Groundwater is used by almost two billion people worldwide. Microplastic (MP) pollution is found in every environment; however, studies on groundwater MP pollution are scarce. Therefore, the present study evaluated the amount and types of microplastics in ten rural wells where drinking water is extracted for two rural Mexican communities. In each well two samples were taken per month for 10 months; one to evaluate MP air deposition, of surface water (first 5 cm of depth) and another of water without contact with air (3 to 5 m depth). There were no differences between the communities in the average number of microplastics in both types of samples. MP measured 2,100 to 4,400 μm in length. 100% of the MP found were fragments. In both communities, color abundance coincided: black > white > blue > green > gray. The polymers identified were nylon, HDPE, PP, PS, PVC, and PET. There were no differences in the abundance of MP by air deposition, between dry and rainy seasons; however, there was a highest abundance (p<0.05) in the dry season (0.41 MP/L) in deep water, which indicates that rainwater dilutes this type of pollution (0.25 MP/L). Ixtacuixtla and Xocoyucan, Mexico, do not adequately manage their urban solid wastes and wastewater, generating plastic pollution in the region's groundwater, which represents a risk to human health.

Heatwaves pose a growing threat to populations, with their intensity and frequency rising due to recent climate change. A combined vulnerability index, based on multiple indicators of exposure, sensitivity, and adaptive capacity, can produce effective vulnerability maps that visualize and identify areas at risk from environmental change. This study aims to create a composite heatwave vulnerability index (CHVI) map by assessing 20 indicators for each municipality in Mexico. Principal component analysis was used to assign weights to each parameter, minimizing overlapping and exaggeration. Geospatial analysis of the data offered valuable insights into the statistical relationships within each indicator and across states. The CHVI map shows that Tabasco (94.63%), Ciudad de Mexico (80.03%), and Campeche (71.83%) have the highest proportions of land in the very high vulnerability category. The calculated exposure, sensitivity, adaptive capacity, and CHVI for each municipality help identify affected areas and populations within each vulnerability class. Population density significantly influences CHVI scores in built-up areas, while socio-economic status, infrastructure, and green spaces lessen the impact of heatwaves. Integrating remote sensing and geographic information system technologies enhances understanding and supports the development of mitigation strategies that government and non-governmental agencies should implement to better manage risks.

Mangroves are vital coastal ecosystems that provide essential services like storm protection, nutrient cycling, and carbon sequestration. However, global warming, rising salinity, and extreme weather events threaten their survival. Mexico, home to 5% of the world's mangroves, faces increasing risks from these stressors. This study analyses the decadal dynamics (2015-2024) of the mangrove ecosystem in the Mar Muerto lagoon, Southern Mexico, aiming to assess the interactions between mangrove health and key environmental factors to identify vulnerability zones. Utilizing Google Earth Engine (GEE) and remote sensing data (Landsat-8, Sentinel-1, Sentinel-2, HYCOM, and NOAA AVHRR), it tracked changes in mangrove cover, Above-Ground Biomass (AGB), Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), Sea Surface Salinity (SSS), and Sea Surface Temperature (SST). The findings indicate a decline in mangrove coverage from 76.23% to 75.91% and a deterioration in vegetation health, with maximum AGB dropping from 36.6 in 2017 to 21.9 in 2024, and peak NDVI decreasing from 0.81 to 0.48. SST rose from 23.8 degrees C to 34.2 degrees C, and SSS increased from 32.6 ps mu to 37.2 ps mu. Tropical storms in 2017 and 2020 were significant contributors to short-term changes. The Dominance Analysis (DA) had predicted SST (83.28%) and SSS (75.99%) as the significant influential factors for mangrove degradation. The fuzzy overlay analysis revealed that 33.20% of the study area is now classified as "highly" or "extremely vulnerable," particularly in the northwestern and northeastern lagoon rims. This research highlights that rising sea temperatures and salinity levels adversely affect mangrove health, exacerbating water stress and biomass loss. The vulnerability map generated provides a crucial framework for conservationists and policymakers to prioritize management and sustain this fragile coastal habitat.

El agua subterránea es utilizada por casi dos mil millones de personas en el mundo. La contaminación por microplásticos (MP) está presente en todos los ambientes, pero los estudios sobre MP en aguas subterráneas son escasos; por ello, este estudio evaluó la cantidad y tipos de MP presentes en diez pozos rurales de donde se extrae agua potable para dos comunidades rurales mexicanas. En cada pozo se tomaron dos muestras al mes por 10 meses: una para evaluar deposición aérea de MP, de agua superficial (primeros 5 cm de profundidad), y otra de agua sin contacto con el aire (de 3 a 5 m de profundidad). No hubo diferencias entre las comunidades en el número promedio de MP para ambos tipos de muestras. Los MP midieron entre 2 100 y 4 400 μm de longitud. El 100 % de los MP encontrados fueron fragmentos. En ambas comunidades la abundancia de colores coincidió: negro > blanco > azul > verde > gris. Los polímeros identificados fueron nailon, HDPE, PP, PS, PVC y PET. No hubo diferencias en la abundancia de MP por deposición aérea en secas y lluvias; sin embargo, en aguas profundas se presentó mayor abundancia (p < 0.05) en la época de secas (0.41 MP/l), lo que indica que el agua de lluvia diluye este tipo de contaminación (0.25 MP/l). Ixtacuixtla y Xocoyucan, México, no gestionan adecuadamente sus residuos sólidos urbanos y aguas residuales, lo que genera contaminación plástica en los mantos acuíferos de la región, representando un riesgo para la salud humana.

This study quantifies microplastics collected from two different feeding zones of whale shark (Rhincodon typus) from Bahia de los Angeles (BLA) and Bahia de La Paz (BLP) from Gulf of California using the Manta trawl method. Higher prevalence in BLP (287 items) than BLA (169 items) is dominated by fibers and fragments. Spatial distribution in BLP revealed MPs was (mean value 0.65 items/m3) among the five transect sites, whereas in BLA is 12.54 items/m3. Observed variability in this study was resulted from sampling technique that included depth, sampling time, speed, which is also found significant through the statistical analysis. Dominating morphotypes were fibers and fragments and surface features showed a strong thermo-oxidative weathering process with severe mechanical weathering process. Detected polymers of PP, PE, HDPE, PS, LDPE, PA also showed multiple origins from preexisting anthropogenic pressures. Though this study doesn't involve any biological samples, yet the current study emphasizes the importance of continuous monitoring of MPs in Gulf of California, where ingestion of MPs will potentially affect the long time survival.

The study compared the pollution level of 16 priority polycyclic aromatic hydrocarbons (PAHs) in the superficial sediments of the low stretch of the Hooghly River, LSHR, with that of the Sundarbans wetland, SW. Mean total PAHs levels were concerning, with mean individual loads exceeding legal limits and literature references, indicating a worsening scenario compared to past surveys. The mean of ∑PAHs in LSHR was significantly higher than in the SW, 2,106 ng/g vs. 1179 ng/g, with a hot spot of 13,785 ng/g. Thus, it is especially in the river location that contaminants accumulate with five compounds concentrating at higher rates compared to the natural area, 103

REEs in wetland sediments from the Oaxaca coast in southern Mexico were used to infer the sources and depositional processes by involving both the geochemical characteristics and geostatistical approaches. Statistically strong positive correlation between REEs confirmed similar origin in all the cores. Light REEs (LREEs) represented >84 % of ΣREE mean concentrations varies between 47.95 (C1) and 87.84 mg/kg (C3). NASC normalized La/Yb, La/Sm, and Gd/Yb ratios indicated more Middle REEs in sediments of C1 and C3 cores and more LREEs in C2 and C4 cores indicating the different mineralogical associations. The absence of Ce anomaly and significant negative Eu anomalies is due to the presence of Fe/Mn oxy-hydroxide, humid subtropical conditions and a strong leaching process. Comparison with REE and possible sources revealed contributions from the Sierra Madre del Sur Mountains with major influences of igneous rocks such as andesite, basaltic andesite, dacite, rhyolitic tuff and rhyolitic vitrophyre.

Category 3 Hurricane John on September 24, 2024, with strong winds (> 190 km/h) and heavy rainfall-induced flooding, caused devastation to the coastal municipalities of Guerrero, Mexico. Sentinel-2A images were used to identify the impacts on vegetation canopy, land use/land cover (LULC) characteristics, and moisture levels in vegetation. An increase in dead plants of 90.2 km2 and a decrease in healthy plants by 265.43 km2 were observed using the Normalized Difference Vegetation Index. Most of the agricultural land, barren land, and low-lying pastureland were flooded (724.8 km2), and high impacts were observed in the agricultural fields along the river Ometepec, particularly in the Las Vigas and Florencio Villarreal municipalities within the study area. The strong winds damaged the deciduous forest at the Veladero Nacional Park and the coniferous forest at Cerro El Guajolote, which experienced high water stress, according to the Normalized Difference Moisture Index. Thus, this study will provide valuable understandings to coastal managers and policymakers, facilitating the formulation of effective action plans for coastal zone management. It will also support and enhance natural resilience and promote sustainable development for the future.

The present study investigated concentrations of metals (Cu, Zn, Fe, Mn, Ni, Pb, and Cd) in paddy soils and rice tissues of nine different widely cultivated indica rice varieties in Salem district, India. The order of DTPA soil available metal contents (mg kg(-1)) were Fe (33.50) > Mn (8.86) > Cu (2.58) > Pb (1.99) > Zn (1.67) > Ni (1.48) > Cd (0.13). Pollution load index (PLI) levels for Cd (1.28) were 'moderately polluted', contamination factor (CF) and enrichment factor (EF) values for all metals showed 'medium contamination' and 'less enrichment' except for Cu and Pb. Ecological risk factor (ERF) and potential ecological risk index (PRI) values of Cd (31.94 and 287.50) showed 'moderate risk' and 'strong ecological risk'. Bio-accumulation factor (BAF) levels of Cd (48.12) and Pb (27.89) are classified as 'high concentrators'. Translocation factor (TF) values of Pb (2.9), Cd (2.5) and Ni (1.7) were greater than one for roots to plants. Children had higher target hazard quotient (THQ) and hazard index (HI) values for Cd, Pb and Ni than adults. Principal component analysis (PCA) revealed with all parameters that they fell within the two primary factors 1 and 2, with an eigenvalue of 4.69 (33.52% variation) and 3.73 (26.66% variation), respectively. However, cluster analysis (CA) revealed three distinct groups between the metals studied. Although the soil metal contents were within the permissible levels, the grain Cd (6.07 mg kg(-1)), Pb (56.20 mg kg(-1)), and Fe (116.11 mg kg(-1)) contents in all the rice varieties exceeded the prescribed limits of 0.4, 0.2, and 15 mg kg(-1), respectively. Our findings will provide important data for metal enrichment in soils to implement more effective measures to reduce the contamination of metals in paddy fields.

Mexico City is the most populated metropolitan city in the Western Hemisphere and the largest Spanish-speaking city in the world, with urban settlements sprawling to accommodate the growing population. Urbanization is changing climatic patterns in our environment by increasing the temperature regime and decreasing the available green spaces. In this quest, the suitability of implementing green rooftops is analyzed using a Geographic Information System (GIS) and Analytical Hierarchical Process (AHP). Initially, eight criteria were selected based on the literature, such as Land Surface Temperature (LST), Build-up area, total population, Normalized Difference Vegetation Index (NDVI), road density, Ozone concentration, atmospheric Carbon monoxide and Nitrogen dioxide level. Next, the weightage of each criterion was calculated based on expert opinion from different institutes. Lastly, the suitability score was estimated by merging the criteria layers to identify the appropriate buildings. The results highlighted the importance of the LST (34.31 %), Build-up area (19.70 %) and total population (15.12 %). Approximately 13 % (177.34 sq.km), 28 % (418.75 sq.km), 20 % (301.25 sq.km), 28 % (421.45 sq.km), 11 % (164.86 sq.km) of Mexico City has been classified as very high suitability, high suitability, medium suitability, low suitability and very low suitability, respectively, for green rooftops installation. Analysis of the existing green roofs suggests the capability to trap 60.81 tons of CO2 annually. The identified building tops using the suitability score reveal the presence of 4,23,451 m2 of roofs, which can capture 10,93,229.86 kgCO2/ m2. Urban planners can use the identified priority roofs from this study to reduce the regional thermal environment and improve urban resilience.

Mercury, cadmium, and selenium contents were quantified in sharks Mustelus henlei, M. californicus, Sphyna zygaena, and Isurus oxyrinchus, which represent important fishery resources in the western coast of Baja California Sur, Mexico. Sample compliance estimations with Mexican dietary standards and human health risks, according to provisional tolerable weekly intake (PTWI), were provided for critical population sectors, including young children, pregnant/nursing women, and adults. The estimated weekly intake was limited to 1.52 kg of M. californicus, 1.35 kg of S. zygaena, 0.5 kg of I. oxyrinchus, and 2.42 kg of M. henlei. Likewise, the Hazard Quotient (HQ) <1 and Hazard Index (THI) <1 were within safe limits; therefore, there will be no chronic noncarcinogenic health hazards in the short or long term. Carcinogenic risk is a concern mainly for children, and the most appropriate approach is for children to consume no >0.5 kg of shark meat per week.

This study presents the first data on a 2018–2021 campaign to monitor polycyclic aromatic hydrocarbon levels, PAHs, in the final stretch of the Hooghly River in West Bengal, India. The range of sedimentary PAHs was 0–47,366 ng/g, higher than the ranges given by the literature for comparable study areas. The assay reveals an outstanding level of PAHs contamination in the fine sediments of the Hooghly River and Sundarban wetland, where the dominance of 4–6 ring PAHs was 83% of the total. The diagnostic ratios based on molecular ratios of PAHs show that the pollution comes mainly from the combustion of petroleum. The ratio of anthracene relative to anthracene plus phenanthrene, ANT/(ANT + PHE), was >0.30, which is higher than the reference discriminant ratio of >0.10, suggesting that PAHs were from the combustion source. In the meantime, fluoranthene over the sum of fluoranthene plus pyrene, FLT/(FLT + PYR), was >0.5 and indicated coal combustion, in agreement with the literature. The mean level of carcinogenic hydrocarbons was at 18% of the total measured PAH, with a peak of 91%, revealing significant potential risk for humans and ecosystems. The toxicity equivalence factors, TEF, of the individual PAHs and the total BaP equivalent toxicity, TEQ, were adopted as a comparison reference of sediment quality. At most sites, toxic effect ranges were classified as high and very high. The results of this research call for public authorities to remedy a situation of severe ecological risk.

Groundwater chemistry of the two different seasons collected between 2020-2021 from the coastal areas of Nagapattinam, Mayiladuthurai and Karaikal in Tamil Nadu state of southeast India were evaluated for seawater intrusion into coastal aquifers. Groundwater types, its classification was evaluated to know the extension of seawater intrusions into coastal aquifers using the Groundwater Quality Indices (GQI) such as GQIPiper(mix), GQIPiper(dom), fsea, GQIfsea and GQISWI. Piper diagram grouped most samples (GQIPiper(mix) and GQIPiper(dom)) in domain-II, representing Na-Cl water type, followed by domain-IV, indicating mixed Ca-Mg-Cl water for both the seasons. As measured by the saltwater Intrusion as Groundwater Quality Index (GQISWI), about 62.5% and 37.5% of the pre-monsoon samples showed low saltwater intrusion and moderate seawater intrusion, respectively. In the post-monsoon samples, the low saltwater intrusion increased to around 82.5% and the moderate seawater intrusion decreased to 17.5% of the groundwater samples. The GIS framework was used to display the geographical distribution of groundwater types as well as the delineation of vulnerable zones from seawater intrusion.

Trace metal enrichments in soil and native maize ( Zea mays L.) in Tehuacán-Cuicatlán Biosphere Reserve was analyzed due to its direct relation with food security. pH and organic matter (OM) content were obtained in soil, concentrations trace metals were determined in agricultural soil and plant collected from 10 maize plots using ICP-OES. Soil contamination was evaluated using contamination factor (CF), enrichment factor (EF), and geoaccumulation index (Igeo), plant contamination was evaluated using bioconcentration factor (BCF). Soils characteristics indicates higher pH values (8–8.9), which favors metal’s translocation from soil > plant. Mean concentrations (mg/kg) of Cr (soil: 0.02–0.04; plant: 0–0.01), Fe (soil: 0.77–1.17; plant: 0–0.40), and Zn (soil: 0–0.01; plant: 0–0.01) were within the FAO/WHO and Mexican government soil standards. CF values were classified as “low contamination,” however, Cd, Mn, and Fe indicates “medium contamination” in maize crops. EF values of metals in farmlands were recorded as “lower enrichment values.” BCF showed accumulation of trace metals (especially Fe and Mn) in roots, which acts as a binding element for other trace metals, where OM is low. Overall results in this study suggest that the selected trace metals in the agricultural soils and plant have no appreciable threat to food safety.

The purpose of this study was to analyze the effect of uronic acid (UA) content of Opuntia Ficus-indica (OFI) mucilages on the removal process of heavy metals (HM) present in water samples (WS) from the Yautepec River, Mexico. For this, mucilages from nopals with different maturation ages were extracted (20-35, 80-100 and 550-600 days, namely, M1, M2 and M3, respectively); and the UA content was determined by UV-vis spectrophotometry. Furthermore, ten WS were collected in different fluvial sites of the river; and the pH, electrical conductivity (EC) and turbidity were determined in situ; and the concentration of HM (cooper, cadmium, chromium, nickel, lead, zinc, iron, manganese, and arsenic) was quantified by atomic absorption spectrometry. Subsequently, the WS were used to evaluate the effect of UA content of M1, M2, and M3 on the removal of HM by the jar method; then, the pH, EC, turbidity, and total percentage concentration of HM removed (%TCHR) were determined. Also, the functional groups of OFI mucilages were identified by Fourier transform infrared spectroscopy (FTIR) before and after the HM removal process. The results show that the UA content increased with the maturation age of the nopals, and M3 exhibited the highest content with 2.22 mg/mL; the WS showed a high content of iron, manganese, and lead with 1546, 209 and 80.8 mu g/L, respectively. After the HM removal process, the %TCHR was determined, and it was found that M3 achieved the highest percentage with 90.3 %. The concentration of UA in the mucilage was a factor that influenced in the removal of HM, as well as the initial pH conditions and the initial concentration of HM. Finally, the spectra of FTIR showed typical bands of pectic polysaccharides such as carboxyl, carbonyl, and hydroxyl, which interacted with HM by electrostatic interactions.

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Metal concentrations in beaches of major coastal cities is directly identified based on the enrichment pattern of bioavailable metals in sediments. The main objective of the study is to know the present level of metal enrichments in beach sediments of Santa Elena Province in Ecuador. Sediment beach quality was assessed in five tourist beach zones (n = 52) by analyzing the bioavailable trace metal concentration. Distribution pattern of trace metals indicates Cd, Co, Pb is on higher side exceeding the UCC. Geochemical indices calculations (Geoaccumulation index, Enrichment factor, Degree of contamination) and ecological risk indices (Hazard quotient, potential risk index, pollution load index) indicates that Cd has the high degree of enrichment level (Cd ≥ 32) followed by Co, Pb and As posing adverse ecological risk (RI ˃ 600). Sediment quality assessment results reveals that the sediments were very unsafe in nature with a probability level of 11 to 21% being toxic. Statistical correlation suggests that carbonates vs Cu, Ni, Co, Pb, Cd (r2 = 0.51 to 0.98) were the main controlling factor for the metal behavior in sediments. Overall results reveals that the toxic elements were derived locally accompanied by anthropogenic influences enriching the geochemical elements affecting the beach quality in the Santa Elena coast region and for future coastal management programs.

Microplastics (MPs) pose a significant and increasing threat globally, with plastics accounting for around 60–80% of marine trash. Plastic particles with a size of 5000 µm or less are referred to as microplastics (MPs). These MPs can enter the marine organisms either through their diet or by trophic transfer. This can potentially expose people to these particles. According to the literature, around 21.9% of fish, 18.4% of seabirds, 11.7% of arthropods, and 7.8% of molluscs in marine systems are at risk from plastic pollution. The LATAM region experiences significant MP contamination that primarily originates from wastewater treatment plants, industrial effluents, maritime sources, and the decomposition of macro–mesoplastics. The majority of research conducted in the LATAM region focuses on MPs in natural habitats, specifically examining the presence of MPs in biota (such as fish, mussels, squids, turtles, and even insects) and sediments. In order to conduct a thorough analysis of the sources and spread of microplastics (MPs) in marine organisms, we conducted a comprehensive assessment of the available literature on microplastic research in Latin American countries. The objective was to evaluate the origin, destinations, and pathways via which MPs are transferred. An assessment of the prevalence of microplastics (MPs) in marine organisms would yield significant insights into the potential health hazards posed by plastic pollution to humans.

Rivers directly support the development of a region/country; however, globally, these aquatic regions are impacted by recent human activity. During a rainfall event, we monitored the baseline information on the spatial variability of microplastics (MPs) in the Cauvery River in South India. Forty surface water samples from two selected sites were collected between 27 September and 16 October 2022 during the commencement of monsoon which indicates 69 and 43 pieces L−1 of MPs, respectively. SEM and FTIR analysis on the surface morphotypes (cracks, grooves, pits) and elemental (Si, Ti, Mg, Cu, Ta) presence/adsorption of these elements’ (in particle) surface indicates surface deformation of fibers, which is mainly due to external input/forces. Fragments of polymers establish a high degree of deterioration indicating its longer trajectory in the aquatic environment. The origin of extended fiber ranges between 631.65 and 5639.9 µm, which is being associated with laundry activities for textiles, household items, and fishing gear. Toxicity and ecological risk assessment suggest significant degree of weathered MPs due to photo-oxidation process and aging owing to exposition of intense UV light. This research serves as a strong illustration of the multiple pressures from urban development and cultural practices that have a bigger influence on the river ecosystem like Cauvery River and regular monitoring.