Regina Maura de Miranda

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.

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.

Cashew nut roasting: chemical characterization of particulate matter and genotocixity analysis.

BACKGROUND Particulate matter (PM) is potentially harmful to health and related to genotoxic events, an increase in the number of hospitalizations and mortality from respiratory and cardiovascular diseases. The present study conducted the first characterization of elemental composition and polycyclic aromatic hydrocarbon (PAH) analysis of PM, as well as the biomonitoring of genotoxic activity associated to artisanal cashew nut roasting, an important economic and social activity worldwide. METHODS The levels of PM2.5 and black carbon were also measured by gravimetric analysis and light reflectance. The elemental composition was determined using X-ray fluorescence spectrometry and PAH analysis was carried out by gas chromatography-mass spectrometry. Genotoxic activity was measured by the Tradescantia pallida micronucleus bioassay (Trad-MCN). Other biomarkers of DNA damage, such as nucleoplasmic bridges and nuclear fragments, were also quantified. RESULTS The mean amount of PM2.5 accumulated in the filters (January 2124.2 µg/m(3); May 1022.2 µg/m(3); September 1291.9 µg/m(3)), black carbon (January 363.6 µg/m(3); May 70 µg/m(3); September 69.4 µg/m(3)) and concentrations of Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br and Pb were significantly higher than the non-exposed area. Biomass burning tracers K, Cl, and S were the major inorganic compounds found. Benzo[k]fluoranthene, indene[1,2,3-c,d]pyrene, benzo[ghi]perylene, phenanthrene and benzo[b]fluoranthene were the most abundant PAHs. Mean benzo[a]pyrene-equivalent carcinogenic power values showed a significant cancer risk. The Trad-MCN bioassay revealed an increase in micronucleus frequency, 2-7 times higher than the negative control and significantly higher in all the months analyzed, possibly related to the mutagenic PAHs found. CONCLUSIONS This study demonstrated that artisanal cashew nut roasting is a serious occupational problem, with harmful effects on workers׳ health. Those involved in this activity are exposed to higher PM2.5 concentrations and to 12 PAHs considered potentially mutagenic and/or carcinogenic. The Trad-MCN with T. pallida was sensitive and efficient in evaluating the genotoxicity of the components and other nuclear alterations may be used as effective biomarkers of DNA damage.

The Evolution of Temporal and Spatial Patterns of Carbon Monoxide Concentrations in the Metropolitan Area of Sao Paulo, Brazil

The Environmental Agency of Sao Paulo has a large dataset of carbon monoxide measurements: 20 years of records in 18 automatic stations inside the metropolitan area. However, a thorough investigation on the time evolution of CO concentration tendency and cycles also considering spatial variability is lacking. The investigation consists of a trend line analysis, a periodogram analysis, a correlation between CO concentration and meteorological variables, and spatial distribution of CO concentration. Local and federal policies helped in decreasing CO concentrations and the highest decreasing rate was 0.7% per month. This tendency is lately stabilizing, since the vehicles fleet is increasing. CO most relevant cycles are annual and diurnal and a few series indicate a weekly cycle. Diurnal cycle shows two peaks, morning and evening rush hours, 1.2 and 1.1 ppm, respectively, in 2012. However, lately there is an extended evening peak (20 h to 23 h), related to changes in emission patterns. The spatial analysis showed that CO concentration has high spatial variability and is influenced by proximity to heavy traffic and vegetated areas. The present work indicates that several processes affect CO concentration and these results form a valuable basis for other studies involving air quality modeling, mitigation, and urban planning.

Application of PMF for Evaluation of the Fine Particles Contribution from Vehicular Emission in Six Brazilian Cities

The vehicular emission is the main source of fine particles in Brazilian Cities. A comprehensive study was performed from 2007 to 2009 with 24 h daily sampling of fine particles in an experimental site in six Brazilian capitals: Sao Paulo, Rio de Janeiro, Curitiba, Porto Alegre, Recife and Belo Horizonte. The polycarbonate filters collected at each site with Harvard sampling, were submitted to gravimetrical analysis for identification of PM2.5 concentration, to reflectance for Black Carbon concentration, to X-ray fluorescence analysis for elemental composition and to ion chromatography for an ion sand cations composition and concentration. The average PM2.5 concentration were 28, 19, 17, 17, 16 and 11 μg/m3 in Sao Paulo, Rio de Janeiro, Belo Horizonte, Curitiba, Porto Alegre and Recife, respectively. Black Carbon accounted for approximately 30 % of the PM2.5 mass concentration in the more air pollution impacted cities: Sao Paulo, Rio de Janeiro and Belo Horizonte. The Black Carbon was used as a tracer for diesel fuel emission and biomass burning. The elemental chemical composition of the PM2.5 was used to identify source-related fractions of fine particles, by means of Receptor Models. The results were used to examine the association of these fractions with daily mortality in each of the six cities. Principal Matrix Factorization (PMF) was applied to the elemental concentration data in order to identify the sources of fine particles, specifically the participation of the vehicular emission. These results were compared to the previous analysis performed with Absolute Principal Component Analysis (APCA). The participation of the vehicular fleet to the PM2.5 mass concentration was significant, explaining in the most urbanized area even 40 % of its mass. These results show the relative importance of the vehicular emission to health injury.

Vehicular Emission Factor of Gases and Particulate Matter Measured in Two Road Tunnels in São Paulo, Brazil

In this paper we show measurements of air pollutants for a mixed vehicle fleet, heavy and light duty vehicles (HDV, LDV), in the Rodoanel and Janio Quadros tunnels in the Metropolitan Region of Sao Paulo (MRSP) in May-July 2011. Measurements of carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx) and Particle Matter (PM10) were performed by the air quality monitoring net from CETESB (Environmental Agency of Sao Paulo State). High concentrations correlated with high density traffic (approximately 3,000 ± 1,000 vehicles per hour), especially during weekdays, and have a characteristic diurnal pattern with two peaks: at morning (06:00–9:00 h) and at afternoon (16:00–19:00 h).