Infiltration of ambient PM 2.5 and levels of indoor generated non-ETS PM 2.5 in residences of four European cities

Ambient fine particle (PM 2.5) concentrations are associated with premature mortality and other health effects. Urban populations spend a majority of their time in indoor environments, and thus exposures are modified by building envelopes. Ambient particles have been found to penetrate indoors very efficiently (penetration efficiency P≈1.0), where they are slowly removed by deposition, adsorption, and other mechanisms. Other particles are generated indoors, even in buildings with no obvious sources like combustion devices, cooking, use of aerosol products, etc.. The health effects of indoor generated particles are currently not well understood, and require information on concentrations and exposure levels. The current work apportions residential PM 2.5 concentrations measured in the EXPOLIS study to ambient and non-ambient fractions. The results show that the mean infiltration efficiency of PM 2.5 particles is similar in all four cities included in the analysis, ranging from 0.59 in Helsinki to 0.70 in Athens, with Basle and Prague in between. Mean residential indoor concentrations of ambient particles range from 7 (Helsinki) to 21 μg m -3 (Athens). Based on PM 2.5 decay rates estimated in the US, estimates of air exchange rates and indoor source strengths were calculated. The mean air exchange rate was highest in Athens and lowest in Prague. Indoor source strengths were similar in Athens, Basle and Prague, but lower in Helsinki. Some suggestions of possible determinants of indoor generated non-ETS PM 2.5 were acquired using regression analysis. Building materials and other building and family characteristics were associated with the indoor generated particle levels. A significant fraction of the indoor concentrations remained unexplained. © 2004 Elsevier Ltd. All rights reserved

The EXPOLIS study: Implications for exposure research and environmental policy in Europe

Exposure analysis is a crucial part of effective management of public health risks caused by pollutants and chemicals in our environment. During the last decades, more data required for exposure analysis has become available, but the need for direct population based measurements of exposures is still clear. The current work (i) describes the European EXPOLIS study, designed to produce this kind of exposure data for major air pollutants in Europe, and the database created to make the collected data available for researchers (ii) reviews the exposure analysis conducted and results published so far using these data and (iii) discusses the implications of the results from the point of view of research and environmental policy in Europe. Fine particle (with 37 elements and black smoke), nitrogen dioxide, volatile organic compounds (30 compounds) and carbon monoxide inhalation exposures and exposure-related questionnaire data were measured in seven European cities during 1996-2000. The EXPOLIS database has been used for exposure analysis of these pollutants for 4 years now and results have been published in approximately 30 peer-reviewed journal papers, demonstrating the versatility, usability and scientific value of such a data set. The multipollutant exposure data from the same subjects in the random population samples allows for analyses of the determinants, microenvironments and sources of exposures to multipollutant mixtures and associations between the different air pollutants. This information is necessary and useful for developing effective policies and control strategies for healthier environment

An alkaline single-cell gel electrophoresis (comet) assay for environmental biomonitoring with native rodents

The main advantages of single-cell gel electrophoresis (SCG) are its applicability to any eukaryotic organism and cell type, its low cost and the short time required to obtain results. These properties make the SCG assay particularly useful in screening for environmental genotoxicity. The present study describes a modified version of this technique for use in field work with native rodents and examines some factors which influence the outcome of the assay. Wild rodents (Ctenomys torquatus, "tuco-tuco") from a region close to a strip coal mine and from a region with no coal mines were used. Animals from the coal mining region had significantly more DNA damage than those from the control area. The use of this SCG technique for direct sampling in the field should facilitate environmental genotoxicity studies with natural populations, without the need to remove the animals from their habitat or to sacrifice them.<br>A mais importante vantagem do Ensaio Cometa é a possibilidade do seu uso em qualquer organismo e tipo celular. Além de ser barato e rápido, se obtem resultados em poucas horas. Devido a isto é que ele vem sendo recomendado como teste inicial para monitoramento genotóxico ambiental. Neste trabalho investigaram-se adaptações na técnica para trabalhos de campo, com o uso de roedores endêmicos de região de mineração de carvão. O organismo utilizado foi o Ctenomys torquatus, capturado em duas diferentes áreas: Pelotas (região sem mineração de carvão-controle) e Candiota (zona de mineração de carvão). Foi coletado sangue periférico de 18 roedores, que após marcação foram liberados. O sangue foi protegido da luz e mantido sob refrigeração, e processado in loco. As concentrações das agaroses e as condições alcalinas de lise e eletroforese foram modificadas a partir das metodologias sugeridas pelas revisões existentes. As amostras restantes foram mantidas em RPMI 1640 (1:10) (4ºC) e pela nossa experiência podem ser utilizadas por até 4 dias. Foram analisadas 50 células por animal. As células foram classificadas de 0-4, segundo seu grau de lesão, além de serem medidas em unidades arbitrárias. Foi demonstrado aumento significante no nível de dano do DNA no grupo de Candiota (P < 0,05 - teste t), quando comparado com Pelotas. Ainda se demonstrou correlação entre o índice de danos e as medidas celulares. Estes resultados, neste estudo piloto, indicam que o carvão induz efeitos no DNA que são detectáveis através do Ensaio Cometa, o que indica a viabilidade deste teste para o biomonitoramento ambiental