Estimation of atmospheric emissions from maritime activity in the Veracruz port, Mexico.

The port of Veracruz is one of the most important ports in Mexico and is currently in the process of a major expansion. The new port area, "Bahía Norte", will be three times larger than the current port, "Bahía Sur". Atmospheric emissions from the Veracruz port system, specifically from the engines of ships undergoing maneuvering and hotelling operations, were determined on a daily basis from 2018 to 2019 for sulfur dioxide (SO2), nitrogen oxides (NOx), carbon monoxide (CO), non-methane volatile organic compounds (NMVOC), particles (PM), particles smaller than 10 micrometers (PM10), particles smaller than 2.5 micrometers (PM2.5) and carbon dioxide (CO2). A bottom-up method was used to estimate the atmospheric emissions, based on official data from the European Environment Agency. The method utilizes on technical information on the type of ship, the power of the main engine (ME) and auxiliary engine (AE), load factor, specific fuel consumption, and spent time in the maneuvering and hotelling phases. The highest atmospheric emissions occurred in the hotelling phase. For the "Bahía Sur" emissions (Mg/year) were 328.6, 993.3, 122.3, 30.6, 22.9, 19.1, 18.5 and 52,723.4 for SO2, NOx, CO, NMVOC, PM, PM10, PM2.5 and CO2, respectively. For "Bahía Norte" the corresponding emissions were 43.9, 132.7, 16.3, 4.1, 3.1, 2.5, 2.3 and 7,040.9, also in the hotelling phase. The average combined of the atmospheric emissions from maneuvering and hotelling phases (Mg/year) were 1.18, 3.49, 0.44, 0.13, 0.09, 0.08, 0.07, and 189.23 for SO2, NOx, CO, NMVOC, PM, PM10, PM2.5 and CO2, respectively. During the 2018-2019 period of the study the "Bahía Sur" contributed ~87% and the "Bahía Norte" ~13% of the atmospheric emissions.Implications: The atmospheric emissions reported in this study can be used for the simulation of air quality considering environmental or photochemical pollution models, since atmospheric emissions are reported on a daily basis and compliance with air quality can be monitored considering the reference-concentration established by the Official Mexican Standards in order to propose prevention, minimization and control measures. In addition, the analysis of the information that was carried out in this study may be applied to other port systems in Mexico that are located on the Pacific coast and the Gulf-Caribbean.

Sulfur and nitrogen compounds in wet atmospheric deposition on the coast of the Gulf of Mexico from 2003 to 2015.

The Gulf of Mexico region has important sources of acid rain precursors, located in all of the countries; U.S., Mexico and Cuba, and so it is very important to study the chemical composition of the wet atmospheric deposition in all coastal areas. For many years along the U.S. Gulf Coast, acidic precipitation has been measured. Measurements along the Mexican Gulf Coast were begun in 2003. The aim of this study was to evaluate pH, sulfate, nitrate and ammonium concentrations in wet atmospheric deposition, collected daily from 2003 to 2015 at La Mancha (LM), Veracruz and compare the values with the National Atmospheric Deposition Program (NADP) sampling sites located along the U.S. coast of the Gulf of Mexico. The annual Volume Weighted Mean (VWM) pH in wet deposition at La Mancha site ranged from 4.81 to 5.40, which is similar to the U.S. Gulf sites. Additionally, the annual VWM SO42- concentration was from 15 to 31 µeq/L, which is higher than the U.S. sites. Annual VWM NO3- concentrations were from of 3.5 to 15 µeq/L, which is lower than all the U.S. sites. At the Mexican site, the SO42-/NO3- ratio was 4.90 and higher than all of the U.S. sites, which were between 1.03 and 2.38. For LM, the median NH4+/NO3- ratio was 0.77, similar to the Florida sites (0.53-0.91), and below the values measured for Louisiana and Texas (1.07-1.5). The Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) was applied in order to identify the emission sources for the pollutants seen at LM. Trajectories showed an important transport to LM from the East (open water) during the rainy season. The region located East of La Mancha shows offshore petroleum operations as sources of acid rain precursors and deposition of acidifying and nitrogen containing compounds. It is important to consider the sulfur dioxide emission sources in the Mexico Gulf region, and to extend the atmospheric deposition sampling to other sites along the Mexican Gulf coast and Cuba.