First multi-compartment approach to microplastics in an urbanized estuary of Argentina: The case of Magallana gigas.

This study assesses MP in water, sediment, gills, and digestive tract of the oyster Magallana gigas in three Bahía Blanca estuary sites, Argentina, using, Pollution Load Index (PLI) and SEM/EDX (Scanning Electron Microscopy with Energy-dispersive X-ray spectroscopy) and FTIR (Fourier-transform infrared spectroscopy) techniques. A total of 51 MPs were detected in water (mean: 16 items L) and 126 in sediments (mean: 1399 items Kg) with no significant differences between sites. In oysters, 186 MPs were found, with no significant differences in the MPs load between gills (mean: 2.

Low prevalence of microplastic contamination in the bottom sediments and deep-sea waters of the Bransfield strait, Antarctica.

Despite the remoteness of the Antarctic continent and Southern Ocean, microplastic (MPs) contamination has been evidenced in recent years. However, the deep-sea compartments of the Southern Ocean are yet to be investigated. In the present study, we conducted a baseline MP assessment of the deep-sea waters and bottom sediments of the Bransfield Strait, Antarctica.

Influence of the geographic location and house characteristics on the concentration of microplastics in indoor dust.

Microplastics (MPs) are known for their ubiquity, having been detected in virtually any environmental compartment. However, indoor MPs concentrations are poorly studied despite being closely related to human exposure. The present study aims to evaluate the presence of MPs in settled atmospheric dust in 60 houses distributed in 12 districts of the metropolitan city of Lima, Peru, and investigate the influence of their geographical location and house characteristics.

Plastic and paint debris in marine protected areas of Peru.

Contamination with anthropogenic debris, such as plastic and paint particles, has been widely investigated in the global marine environment. However, there is a lack of information regarding their presence in marine protected areas (MPAs). In the present study, the abundance, distribution, and chemical characteristics of microplastics (MPs; <5 mm), mesoplastics (MePs; 5-25 mm), and paint particles were investigated in multiple environmental compartments of two MPAs from Peru.

Microplastics distribution in river side bars: The combined effects of water level and wind intensity.

Rivers are the main pathway for microplastics (MP) transport toward the ocean. However, the understanding of the processes involved in the deposition and mobilization of MP in rivers, specifically in sediment side bars (SB), remains very limited. The objectives of this study were: (i) to examine the effect of hydrometric fluctuations and wind intensity on the distribution of microplastics (MP < 5 mm) in the SB of large river (the Paraná River), (ii) to determine the characteristics of MP to infer their origin and fate, and (iii) to discuss potential similarities or differences between MP suspended in the water column and MP found in sediment.

Microplastics in commercial seafood: Pleoticus muelleri as a case study in an estuarine environment highly affected by human pressure (Southwestern Atlantic).

Plastic pollution in seafood has become a worldwide safety concern due to its possible harm to humans. This is the first study which has investigated the length-weight relationship, growth patterns and condition factor, together with the concentrations of microplastics (MPs) and mesoplastics (MesoPs) in Pleoticus muelleri from the Bahia Blanca Estuary (BBE), Argentina. Forty-nine individuals were collected from three sampling stations in the BBE, and each abdominal muscle with the gastrointestinal tract was analyzed.

Thermal Decomposition of CFC(O)OONO ( = 2, 3, 4).

The atmospheric degradation of molecules containing the CFC(O) moiety, such as perfluoroaldehydes CFC(O)H ( = 2-4) formed in the degradation of telomeric alcohols, could lead to the formation of perfluoroacyl peroxynitrates CFC(O)OONO. The thermal decomposition of the CFC(O)OONO family ( = 2, 3, 4) was investigated by infrared spectroscopy and computational models. Each peroxynitrate synthesis was performed through the photolysis of gas mixtures of the corresponding perfluoroaldehyde, chlorine, nitrogen dioxide, and oxygen.

Atmospheric Photo-oxidation of Diethyl Carbonate: Kinetics, Products, and Reaction Mechanism.

The rate coefficient for the gas phase of diethyl carbonate with chlorine atoms has been determined at 298 K using a relative method, employing ethyl formate and ethyl acetate as reference compounds. The experimental value, (1.0 ± 0.

Photo-oxidation of Dimethyl Malonate Initiated by Chlorine Atoms in Gas Phase: Kinetics and Mechanism.

The rate coefficient for the gas-phase reaction of chlorine atoms with dimethyl malonate (DMM, CHOC(O)CHC(O)OCH) was determined at 298 K using relative methods giving a value of (3.8 ± 0.4) × 10, cm molecule s).

Photooxidation of Di-tert-butyl Malonate in the Presence and Absence of Nitrogen Dioxide.

The rate constant for the reaction of di-tert-butyl malonate (DTBM) with chlorine atoms in the gas phase was measured using cyclohexane and pentane as references. The measurements lead to a value of (1.5 ± 0.

Photolysis of n-Propyl Formate in the Presence of O2 and NO2: Peroxy Formyl Propyl Nitrate CH3CH2CH2OC(O)OONO2 Synthesis and Characterization.

The photo-oxidation of n-propyl formate (initiated by chlorine atoms) was studied in the presence of NO2, and the products were identified. The Cl atom attack to the molecule occurs in four sites, leading to the formation of formic acid, carbon dioxide, dicarbonylic products, nitrates, peroxy propionyl nitrate (CH3CH2C(O)OONO2, PPN), and a new peroxynitrate, peroxy formyl propyl nitrate (CH3CH2CH2OC(O)OONO2, PFPN). To characterize bulk quantities of the PFPN, its synthesis was carried out by the photolysis of mixtures of CH3CH2CH2OC(O)H, NO2, Cl2, and O2.

Thermal stability of peroxy acyl nitrates formed in the oxidation of C(x)F(2x+1)CH2C(O)H (x = 1,6) in the presence of NO2.

The formation of C(x)F(2x+1)CH2C(O)OONO2 (x = 1,6) from the photooxidation of C(x)F(2x+1)CH2C(O)H (x = 1,6) in the presence of NO2 was investigated. The infrared spectrum of C6F13CH2C(O)OONO2 is reported for the first time, and thermal stability for both peroxynitrates at 295 K and 9.0 mbar is informed.

Mechanism of photo-oxidation of heptafluorobutyric anhydride in the presence of NO2. Synthesis and characterization of heptafluoropropyl peroxynitrate, CF3CF2CF2OONO2.

The photolysis of heptafluorobutyric anhydride at 254 nm in the presence of NO(2) and O(2) has been studied. It leads to the formation of CF(3)CF(2)CF(2)OONO(2), CF(3)CF(2)OONO(2), and CF(2)O as the only fluorine-containing carbonaceous products. The formation of the new heptafluoropropyl peroxynitrate (HFPN, CF(3)CF(2)CF(2)OONO(2)), as one of the main products, is a consequence of the formation of CF(3)CF(2)CF(2)OO(•) radicals followed by the reaction with NO(2).

Atmospheric chemistry of perfluoroaldehydes (CxF2x+1CHO) and fluorotelomer aldehydes (CxF2x+1CH2CHO): quantification of the important role of photolysis.

The UV absorption spectra of CF(3)CHO, C(2)F(5)CHO, C(3)F(7)CHO, C(4)F(9)CHO, CF(3)CH(2)CHO, and C(6)F(13)CH(2)CHO were recorded over the range 225-400 nm at 249-297 K. C(x)F(2)(x)(+1)CHO and C(x)F(2)(x)(+1)CH(2)CHO have broad absorption features centered at 300-310 and 290-300 nm, respectively. The strength of the absorption increases with the size of the C(x)F(2)(x)(+1) group.

Synthesis and characterization of trifluoromethyl fluoroformyl peroxycarbonate, CF3OC(O)OOC(O)F.

The synthesis of CF(3)OC(O)OOC(O)F is accomplished by the photolysis of a mixture of (CF(3)CO)(2)O, FC(O)C(O)F, CO, and O(2) at -15 degrees C using a low-pressure mercury lamp. The new peroxide is obtained in pure form in low yield after repeated trap-to-trap condensation and is characterized by NMR, IR, Raman, and UV spectroscopy. Geometrical parameters were studied by ab initio methods [B3LYP/6-311+G(d)].