NO2 ambient concentrations were measured in a coastal Caribbean city. Barranquilla is a Caribbean city located in the North of Colombia that has approximately 1.200.000 inhabitants and possesses a warm, humid climate. In order to obtain the concentration of the contaminant in an adequate resolution, 137 Passive diffusion tubes from Gradko© were installed. Tubes prepared with 20% Triethanolamine/De-ionised water were located at the roadside between 1 and 5 m from the kerb edge. The sampling period was two weeks, from 3/16/2019 to 3/30/2019. Samples were analyzed on the UV CARY1 spectrophotometer by Gradko©. Results showed an average of 19.92 ± 11.50 μg/m3, with a maximum and minimum value of 70.27 and 0.57 μg/m3, respectively. NO2 correlation with load traffic load was higher than with maximum traffic. The expected results include the analysis of the areas of the city with high concentrations of this pollutant that exceed the limit values established by the WHO in six (6) points; however, they never exceed the local legal limit for annual exposure, which is significantly less restrictive. Overall, the multiregression analysis is a very effective method to enrich the understanding of NO2 distributions. It can provide scientific evidence for the relationship between NO2 and traffic, beneficial for developing the targeted policies and measures to reduce NO2 pollution levels in hot spots. This research may subsidize knowledge to serve as a tool for environmental and health authorities.

Despite their significant impact on public health, antibiotic resistance and size distributions of airborne viable bacteria in indoor environments in neonatal intensive care units (NICU) remain understudied. Therefore, the objective of this study was to assess the antibiotic resistance of airborne viable bacteria for different sizes (0.65–7 µm) in private-style and public-style neonatal intensive care units (NICU). Airborne bacteria concentrations were assessed by a six-stage Andersen impactor, operating at 28.3 L/min. Public-style NICU revealed higher concentrations of airborne viable bacteria (53.00 to 214.37 CFU/m³) than private-style NICU (151.94–466.43), indicating a possible threat to health. In the public-style NICU, Staphylococcus was the highest bacterial genera identified in the present study, were Staphylococcus saprophyticus and Staphylococcus epidermidis predominated, especially in the second bronchi and alveoli size ranges. Alloiococcus otitidis, Bacillus subtiles, Bacillus thuringiensis, Kocuria rosea, and Pseudomonas pseudoalcaligene, were identified in the alveoli size range. In NICU#2, eight species were identified in the alveoli size range: Bacillus cereus, Bacillus subtilis, Bacillus thuringiensis, Eikenella corrodens, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus gordoni. Multi-drug-resistant organisms (MDROs) were found in both of the NICUs. Bacillus cereus strains were resistant to Ampicillin, Cefoxitin, Ceftaroline, and Penicillin G. Staphylococcus cohnii ssp. cohnii was resistant in parallel to ampicillin and G penicillin. Staphylococcus saprophyticus strains were resistant to Ampicillin, Penicillin G, Oxaxilin, and Erythromycin. Results may indicate a potential threat to human health due to the airborne bacteria concentration and their antibiotic resistance ability. The results may provide evidence for the need of interventions to reduce indoor airborne particle concentrations and their transfer to premature infants with underdeveloped immune systems, even though protocols for visitors and cleaning are well-established.

Efficient use of environmental nucleic acids (eNAs) in freshwater biodiversity monitoring requires understanding their degradation and detectability in interconnected ecosystems. We employed a novel field‐scale assay to compare environmental DNA (eDNA) and environmental RNA (eRNA) decay rates and detectability across four genetic markers (16S, 18S, COI and LDHA) in connected and isolated 1000‐L mesocosms containing natural planktonic assemblages. This design provides ecologically relevant and complex settings to assess how connectivity influences the detectability of eNA over time. Isolated and head mesocosms were spiked with eNAs from cultured Daphnia pulex , absent from the water source, while downstream mesocosms received eNAs via unidirectional water transfers. Using digital PCR (dPCR), we captured fine‐scale temporal patterns across mitochondrial and nuclear markers and transcript types (mRNA and rRNA), an approach rarely combined in previous research. eRNA degraded significantly faster than eDNA across markers and mesocosm types. Among RNA types, mRNA (COI, LDHA) degraded faster than rRNA (16S, 18S). eRNA followed a uniform monophasic decay pattern, whereas eDNA displayed biphasic decay for nuclear markers and monophasic decay for mitochondrial markers. eNA decay rates in this field‐relevant mesocosm network exceeded those from laboratory scale. While decay rates remained consistent across networks, detectability declined with dilution. Even after a 10,000‐fold dilution, both eNAs were detected in terminal mesocosms, demonstrating effective transport across the network. Although RNA degrades rapidly, high detectability was achieved across diverse dilutions using dPCR, highlighting eRNA's potential for detecting active biological communities in freshwater systems.