A reliable method to determine airborne microplastics using quantum cascade laser infrared spectrometry.

The number of studies dealing with airborne microplastics (MPs) is increasing but sampling and sample treatment are not standardized, yet. Here, a fast and reliable method to characterize MPs is presented. It involves the study of two passive sampling devices to collect atmospheric bulk deposition (wet and dry deposition) and three digestion methods (two alkaline-oxidative and an oxidative) to treat the samples. The alkaline-oxidative method based on KOH and NaClO was selected for a mild organic matrix digestion. In addition, some operational parameters of a high-throughput quantum cascade laser-based infrared device (LDIR) were optimized: an effective automatic tiered approach to differentiate fibres from particles (>90 % success in validation) and a criterion to establish positive matches when comparing an unknown spectrum against the spectral database (proposed match index > 0.85). The procedural analytical recoveries were very good for particles (82-90 %) and slightly lower for fibres (62-73 %). Finally, the amount and type of MPs deposited at a sub-urban area NW Spain were evaluated. Most common polymers were Polyethylene (PE), Polypropylene (PP) and Polyethylene terephthalate (PET). The deposition rates ranged 98-1220 MP/m2/day, ca. 1.7 % of the total collected particles. More than 50 % of the total MPs deposited were in the 20-50 µm size range, whereas fibres were mostly in the 50-500 µm size range.

Inhalation bioaccessibility estimation of polycyclic aromatic hydrocarbons from atmospheric particulate matter (PM10): Influence of PM10 composition and health risk assessment.

Polycyclic aromatic hydrocarbons (PAHs) inhalation bioaccessibility was assessed in 65 atmospheric particulate matter samples (PM10) collected at an Atlantic coastal European urban site. The proposed method consists on a physiologically based extraction (PBET) by using Gamble's solution followed by a vortex assisted liquid-liquid micro-extraction (VALLME) and quantification by high performance liquid chromatography with fluorescence detection (HPLC-FLD). The use of a micro-extraction technique combined with FLD detection, provides a simple, fast, sensitive, accurate and low-cost methodology to PAHs quantification in bioaccessible fractions. Accuracy of the bioaccessibility study was assessed by means of a mass balance approaches using a PM10 filter and a certified reference material (ERM-CZ100). High-moderate inhalation bioaccessibilities were found for phenanthrene (Phe), fluoranthene (Ft) and pyrene (Pyr) (average ratios in the 52-65% range); while dibenz (a,h)anthracene (DBahA), indeno (1,2,3-cd)pyrene (IP) and benzo (g,h,i)perylene (BghiP) were observed to be less bioaccessibles (average ratios in the 11-14% range). Relationship between PM10 composition (major ions, trace metals, equivalent black carbon (eBC) and UV-absorbing particulate matter (UVPM)) and PAHs bioaccessibility ratios was also assessed. Principal Component Analysis (PCA) showed that PAHs bioaccessibility percentage is dependent on anthropogenic (eBC, UVPM and Sb concentrations) and marine sources of PM10. Predicted PAHs bioaccessibilities after applying a multiple linear regression model based on marine and anthropogenic source of PM10 could also be established. Health risk assessment of target PM10-associated PAHs via inhalation was assessed considering bioaccessibility concentrations by using hazard index (HI) and BaP equivalent concentration (BaPeq) approaches, suggesting no carcinogenic risk in the area during the sampling campaign.

The loleva oral and written language test: psychometric properties.

LolEva, a computerized test for ages 3 to 8 years old, identifies issues in the development of skills that can lead to reading acquisition difficulties. Its structure captures two distinct areas: Phonological Awareness (PA, seven subtests: rhyme, identification-addition-omission of syllable and phoneme at the beginning and end of a word), and Initial Reading Competence (IRC, six subtests: reading uppercase and lowercase letters, simple words, complex words, and pseudowords, and word segmentation). With results collected in a sample of 341 children with the target ages and attending public or private schools, the alpha coefficient was .94 for PA, and .92 for IRC. Factor analysis indicated three factors are present (performance on PA and IRC, and word reading times), together explaining 75% of variance, providing evidence to support the construct validity of the test. On the other hand, analysis of variance showed significant differences for year-in-school variable for PA subscale, F(4, 336) = 191.385, p < .001, η2 p = .695, 1-ß = 1.0, as well as for IRC subscale, both in number of correct answers, which increased as schooling progressed: F(4, 336) = 197.897, p < .001, η2 p = .702, 1-ß = 1.0, and task completion time, which decreased as education progressed: F(4, 335) = 47.048, p < .001, η2 p = .360, 1-ß = 1.0. Also, PA repeated measures analysis revealed that was easier Identification than Addition and Omission , F(2, 672) = 31.639, p < .001, η2 p = .086, 1-ß = 1.0, syllable-related tasks than phoneme-related task, F(1, 336) = 229.000, p < .001, η2 p = .405, 1-ß = 1.0, and syllable or phoneme at the end of the word than at the beginning, F(1, 336) = 59.201, p < .001, η2 p = .150, 1-ß = 1.0. Moreover, all items were examined and indexes of difficulty and discrimination were obtained.

The loleva oral and written language test: psychometric properties

LolEva, a computerized test for ages 3 to 8 years old, identifies issues in the development of skills that can lead to reading acquisition difficulties. Its structure captures two distinct areas: Phonological Awareness (PA, seven subtests: rhyme, identification-addition-omission of syllable and phoneme at the beginning and end of a word), and Initial Reading Competence (IRC, six subtests: reading uppercase and lowercase letters, simple words, complex words, and pseudowords, and word segmentation). With results collected in a sample of 341 children with the target ages and attending public or private schools, the alpha coefficient was .94 for PA, and .92 for IRC. Factor analysis indicated three factors are present (performance on PA and IRC, and word reading times), together explaining 75% of variance, providing evidence to support the construct validity of the test. On the other hand, analysis of variance showed significant differences for year-in-school variable for PA subscale, F(4, 336) = 191.385, p < .001, η2 p = .695, 1-β = 1.0, as well as for IRC subscale, both in number of correct answers, which increased as schooling progressed: F(4, 336) = 197.897, p < .001, η2 p = .702, 1-β = 1.0, and task completion time, which decreased as education progressed: F(4, 335) = 47.048, p < .001, η2 p = .360, 1-β = 1.0. Also, PA repeated measures analysis revealed that was easier Identification than Addition and Omission , F(2, 672) = 31.639, p < .001, η2 p = .086, 1-β = 1.0, syllable-related tasks than phoneme-related task, F(1, 336) = 229.000, p < .001, η2 p = .405, 1-β = 1.0, and syllable or phoneme at the end of the word than at the beginning, F(1, 336) = 59.201, p < .001, η2 p = .150, 1-β = 1.0. Moreover, all items were examined and indexes of difficulty and discrimination were obtained (AU)

No disponible