Methodology for determining indoor air quality and identifiying the origin of odour episodes in indoor environments through dynamics VOC sampling and TD-GC/MS analysis

A methodology for identifying volatile organic compounds (VOCs) and determining air quality of indoor air has been developed. The air samples are collected using pump samplers by the inhabitants when they perceive odorous and/or discomfort episodes. Glass multi-sorbent tubes are connected to the pump samplers for the retention of VOC. The analysis is performed by automatic thermal desorption (ATD) coupled with gas chromatography-mass spectrometry (GC/MS). This methodology can be applied in cases of sick building syndrome (SBS) evaluation, in which building occupants experience a series of varied symptoms that appear to be linked to time spent in the building. Chemical pollutants concentrations (e.g., VOC) have been described to contribute to SBS. To exemplify the methodology, a qualitative determination and an evaluation of existing VOC were performed in a dwelling where the occupants experienced the SBS symptoms. Higher total VOC (TVOC) levels were detected during episodes in indoor air (1.33 ± 1.53 mg/m3) compared to outdoor air (0.71 ± 0.46 mg/m3). The concentrations of individual VOCs, such as ethanol, acetone, isopropanol, 1-butanol, acetic acid, acetonitrile and 1-methoxy-2-propanol, were also higher than the expected for a standard dwelling. The external source of VOC was found to be an undeclared activity of storage and manipulation of solvents located at the bottom of a contiguous building.Peer ReviewedPostprint (author’s final draft

Comparative of the adsorption performance of a multi-sorbent bed (Carbotrap, Carbopack X, Carboxen 569) and a Tenax TA adsorbent tube for the analysis of volatile organic compounds (VOCs)

A comparison between two types of adsorbent tubes, the commonly used Tenax TA and a multi-sorbent bed (Carbotrap, Carbopack X, Carboxen 569) tube developed in our laboratory, has been done to evaluate their usefulness in the analysis of VOCs in ambient air. Duplicate indoor and outdoor samples of Tenax TA and multi-sorbent tubes of 10, 20, 40, 60 and 90 litres were taken in Barcelona city (Spain) on July and October of 2009. Breakthrough values (defined as %VOCs found in the back tube) were determined for all sampling volumes connecting two sampling tubes in series. The analysis was performed by automatic thermal desorption (ATD) coupled with capillary gas chromatography (GC)/mass spectrometry detector (MSD). Significant differences between the concentrations obtained form multi-sorbent bed and Tenax TA tubes are observed for the very volatile compounds (56ºC<boiling point<100ºC and 4kPa<vapour pressure (20ºC)<47kPa) (e.g. acetone, isopropanol, n-hexane) and for alcohols and chlorinated compounds (e.g. 1-butanol, carbon disulphide, dichloromethane, chloroform, carbon tetrachloride, trichloroethylene, tetrachloroethylene), being the concentrations higher in multi-sorbent bed than in Tenax TA tubes. On the other hand, mainly all compounds with boiling points higher than 100ºC (except α-pinene, chlorinated and polar compounds) do not show significant differences between the obtained multi-sorbent bed and Tenax TA tubes concentrations. For the concentrations obtained, Tenax TA present high breakthrough values (from 0 to 77%) for mainly all compounds and sampling volumes studied. On the other hand, multi-sorbent bed tubes do not exhibit important breakthrough values for these compounds, except the VVOCs ethanol (for all sampled volumes), and acetone, dichloromethane and isopropanol (for sampling volumes over 40 litres). The concentration differences observed between Tenax TA and multi-sorbent bed tubes are directly related to the high breakthrough values determined for Tenax TA adsorbent.Peer ReviewedPostprint (published version

Evaluation of Radiello diffusive sampler indicated for thermal desorption for measuring VOCs in ambient air.

- One of the key aspects regarding air monitoring is to determine the suitability of the methodology chosen. -The comparison between validated active air multi-sorbent tubes and Radiello diffusive samplers show no significant differences between the two methodologies for several compounds studied. -For the Radiello passive sampler, relevant differences have not been observed between the sum of two shorter sampling periods (4 days + 3 days) and a longer sampling period (7 days). -The Radiello diffusive sampler provides satisfactory quantitative measurements and is suitable for the determination of several VOCs in ambient air. -Radiello passive sampler coupled with ATD-GC/MS is a simple to use, sensible and cheap method to assess ambient air concentrations of VOCs. -More research has to be done to enhance the results obtained in this study.Peer ReviewedPostprint (published version

Impact of formaldehyde and VOCs from waste treatment plants upon the ambient air nearby an urban area (Spain)

Emission factors of formaldehyde and VOCs were determined for two waste treatment plants (WTP) located in the metropolitan area of Barcelona city. Formaldehyde emission factors were determined from the biogas engines exhausts and the process chimneys (after the biofilter process), and VOC emission factors were determined in the process chimneys. Formaldehyde and VOC were dynamically sampled usingDNPH-coated adsorbent tubes with ozone scrubber and multi-sorbent bed tubes (Carbotrap, Carbopack X and Carboxen 569), respectively, using portable pump equipment. Formaldehyde emission factors from biogas engines were found between 0.001–0.04 g s-1. Additionally, formaldehyde and VOC emission factors from process chimneys were found to be between 0.0002–0.003 g s-1 and 0.9 ± 0.3 g s-1, respectively. Employing real emission factors, the expected concentrations derived from the WTPs in their nearby urban areaswere calculated using The Atmospheric Pollution Model (TAPM, CSIRO), and impact maps were generated. On the other hand, ambient air formaldehyde and VOC concentrations were determined in selected locations close to the evaluated waste treatment facilities using both active and passive samplers, and were between 2.5±0.4–5.9±1.0 µgm-3and91±48–242±121 µgm-3, respectively. The concentrations of formaldehyde and VOC derived exclusively from the waste treatment plants were around 2% and 0.3 ± 0.9% of the total formaldehyde and VOC concentrations found in ambient air, respectively.Postprint (author's final draft

Development of a method for determination of VOCs (including methylsiloxanes) in biogas by TD-GC/MS analysis using Supel™ Inert Film bags and multisorbent bed tubes

An analytical method based on TD-GC/MS was developed and validated for the determination of volatile organic compounds (VOCs), including linear and cyclic volatile methylsiloxanes (VMSs), in biogas. Biogas was first sampled in Supel™ Inert Film bags and subsequently dynamically sampled onto multisorbent bed tubes (Carbotrap, Carbopack X and Carboxen 569) using portable pump equipment. Two sample volumes, 100 and 250 ml, were evaluated. Desorption efficiency values for both volumes are in the range of 99–100% for almost all studied compounds while breakthrough values (%VOC on sample tube back section) are below 1% for most evaluated VOCs. However, acetaldehyde, carbon disulphide, ethanol and 1,3-butadiene have breakthrough values higher than 5%. Method detection limits were in the range of 0.01–0.8 ng per sample. The most abundant VOCs in biogas were terpenes with concentrations between 500 and 700 mg m-3. Other important families were ketones, aromatic hydrocarbons and alkanes, with concentrations in the range of 36–46 , 20–35 and 14–16 mg m-3, respectively. VMSs presented average concentrations of 4.9 ± 0.4 mg m-3. Additionally, the Supel™ Inert Film bags were evaluated for stability for 4 days at room temperature. Although several VOC families’ concentrations in the bag increased or decreased significantly (t-test; p = 0.01, n = 5) 2 days after collection, recoveries were around 70–130% for most studied VOCs. The results shown demonstrate that the presented methodology is reliable and satisfactory for the evaluation of VOCs in biogas and presents an alternative to the currently existing biogas analytical techniques.Peer ReviewedPostprint (author’s final draft

Volatile methyl siloxanes (VMS) concentrations in outdoor air of several Catalan urban areas

Volatile methyl siloxanes (VMS) were evaluated in ten Catalan urban areas with different industrial impacts, such as petrochemical industry, electrical and mechanical equipment, metallurgical and chemical industries, municipal solid waste treatment plant and cement and food industries, during 2013–2015. 24 h samples were taken with LCMA-UPC pump samplers specially designed in our laboratory, with a flow range of 70 ml min-1. A sorbent-based sampling method, successfully developed to collect a wide-range of VOC, was used. The analysis was performed by automatic thermal desorption coupled with capillary gas chromatography/mass spectrometry detector. The presented methodology allows the evaluation of VMS together with a wide range of other VOC, increasing the number of compounds that can be determined in outdoor air quality assessment of urban areas. This aspect is especially relevant as a restriction of several VMS (D4 and D5) in consumer products has been made by the European Chemicals Agency and US EPA is evaluating to include D4 in the Toxic Substances Control Act, regarding the concern of the possible effects of these compounds in human health and the environment. SVMS concentrations (L2-L5, D3-D6 and trimethylsilanol) varied between 0.3 ± 0.2 µg m-3 and 18 ± 12 µg m-3, determined in a hotspot area. Observed VMS concentrations were generally of the same order of magnitude than the previously determined in Barcelona, Chicago and Zurich urban areas, but higher than the published from suburban sites and Arctic locations. Cyclic siloxanes concentrations were up to two-three orders of magnitude higher than those of linear siloxanes, accounting for average contributions to the total concentrations of 97 ± 6% for all samples except for the hotspot area, where cyclic VMS accounted for 99.9 ± 0.1%. D5 was the most abundant siloxane in 5 sampling points; however, differing from the generally observed in previous studies, D3 was the most abundant compound in the other 5 sampling points.Peer ReviewedPostprint (author's final draft

Compuestos orgánicos volátiles: determinación por captación en tubos multilecho y análisis por DT-CG-EM

Nota tècnica de prevenció. Metodologia per la determinació de COV en aire interior i exteriorPreprin

La información del riesgo químico en Europa: estado de la cuestión

Aunque los productos químicos se han vuelto imprescindibles en el día a día de muchos sectores de la sociedad moderna, es un hecho cierto que muchos de ellos son peligrosos, tanto para la salud como para el medio ambiente, por lo que es necesario disponer de una información suficiente, concreta y estandarizada sobre los mismos y los riesgos que presentan, para así poder establecer procedimientos de trabajo seguros y adoptar medidas preventivas adecuadas. En este sentido, la Unión Europea (UE) lleva a cabo una política de control, basada en el reconocimiento de las sustancias existentes en su momento (1981), la reevaluación de las que se considera conveniente y un férreo control de las que se van a lanzar al mercado. Como se verá más adelante, la propia UE considera que esta política no ha dado suficientes resultados, por lo que va a llevar a cabo modificaciones en la misma

Los reglamentos REACH-CLP y la prevención del riesgo químico

En el presente artículo se revisa la actual legislación europea sobre productos químicos basada en el Reglamento REACH (Registry, Evaluation, Authorisation and Restriction of Chemicals) y su más importante modificación, el Reglamento CLP (Classification, Labelling and Packaging), que representa la incorporación a la legislación europea de sistema GHS (Globally Harmonized System), destinado a lograr una uniformización a nivel mundial de los mecanismos de identificación y comunicación del riesgo químico.Aunque ambos reglamentos no estarán plenamente operativos hasta 2018, su nivel de desarrollo es suficiente para evaluar sus efectos positivos sobre gestión de la prevención frente al riesgo químico desde el punto de vista de la protección de la salud de los trabajadores en el trabajo, aspecto al que está dedicado el artículo en su conjunto. Se concluye que las mejoras van a ser y ya son ostensibles en muchos aspectos como en las fichas de datos de seguridad, la evaluación de riesgos, las políticas de sustitución y el control operativo de las sustancias de muy alta preocupación. También se ha comprobado que estos reglamentos fomentan claramente la correcta comunicación de riesgos entre las personas relacionadas con el riesgo químic

Especialización en Higiene industrial I, septiembre 2012

Recurs d'aprenentatge de la Universitat Oberta de Catalunya.Recurso de aprendizaje de la "Universitat Oberta de Catalunya".Learning material of the "Universitat Oberta de Catalunya"