1-Nitropyrene, a well known mutagenic and highly possible carcinogenic polycyclic aromatic hydrocarbon (PAH), is the most abundant nitrated PAH emitted in diesel engine exhaust and also found in coal combustion fly ash, cooked meat products and kerosene heaters emissions. It has been found at concentrations in the pg/m3 range in the air over urban and suburban areas and thus it has potential for human exposure through inhalation. The transformations in the atmosphere of these ubiquitous pollutants is still debated and a possible environmental fate for nitroPAHs is through their photodecomposition on particulate matter. Although some photodegradation rates and products have been determined in solution studies no reactive intermediates have been characterized to support the proposed mechanisms. Similar studies on these molecules adsorbed on substrates, which resemble their state on the environment, have been much more limited. In this work we are proposing to utilize techniques, we have already developed in our laboratory, to study the photochemical transformation mechanisms of nitropyrenes adsorbed into models of atmospheric aerosols in order to provide some understanding of the fate of these contaminants in the atmosphere. As we have found with PAHs, phototransformations at the solid/air interface can have a significant impact in controlling their residence time in the environment and are thus important in the evaluation of the potential risks of these contaminants, as well as in the possible design of systems for their removal. In order to understand the phototransformation mechanism of adsorbed nitropyrenes we will: (1) examine the interactions of the adsorbed molecules with the different substrates and establish the nature of the participating excited states by absorption and fluorescence techniques, (2) determine relative photodegradation rates, (3) identify intermediate species and triplet states by time resolved diffuse reflectance laser spectroscopy and electron spin resonance and (4) identify the stable products and compare them with those found in the solution photochemistry. A fundamental aim of this proposal is to study the effect of some chemical and physical properties of the adsorbent such as composition, water content, presence of coadsorbed gases, average pore diameter and surface coverage on the photophysical and photochemical processes of the adsorbed nitropyrenes. Also, the resulting excited states and reactive intermediates from the laser irradiation in polar and non polar solvents that mimic the aerosol will be characterized by laser flash transient spectroscopy. The accomplishment of this last aim is of most importance since nitroPAHs can be also found in the organic liquid like-core of combustion aerosols.
| Ramírez-Camejo, Luis A; Maldonado-Morales, Génesis; Bayman, Paul (2017) Differential Microbial Diversity in Drosophila melanogaster: Are Fruit Flies Potential Vectors of Opportunistic Pathogens? Int J Microbiol 2017:8526385 |
| Morales-Rivera, Keyla F; Piñero Cruz, Dalice M; Prieto, Jose A (2017) Crystal structure of (-)-(S)-4-[(2S,3S,4S,Z)-3-hydroxy-4-methyl-hept-5-en-2-yl]-1,3-dioxolan-2-one. Acta Crystallogr E Crystallogr Commun 73:1070-1072 |
| García-Arriaga, Marilyn; Acosta-Santiago, Maxier; Cruz, Antony et al. (2017) Probing the Limits of Supramolecular G-Quadruplexes Using Atomistic Molecular Dynamics Simulations. Inorganica Chim Acta 468:209-222 |
| Huang, Qing; Quiñones, Edwin (2016) A spectroscopic method to determine the activity of the restriction endonuclease EcoRV that involves a single reaction. Anal Biochem 497:103-5 |
| Mège, Pascal; Schizas, Nikolaos V; Reyes, Joselyd García et al. (2015) Genetic seascape of the threatened Caribbean elkhorn coral, Acropora palmata, on the Puerto Rico Shelf. Mar Ecol (Berl) 36:195-209 |
| Morales-Rivera, Amarilys; Hernández-Burgos, Mayté M; Martínez-Rivera, Arlene et al. (2014) Anxiolytic effects of oxytocin in cue-induced cocaine seeking behavior in rats. Psychopharmacology (Berl) 231:4145-55 |
| Ramírez-Camejo, Luis A; Torres-Ocampo, Ana P; Agosto-Rivera, José L et al. (2014) An opportunistic human pathogen on the fly: strains of Aspergillus flavus vary in virulence in Drosophila melanogaster. Med Mycol 52:211-9 |
| Martínez-Rivera, Arlene; Rodríguez-Borrero, Enrique; Matías-Alemán, María et al. (2013) Metabotropic glutamate receptor 5 within nucleus accumbens shell modulates environment-elicited cocaine conditioning expression. Pharmacol Biochem Behav 110:154-60 |
| Galindo-Cardona, Alberto; Acevedo-Gonzalez, Jenny P; Rivera-Marchand, Bert et al. (2013) Genetic structure of the gentle Africanized honey bee population (gAHB) in Puerto Rico. BMC Genet 14:65 |
| Santiago-Rodriguez, Tasha M; Rivera, Jessica I; Coradin, Mariel et al. (2013) Antibiotic-resistance and virulence genes in Enterococcus isolated from tropical recreational waters. J Water Health 11:387-96 |
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