Comparison of rural and urban atmospheric aldehydes in Londrina, Brazil

Ambiental levels of formaldehyde and acetaldehyde were measured at three sites in the city of Londrina: at the central bus station, downtown (night and day profiles) and in a rural area, during the summer and winter seasons of 2002. Atmospheric aldehydes were collected using C18 Sep-Pak cartridges coated with 2,4-DNPH and analyzed by HPLC-DAD. At the central bus station, the measured mixing atios for formaldehyde and acetaldehyde ranged, respectively, from 6.17 to 10.43 ppbv and from 0.49 to 2.12 ppbv. Downtown, during the summer, formaldehyde levels ranged from 2.07 to 5.65 ppbv, and acetaldehyde levels ranged from 1.05 to 5.06 ppbv. During the winter, the daytime concentrations for formaldehyde and acetaldehyde were higher than nighttime levels. Formaldehyde and acetaldehyde mixing ratios ranged from 3.24 to 9.46 ppbv and from 2.81 to 10.83 ppbv, respectively. At the rural site, formaldehyde and acetaldehyde mixing ratios ranged from 0.64 to 1.41 ppbv and from 0.10 to 0.87 ppbv, respectively. The acetaldehyde/formaldehyde ratios were compared with values from other Brazilian cities

Concentration and Size Distribution of Particulate Matter in a Broiler House Ambient Air

Atmospheric particulate matter (PM) is an important constituent of ambient air. The determination of its concentration and size distribution in different environments is essential because of its ability to penetrate deeply into animal and human respiratory tract. In this study, air sampling was performed in a broiler house to estimate the concentration and size distribution of PM emitted along with its activities. Low-vol impactor ( 2.5; 1.0 – 2.5; 0.50 – 1.0; 0.25 – 0.50; < 0.25 mm) connected with membrane pumps were used. PM10 showed high concentration (209 - 533 mg m-3). PM2.5 and PM1.0 initially showed relatively low concentration (20.8 and 16.0 mg m-3 respectively) with significantly increasing levels (412.9 and 344.8 mg m-3 respectively) during the samplings. It was also possible to observe the contribution of fine particles. This was evidenced by the high correlation between PM2.5 and PM1.0 and by the profile of particle distribution in the Sioutas sampler. PM concentration levels are considered excessively high, with great potential to affect animal and human health. DOI: http://dx.doi.org/10.17807/orbital.v8i3.84

Composição química e atividade antifúngica do óleo essencial de poejo em diferentes estágios de desenvolvimento

<p class="Pa7"> </p><p class="Default">O objetivo deste estudo foi comparar o rendimento, a composição química e a atividade antifúngica do óleo essencial de <em>Mentha pulegium </em>(poejo) em diferentes estágios de desenvolvimento, cultivada sob condições controladas no sul do Brasil. A hidrodestilação de folhas frescas de <em>M. pulegium</em>, coletadas aos 60, 70 e 85 dias após o transplante, apresentou rendimento de óleo essencial de 0,17 %, 0,23 % e 0,17 %, respectivamente. Todas as amostras de óleo apresentaram atividade contra <em>Cladosporium herbarum</em>. Através das análises de cromatografia gasosa (GC) e GC/MS do óleo essencial, foram identificados onze constituintes, sete (mentona, isomentona, neoisomentol, pulegona, piperitona, 1.1- dimetoxi-2- nonino e piperitenona) comuns às três amostras, enquanto dois outros (mentofurano, mirtenal) foram detectados somente nas amostras da primeira e segunda coletas. A pulegona foi o principal constituinte nas duas primeiras amostras (26,65 %), seguida pela piperitenona (20,41; 12,60 %). A concentração de pulegona aumentou para 31,05 % na última coleta, porém o constituinte majoritário foi a piperitenona (36,32 %). Os resultados demonstraram que o óleo essencial de <em>M. pulegium </em>apresenta potencial como agente antifúngico e sua composição química depende do estágio de desenvolvimento da planta.</p

HPA e Nitro-HPA em Ambiente Semifechado Impactado por Emissão da Combustão de Diesel/Biodiesel (B5)

In order to verify the presence of polycyclic aromatic hydrocarbons (PAHs) and nitro-PAH (NPAH) associated with the fine fraction of particulate matter (PM1.0 and PM2.5) from the combustion of diesel/biodiesel mixture (B5), daily samples were carried out in the urban bus station of Londrina. A high performance liquid chromatography with mass spectrometry (LC-APCI-MS) was used for the determination of nitro-PAH and the PAHs were determined by high performance liquid chromatography equipped with fluorescence detector (LC-FLD). 9 PAHs and 1-nitropyrene were determined. The concentrations of the PAHs with 4 to 6 rings (fluoranthene, pyrene, crysene, benzo(b)fluoranthene, benzo(k)fluoranthene and dibenzo(a,h)antharacene) were higher in comparison to the lighter PAHs (acenaphthene, fluorene and anthracene). The ∑PAH associated to the PM1.0 corresponded to 66% of the PM2.5 with concentrations that exceed the levels recommended by WHO. The diagnostic ratios (DR) of PAHs and NPAH were calculated and the results suggest diesel/biodiesel (B5) emissions. The use of biofuel in Brazil is encouraged and the monitoring of changes in emissions arising from combustion processes is important and necessary to follow the change of air quality and the impact on the environment.  DOI: http://dx.doi.org/10.17807/orbital.v7i3.73