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.

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.

Indoor-outdoor distribution and risk assessment of volatile organic compounds in the atmosphere of industrial and urban areas.

Volatile organic compounds (VOCs), which play an important part indoors and outdoors, comprise differing compound groups such as n-alkanes, cycloalkanes, aromatic and chlorinated hydrocarbons and terpenes. In the current study, samples were analyzed from indoor (schools and houses, n = 92) and outdoor (n = 33) air in urban, industrial, semirural and residential areas from the region of La Plata (Argentine) to consider VOC exposure in different types of environments. VOCs were sampled for 1 month during winter for 3 years, with passive 3M monitors. Samples were extracted with CS(2) and analyzed by GC/MS detectors. The results show significant differences in concentration and distribution between indoor and outdoor samples, depending on the study area. Most VOCs predominantly originated indoors in urban, semirural and residential areas, whereas an important outdoor influence in the industrial area was observed. In all areas alkanes and aromatic compounds dominated, even though a different chemical distribution was seen. Traffic burden was determined as the major source of outdoor VOC with a benzene/toluene ratio close to 0.5. Indoors, C9-C11 alkanes, toluene and xylenes dominated, caused by human activities. In contrast, in the industrial area higher concentrations of hexane, heptane and benzene occurred outdoors and affected the indoor air significantly. The lifetime cancer risk (LCR) associated to the benzene exposure was calculated for children from the different study areas. For all groups the study showed a LCR value greater than 1 x 10(-6) related to the benzene exposure indoors as well outdoors. A value two magnitudes higher was detected indoors in the industrial area, what demonstrates the high risk for children living in this area of La Plata.

Different immunomodulatory effects associated with sub-micrometer particles in ambient air from rural, urban and industrial areas.

Immunomodulatory effects of chemicals adsorbed to particles with aerodynamic diameter below 0.49 microm (PM(0.5)) collected in winter 2001 at three sampling points (industrial area [LPIn], traffic-influenced urban area [LPCi], and control area [LPCo]) of La Plata, Argentina, were investigated. The sampling of particulate matter was carried out with high-volume collectors using cascade impactors. PM(0.5)-adsorbed compounds were hexane-extracted by accelerated solvent extraction. For immunological investigations, human peripheral blood lymphocytes were activated by phytohemagglutinin and exposed to dimethyl-sulfoxide dilutions of PM(0.5)-extracts for 24h. Vitality/proliferation was quantified using MTT, released interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) by ELISA. Cytokine production but not vitality/proliferation was significantly suppressed by all of the highest extract concentrations. Generally, suppression of IFN-gamma by PM(0.5)-extracts was stronger than those of IL-4. Based on administered mass of PM(0.5), all extracts suppressed IFN-gamma production nearly uniform. Contrary, LPCi-extracts exerted maximum IFN-gamma suppression based either on air volume or regarding PM(0.5)-adsorbed PAH. Also the ranking of PM(0.5)-associated effects on IL-4 production differs in dependence of the chosen reference points, either mass or [microg/ml] or air volume [m(3)/ml] related dust quantities in cell culture. Based on the corresponding air volume, LPCi-extracts inhibited IL-4 production to the maximum extend, whereas suppression of IL-4 was comparable based on concentrations. This indicates that not only the disparate PM(0.5)-masses in air cause varying impacts, but also that disparities in PM(0.5)-adsorbed chemicals provoke different effects on immune responses and shifts in the regulatory balance that might have implications for allergy and cancer development.

Increased asthma and respiratory symptoms in children exposed to petrochemical pollution.

BACKGROUND: Epidemiologic studies show statistical associations between levels of air pollutants and respiratory outcomes. OBJECTIVE: We sought to determine the effects of exposure to petrochemical pollution on the respiratory health of children. METHODS: Children aged 6 to 12 years living close to the petrochemical plants in La Plata, Argentina (n = 282), were compared with those living in a region with exposure to heavy traffic (n = 270) or in 2 relatively nonpolluted areas (n = 639). Parents answered a validated questionnaire providing health and demographic data. A random sample (n = 181) had lung function measured. Particulate matter and outdoor and indoor volatile organic compound levels were measured during 4-week study periods and reported as overall means for each study area. RESULTS: Children living near the petrochemical plant had more asthma (24.8% vs 10.1% to 11.5%), more asthma exacerbations (6.7 vs 2.9-3.6 per year), more respiratory symptoms (current wheeze, dyspnea, nocturnal cough, and rhinitis), and lower lung function (>13% decrease in FEV(1) percent predicted) than those living in other regions. Length of residence in the area was a significant risk factor, but age, sex, body mass index, proximity to busy roads and other nonpetrochemical industries, length of breast-feeding, and socioeconomic and demographic characteristics of children or their families were not. CONCLUSION: Exposure to particulate matter and volatile organic compounds arising from petrochemical plants but not from high traffic density was associated ith worse respiratory health in children.

Contaminación atmosférica y salud infantil en áreas urbanas e industriales de La Plata, Argentina / Air pollution and children's health in urban and industrial areas of La Plata, Argentina

El impacto de la exposición a contaminantes ambientales sobre la salud humana ha sido ampliamente investigado, encontrándose que muchos problemas de salud están relacionados con la contaminación del aire. En el presente trabajo se analizan los resultados obtenidos de un relevamiento empleando cuestionarios epidemiológicos a niños en edad pre-escolar de la ciudad de La Plata, capital de la Provincia de Buenos Aires, Argentina, y sus alrededores. Para el estudio se consideraron cuatro zonas, una típicamente urbana, otra con influencia industrial, otra de característica semi-rural y una residencial. Los resultados obtenidos evidencian, en cuanto a las enfermedades asociadas a las zonas en estudio, correlaciones significativas entre la zona industrial y dos tipos de afecciones: bronquitis crónica y piel fotosensible. Estos resultados están en concordancia con el elevado nivel de partículas, compuestos orgánicos asociados con las mismas y compuestos orgánicos volátiles hallados en la zona industrial en comparación con las zonas control. Otras correlaciones significativas encontradas se refieren a mayor predisposición a padecer bronquitis en la población que utiliza querosén como combustible para cocinar y calefacción doméstica y el desarrollo de bronquiolitis en zonas con tránsito vehicular congestionado. Estos resultados contribuyen con información de base de gran utilidad para contextualizar futuros estudios epidemiológicos en la región.

The influence of air pollution on human health has been studied during the last decades. In this sense, several epidemiological studies have shown an association between air pollutants and various diseases. In the present study an epidemiological questionnaire was applied to a population of children between 3 and 6 years of La Plata and its neighbouring areas, in Buenos Aires, Argentina. Four different areas were considered: urban, industrial, semi-rural and residential. Results show significant correlations between industrial area and chronic bronchitis and skin photosensitivity. These results depend on the high levels of particles, organic compounds bound to particles and volatile organic compounds found in the industrial area compared to control zones. Other significant correlations are related to the use of kerosene for heating and cooking, and a predisposition to develop bronchitis. Besides, the analyses of questionnaires show a correlation between bronchiolitis and heavy traffic. This investigation contributes with preliminary information to future epidemiological studies in the region.

Cytotoxicity and oxidative stress caused by chemicals adsorbed on particulate matter.

Air particulate matter (PM) and bound chemicals are potential mediators for adverse health effects. The cytotoxicity and changes in energy-providing processes caused by chemical compounds bound to PM of different size fractions were investigated in Tetrahymena pyriformis. The PM samplings were carried out using a high volume cascade impactor (6 size fractions between 10 microm and less than 0.49 microm) at three points of La Plata, Argentina: in an industrial area, a traffic-influenced urban area, and a control area. Extracts from respirable particles below 1 mum initiated the highest cytotoxic effects, demonstrating their higher risk. In contrast, an increase on oxygen consumption was observed especially in tests of extracts from particles less than 1 mum from urban and industrial areas. The increase on oxygen consumption could be caused by decoupling processes in the respiratory chain. Otherwise the ATP concentration was increased too, even though to a lower extent. The observed imbalance between oxygen consumption and ATP concentration in exposed T. pyriformis cells may be due to oxidative stress, caused by chemical compounds bound to the particles. Owing to the complexity of effects related to PM and their associated chemical compounds, various physiological parameters necessarily need to be investigated to obtain more information about their possible involvement in human relevant pathogenic processes. As shown here, effects on cell proliferation and on energy-providing processes are suitable indicators for the different impact of PM and adsorbed chemicals from various sampling locations.

Contaminación del aire en La Plata y alrededores: Factores de riesgo y patologías respiratorias en niños / La Plata's air pollution: Risk factors and respiratory pathologies in children

Mediante un proyecto de investigación desarrollado por profesionales del Centro de Investigaciones del Medio Ambiente, la Facultad de Trabajo Social, ambos de la UNLP, y el Hospital de Niños de La Plata se estudian los efectos de la contaminación ambiental sobre la salud infantil. A tal efecto, se aplican metodologías epidemiológicas(encuestas según criterios ISAAC, analizadas por Epi-info), la determinación de volúmenes respiratorios en niños de 6-10años y la cuantificación de compuestos volátiles orgánicos (COVs) en el aire intramuros y extramuros, sobre la base de una caracterización previa química, mutagénica y citotóxica del aire ambiente realizada en la zona, por profesionales participantes. El estudio se realiza en niños residentes en el Polo Petroquímico de Ensenada, en la ciudad de La Plata (alto tránsito) y en zonas con bajos niveles de COVs extramuros: una residencial y otra semi-rural. En esta etapa fueron completadas, cargadasy analizadas 1102 encuestas. Se realizaron 130 espirometrías y se determinaron niveles de COVs, intramuros y extramuros, mediante monitoreadores pasivos. El análisis estadístico preliminar evidencia correlaciones (Odds Ratio >1) entre exposición a contaminantes y diversaspatologías: cercanía a industria petroquímica con patologías de tipo respiratorio; vivir sobre una calle de tránsito intenso con cefalea, alergia y fotosensibilidad; ambientes interiores contaminados con tos persistente y rinitis. El análisis espirométricoseñala que los niños de Ensenada presentaron mayor respuesta broncodilatadora que los de las zonas restantes. Los niveles de COVs obtenidos coinciden con los hallados en estudios anteriores en cuanto a sus valores y las tendencias observadas.Así, la concentración de COVs totales en aire extramuros, es superior en Mosconi, siguiendo La Plata; las zonas residencial y semi-rural presentan valores menores y similares entre sí.

Polycyclic aromatic hydrocarbons associated with particles in ambient air from urban and industrial areas.

This study takes into consideration an analysis of the chemical polycyclic aromatic hydrocarbon (PAH) profile and its distribution in inhalable and respirable particulate matter in urban and industrial areas in La Plata, Argentina, and Leipzig, Germany. Representative samples from three locations in La Plata (industrial, traffic influenced and control area) and two locations in Leipzig (traffic influenced and control area) were obtained in summer and winter. The sampling of particulate matter was carried out with high volume collectors using cascade impactors to separate six size fractions. PAHs were extracted with hexane through a solid-liquid equilibrium extraction and analysed by HPLC/UV/fluorescence detection. The results showed a PAH seasonal behaviour in both regions, with lower contents in summer and higher ones in winter. Highest concentrations of total PAHs were found in the industrial area in La Plata. The size distribution of particles demonstrates the greater relevance of smaller particles. More than 50% of PAHs were associated with particles of less than 0.49 microm. Moreover, this particle size fraction was associated with traffic, whereas other sources of combustion were related also to particles between 0.49 and 0.95 microm. Considering the ratio of benzo(ghi)perylene (BgP)/benzo(a)pyrene (BaP) as an indicator for traffic influence, it was observed that La Plata City was more affected than Leipzig by the same proportion in summer and in winter. The BgP/InP (indeno(123-cd)pyrene) ratio was lower in winter than in summer in both places and indicates the presence of domestic combustion sources. It is important to point out the significance of using fingerprint compound ratios to identify possible sources of pollution with PAHs bound to particles.