Maria de Fátima Andrade

Air pollution and pediatric respiratory hospital admissions in São Paulo, Brazil

In order to investigate the relation between air pollution and child morbidity in Sao Paulo, a time-series study was carried out. Daily records of hospital admissions for children under 13 years old were obtained at the Health State Secretary, covering 112 hospitals in the period from October 1992 to October 1993. Daily levels of PM10, ozone, SO2, CO and NO2 were obtained from the environmental state agency (CETESB), while both CETESB and the Institute of Astronomy and Geophysics (IAG) of the University of Sao Paulo provided daily measures of temperature and relative humidity. Daily counts of child respiratory admissions (RESP) were considered as the dependent variable of pollutants in regression models, controlled for months of the year, days of the week, weather factors, and the daily number of non respiratory admissions (NORESP). PM10 and ozone were the pollutants that exhibited the most robust association with RESP. The mean levels of PM10observed during the period of study (70 μg m−3) were associated with an increase of 12% in RESP. The association between air pollution and RESP was significant within a time lag between 1 to 7 days and was dose-dependent. This result indicates that air pollution represents a significant pediatric health problem in Sao Paulo. Copyright

Characteristics of fine and coarse particles of natural and urban aerosols of Brazil

Abstract Fine and coarse particles have been sampled from 1982 to 1985 in one natural forest seacoast site (Jureia) and five urban-industrial cities (Vitoria, Salvador, Porto Alegre, Sao Paulo and Belo Horizonte). The time variations of concentrations in air and the relative elemental compositions of fine and coarse particle fractions, sampled by Nuclepore stacked filter units (SFU), have been determined gravimetrically and by PIXE analysis, respectively. Enrichment factors and correlation coefficients of the trace elements measured led to unambiguous characterization of soil dust and sea salt, both major aerosol sources that emit coarse particles, and soil dust is also a significant source of fine particles.

Characterisation of aerosol particles in the São Paulo Metropolitan Area

Abstract Aerosol samples were collected in the Sao Paulo Metropolitan Area, Brazil, during two periods (winter and summer) for fine and coarse particles; they were analysed by gravimetry, scanning electron microscopy, particle induced X-ray emission (PIXE) and electron probe X-ray micro analysis (EPXMA) in order to investigate the mass concentration, morphology and physico–chemical properties of the particles. The gravimetry and PIXE results confirmed that the aerosol concentration is higher in winter than in summer, as expected from the climatological conditions (dry winter and humid summer). Hierarchical cluster analysis of the EPXMA results showed the presence of metal compounds, silicon-rich particles, sulphates, carbonates, chlorides, organics and biogenic particles.

Air quality model simulating photochemical formation of pollutants: the São Paulo Metropolitan Area, Brazil

The main sources of ozone precursors in the atmosphere of the Sao Paulo Metropolitan Area (SPMA) in Brazil are emissions from gasoline-, ethanol-, and diesel-powered vehicles. Ozone is a significant air quality problem in the SPMA. To come into compliance with the National Ambient Air quality Standard for Ozone, emission reduction policies must be established. An adequate emissions inventory and a description of the meteorology and chemistry involved are needed in order to evaluate the effectiveness of methodologies that reduce the effect of vehicle emissions on ozone formation. During the period 10–12 August 1999, concentrations of ozone in the SPMA and the impact of the official emissions inventory were simulated through application of an urban-scale Eulerian model. We found that using the official inventory in simulations resulted in ozone values much lower than those observed and nitrogen oxide emission profiles that were overestimated by a factor of approximately two.

Size-resolved mass balance of aerosol particles over the Sao Paulo Metropolitan Area of Brazil

During an eight-day period in August of 1999, a nine-stage, micro-orifice, uniform-deposit impactor was used to determine the mass size distribution of atmospheric aerosol particles in the heavily polluted Metropolitan Area of São Paulo (MASP) in Brazil. Particle-induced X-ray emission analysis (PIXE) was used to identify up to 20 trace elements in particles collected in the five lower stages. All nine stages, as well as the after filter, were also analyzed for mass, black carbon, and various inorganic ions. A real-time carbon monitor provided organic and elemental carbon concentrations of PM 10 . For the five lower stages, the crustal material concentration was estimated by the sum of the main oxides and carbonates. In the after filter, PIXE analysis was not performed. The averaged mass balance analysis showed that black carbon was concentrated in the after filter, revealing black carbon particles to be very small in diameter. Ammonium sulfate showed simple unimodal size distribution during the day (peak diameter, 0.38 m) and bimodal size distribution at night (0.38 and 0.59 μ m). The crustal material contribution was greater in larger cutoff diameter stages. No explanation was found for a significant fraction of the fine particulate matter. The difference between the mass concentration and the sum of the component concentrations could be attributed to organic carbon being in fine mode. This could explain 38% of the difference and almost all of the missing diurnal and nocturnal mass. Based on these results and assumptions, we can conclude that the fine mode receives a greater contribution from organic and black carbon than from ammonium sulfate. The three together appear to constitute the bulk of fine particulate matter in the MASP.

Preliminary estimation of the rainfall chemical composition evaluated through the scavenging modeling for north-eastern Amazonian region (Amapá State, Brazil)

Numerical modeling of scavenging processes has been compared with data obtained for rainwater and aerosol chemistry at Serra do Navio, in the state of Amapá in the Brazilian Amazon region. Sulfate, nitrate and ammonium concentrations were determined in rainwater samples collected from May 1995 until June 1997. The levels of these same chemicals were also determined in aerosols for the same period and region. Scavenging processes have been evaluated on a rainfall event basis, via numerical modeling, in order to simulate the rainwater concentrations and compare them with the observed data. RAMS (Regional Atmospheric Modeling System) was used to simulate cloud structures. A model of below-cloud scavenging was evaluated, as well. The determinations made from the results of the scavenging model are the following: a) aerosol vertical profiles are quite important to rainwater concentrations; b) modeled sulfate in rainwater is a better fit to the observed data values than ammonium and nitrate; c) the obtained sulfate aerosol concentrations samples are similar to ones found in the literature, although the sulfate concentrations in rainwater are much lower than other studies in the literature; d) the in-cloud scavenging process dominates, e) our modeled results, using an input gas vertical profile extracted from the ABLE2B experimental data set, present a smaller ratio between gas and aerosol scavenging than found in other studies in the literature, other studies may have had larger rainfall times, which increase the importance of gas phase scavenging.

Characterization of atmospheric aerosols in the city of São Paulo, Brazil: comparisons between polluted and unpolluted periods

The objective of this study was to determine the size and composition of atmospheric aerosols in the downtown area of the city of São Paulo, Brazil, for a polluted and an unpolluted period. Aerosols were sampled with a portable air sampler (PAS), Micro-Orifice Uniform Deposit Impactor (MOUDI), and Scanning Mobility Particle Sizer. At the study site, air quality is poor, especially during the winter, high concentrations of pollutants being emitted primarily by the light- and heavy-duty vehicle fleet. We analyzed mass, black carbon (BC), Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sn, Zr, and Pb. During the polluted period, diurnal PM10 was higher than nocturnal PM10, whereas the inverse was true during the unpolluted period. The FPM was rich in BC, S, and Pb, whereas CPM was rich in Al, Si, Ca, Ti, and Fe. Mass balance was performed by category: ammonium sulfate, sodium chloride, crustal material, BC, and other. The PAS-determined FPM was mainly BC. The MOUDI-determined FPM crustal material explained more mass than did ammonium sulfate and BC during the polluted period, whereas ammonium sulfate had the largest mass during the unpolluted period. Crustal material was the major CPM component, followed by ammonium sulfate and BC. During the unpolluted period, FPM concentrations were lower, whereas those of ammonium sulfate were relatively higher, especially at night, and particle number was inversely proportional to particle size. Aerosol growth was more intense during the polluted period.

Air quality forecasting system for Southeastern Brazil

Southeastern Brazil, the most populous and developed region of the country, faces various environmental problems associated with the growth of its population in urban areas. It is the most industrialized area in the country, comprising the metropolitan areas of Sao Paulo, Rio de Janeiro, Belo Horizonte, and other major cities. Air quality is a major concern, because the reported concentrations of certain regulated pollutants, typically ozone and fine particulate, have exceeded national standards. Due to the difficulty in taking measurements over many different areas, air quality modeling is a useful tool to estimate air pollutant concentrations. For southeastern Brazil, air quality modeling has been performed mostly with the Brazilian Regional Atmospheric Modeling System with Simplified Photochemical Module and the Weather Research and Forecast with Chemistry models. One of the main objectives was to study the evolution of air quality associated with improved vehicle emission factors in urban areas, the impact of climate change on air quality, and the relationship between pollutant concentrations and health. Knowledge of mobile source emission factors has been continuously expanded by in-tunnel measurements and dynamometer protocols, which provide accurate data as inputs to photochemical air quality models. The spatial distribution of the mobile source emissions was constructed based on open access data related to the streets and traffic distribution. The mobile emission module was combined to the chemistry modeling and this implementation can be an example to be applied to other places that do not have a spatial distribution of this kind of source. Forecasts of pollutant concentrations can inform public policies, including those addressing the effects of pollutants on health of the general population, and studies of the impacts of using different fuels and implementation of emissions regulations programs.

Characterization of Metal and Trace Element Contents of Particulate Matter (PM10) Emitted by Vehicles Running on Brazilian Fuels—Hydrated Ethanol and Gasoline with 22% of Anhydrous Ethanol

Emission of fine particles by mobile sources has been a matter of great concern due to its potential risk both to human health and the environment. Although there is no evidence that one sole component may be responsible for the adverse health outcomes, it is postulated that the metal particle content is one of the most important factors, mainly in relation to oxidative stress. Data concerning the amount and type of metal particles emitted by automotive vehicles using Brazilian fuels are limited. The aim of this study was to identify inhalable particles (PM10) and their trace metal content in two light-duty vehicles where one was fueled with ethanol while the other was fueled with gasoline mixed with 22% of anhydrous ethanol (gasohol); these engines were tested on a chassis dynamometer. The elementary composition of the samples was evaluated by the particle-induced x-ray emission technique. The experiment showed that total emission factors ranged from 2.5 to 11.8 mg/km in the gasohol vehicle, and from 1.2 to 3 mg/km in the ethanol vehicle. The majority of particles emitted were in the fine fraction (PM2.5), in which Al, Si, Ca, and Fe corresponded to 80% of the total weight. PM10 emissions from the ethanol vehicle were about threefold lower than those of gasohol. The elevated amount of fine particulate matter is an aggravating factor, considering that these particles, and consequently associated metals, readily penetrate deeply into the respiratory tract, producing damage to lungs and other tissues.

Traffic-related air quality trends in São Paulo, Brazil

The urban population of South America has grown at 1.05%/yr, greater urbanization increasing problems related to air pollution. In most large cities in South America, there has been no continuous long-term measurement of regulated pollutants. One exception is Sao Paulo, Brazil, where an air quality monitoring network has been in place since the 1970s. In this paper, we used an air quality-based approach to determine pollutant trends for emissions of carbon monoxide (CO), nitrogen oxides (NOx), ozone (O3), and coarse particulate matter (PM10), mostly from mobile sources, in the Metropolitan Region of Sao Paulo for the 2000–2013 period. Mobile sources included light-duty vehicles (LDVs, comprising gasoline- or ethanol-powered cars and motorcycles) and heavy-duty vehicles (HDVs, comprising diesel-powered trucks and buses). Pollutant concentrations for mobile source emissions were measured and correlated with fuel sales by the emission factors. Over the 2000–2013 period, concentrations of NOx, CO, and PM10 decreased by 0.65, 0.37, and 0.71% month−1, respectively, whereas sales of gasoline, ethanol, and diesel increased by 0.26, 1.96, and 0.38% month−1, respectively. LDVs were the major mobile source of CO, whereas LDVs were the major source of NOx and PM10. Increases in fuel sales and in the corresponding traffic volume were partially offset by decreases in pollutant concentrations. Between 2000 and 2013, there was a sharp (−5 ppb month−1) decrease in the concentrations of LDV-emitted CO, together with (less dramatic) decreases in the concentrations of HDV-emitted NOx and PM10 (−0.25 and −0.09 ppb month−1, respectively). Variability was greater for HDV-emitted NOx and PM10 (R = −0.47 and −0.41, respectively) than for LDV-emitted CO (R = −0.72). We draw the following conclusions: the observed concentrations of LDV-emitted CO decreased at a sharper rate than did those of HDV-emitted NOx and PM10; mobile source contributions to O3 formation varied significantly, LDVs making a greater contribution during the 2000–2008 period, whereas HDVs made a greater contribution during the 2009–2013 period, and decreases in NOx emissions resulted in increases in O3 observations.