Influence of vehicular emissions on the levels of polycyclic aromatic hydrocarbons (PAHs) in urban and industrial areas of La Plata, Argentina.

Polycyclic aromatic hydrocarbons (PAHs) are considered potentially toxic, even carcinogenic, because of their affection to public health and the environment. It is necessary to know their ambient levels and the origin of these pollutants in order to mitigate them. A concerning scenario is the one in which commercial/administrative, industrial, and residential activities coexist. In this context, Gran La Plata (Argentina) presents such characteristics, in addition to the presence of one of the most important petrochemical complexes in the country and intense vehicular traffic. The source apportionment of PAH emission in the region, associated to 10-µm and 2.5-µm particulate matter fractions, was studied. First, different missing value imputation methods were evaluated for PAH databases. GSimp presented a better performance, with mean concentrations of ∑PAHs of 65.8 ± 40.2 ng m-3 in PM10 and 39.5 ± 18.0 ng m-3 in PM2.5. For both fractions, it was found that the highest contribution was associated with low molecular weight PAHs (3 rings), with higher concentrations of anthracene. Emission sources were identified by using principal component analysis (PCA) together with multiple linear regression (MLR) and diagnostic ratios of PAHs. The results showed that the main emission source is associated with vehicular traffic in both fractions. Classification by discriminant analysis showed that emissions can be identified by region and that fluoranthene, benzo(a)anthracene, and anthracene in PM10 and anthracene and phenanthrene in PM2.5 are a characteristic of emissions from the petrochemical complex.

Characterization and cancer risk assessment of VOCs in home and school environments in gran La Plata, Argentina.

Three areas are highlighted in Gran La Plata, Argentina: industrial, urban, and residential. In this work, the levels of volatile organic compounds (VOCs) in indoor air of homes and schools in those areas were analyzed, through the use of passive monitors. The study period is between 2007 and 2010. Higher levels of VOCs were found in homes and schools in the industrial zone, higher than the levels corresponding to urban and residential. Taking into account the relationship between indoor and outdoor levels of VOCs, they have ratios (I/O) between 1.5 and 10 are evidenced contributions of emission sources of VOCs both indoor and outdoor. Complementarily, we estimated the life time cancer risk (LCR) for benzene, styrene, trichloroethylene, and tetrachloroethylene in children who spend their time mostly in such indoor environments. The results show high LCR values for benzene, which exceed acceptable values for the US EPA.

Expresión del síndrome metabólico frente a factores ambientales / Expression of metabolic syndrome against environmental factors / Expressão da síndrome metabólica frente a fatores ambientais

El Síndrome Metabólico (SM) se define como la asociación de alteraciones metabólicas e inflamatorias a nivel molecular, celular o hemodinámico, que pueden presentarse en forma simultánea o secuencial en un mismo individuo. Esto imprime un mayor riesgo de desarrollar diabetes y enfermedades cardiovasculares, teniendo como base la resistencia insulínica. Su diagnóstico se presenta cuando existe obesidad abdominal y dos o más componentes adicionales: triglicéridos elevados, lipoproteína de alta densidad (HDL) baja, alteración en la regulación de la glucemia y presión arterial alta. En este contexto, y dada su relación con los factores ambientales, el objetivo del presente trabajo fue evaluar la relación del SM en poblaciones expuestas a diferentes niveles de contaminación atmosférica, determinando dicha asociación mediante las respuestas obtenidas de una encuesta socioeconómica, de antecedentes de salud, y contrastándolas con análisis sanguíneos. Finalmente, los resultados obtenidos evidencian intercurrencias entre el grado de contaminación atmosférica y el SM.

The metabolic syndrome (MS) is defined as the association of metabolic disorders and inflammatory diseases at molecular, cellular or hemodynamic levels, which may occur simultaneously or sequentially in the same individual. This adds an increased risk of developing diabetes and cardiovascular disease, based on insulin resistance. MS diagnosis is made when there are two or more additional components and abdominal obesity: elevated triglycerides, high density lipoprotein (HDL) low, altered regulation of blood glucose and high blood pressure. In this context, and given its relationship with environmental factors, the objective of this study was to evaluate the relationship of MS in populations exposed to different levels of air pollution,determining the association with the responses obtained from a socio-economic survey and health history, and contrasting them with a blood test. Finally, the results show intercurrences between the degree of air pollution and SM.

A síndrome metabólica (SM) é definida como a associação de alterações metabólicas e inflamatórias em nível molecular, celular ou hemodinâmico, que podem ocorrer em forma simultânea ou sequencial num mesmo indivíduo. Isto adiciona um maior risco de desenvolver diabetes e doenças cardiovasculares, tendo como base a resistência à insulina. Seu diagnóstico ocorre quando há obesidade abdominal e dois ou mais componentes adicionais: aumento dos triglicerídeos, lipoproteína de alta densidade (HDL) baixa, alteração na regulação da glicemia e pressão arterial elevada. Neste contexto, e devido a sua relação com os fatores ambientais, o objetivo desse estudo foi avaliar a relação da SM em populações expostas a diferentes níveis de poluição do ar, determinando tal associação através das respostas obtidasa em um levantamento socioeconômico, histórico de saúde e em contraste com análises de sangue. Por fim, os resultados mostram intercorrências entre o grau de poluição do ar e a SM.

Improvement of health risk factors after reduction of VOC concentrations in industrial and urban areas.

After reductions of fugitive and diffuse emissions by an industrial complex, a follow-up study was performed to determine the time variability of volatile organic compounds (VOCs) and the lifetime cancer risk (LCR). Passive samplers (3 M monitors) were placed outdoors (n = 179) and indoors (n = 75) in industrial, urban, and control areas for 4 weeks. Twenty-five compounds including n-alkanes, cycloalkanes, aromatics, chlorinated hydrocarbons, and terpenes were determined by GC/MS. The results show a significant decrease of all VOCs, especially in the industrial area and to a lesser extent in the urban area. The median outdoor concentration of benzene in the industrial area declined compared to the former study, around 85% and about 50% in the urban area, which in the past was strongly influenced by industrial emissions. Other carcinogenic compounds like styrene and tetrachloroethylene were reduced to approximately 60%. VOC concentrations in control areas remained nearly unchanged. According to the determined BTEX ratios and interspecies correlations, in contrast to the previous study, traffic was identified as the main emission source in the urban and control areas and showed an increased influence in the industrial area. The LCR, calculated for benzene, styrene, and tetrachloroethylene, shows a decrease of one order of magnitude in accordance to the decreased total VOC concentrations and is now acceptable according to values proposed by the World Health Organization.

A method for computing the damage level due to the exposure to an airborne chemical with a time-varying concentration.

The calculation of damage level due to the exposure to a toxic cloud is usually not included in most popular software, or it is included using techniques that do not take into account the variation in concentration over a period of time. In this work, a method is introduced for calculating the temporal evolution of the potential damage level and to obtain a more precise and descriptive estimation of this level. The proposed goal is: to estimate the maximum and minimum damage level experienced by a population due to the exposure to an airborne chemical with a time-varying concentration; to be able to assess the damage level experienced in a progressive way, as the exposure to the airborne chemical occurs. The method relies on transformations of time-concentration pairs on a continuum of damage level curves based on the available guideline levels, obtaining maximum and minimum approximations of the expected damage level for any exposure duration. Consequently, applying this method to transport model output data and demographic information, damage evolution in relation to time and space can be predicted, as well as its effect on the local population, which enables the determination of threat zones. The comparison between the proposed method and the current (Spanish and ALOHA) ones showed that the former can offer a more precise estimation and a more descriptive approach of the potential damage level. This method can be used by atmospheric dispersion models to compute damage level and graphically display the regions exposed to each guideline level on area maps.