PM₁₀ composition was studied in a petrochemical-influenced industrial area of central Spain, focusing on polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), oxygenated PAHs (OPAHs), and aliphatic hydrocarbons (AHs) together with their seasonal variability. Median PM₁₀ concentrations remained below the legal limit but exceeded the WHO guideline. Short-term exceedances were linked to episodic Saharan dust intrusions. Air-mass trajectory analysis showed that most PM₁₀ came from the city center, while winter peaks were associated with air masses from the nearby petrochemical complex, indicating combined industrial and natural contributions. The median concentration of ∑27PACs (Polycyclic Aromatic Compounds) was 1.69 ng m⁻³, with higher levels in winter. Benzo[b]fluoranthene, Benzo[ghi]perylene, Indeno[1,2,3-cd]pyrene, Benzo[a]pyrene, Benz[a]anthracene and 1-Phenylnaphthalene were the dominant compounds. Seasonal patterns suggested higher combustion emissions in winter and greater photochemical degradation in summer. The lack of correlation between PACs and PM₁₀ indicates different sources, including Saharan dust and industrial emissions. Alkanes showed both anthropogenic and biogenic origins, C₁₇-C₂₈ were associated with fugitive emissions and unburned fuels, while > C₂₈ alkanes mainly biogenic. Temperature, solar radiation, and ozone, significantly influenced PAC and AH concentrations. Health risk assessment estimated 30 excess cancer cases per million inhabitants over a 70-year lifetime from inhalation of PM₁₀-bound PACs. Although not indicating high risk, it underscores the need for continued monitoring and mitigation in complex industrial environments.

This study explored the extraction of pectin from garlic peels and its potential application as a food hydrocolloid due to its liquid-holding, emulsifying, thickening, and gelling properties. A Box-Behnken optimization of microwave-assisted hydrothermal extraction (MAHE) was performed to examine the effects of pH, temperature, and irradiation time on pectin yield (PY), galacturonic acid concentration (GalAC), degree of methylation (DM), and degree of acetylation (DA). Low methoxyl (36.1% DM) and low-acetyl (0.9% DA) pectin (MAHEP) were obtained at optimal MAHE conditions, achieving a high GalAC (74.9%) and a notable PY (14.5%). Following MAHE optimization, a 2-h conventional heat extraction (CE) was conducted under the same temperature, pH, and ratio. Pectin obtained through CE (CEP) demonstrated a lower PY (12.1%) but maintained a high purity level (67.1%) and exhibited higher DM (46.6%) and DA values (1.1%). Both MAHEP and CEP were rich in homogalacturonan (HG) domains (83.6-92.2% HG ratio) but differed in DM, thermal degradation behavior, and functionality. CEP showed excellent water retention (9.0 g/g) and thickening properties (2.5 Pa s at 4% w/w and 1 s(-1)), whereas MAHEP excelled in emulsifying stability (85-99% under all conditions tested) as well as gelling performance (G' > G '' for all frequencies tested at 4% w/w). This study highlights the potential of garlic peels as a source of two distinct pectic polysaccharides with high purity and functional versatility. It also provides insights into how the extraction system influences pectin structure and functional behavior.

3,3-dimethylbutanal (33DMbutanal, (CH3)3CCH2C(O)H) and 3,3-dimethylbutanone (33DMbutanone, (CH3)3CC(O)CH3) are carbonyl compounds that could play a key role in tropospheric chemistry. To better understand the effects of carbonyl compounds in the atmosphere, a kinetic and mechanistic study was conducted on the degradation of 33DMbutanal and 33DMbutanone with atmospheric oxidants (Cl atoms, OH and NO3 radicals). The kinetic experiments were performed at 710 ± 30 Torr and at room temperature (298 ± 5 K) using a relative method and Fourier transform infrared (FTIR) spectroscopy to monitor the reactions. The rate coefficients (k in units of cm3molec.-1s-1) obtained were kCl+33DMbutanal = (1.27 ± 0.08) × 10−10, kCl+33DMbutanone = (4.22 ± 0.27) × 10−11, and kOH+33DMbutanone = (1.26 ± 0.05) × 10−12. The reaction products were also determined using FTIR spectroscopy and gas chromatography–mass spectrometry (GC-MS). The main products observed were carbonyl compounds, including acetone, formaldehyde, and 2,2-dimethylpropanal. In the presence of NO, nitrated compounds were also formed, and, at high NO2 concentrations, peroxyacetyl nitrate (PAN) and peroxy-3,3-dimethylbutyryl nitrate were identified. Other unquantified compounds were multifunctional organic compounds and organic acid of low volatility. Both 33DMbutanal and 33DMbutanone degrade rapidly near emission sources with minimal impact on radiative forcing. However, they may contribute to tropospheric ozone (O3), with a photochemical ozone creation potential (POCP) range of 15–69, and secondary organic aerosol (SOA) formation, potentially worsening air quality and contributing to photochemical smog.

It is well known that carbonyl compounds play an important role in air pollution and the formation of secondary pollutants, such as peroxyacetyl nitrates (PAN). Additionally, airborne carbonyls have been described as cytotoxic, mutagenic and carcinogenic. In this research, several carbonyl compounds, including aldehydes and ketones, as well as ozone, were monitored during a campaign conducted in July and September-October 2023 at Golf Ciudad Real, a golf course located in a non-industrial area of a south-central province in Spain. Extraction and analysis were carried out following procedures outlined by Radiello®. Analyses were performed using HPLC-DAD and UV-Visible spectrophotometry. Ozone shows seasonal variation (temperature-dependent) concentrations displaying lower values in September/October. Among all the identified carbonyls, butanal was the most abundant, accounting for 40% of the total concentration. The C1/C2 and C2/C3 ratios were also calculated to provide information about the main emissions sources of the analyzed carbonyl compounds, indicating that mainly anthropogenic sources contribute to air quality in the area. The data were further supported by Quantitative Structure-Activity Relationship (QSAR) models using the ProtoPRED online server, which employs in silico methods based on European Chemicals Agency (ECHA) regulations to assess the (eco)toxicity of the measured carbonyl compounds.

Alkyl levulinates (ALs) represent a family of bio-compounds derived from levulinic acid (LA), a platform chemical obtained from lignocellulosic biomass. Medium- and long-chain ALs (pentyl levulinate or longer) have shown potential as biofuel and fuel additives due to their relatively low oxygen content and resemblance to biodiesel. This study reports a fast and environmentally friendly method for synthesizing ALs via microwave (MW)-assisted LA esterification, laying emphasis on medium- and long-chain ALs. By combining p-toluenesulfonic acid (5 wt % loading) as catalyst and MW radiation as heating source for a short time (5 minutes), excellent yields of ALs (≥89 mol %) were achieved for a wide range of primary and secondary alcohols (2-10 carbons), overcoming the expected lower reactivity of long chain alcohols. Additionally, formation of undesired side products, such as dialkyl ethers or LA aldol condensation products, was significantly minimized. The feasibility of recovering the unreacted alcohol was successfully proved by simple distillation (88 wt % recovery). The green chemistry metrics assessment proved that this approach aligns with the green chemistry principles and the United Nations Sustainable Development Goals, offering a more sustainable pathway for biofuel and fuel additive production.

Within the framework of circular economy and process intensification, this work aimed to develop a two-way, microwave (MW)-assisted valorisation protocol for winemaking waste, namely grape stalk (GS), grape marc (GM) and exhausted grape marc (EGM). The first step evaluates the recovery of biologically active compounds (BACs). In this context, MW-assisted extraction (MAE) (200W, 100 ºC, 2h) demonstrated to be an intensified approach for processing EGM, enhancing the total antioxidant capacity (TAC) by up to 436% (TAC) compared to conventional soaking. Various polyphenols including flavonols (quercetin), flavanols (catequin, epicatechin), anthocyanins (procyanidins (B1-B7)), as well as glycosylated structures (i.e., kaempferol 3-O-glucoside), were detected by LC-MS analysis in this matrix. Simultaneously, the conversion to the bio-based chemical levulinic acid (LevA) was carried out. Considering the environmental factor involved in the dimension of sustainability, environmentally friendly practices were adopted, based on an aqueous single-phase without organic solvent, reusable catalysts as p-toluenesulfonic acid (p-TsA), and short reaction times (20min). LevA yield reached 33.09% molar from the extractives-free (EF)-EGM matrix, surpassing the 22.31% obtained from the untreated one. Nonetheless, GS exhibited higher efficiency, yielding up to 34.75 and 59.83% from the untreated- and EF-GS matrices, respectively.

This work outlines the first microwave (MW)-assisted protocol for the production of biofuel precursor furfural (FF) from the raw agricultural waste almond hull (AH), olive stone (OS), and the winemaking-derived grape stalk (GS), grape marc (GM) and exhausted grape marc (EGM) through a one-pot synthesis process. To enhance the overall yield, a catalytic process was firstly developed from xylose, major constituent of hemicellulose present in lignocellulosic biomass. This method afforded FF with 100 % selectivity, yielding over 85 % in isolated product when using H2SO4, as opposed to a 37 % yield with AlCl3·6H2O, at 150 °C in only 10 min. For both catalysts, the developed methodology was further validated, proving adaptable and efficient in producing the targeted FF from the aforementioned lignocellulosic raw materials. More specifically, the employment of AlCl3·6H2O resulted in the highest selectivity (up to 89 % from GM) and FF yield (42 % and 39 % molar from OS and AH, respectively), maintaining notable selectivity for the latter (61 and 48 % from AH and OS). At this regard, and considering the environmental factor of sustainability, it is important to point out the role of AlCl3·6H2O in contrast to H2SO4, thus mitigating detrimental substances. This study provides an important management of agricultural waste through sustainable practises for the development of potential bio-based chemicals, aligning with Green Chemistry and process intensification principles.

Educational buildings tend to fail in the contagion containment of airborne infectious diseases because of the high number of children, for several hours a day, inside enclosed environments that often have inadequate indoor air quality (IAQ) conditions. This study aimed to assess indoor environmental quality and test the effectiveness of portable air cleaners (PACs) in alleviating airborne particle levels in schools of Central–Southern Spain during the period of reopening after the lockdown due to the COVID-19 outbreak. To accomplish this, three sampling campaigns were organized from September to December 2020 to consistently monitor temperature and relative humidity, carbon dioxide, and particulate matter in nineteen classrooms (seven school buildings). Results showed that although the recommendation of maintaining the windows open throughout the day seemed to be effective in promoting, in general, proper ventilation conditions (based on CO2 levels). For the colder campaigns, this practice caused notorious thermal comfort impairment. In addition, a great number of the surveyed classrooms presented levels of PM2.5 and PM10, attributable to outdoor and indoor sources, which exceeded the current WHO guideline values. Moreover, considering the practice of having the windows opened, the installation of 1 unit of PACs per classroom was insufficient to ensure a reduction in particle concentration to safe levels. Importantly, it was also found that children of different ages at different education levels can be exposed to significantly different environmental conditions in their classrooms; thus, the corrective measures to employ in each individual educational setting should reflect the features and needs of the target space/building.

The use of glycol ethers as solvents and chemical intermediates has increased markedly in recent years. Once released into the atmosphere, they can undergo degradation processes mainly by reactions with the atmospheric oxidants that can have significant effects on the environment. In this work, the kinetic and products study of reactions of 2-isopropoxyethanol (2-iPE, (CH3)2CHOCH2CH2OH) with OH and NO3 radicals and Cl atoms have been performed using FTIR (Fourier Transform Infrared Spectroscopy) and GC -MS (Gas Chromatography/Mass Spectrometry) as detection techniques. The rate coefficients obtained were (units cm3 molecule- 1 s- 1): (2.18 +/- 0.15) x 10-10, (1.88 +/- 0.10) x 10-11 and (3.16 +/- 0.45) x 10-15 for Cl, OH & sdot; and NO3 & sdot; reactions, respectively. The kinetic results obtained have been included in comparison tables of the general reactivity of hydroxy ethers to extract conclusions of the atmospheric behaviour of this type of compounds. The main products detected and quantified have been isopropyl formate, formaldehyde, 2-hydroxyethyl acetate and, in the case of NO3 & sdot; reactions, nitrated compounds. A reaction mechanism has been proposed according to the reaction products obtained. The calculated lifetimes have been determined and Global Warming Potential (GWP) and Photochemical Ozone Creation Potential (POCPE) have been estimated, concluding, first, that the reaction with OH radicals is the main pathway of degradation of this and others glycol ethers in the atmosphere, second, that these compounds have GWP negligible and third, that they could have influence on ozone generation at local and regional level.

Abstract. 3,3-dimethylbutanal and 3,3-dimethylbutanone are carbonyl compounds that could play a key role in tropospheric chemistry. To better understand the effects of carbonyl compounds in the atmosphere, a kinetic and mechanistic study was conducted on the degradation of 3,3-dimethylbutanal and 3,3-dimethylbutanone with atmospheric oxidants (Cl atoms, OH and NO3 radical). The kinetic experiments were performed at 710 ± 30 Torr and at room temperature (298 ± 5 K) using a relative method and FTIR (Fourier Transform Infrared Spectroscopy) to monitor the reactions. The rate coefficients (k in units of cm3 molecule-1 s-1) obtained were: kCl+33DMbutanal = (1.27 ± 0.08) × 10-10, kCl+33DMbutanone = (4.22 ± 0.27) × 10-11, and kOH+33DMbutanone = (1.25 ± 0.05) × 10-12. The reaction products were also determined using FTIR and GC-MS (Gas Chromatography/Mass Spectrometry). The main products observed were short carbonyl compounds, including acetone, formaldehyde and 2,2-dimethylpropanal. In the presence of NO, nitrated compounds are formed, and in large NO2 concentrations peroxyacetyl nitrate (PAN) and peroxy-3,3-dimethylbutyryl nitrate were clearly identified. Other unquantified compounds were multifunctional organic compounds and organic acid of low volatility. Both 33DMbutanal and 33DMbutanone degrade rapidly near emission sources with minimal impact on radiative forcing. However, they may contribute to tropospheric ozone, with a range of POCPE of 15–69, and secondary organic aerosol formation, potentially worsening air quality and contributing to photochemical smog.

The characteristics and atmospheric reactivity of soot generated from an alternative fuel (soybean/palm biodiesel) have been investigated for the first time using a Knudsen flow reactor with a mass spectrometer as detector for gaseous species. The heterogeneous reactions with nitrogen dioxide (NO2) and trifluoroacetic acid (CF3COOH, TFA) have been investigated. Uptake coefficients calculated for the reaction of NO2 (gamma 0= (3.85 +/- 0.70) center dot 10-3) are one order of magnitude higher than the corresponding TFA reactions (gamma 0= (6.06 +/- 0.24) center dot 10-4). NO is the only product observed in the gas phase. Knudsen cell reactor has also been used in the characterization of chemical functions on the surface since NO2 can be used to identify reducing groups, while TFA is used to evaluate basic sites. Compared to other soot samples, biodiesel soot shows higher reactivity with NO2 which has implications in the regeneration process of the diesel particulate filter (DPF). IR bands attributable to polycyclic aromatic compounds have been observed by Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFTs). Bands of carbonyl compounds are also clearly observed. Thermogravimetric analysis/ differential scanning calorimetry-mass spectrometry (TGA/DSC-MS) is used to obtain more information about the volatile organic compounds present on the soot surface. Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS) analysis indicates a particle size in the range 14-40 nm and carbon as the major element (92 %). According to the obtained results, a mechanism of processes occurring at the surface has been proposed.

The circular economy considers waste to be a new raw material for the development of value-added products. In this context, agroindustrial lignocellulosic waste represents an outstanding source of new materials and platform chemicals, such as levulinic acid (LA). Herein we study the microwave (MW)-assisted acidic conversion of microcrystalline cellulose (MCC) into LA. The influence of acidic catalysts, inorganic salt addition and ball-milling pre-treatment of MCC on LA yield was assessed. Depolymerization and disruption of cellulose was monitored by FTIR, TGA and SEM, whereas the products formed were analyzed by HPLC and NMR spectroscopy. The parameters that afforded the highest LA yield (48 %, 100 % selectivity) were: ball-milling pre-treatment of MCC for 16 min at 600 rpm, followed by MW-assisted thermochemical treatment for 20 min at 190 °C, aqueous p-toluenesulfonic acid (p-TSA) 0.25 M as catalyst and saturation with KBr. These optimal conditions were further applied to a lignocellulosic feedstock, namely melon rind, to afford a 51 % yield of LA. These results corroborate the suitability of this method to obtain LA from agroindustrial wastes, in line with a circular economy-based approach.

It is well-documented that carbonyl compounds have adverse effects on human health. On the other hand, these oxygenated volatile organic compounds (OVOCs) are precursors of secondary pollutants such as tropospheric ozone or peroxy acetyl nitrate (PAN). In particular, formaldehyde, the simplest carbonyl, is the most abundant carbonyl in the air generated from the degradation of most volatile organic compounds (VOCs). This work presents for the first time the characterization and determination of levels of carbonyl compounds by passive monitoring performed from April–December 2021 in the city of Córdoba, Argentina, the second most populated Mediterranean city located in the center of the country. Annual concentrations, considering the 11 carbonyls measured, were in the range of 0.13–8.75 μgm−3. Formaldehyde and acetaldehyde were the carbonyls detected in the highest annual average concentrations of 4.44 ± 1.75 μgm−3 and 3.85 ± 1.44 μgm−3, respectively. These carbonyls represent a contribution of around 40–57% on total carbonyls measured. Statistical analysis to determine significant differences and Pearson correlations with the meteorological parameters were performed. Spring and summer were found to be the seasons with the highest carbonyl concentration linked to forest fire episodes, especially in springtime. The values for the C1/C2 and C2/C3 ratios showed that sources of carbonyl formation are anthropogenic. In addition, the prop-Equiv concentration was determined, where formaldehyde and acetaldehyde were the main producers of tropospheric ozone. The ozone formation potential (OFP) showed that spring and summer are the seasons where carbonyls contribute to the formation of tropospheric ozone.This study represents a first approach of the carbonyl concentration in the city and of the influence of meteorological parameters on the behavior of carbonyls.

Educational buildings tend to fail in contagion containment of airborne infectious diseases due to the high number of students, for several hours a day, inside enclosed environments that often have inadequate ventilation conditions. This study aimed to assess indoor environmental quality in preschool, primary and secondary schools of Central-Southern Spain during the period of reopening after the lockdown due to the COVID-19 outbreak. To accomplish this, 3 sampling campaigns were organized from September to December 2020 to consistently monitor temperature and relative humidity, carbon dioxide and particulate matter in 19 classrooms (7 school buildings). Results showed that although the recommendation of maintaining the windows opened throughout the school day seemed to be effective in promoting, in general, proper ventilation conditions (based on CO2 levels), for the colder campaigns, this practice caused notorious thermal comfort impairment. In addition, a great number of the surveyed classrooms presented levels of PM2.5 and PM10, attributable to outdoor and indoor sources, which exceeded the current WHO guideline values. And, considering the practice of having the windows opened, the installation of 1 unit of portable air cleaners (PACs) per classroom could not be enough to ensure the reduction of particle concentration to safe levels. Importantly, it was also found that children of different ages at different education levels can be exposed to significantly different environmental conditions in their classrooms, thus, the corrective measures to employ in each classroom/school should reflect the features and needs of the target space/building.

A qualitative and quantitative analysis of polycyclic aromatic compounds (PACs; polycyclic aromatic hydrocarbons (PAHs), oxygenated and nitrated polycyclic aromatic hydrocarbons (OPAHs and NPAHs)) present in the soluble organic fraction (SOF) of different soot samples has been carried out to determine the effect of sootgeneration conditions on their composition and health effects. The soot samples were generated using a diesel engine bench powered by diesel (DS) and biodiesel (BS) fuels under different combustion conditions. To optimize the procedure, a surrogate soot (Printex-U) and a certified reference material (SRM1650b) were also tested. Different extraction methods were used to extract the PAHs, OPAHs and NPAHs, and the Soxhlet technique using pyridine:acetic acid 1 % was found to be the most suitable procedure to extract the highest concentration (ng mg-1) and more types of PAHs and OPAHs from the soot. The results show that the PACs identified, and their concentrations, depend on the formation and collection conditions. The predominant compounds in all soot samples studied were fluorene (Flo), phenanthrene (Phe), fluoranthene (Fla), pyrene (Pyr), 9-fluorenone (9Flo) and 9,10-anthraquinone (9,10Anq). As such, the presence of these PACs in the atmosphere of urban and rural areas can mainly be attributed to the emissions from diesel vehicles. The percentage of OPAHs with respect to total PACs was highest in the soot generated from a biofuel. These oxidized compounds favor regeneration of the diesel particulate filter (DPF). The results also indicate that the carcinogenicity of the soot depends on the combustion conditions and type of fuel.

Fifteen carbonyl compounds were investigated in the living rooms and bedrooms of 25 university student flats in the urban area of Ciudad Real (Central Southern Spain) in wintertime. Carbonyls were sampled using Radiello (R) passive samplers refilled in the laboratory according to the method described in ISO 16000-3 Standard. The most abundant carbonyls in the living rooms and bedrooms were formaldehyde, acetone, acetaldehyde, hexaldehyde and butyraldehyde. The median concentration levels in the living rooms and bedrooms were: 28.6 and 34.2 mu g m(-3) for formaldehyde, 18.3 and 23.1 mu g m(-3) for acetone, 14.3 and 15.8 mu g m(-3) for acetaldehyde, 11.4 and 14.1 mu g m(-3) for hexaldehyde and 10.8 and 12.4 mu g m(-3) for butyraldehyde. The median concentration of formaldehyde, benzaldehyde, valeraldehyde and hexaldehyde was significantly higher in the bedrooms than in the living rooms. Indoor concentrations were significantly higher than outdoor concentrations for all carbonyl measured, indicating that sources in the indoor environment are prevailing in all flats. Principal component analysis, multiple linear regressions and Spearman correlation coefficients were used to investigate the origin, the indoor pollutants determinants and to establish common sources between carbonyls. Eight components were extracted from the application of PCA to the indoor and outdoor measurements accounting for 97.7% of the total variance. Formaldehyde, acetone, acetaldehyde and acrolein presented different indoor sources. In the multiple linear regression analysis, higher formaldehyde concentrations were found in those living rooms with wood floor and smoking was positively associated to acetone, pmpionaldehyde, benzaldehyde and isovaleraldehyde. Formaldehyde, acetaldehyde, acrolein, acetone, pmpionaldehyde and benzaldehyde concentrations were compared with relevant international guidelines, being their concentrations below recommended values except acrolein, where all measured flats exceeded the reference levels; it would be important to focus on the characterization of emission sources of acrolein in indoor air in order to minimise the exposure and health risk.

An experimental kinetic and mechanistic study of the reactions of 3-ethoxy-1-propanol (CH3CH2OCH2CH2CH2OH) with Cl atoms and OH and NO3 radicals has been carried out at room temperature and atmospheric pressure. FTIR (Fourier Transform Infrared Spectroscopy) and GC-MS (Gas Chromatography/Mass Spectrometry) were used as detection techniques. The rate coefficients were measured with a relative method (units cm3 molecule-1 s-1): (3.46 ± 0.22) × 10-10, (3.48 ± 0.19) × 10-11 and (1.08 ± 0.07) × 10-14 for Cl, OH and NO3 reactions, respectively. Qualitative and quantitative products analysis was carried out and formaldehyde, ethyl formate, ethyl 3-hydroxypropanoate and nitrated compounds were positively identified. A reaction mechanism has been proposed which involves attack by the oxidant at the methylene group in the α-position to an oxygen atom of the ether or alcohol groups, followed by the subsequent reactions of the resulting radicals. The tropospheric reactivity of 3-ethoxy-1-propanol (3E1P) has been compared with the reactivity of other hydroxy ethers to extend our knowledge of this type of compound. The atmospheric implications for 3E1P have been established by estimating parameters such as lifetimes, global warming potential (GWP) and the Photochemical Ozone Creation Potential (POCPE). According to the calculated tropospheric lifetimes, the dominant loss process of 3E1P is its daytime reaction with the OH radical and this has an impact on a local scale.

Carbonyls are important pollutants in urban atmospheres not only for their contribution to the formation of oxidants such as ozone and peroxyacetyl nitrate (PAN) but also for their adverse effects on human health. Formaldehyde is toxic and carcinogenic to humans. Seasonal variations of carbonyl compounds were investigated at two sampling sites in the atmosphere of Ciudad Real, a small city in central southern Spain. Air samples were collected for one year from February 2015 to February 2016 using passive samplers. Between the eleven carbonyls identified formaldehyde, acetone and acetaldehyde were the most abundant carbonyls accounting for 34%, 20% and 14%, respectively of the total concentration of carbonyls. The total concentration of carbonyls detected ranged from 2.35 to 22.46 ,ig -3 with an average of 6.89 +/- 4.7 ,ig m-3. A comprehensive statistical analysis has been carried out in order to determine the differences in the carbonyl concentrations between both sampling points and the main emission sources taking into account the sample size. The seasonal trend observed for formaldehyde, acetaldehyde and acetone implies the presence of significant photochemical reactions in summer to produce carbonyls. The C1/C2 ratios, Spearmans correlation coefficients, the propene-equivalent and the total ozone formation potentials were also calculated in this study.