenges to obtain a reasonable signal-to…
Current air quality analytics and monitoring: a review.
2014
This review summarizes the different tools and concepts that are commonly applied in air quality monitoring. The monitoring of atmosphere is extremely important as the air quality is an important problem for large communities. Main requirements for analytical devices used for monitoring include a long period of autonomic operation and portability. These instruments, however, are often characterized by poor analytical performance. Monitoring networks are the most common tools used for monitoring, so large-scale monitoring programmes are summarized here. Biomonitoring, as a cheap and convenient alternative to traditional sample collection, is becoming more and more popular, although its main …
Combined target and post-run target strategy for a comprehensive analysis of pesticides in ambient air using liquid chromatography-Orbitrap high reso…
2014
Abstract A comprehensive strategy for the analysis of current airborne pesticides has been developed using liquid chromatography coupled to high resolution mass spectrometry. The methodology includes both quantitative target analysis and post-run target screening analysis. The quantitative method was validated after a previous statistical optimisation of the main factors governing the ion source ionization and a study of the single-stage Orbitrap fragmentation through the HCD cell. The quantitative method presented recoveries ranging from 73 to 116%, with precision (RSD) lower than 20%, for the 35 substances in the scope of the target method. The full-scan accurate mass data were acquired w…
Sampling and analysis of pesticides in ambient air.
2008
Developments in the sampling and determination of pesticides in ambient air have been discussed and data on the occurrence of pesticides in atmosphere have been presented. Developments in active sampling methods were reviewed and the different materials used for trapping pesticides from gas and particulate phases were discussed. Likewise, the use and developments of passive air samplers were reviewed. This article pays special attention to the analysis of pesticides trapped from ambient air, and recapitulate the procedures for extraction, clean-up and determination of these substances. Improvements in sampling procedures, analytical methods and monitoring activities are necessary to advance…
Temperature dependent properties of environmentally important synthetic musks.
2002
Environmental fate determining physical properties including their temperature dependence for five nitro musks and for seven polycyclic musks were estimated. The properties evaluated were vapor pressure in a solid and liquid state (PS and PL), solubility in water (S), Henry's law coefficient (H = PL/S) and log octanol-water partition coefficient (log KOW). Gas chromatography for starting values of vapor pressure estimation and HPLC experiments at 5-20 degrees C for comparison of the theoretical versus experimental solubilities in water were performed. The values of temperature (T) dependence coefficients (Ai and Bi) in equations: log (Property)i = Ai - Bi/T were determined. Values of proper…