**4. Vehicular emissions and the impacts on air quality**

tested and showed no statistically significant influence on PAH emissions. Emissions of PAH from LDV running with ethanol or gasohol are lower than vehicles running with diesel, being that the diesel-powered vehicles showed emission about 200 times higher than vehicles running with ethanol [64]. Total PAH values from diesels ranged from 1.133 to 5.801 mg/km. Naphthalene, phenanthrene, fluoranthene, pyrene, and chrysene were detected in all test samples. Another study developed by da Silva et al. [65] evaluated the composition of inhalable particles and their trace metal content in LDV fueled with ethanol and gasohol. The results showed that the 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. The results also showed that PM10 emissions from the ethanol vehicle were about threefold lower

Correa and Arbilla [66] evaluated the emissions of mono- and polycyclic aromatic hydrocar‐ bons (MAHs and PAHs, respectively) from a six cylinder heavy-duty engine, typical of the urban buses of Brazilian fleet, fueled with pure diesel (D) and biodiesel blends (v/v) of 2% (B2), 5% (B5), and 20% (B20). The results showed the following average reduction of MAHs: 4.2% for B2 blend, 8.2% for B5 blend, and 21.1% for B20 blend. The average reductions for PAHs were 2.7% (B2), 6.3% (B5), and 17.2% (B20). However, some PAHs and MAHs emissions increased due to the biodiesel blends like phenanthrene, ethyl benzene, and trimethyl

In order to characterize current concentrations of PM2.5 from LDV and HDV in the MASP, Brazil, measurements of physical and chemical properties of aerosol were undertaken inside two tunnels located in the MASP in 2011 [67]. The two tunnels showed very distinct fleet profiles: in the Janio Quadros (JQ) tunnel, the vast majority of the circulating fleet are LDV, fuelled on average with the same amount of ethanol as gasoline. In the Rodoanel tunnel (RA), PM emission is dominated by HDV fuelled with diesel + 5% biodiesel blend. The study shows

contribution from organic mass (42 %), followed by elemental carbon (17 %) and crustal

of elemental carbon (52 %) and organic mass (39 %). The work showed that average organic mass:elemental carbon ratio in the JQ tunnel was 1.59, indicating an important contribution of elemental carbon despite the high ethanol fraction in the fuel composition. The study also

and JQ tunnel, respectively. In the JQ tunnel, benzo(a) pyrene (BaP) ranged from 0.9 to 6.7 ng/ m3 (0.02-0. 1 parts per thousand of PM2.5) whereas in the RA tunnel BaP ranged from 0.9 to 4.9

The concentrations of PM2.5 and PM10, including their ionic composition was evaluable at an underground bus terminal, being that buses burning fuel blend of 95% diesel + 5% biodiesel (B5) in Salvador, Bahia, Brazil, in 2010 [68]. The results showed that the mean mass concen‐

, during the same period of the day. Three times lower PM10 concentration (110 µg/m3

(0.004-0.02 parts per thousand of PM2.5), indicating an important relative contribution

during the daytime (8 am-7 pm), while the PM10 were 309 µg/

, with the largest

, mostly composed

in the RA

) was

and 45 ± 9 ng/m3

that in the JQ tunnel, PM2.5 concentrations were on average, 52 µg/m3

elements (13 %). While in the RA tunnel, PM2.5 was on average 233 µg/m3

shows that the sum of the PAHs concentration was 56 ± 5 ng/m3

of LDV emission to environmental BaP concentration.

trations of PM2.5 were 201 µg/m3

than those of gasohol.

394 Biofuels - Status and Perspective

benzenes.

ng/m3

m3

Vehicular emissions contain lead to a generation of various toxic substances such as carbon monoxide (CO), nitrogen oxides (NOx = NO + NO2), hydrocarbons (HC), sulfur oxides (SOx), and particulate matter (PM) which, when in contact with the respiratory system, can produce several harmful health effects. The effects are related to respiratory diseases, increased incidence of cancer, cardiovascular diseases, neurological problems, and reproductive problems [72]. Biofuels have met a niche in the growing market as a consequence of economic policies (substitution of fossil fuels) or efforts to reduce air pollution caused by vehicular emissions. In Brazil, the CONAMA Resolution Nº 3 by 28/06/1990 determines the standards for air quality and suitable measurement methods. This resolution establishes standards for PM, smoke, inhalable PM, SO2, CO, O3, NO2, and several sampling methods and analysis of pollutants. Table 4 shows the maximum and the desirable levels of standard concentration of air pollutants, which aims to protect people's health and the environment.

Despite the guidelines of the World Health Organization [46] for PM10 and PM2.5, there is only national air quality standard for PM10 in Brazil (Table 4), being the Brazilian values higher than the WHO guidelines (50 µg/m3 24 h mean and 20 µg/m3 annual arithmetic mean for PM10; and 25 µg/m3 24 h mean and 10 µg/m3 annual arithmetic mean for PM2.5). The monitoring of air quality in Brazil is the responsibility of the States. However, few states have established air quality network, and only eight metropolitan areas (States' capitals) have been continuously monitored: Distrito Federal, Vitória, Belo Horizonte, Rio de Janeiro, São Paulo, Porto Alegre, Curitiba, and Salvador. In Rio de Janeiro and São Paulo States, other cities have also been monitored [73].


**Table 4.** National standards for air quality [99].

Thus, MASP quality monitoring data are more complete (in time and space), enabling the evaluation of air quality trends as a result of actions to control pollutants emissions. Almost 30 years after the creation of PROCONVE, results show that the implemented strategy is correct, and the adoption of increasingly restrictive phases was successful. As observed in Figure 8, atmospheric concentration data show a clear downward tendency for CO, a recog‐ nized pollutant emitted from incomplete fuel combustion, in the MASP over the past years. These data show that LDVs emitted 20 g/km on average in the 1980s and 0.3 g/km in 2010. Meanwhile, CO concentrations recorded in CETESB monitoring network reached values close to 30 ppmv. On the other hand, since 2008, the air-quality standards for 8-hour carbon monoxide (9 ppmv) have not been exceeded at any of the automatic monitoring stations in the MASP. In agreement, analysis about the trends of air quality in the MASP showed that although the fleet had increased at a substantial rate, annual mean values showed that all pollutants except for ozone have been decreasing in the latest years [74], as a result of the vehicular emission control program established by PROCONVE. The trend evaluation of all monitoring stations showed a decrease in the annual mean concentration levels of CO, NOx, PM10, and SO2, being on average -0.09 ppm/year, -1.82 µg/m3 /year, -1.97 µg/m3 /year, and -0.82 µg/m3 /year, respectively [74].

An important analysis about air quality studies in MASP reported that atmospheric concen‐ trations of acetaldehyde and ethanol were higher in Brazil than in other areas of the world,

**Pollutant Averaging Time**

Total suspendend Particles

396 Biofuels - Status and Perspective

Inhalable particles

Smoke

SO2

NO2

CO

µg/m3

**Table 4.** National standards for air quality [99].

/year, respectively [74].

**Maximum Level (µg/m³)**

24 hours 240 150

24 hours 150 150

24 hours 150 100

1 hour 320 190

1 hour 40.000 40.000

8 hours 10.000 10.000

O3 1 hours 160 160 Ultraviolet

Thus, MASP quality monitoring data are more complete (in time and space), enabling the evaluation of air quality trends as a result of actions to control pollutants emissions. Almost 30 years after the creation of PROCONVE, results show that the implemented strategy is correct, and the adoption of increasingly restrictive phases was successful. As observed in Figure 8, atmospheric concentration data show a clear downward tendency for CO, a recog‐ nized pollutant emitted from incomplete fuel combustion, in the MASP over the past years. These data show that LDVs emitted 20 g/km on average in the 1980s and 0.3 g/km in 2010. Meanwhile, CO concentrations recorded in CETESB monitoring network reached values close to 30 ppmv. On the other hand, since 2008, the air-quality standards for 8-hour carbon monoxide (9 ppmv) have not been exceeded at any of the automatic monitoring stations in the MASP. In agreement, analysis about the trends of air quality in the MASP showed that although the fleet had increased at a substantial rate, annual mean values showed that all pollutants except for ozone have been decreasing in the latest years [74], as a result of the vehicular emission control program established by PROCONVE. The trend evaluation of all monitoring stations showed a decrease in the annual mean concentration levels of CO, NOx,

An important analysis about air quality studies in MASP reported that atmospheric concen‐ trations of acetaldehyde and ethanol were higher in Brazil than in other areas of the world,

Annual arithmetic 100 100

PM10, and SO2, being on average -0.09 ppm/year, -1.82 µg/m3

Annual geometric 80 60

Annual arithmetic 50 50

Annual arithmetic 60 40

**Desirable Level (µg/m³)**

24 hours 365 100 Fluorescence pulse / pararosaniline method / ion

Annual arithmetic chromatography 80 40

**Method of measuring**

High volume air sample / gravimetric

Gravimetric / inertial separation

Reflectance

Chemiluminescence

Nondispersive infrared sensor

/year, -1.97 µg/m3

/year, and -0.82

**Figure 8.** Carbon monoxide (CO) emissions from LDV by type of fuel and CO environmental concentrations (annual average) recorded by CETESB at automatic monitoring stations Parque Dom Pedro, Ibirapuera, Congonhas, and Cer‐ queira Cesar.

whereas the concentrations of aromatic compounds and carboxylic acids were lower [75]. More recent results analyzed atmospheric concentrations of ozone, nitrogen oxides (NO and NO2), formaldehyde, and acetaldehyde measured in the MASP, over four seasons in 2012 and 2013 [76]. These results demonstrated that although there was a large increase in the number of vehicles in the MASP that use ethanol ("flex-fuel" vehicles), technological advances in vehicle emissions control have prevented any significant increase in the atmospheric concentrations of aldehydes. The average concentrations of formaldehyde and acetaldehyde were 8.6 ± 6.7 ppbv and 5.4 ± 5.2 ppbv, respectively. Both carbonyls are important constituents of the urban troposphere in the MASP (third and fourth in terms of concentration), representing an important fraction of the total VOCs.

In recent years, Brazilian LDVs have shown a reduction in aldehyde emissions. During the 1980s, most Brazilian vehicles did not use catalytic systems for the conversion of exhaust gases and the engines were less efficient. Since 2003, flex-fuel vehicles available on the Brazilian market have been equipped with modern three-way catalytic converters. Additionally, regulations in the PROCONVE program have been of great importance in reducing the emissions of pollutants (e.g., aldehydes) in the atmosphere. In the study developed by Martins et al. [77], the data also suggest a decrease of aldehydes concentration in the MASP between years 1986 and 2003. On the other hand, comparing to previous data, this study showed that the concentration of HC presented no decrease in the concentration. Among the HCs species analyzed, the highest concentrations observed were those of toluene (7.5 ± 3.4 ppbv), n-decane (3.2 ± 2.0 ppbv), benzene (2.7 ± 1.4 ppbv), and 1,3,5-trimethylbenzene (2.2 ± 1.5 ppbv) [77]. In some years, the highest formaldehyde values in Brazil have been recorded in the city of Rio de Janeiro, where those values increased considerably between 1998 and 2004, whereas formaldehyde and acetaldehyde levels both decreased sharply between 2004 and 2009. In the latter period, values ranged from 1.52 to 54.3 ppbv for formaldehyde and from 2.36 to 45.6 ppbv for acetaldehyde [78, 79]. The authors attributed high aldehyde concentrations to the increasing use of biofuel. Several researchers have worked out the reaction pathways in the combustion of different biofuels and have concluded that such processes can generally be expected to produce carbonyl compounds, particularly formaldehyde [80, 81]. In a study developed in 2000 showed ambient concentrations of up to 61 carbonyls measured in Rio de Janeiro, Brazil. The most abundant carbonyls were formaldehyde and acetaldehyde (8.8 pbbv and 5.8, respectively) followed by acetone, 2-butanone, and benzaldehyde. Ambient concen‐ trations of other carbonyls (except acetophenone) correlated well with those of acetaldehyde and formaldehyde [82].

The concentration of atmospheric VOCs in the MASP, such as alcohols and aldehydes, were measured and compared with the data obtained in Osaka, Japan [83]. The results showed that concentrations of several pollutants found in Brazil were higher than in Japan. Ethanol concentrations found in Sao Paulo were significantly higher than those in Osaka, where the average concentrations of atmospheric methanol, ethanol, and isopropanol were 5.8 ± 3.8, 8.2 ± 4.6, and 7.2 ± 5.9 ppbv, respectively, while the average ambient levels of methanol, ethanol, and isopropanol measured in Sao Paulo were 34.1 ± 9.2, 176.3. ± 38.1, and 44.2 ± 13.7 ppbv, respectively. The levels of aldehydes, which were expected to be high due to the use of alcohol fuel during this period, were also measured at these sampling sites and the atmospheric formaldehyde average concentration measured in Osaka was 1.9 ± 0.9 ppbv; the average acetaldehyde concentration was 1.5 ± 0.8 ppbv. The atmospheric formaldehyde and acetalde‐ hyde average concentrations measured in Sao Paulo were 5.0 ± 2.8 and 5.4 ± 2.8 ppbv, respec‐ tively. The ethanol/methanol and acetaldehyde/formaldehyde were compared between the two measurement sites and elsewhere in the world, which have already been reported in the literature. Due to the use of ethanol-fueled vehicles, these ratios, especially ethanol/methanol, are much higher in Brazil than those measured elsewhere in the world. Colon [84] compared environmental concentrations of some VOCs in the MASP with data obtained from EPA in Los Angeles. In their study, the overall MASP results demonstrated that the mean concentra‐ tions of single-ring aromatics are 2-3 times higher; volatile aldehydes are 5-10 times higher; and simple alcohols 10-100 times higher as compared to results of an EPA in the Los Angeles basin. In addition, n-alkanes containing between 4 and 11 carbons were only slightly elevated in Sao Paulo.

Particulate matter, main for PM10, had more data about mass concentrations, due to States air quality monitoring stations, as well as studies by different research groups around the country. The first diagnosis of air quality monitoring network in Brazil showed the representation of differences both in space and in time. In the analysis for PM10 concentration, few stations had values above the national primary standard in 2012, but considering WHO guidelines the majority showed values above 20 reaching up to 100 µg/m3 , being that the higher values were observed in São Paulo and Rio de Janeiro, more populated urban areas in Brazil (IEMA, 2014). In urban areas, such as the MASP, the fuel burning by vehicles is an important source of PM; when comparing current levels to those observed in the past, it appears that there has been an improvement in concentration levels of this pollutant, as result of the actions and emission control programs that took place over time. In recent years, the average concentra‐ tions tended to stabilize, indicating that even with diminishing vehicle emissions these levels are only sufficient to offset the increase in the fleet and the ensuing traffic condi‐ tions. Figure 9 shows the reduction on PM10 concentrations recorded in selected CETESB monitoring network. Since 2004, the value of Brazilian air quality standard (50 µg/m3 ) for PM10 was not exceeded, but for all monitoring stations the annual mean values were above the WHO (20 µg/m3 ) guidelines (Figure 9). Although there is no national air quality standard for PM2.5, CETESB has monitored this pollutant; and since 1987 it corresponds to 60% of the PM10 mass in MASP atmosphere [28].

de Janeiro, where those values increased considerably between 1998 and 2004, whereas formaldehyde and acetaldehyde levels both decreased sharply between 2004 and 2009. In the latter period, values ranged from 1.52 to 54.3 ppbv for formaldehyde and from 2.36 to 45.6 ppbv for acetaldehyde [78, 79]. The authors attributed high aldehyde concentrations to the increasing use of biofuel. Several researchers have worked out the reaction pathways in the combustion of different biofuels and have concluded that such processes can generally be expected to produce carbonyl compounds, particularly formaldehyde [80, 81]. In a study developed in 2000 showed ambient concentrations of up to 61 carbonyls measured in Rio de Janeiro, Brazil. The most abundant carbonyls were formaldehyde and acetaldehyde (8.8 pbbv and 5.8, respectively) followed by acetone, 2-butanone, and benzaldehyde. Ambient concen‐ trations of other carbonyls (except acetophenone) correlated well with those of acetaldehyde

The concentration of atmospheric VOCs in the MASP, such as alcohols and aldehydes, were measured and compared with the data obtained in Osaka, Japan [83]. The results showed that concentrations of several pollutants found in Brazil were higher than in Japan. Ethanol concentrations found in Sao Paulo were significantly higher than those in Osaka, where the average concentrations of atmospheric methanol, ethanol, and isopropanol were 5.8 ± 3.8, 8.2 ± 4.6, and 7.2 ± 5.9 ppbv, respectively, while the average ambient levels of methanol, ethanol, and isopropanol measured in Sao Paulo were 34.1 ± 9.2, 176.3. ± 38.1, and 44.2 ± 13.7 ppbv, respectively. The levels of aldehydes, which were expected to be high due to the use of alcohol fuel during this period, were also measured at these sampling sites and the atmospheric formaldehyde average concentration measured in Osaka was 1.9 ± 0.9 ppbv; the average acetaldehyde concentration was 1.5 ± 0.8 ppbv. The atmospheric formaldehyde and acetalde‐ hyde average concentrations measured in Sao Paulo were 5.0 ± 2.8 and 5.4 ± 2.8 ppbv, respec‐ tively. The ethanol/methanol and acetaldehyde/formaldehyde were compared between the two measurement sites and elsewhere in the world, which have already been reported in the literature. Due to the use of ethanol-fueled vehicles, these ratios, especially ethanol/methanol, are much higher in Brazil than those measured elsewhere in the world. Colon [84] compared environmental concentrations of some VOCs in the MASP with data obtained from EPA in Los Angeles. In their study, the overall MASP results demonstrated that the mean concentra‐ tions of single-ring aromatics are 2-3 times higher; volatile aldehydes are 5-10 times higher; and simple alcohols 10-100 times higher as compared to results of an EPA in the Los Angeles basin. In addition, n-alkanes containing between 4 and 11 carbons were only slightly elevated

Particulate matter, main for PM10, had more data about mass concentrations, due to States air quality monitoring stations, as well as studies by different research groups around the country. The first diagnosis of air quality monitoring network in Brazil showed the representation of differences both in space and in time. In the analysis for PM10 concentration, few stations had values above the national primary standard in 2012, but considering WHO guidelines the

observed in São Paulo and Rio de Janeiro, more populated urban areas in Brazil (IEMA, 2014).

, being that the higher values were

majority showed values above 20 reaching up to 100 µg/m3

and formaldehyde [82].

398 Biofuels - Status and Perspective

in Sao Paulo.

**Figure 9.** Annual arithmetic mean of MP10 concentrations recorded at CETESB automatic monitoring stations: Parque Dom Pedro, Ibirapuera, Congonhas, and Cerqueira Cesar, from 1987 to 2013.

Sampling and analysis of chemical composition of PM2.5 were held for six Brazilian capitals (São Paulo, Rio de Janeiro, Belo Horizonte, Curitiba, Recife, and Porto Alegre) between 2007 and 2008 [85, 86], evaluating differences between summer and winter concentrations, mete‐ orological influences, physicochemical profiles, and the effects on human health. The sources evaluation by receptor models identified the principal factors: soil and crustal material; vehicle emissions and biomass burning; and fuel oil combustion in industries (sulfur factor), being that vehicle emissions explained at least 40% of the PM2.5 mass [86]. The concentrations of mass, black carbon (BC) and major ions in PM2.5 are shown in Table 5, together with concentrations obtained in other places of Brazil, like as industrial site and region where sugar cane is routinely burned. The PM2.5 mass concentrations were higher than the WHO guidelines, except in Recife. In urban areas, BC concentrations were higher than ions concentrations, being the sulfate concentrations higher than those of any other ion. The lowest sodium concentrations were observed in Belo Horizonte and Curitiba, which are farther from the ocean, on the contrary those observed in Seropédica and Santa Cruz (Rio de Janeiro) [87], which are near the ocean (Table 5). São José dos Campos and Araraquara had the highest potassium contents, which were associated with the occurrence of biomass burning events (for instance, sugar cane). Regarding trace elements and/or metals (Table 6), iron concentration was the highest followed by aluminum and zinc. The MP2.5 PAH results are shown in Table 7, highlighting the high concentrations of total PAHs observed in São Paulo and Cubatão, more polluted areas among the cities evaluated.


**Table 5.** Particulate matter (PM2.5 or fine fraction) mass, black carbon (BC) and ions average concentrations in some Brazilian regions.

Bioethanol and Biodiesel as Vehicular Fuels in Brazil — Assessment of Atmospheric Impacts from the Long Period... http://dx.doi.org/10.5772/60944 401


**Table 6.** Trace elements concentrations in PM2.5 (fine fractions) in some Brazilian cities.

concentrations higher than those of any other ion. The lowest sodium concentrations were observed in Belo Horizonte and Curitiba, which are farther from the ocean, on the contrary those observed in Seropédica and Santa Cruz (Rio de Janeiro) [87], which are near the ocean (Table 5). São José dos Campos and Araraquara had the highest potassium contents, which were associated with the occurrence of biomass burning events (for instance, sugar cane). Regarding trace elements and/or metals (Table 6), iron concentration was the highest followed by aluminum and zinc. The MP2.5 PAH results are shown in Table 7, highlighting the high concentrations of total PAHs observed in São Paulo and Cubatão, more polluted areas among

**- SO4**

**2- NH4**

12.1 - 1.07 1.70 3.30 - 1.59 0.23 0.24 0.07

12.4 - 1.00 1.64 3.81 - 1.56 0.23 0.24 0.05

<sup>2001</sup> - - 0.18 0.38 1.58 0.26 0.07 0.38 0.16 0.03 [101]

28.1 10 0.24 1.22 3.09 1.25 0.24 0.25 0.08 -

17.2 3.4 0.11 0.56 1.91 0.80 0.21 0.18 0.04 -

14.7 4.5 0.04 0.19 1.15 0.34 0.08 0.19 0.10 -

13.4 3.9 0.15 0.43 1.17 0.35 0.19 0.27 0.04 -

7.3 1.9 0.15 0.11 0.61 0.18 0.33 0.14 0.05 -

Curitiba/Paraná 14.4 4.4 0.07 0.16 1.08 0.37 0.10 0.28 0.04 -

**Table 5.** Particulate matter (PM2.5 or fine fraction) mass, black carbon (BC) and ions average concentrations in some

15.7 - 0.36 0.37 2.17 0.96 0.34 0.46 0.30 0.03 [100]

11.9 - 0.11 0.43 1.20 0.30 0.13 0.14 0.10 0.02 [102]

**Average Concentrations / µg m-3 References**

[87]

[85, 86]

**<sup>+</sup> Na+ K+ Ca2+ Mg2+**

the cities evaluated.

400 Biofuels - Status and Perspective

de Janeiro Aug. 2010-July

2011

Feb. 2004-Feb. 2005

April 1999-Feb.

13 May-19 July, 2002

June 2007- August 2008

Seropédica/Rio

Santa Cruz/Rio de Janeiro

São Jose dos Campos/São Paulo

Araraquara/São Paulo

São Paulo/São Paulo

São Paulo/São Paulo

Rio de Janeiro/Rio de Janeiro

Belo Horizonte/ Minas Gerais

Porto Alegre/Rio Grande do Sul

Recife/ Pernambuco

Brazilian regions.

**City/State Sampling data Mass BC Cl- NO3**


**Table 7.** Atmospheric concentrations of total PAHs in some Brazilian cities.
