RESUMEN
Recent advances in field-portable X-ray fluorescence (FP XRF) spectrometer technology have made it a potentially valuable screening tool for the industrial hygienist to estimate worker exposures to airborne metals. Although recent studies have shown that FP XRF technology may be better suited for qualitative or semiquantitative analysis of airborne lead in the workplace, these studies have not extensively addressed its ability to measure other elements. This study involved a laboratory-based evaluation of a representative model FP XRF spectrometer to measure elements commonly encountered in workplace settings that may be collected on air sample filter media, including chromium, copper, iron, manganese, nickel, lead, and zinc. The evaluation included assessments of (1) response intensity with respect to location on the probe window, (2) limits of detection for five different filter media, (3) limits of detection as a function of analysis time, and (4) bias, precision, and accuracy estimates. Teflon, polyvinyl chloride, polypropylene, and mixed cellulose ester filter media all had similarly low limits of detection for the set of elements examined. Limits of detection, bias, and precision generally improved with increasing analysis time. Bias, precision, and accuracy estimates generally improved with increasing element concentration. Accuracy estimates met the National Institute for Occupational Safety and Health criterion for nearly all the element and concentration combinations. Based on these results, FP XRF spectrometry shows potential to be useful in the assessment of worker inhalation exposures to other metals in addition to lead.
Asunto(s)
Monitoreo del Ambiente/instrumentación , Filtración , Metales Pesados/análisis , Espectrometría por Rayos X/instrumentación , Monitoreo del Ambiente/normas , Exposición por Inhalación/análisis , Exposición Profesional/análisis , Estándares de Referencia , Espectrometría por Rayos X/normas , Factores de TiempoRESUMEN
A 3-year, multichannel intervention project assessed adoption of federal government workplace safety testing methods among 3 randomly drawn samples of industrial hygienists. A communication matrix (McGuire, 1985, 1989) framework focusing on stages of reception, processing, and response was used to create, implement, and evaluate the intervention. Participants were interviewed by phone during 3 waves: baseline, immediately following year 1 of the intervention, and immediately following year 2 of the intervention. Results indicate a gain in reception over the course of the intervention. Increases in attitudes, control beliefs, intentions, and self-reported behavior were found between baseline and the 1st year of the intervention, and were maintained (although not increased) during the 2nd year of the intervention. Strengths and weaknesses of the intervention are viewed through the scope of the communication matrix.
Asunto(s)
Comunicación , Difusión de Innovaciones , Salud Laboral , Administración de la Seguridad/métodos , Adhesión a Directriz , Humanos , Entrevistas como Asunto , Evaluación de Programas y Proyectos de Salud , Administración de la Seguridad/legislación & jurisprudencia , Estados Unidos , Lugar de TrabajoRESUMEN
Residual oil fly ash (ROFA) is a particulate pollutant comprised of soluble and insoluble metals and is produced by the combustion of fossil fuels. The objective was to examine the pulmonary responses to chemically distinct ROFA samples collected from either a precipitator or air heater within the same power plant. The collected ROFA samples were suspended in saline (total sample), incubated for 24 h at 37 degrees C, centrifuged, separated into soluble and insoluble fractions, and the metal composition was determined. In addition, electron spin resonance (ESR) was used to detect short-lived free radical intermediates produced by the ROFA samples and the different fractions. On day 0, Male Sprague-Dawley rats were intratracheally instilled with saline (vehicle control) or the ROFA samples (1 mg/100 g body wt). At day 1, bronchoalveolar lavage was performed, and lung inflammation was assessed. On day 3, additional rats that had been treated with ROFA were intratracheally inoculated with 5 x 10(5) Listeria monocytogenes, and pulmonary bacterial clearance was measured at days 6, 8, and 10. The precipitator ROFA was found to be more soluble and acidic with a significantly greater mass of each metal compared with the air heater ROFA. A prominent hydroxyl radical signal was measured for the total and soluble precipitator ROFA after the addition of H2O2, whereas the air heater ROFA and its fractions did not produce a signal. Precipitator ROFA induced a greater inflammatory response than air heater ROFA illustrated by a significant elevation in lung neutrophils. In addition, pulmonary clearance of L. monocytogenes was greatly diminished in the rats treated with the soluble and total precipitator ROFA samples. None of the air heater ROFA samples had an effect on lung bacterial clearance. In conclusion, precipitator ROFA, particularly the soluble fraction, generated a metal-dependent hydroxyl radical as measured by ESR and was shown to cause more inflammation and result in reduced lung defense against infection compared with air heater ROFA. These results are most likely due to differences in metal composition and solubility of the ROFA samples.
Asunto(s)
Carbono/toxicidad , Enfermedades Pulmonares/etiología , Metales/análisis , Metales/toxicidad , Centrales Eléctricas , Administración por Inhalación , Contaminantes Atmosféricos/toxicidad , Contaminantes Ocupacionales del Aire/toxicidad , Animales , Líquido del Lavado Bronquioalveolar/microbiología , Carbono/administración & dosificación , Ceniza del Carbón , Espectroscopía de Resonancia por Spin del Electrón , Humanos , Listeriosis/microbiología , Enfermedades Pulmonares/microbiología , Macrófagos Alveolares/microbiología , Masculino , Material Particulado , Neumonía/etiología , Neumonía/microbiología , RatasRESUMEN
Two methods for measuring airborne lead using field-portable instruments have been developed by the National Institute for Occupational Safety and Health (NIOSH): Method 7702 uses X-ray fluorescence (XRF), and Method 7701 employs ultrasonic extraction (UE) followed by anodic stripping voltammetry (ASV). The two portable methods were evaluated at mining sites. Area air samples were collected throughout two mills where ore from nearby mines was processed; the primary constituent of the ore was lead sulfide (galena). The air samples were collected on 37 mm mixed cellulose ester membrane filters housed within plastic filter cassettes. At the end of the work shift, the cassettes were collected and taken to a room off-site for analysis by the two portable methods. The filter samples were first analyzed by XRF and then by UE/ASV. Calibration was verified on both instruments according to standard procedures. The samples were then sent for confirmatory analysis via flame atomic absorption spectrometry (FAAS) according to NIOSH Method 7082. Pairwise comparisons between the methods using the paired t-test showed no statistically significant differences between ASV and FAAS (P>0.05); however, the comparison between XRF and FAAS was statistically significant (P<0.05). The elevated lead concentrations reported by XRF relative to FAAS were likely the result of the ability of XRF to report total lead, including lead silicates. This form of lead is not liberated in the digestion process prior to FAAS analysis, and is therefore not detected by this method. Despite this discrepancy, lead concentrations measured by both portable technologies were found to be highly correlated with the laboratory method (R2>0.96), suggesting that they are suitable as screening methods for airborne lead at mining sites.