Importance of size-selective particle sampling for assessing occupational exposures: results from three different occupational settings

Sampling the total air concentration of particulate matter (PM) only provides a basic estimate of exposure that normally not allows correlating with the observed health effects. Therefore is of extreme importance to know the particles size distribution and, in more detail, the exposure to fine particles (≤ 2.5 µm). This particles dimension corresponds to the respirable fraction. This particle fraction can result, besides local effects, in systemic effects due to particle deposition and clearance from the lungs and transport within the organism. This study intended to describe occupational exposure to PM2.5 in three different units located near Lisbon and related with occupational exposure to organic dust, namely: swine and poultry feed production and waste management.

Indoor air quality in Portuguese schools: levels and sources of pollutants

Indoor air quality (IAQ) parameters in 73 primary classrooms in Porto were examined for the purpose of assessing levels of volatile organic compounds (VOCs), aldehydes, particulate matter, ventilation rates and bioaerosols within and between schools, and potential sources. Levels of VOCs, aldehydes, PM2.5 , PM10 , bacteria and fungi, carbon dioxide (CO2 ), carbon monoxide, temperature and relative humidity were measured indoors and outdoors and a walkthrough survey was performed concurrently. Ventilation rates were derived from CO2 and occupancy data. Concentrations of CO2 exceeding 1000 ppm were often encountered, indicating poor ventilation. Most VOCs had low concentrations (median of individual species <5 μg/m(3) ) and were below the respective WHO guidelines. Concentrations of particulate matter and culturable bacteria were frequently higher than guidelines/reference values. The variability of VOCs, aldehydes, bioaerosol concentrations, and CO2 levels between schools exceeded the variability within schools. These findings indicate that IAQ problems may persist in classrooms where pollutant sources exist and classrooms are poorly ventilated; source control strategies (related to building location, occupant behavior, maintenance/cleaning activities) are deemed to be the most reliable for the prevention of adverse health consequences in children in schools.

Indoor air quality in schools and its relationship with children's respiratory symptoms

A cross-sectional survey was conducted to characterize the indoor air quality (IAQ) in schools and its relationship with children's respiratory symptoms. Concentrations of volatile organic compounds (VOC), aldehydes, PM2.5, PM10, carbon dioxide, bacteria and fungi were assessed in 73 classrooms from 20 public primary schools located in Porto, Portugal. Children who attended the selected classrooms (n = 1134) were evaluated by a standardised health questionnaire completed by the legal guardians; spirometry and exhaled nitric oxide tests. The results indicated that no classrooms presented individual VOC pollutant concentrations higher than the WHO IAQ guidelines or by INDEX recommendations; while PM2.5, PM10 and bacteria levels exceeded the WHO air quality guidelines or national limit values. High levels of total VOC, acetaldehyde, PM2.5 and PM10 were associated with higher odds of wheezing in children. Thus, indoor air pollutants, some even at low exposure levels, were related with the development of respiratory symptoms. The results pointed out that it is crucial to take into account the unique characteristics of the public primary schools, to develop appropriate control strategies in order to reduce the exposure to indoor air pollutants and, therefore, to minimize the adverse health effects.

Children's health and indoor air quality in primary schools and homes in Portugal-Study design

The main aim of the research project "On the Contribution of Schools to Children's Overall Indoor Air Exposure" is to study associations between adverse health effects, namely, allergy, asthma, and respiratory symptoms, and indoor air pollutants to which children are exposed to in primary schools and homes. Specifically, this investigation reports on the design of the study and methods used for data collection within the research project and discusses factors that need to be considered when designing such a study. Further, preliminary findings concerning descriptors of selected characteristics in schools and homes, the study population, and clinical examination are presented. The research project was designed in two phases. In the first phase, 20 public primary schools were selected and a detailed inspection and indoor air quality (IAQ) measurements including volatile organic compounds (VOC), aldehydes, particulate matter (PM2.5, PM10), carbon dioxide (CO2), carbon monoxide (CO), bacteria, fungi, temperature, and relative humidity were conducted. A questionnaire survey of 1600 children of ages 8-9 years was undertaken and a lung function test, exhaled nitric oxide (eNO), and tear film stability testing were performed. The questionnaire focused on children's health and on the environment in their school and homes. One thousand and ninety-nine questionnaires were returned. In the second phase, a subsample of 68 children was enrolled for further studies, including a walk-through inspection and checklist and an extensive set of IAQ measurements in their homes. The acquired data are relevant to assess children's environmental exposures and health status.

Avaliação do potencial genotóxico e citotóxico associado a queima artesanal da castanha de caju no Município de João Câmara

The Brazil is the third largest producer of cashew nuts in the world. Despite the social and economic importance of the cashew nut, its production is still carried out artisanally. One of the main problems encountered in the cashew production chain are the conditions under which the roasting of the nut occurs to obtain the kernel from the shell. In the present study was conducted a biomonitoring of the genotoxic and cytotoxicity effects associated with the elements from the cashew nut roasting in João Câmara - RN, semi-arid region of Brazil. To assess the genotoxic was used the bioassay of micronucleus (MN) in Tradescantia pallida. In addition, it was performed a comparative between the Tradescantia pallida and KU-20 and other biomarkers of DNA damage, such as the nucleoplasmic bridges (NBP) and nuclear fragments (NF) were quantified. The levels of particulate matter (PM1.0, PM2.5, PM10) and black carbon (BC) were also measured and the inorganic chemical composition of the PM2.5 collected was determined using X-ray fluorescence spectrometry analysis and the assessment of the cytotoxicity by MTT assay and exclusion method by trypan blue. . For this purpose, were chosen: the Amarelão community where the roasting occurs and the Santa Luzia farm an area without influence of this process. The mean value of PM2.5 (Jan 2124.2 56;g/m3; May 1022.2 56;g/m3; Sep 1291.9 56;g/m3) and BC (Jan 363.6 56;g/m3; May 70.0 56;g/m3; Sep 69.4 56;g/m3) as well as the concentration of the elements Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br and Pb obtained at Amarelão was significantly higher than at Santa Luzia farm. The genotoxicity tests with T. pallida indicated a significant increase in the number of MN, NBP and NF and it was found a negative correlation between the frequency of these biomarkers and the rainfall. The concentrations of 200 56;g/mL and 400 56;g/mL of PM2.5 were cytotoxic to MRC-5 cells. All together, the results indicated genotoxicity and citotoxicity for the community of Amarelão, and the high rates of PM2.5 considered a potential contributor to this effect, mainly by the high presence of transition metals, especially Fe, Ni, Cu, Cr and Zn, these elements have the potential to cause DNA damage. Other nuclear alterations, such as the NPBs and NFs may be used as effective biomarkers of DNA damage in tetrads of Tradescantia pallida. The results of this study enabled the identification of a serious occupational problem. Accordingly, preventative measures and better practices should be adopted to improve both the activity and the quality of life of the population. These measures are of fundamental importance for the sustainable development of this activity.

Impact of a Changing Climate on Fine Particulate Concentrations in Butte, MT

A model was developed to assess the potential change in PM2.5 concentrations in Butte, Montana over the course of the 21st century as the result of climate change and changes in emissions. The EPA AERMOD regulatory model was run using NARCCAP climate data for the years of 2040, 2050, 2060 and 2070, and the results were compared to the NAAQS to determine if there is the potential for future impacts to human health. This model predicted an average annual concentration of 15.84 µg/m3 in the year 2050, which would exceed the primary NAAQS of 12 µg/m3 and is a large increase over the average concentration from 2010 – 2012 of 10.52 µg/m3. The effectiveness of a wood stove change out program was also evaluated to determine its efficacy, and modeled results predicted that by changing out 100% of inefficient stoves with an EPA approved model, concentrations could be reduced below the NAAQS.

Evaluación de la exposición laboral a material particulado en empresas pertenecientes a diferentes sectores económicos en Colombia, 2014

Introducción El material particulado son partículas sólidas y líquidas emitidas al aire, las cuales pueden generar diferentes alteraciones en la salud, variando desde cuadros respiratorios alérgicos, a episodios asmáticos, dermatitis o inclusive llegar a facilitar la génesis de enfermedades de tipo neoplásico. Estos pueden tener origen natural e industrial, encontrandose en diferentes actividades económicas. Objetivo Evaluar la exposición laboral a material particulado en empresas pertenecientes a diferentes sectores económicos afiliadas a una ARL en Colombia, en el periodo comprendido entre 2011 al 2014 Metodología Es un estudio de corte transversal, analizando una base de datos de 257 empresas con 1108 mediciones de material particulado, recolectados entre 2011 – 2014. Las variables usadas fueron: región, actividad económica, área, oficio, tiempo de exposición y concentración de material particulado. Se realizó distribuciones de frecuencia, medidas de tendencia central y de dispersión. Se evaluaron las diferencias de las distribuciones de los tiempos de exposición y el porcentaje de exposición entre los grupos con y sin riesgo (los que sobrepasaban o no los límites permisibles), con la prueba asintótica no paramétrica de Mann Whitney. Resultados Las principales mediciones ambientales en las empresas fueron en la industria química con un 31%, siendo 2 de cada 3 datos pertenecientes a la región andina, las cuales tienen como principales contaminantes químicos las partículas no fraccionadas con el 70,9%. Respecto a las concentraciones ambientales de material particulado en las empresas participantes, se encontró un promedio de 1,72 mg/m3 ± 3,613, con una mediana de 0,480 mg/m3 y un coeficiente de variación de 210,05%. El 2,9% sobrepasaron los valores límites establecidos por la ACGIH (American Conference of Governmental Industrial Hygienists) y el 92,5% según los límites de la EPA (Agencia de Protección del Ambiente), presentando mayor riesgo en el personal operativo con 93,3% (p= 0,002). Conclusión El riesgo según los límites establecidos por la ACGIH para las mediciones realizadas en Colombia fue bajo, aunque al utilizar los parámetros de la EPA, el riesgo fue alto, por lo cual se requiere hacer un seguimiento específico a estas empresas y fomentar la implementación del sistema de gestión en seguridad y salud en el trabajo.

INDUCTION OF DNA STRAND BREAKS AND CROSS-LINKS BY THE NEW ANTICANCER AGENT 3,6-DIAZIRIDINYL-2,5-BIS(CARBOETHOXYAMINO) -1,4-BENZOQUINONE

The DNA breakage effect of the anticancer agent 3,6-diaziridinyl-2,5-bis(carboethoxyamino)-1,4-benzoquinone (AZQ, NSC-182986) on bacteriophage PM2 DNA was investigated using agarose gel electrophoresis. AZQ caused both single-stranded and double-stranded breaks after reduction with NaBH(,4), but it was not active in the native state. At 120 (mu)M, it degraded 50% of the closed circular form I DNA into 40% form II DNA (single-stranded break) and 10% form III DNA (double-stranded break). It produced a dose-response breakage between 1 (mu)M and 320 (mu)M. The DNA breakage exhibited a marked pH dependency. At 320 (mu)M, AZQ degraded 80% and 60% of form I DNA at pH 4 and 10 respectively, but none between pH 6 to 8. The DNA breakage at physiologic pH was greatly enhanced when 10 (mu)M cupric sulfate was included in the incubation mixture. The DNA strand scission was inhibited by catalase, glutathione, KI, histidine, Tiron, and DABCO. These results suggest that the DNA breakage may be caused by active oxygen metabolites including hydroxyl free radical. The bifunctional cross-linking activity of reduced AZQ on isolated calf thymus DNA was investigated by ethidium fluorescence assay. The cross-linking activity exhibited a similar pH dependency; highest in acidic and alkaline pH, inactive under neutral conditions. Using the alkaline elution method, we found that AZQ induced DNA single-stranded breaks in Chinese hamster ovary cells treated with 50 (mu)M of AZQ for 2 hr. The single-stranded break frequencies in rad equivalents were 17 with 50 (mu)M and 140 with 100 (mu)M of AZQ. In comparison, DNA cross-links appeared in cells treated with only 1 to 25 (mu)M of AZQ for 2 hr. The cross-linking frequencies in rad equivalents were 39 and 90 for 1 and 5 (mu)M of AZQ, respectively. Both DNA-DNA and DNa-protein cross-links were induced by AZQ in CHO cells as revealed by the proteinas K digestion assay. DNA cross-links increased within the first 4 hr of incubation in drug-free medium and slightly decreased by 12 hr, and most of the cross-links disappeared after cells were allowed to recovered for 24 hr.^ By electrochemical analysis, we found that AZQ was more readily reduced at acidic pH. However, incubation of AZQ with NaBH(,4) at pH 7.8 or 10, but not at 4, produced superoxide anion. The opening of the aziridinyl rings of AZQ at pH 4 was faster in the presence of NaBH(,4) than in its absence; no ring-opening was detected at pH 7.8 regardless of the inclusion of NaBH(,4). . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI ^

Raman spectroscopic characteristics of phthalocyanine and naphthalocyanine in sandwich-type phthalocyaninato and porphyrinato rare earth complexes Part 5. – Raman spectroscopic characteristics of naphthalocyanine in mixed [tetrakis(4-tert-butylphenyl)porphyrinato]-(naphthalocyaninato) rare earth double-deckers

Raman spectra were recorded in the range 400–1800 cm−1 for a series of 15 mixed \[tetrakis(4-tert-butylphenyl)porphyrinato](2,3-naphthalocyaninato) rare earth double-deckers M(TBPP)(Nc) (M = Y; La–Lu except Pm) using laser excitation at 632.8 and 785 nm. Comparisons with bis(naphthalocyaninato) rare earth counterparts reveal that the vibrations of the metallonaphthalocyanine M(Nc) fragment dominate the Raman features of M(TBPP)(Nc). When excited with radiation of 632.8 nm, the most intense vibration appears at about 1595 cm−1, due to the naphthalene stretching. These complexes exhibit the marker Raman band for Nc•− as a medium-intense band in the range 1496–1507 cm−1, attributed to the coupling of pyrrole and aza stretching, while the marker Raman band of Nc2− in intermediate-valence Ce(TBPP)(Nc) appears as a strong band at 1493 cm−1 and is due to the isoindole stretchings. By contrast, when excited with radiation of 785 nm that is in close resonance with the main Q absorption band of the naphthalocyanine ligand, the ring radial vibrations at ca 680 and 735 cm−1 for MIII(TBPP)(Nc) are selectively intensified and are the most intense bands. For the cerium double-decker, the most intense vibration also acting as the marker Raman band of Nc2− appears at 1497 cm−1 with contributions from both pyrrole CC and aza CN stretches. The same vibrational modes show weak to medium intensity scattering at 1506–1509 cm−1 for MIII(TBPP)(Nc) and this is the marker Raman band of Nc•− when thus excited. The scatterings due to the Nc breathings, ring radial vibration, aza group stretchings, naphthalene stretchings, benzoisoindole stretchings and the coupling of pyrrole CC and aza CN stretchings in MIII(TBPP)(Nc) are all slightly blue shifted along with the decrease in rare earth ionic radius, confirming the effects of increased ring–ring interactions on the Raman characteristics of naphthalocyanine in the mixed ring double-deckers.