A conventional thermoelectric plant (TP) in the sandy bar of the Tampamachoco Lagoon (Gulf of Mexico slope) emits particulate matter (PM) transporting trace metals that affect a mangrove forest. Wind transports the emission plume from north to south in the northerly wind season (NWS); the dry season (DS) showed calm periods. We analyzed whether PM_2.5 and PM₁₀ emissions from the TP and their trace metals impact Rhizophora mangle leaves. The experimental design included three sampling sites along the main lagoon axis (north to south) during the NWS and DS. Mangrove leaves were collected; PM was obtained with a cascade impactor and trace elements were analyzed by atomic absorption spectrophotometry. Leaves were measured and tested for metal and chlorophyll content, and for metal detection with SEM-EDX. Calm periods in the DS promote high atmospheric PM concentrations. Wet deposition in the NWS caused the highest trace metal deposition on mangrove leaves. A north-to-south gradient was identified on the mangrove forest, being the south site of the lagoon where lower chlorophyll and leaf area, higher stomatal width and density, and higher Cd concentrations were recorded. The morpho-physiological modifications observed on mangrove leaves affect functions such as photosynthesis and gas exchange.

Heavy metal pollution in aquatic ecosystems is a critical environmental issue worldwide. In these ecosystems, the seston adsorbs heavy metals from the water and introduces them into the food web, causing potential environmental and health risks. This study analyses how heavy metals (Cd, Hg, Cr, Cu, Pb, Fe, and Mn) are distributed in the water and seston of the Tampamachoco Lagoon, an ecosystem affected by pollution from a thermoelectric plant and by hydrometeorological variability, both of which influence their concentrations. The relationships among metal distribution, physicochemical variables, and the influence of plant emissions in three seasons (rainy, northerly windstorms, and dry) were analyzed. The metal concentrations in seston (Fe > Mn > Pb > Cu > Cr > Hg) were up to four times higher than in the water column (Fe > Mn > Cr > Cd > Pb > Cu > Hg), emphasizing the key role of particulate matter in metal transport and bioavailability. Particularly, the Cd concentrations exceeded WHO thresholds by 527.6% in the water column during the rainy season, while Hg and Pb exceeded the thresholds of the Mexican criteria for the protection of marine aquatic life by 4.05% and 41.6%, respectively. Principal Component Analyses revealed distinct spatiotemporal distribution patterns for metals in water and seston, reflecting the combined effects of natural variability and anthropogenic inputs. The strong association between metals and seston indicates continued contamination and potential risks to aquatic ecosystems. These findings highlight the environmental impact of metals on seston and the need for monitoring to assess aquatic ecosystems’ health. Our results highlight the importance of understanding how metals are distributed between seston and water, and how climate variability affects pollutant redistribution patterns. We propose that water quality regulations need to be rethought and redirected towards the achievement of new strategic objectives that truly integrate the different pollutant sources whose final destination is water bodies, so as to protect and conserve biodiversity and aquatic ecosystems.

The Tula industrial complex, located in Hidalgo, is a major contributor to air pollution in Mexico, particularly NO₂ and SO₂. This study used the mobile mini-DOAS technique to quantify the emissions of these gases over a period of seven measurement campaigns conducted from 2022 to 2024. The measurement campaigns carried out in summer and winter recorded the highest emission fluxes, which correlated with a higher electricity demand. The variations observed were associated with fluctuations in industrial activity and meteorological conditions. The results for 2022 and 2023 showed a decrease in emissions compared to previous studies, which could be attributed to the recent introduction of natural gas for electricity generation. However, a significant increase was observed in 2024, which was correlated with an increase in activity at the Miguel Hidalgo Refinery. The emissions quantified with DOAS were used to implement the AERMOD model, which allowed the dispersion of NO₂ and SO₂ to be assessed. This model was implemented in a 15 km radius around the Tula industrial complex, considering meteorological and topographical variations in the region. The dispersion of pollutants was mainly directed to the west and south of the industrial complex. The results indicate that the concentrations of NO₂ and SO₂ exceeded the permissible limits established by official Mexican standards in several of the measurement campaigns. While all of the identified communities were affected by the emissions, Bomintzha, La Amistad, and San Miguel Vindho were the most affected due to their proximity to the complex, altitude, and prevailing wind direction.

Sulfur dioxide (SO2) and nitrogen dioxide (NO2) emissions to the atmosphere released by three power plants located in Baja California Sur, Mexico, were quantified using mini-DOAS instruments. In La Paz municipality, the Punta Prieta Power Plant released 65.67±77.80 tons/day of SO2 and 6.66±12.57 tons/day of NO2, while the Internal Combustion Power Plant Baja California Sur released 44.72±5.37 tons/day of SO2 and 8.27±1.72 tons/day of NO2. In the municipality of Comondú, the Internal Combustion Power Plant Agustín Olachea released 18.17±8.00 tons/day of SO2 and 0.67±0.32 tons/day of NO2. Comparisons of our measurements with emissions inventories and annual operating reports for the Punta Prieta Power Plant are in good agreement, however, we found differences for the Internal Combustion Power Plant Baja California Sur and the Internal Combustion Power Plant Agustín Olachea. Our analyses show that the Punta Prieta Power Plant has increased its SO2 and NO2 emissions between 2013 and 2022. The Internal Combustion Power Plant Baja California Sur has increased its SO2 emissions, while NO2 emissions have declined between 2013 and 2022. The Internal Combustion Power Plant Agustín Olachea has been decreasing its SO2 and NO2 emissions between 2010 and 2022, albeit in 2018, there was a considerable increase of NO2 emissions.