Assessment of the NO distribution and relationship with traffic load in the Caribbean coastal city.

NO 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/m, with a maximum and minimum value of 70.27 and 0.57 μg/m, respectively. NO 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 NO distributions. It can provide scientific evidence for the relationship between NO and traffic, beneficial for developing the targeted policies and measures to reduce NO pollution levels in hot spots. This research may subsidize knowledge to serve as a tool for environmental and health authorities.