Identifying pollution dynamics using discrete Fourier transform: From an urban-rural river, Central Mexico.

The quality of life and human survival is dependent on sustainable development and sanitation of water bodies in an environment. The present research focuses on cyclicity data of more than 750,000 records of parameters associated with the water quality from a rural-urban river monitoring stations in real-time from River Atoyac in Central Mexico. The events detected in the instrumental records correlated with 2528 laboratory and instrumental determinations. The 64 polluting compounds were grouped into inorganic compounds (metals and metalloids) and organic compounds (pesticides, herbicides, hydrocarbons). Metal associated compounds were grouped along mechanical, pharmaceutical and textile industries which associates itself with the entry of polluting components. The cyclicity of the events was detected through Discrete Fourier Transformation time series analysis identifying the predominant events in each station. These highlight the events at 23-26 h corresponding to a circadian pattern of the metabolism of the city. Likewise, pollution signals were detected at 3.3, 5.5, and 12-14 h, associated with discharges from economic activities. Multivariate statistical techniques were used to identify the circadian extremes of a regionalized cycle of polluting compounds in each of the stations. The results of this research allow pollution prevention using a mathematical analysis of time series of different quality parameters collected at monitoring stations in real-time as a tool for predicting polluting events. The DFT analysis makes it possible to prevent polluting events in different bodies of water, allowing to support the development of public policies based on the supervision and control of pollution.

Four-decade (1977-2017) landscape tale of tourist reservoir hotspot El Piñol-Guatapé, Colombia.

Efficient management of land use/land cover (LULC) features is vital for a balanced sustainable ecosystem. Thus, this work aimed to document the LULC changes in the less studied El Peñol-Guatapé reservoir, Antioquia, Colombia, especially in the reservoir area due to the construction of a hydro-electric power plant. For this study, Landsat images of 1977, 1986, 1997, and 2017 were used and the results indicated an increase in the settlement area and road networks by 0.10 and 0.60%, respectively, while during 1986 to 2017, cropland, plantation, dense forest, and open forest areas presented an increase of 0.52, 1.06, 2.87 and 2.61%, respectively. However, the marshy vegetation, scrub forest and fallow land decreased to - 0.51, - 3.79 and - 4.29%, respectively, in the same period. The water body before and after the completion of reservoir project denoted an increase from 13.1 km2 in 1977 to 45.7 km2 in 1986. This study provides a first-hand report on LULC dynamics in this tourism dominated municipalities that will serve as a reference for ecosystem management to reconcile the conflicts between different LULC classes in ecologically enriched regions.

Response orientation modulates pitch-space relationships: the ROMPR effect.

Congruency between auditory and visuospatial stimuli has been previously shown to affect responses to multisensory stimulus pairs, and congruency between stimuli and response devices may play a role in response speed and accuracy. Across two experiments, we tested whether the accuracy and speed of pitch judgments were affected by a congruent or incongruent paired visual stimulus, and whether the relationship was modulated by response orientation. In Experiment 1, participants using a vertically (transversely) oriented keyboard demonstrated a large crossmodal vertical effect, but a minimal crossmodal horizontal effect. In contrast, Experiment 2 used a horizontally oriented keyboard, while also examining whether musical training impacts pitch judgments. As in the first experiment, we found an effect of response mapping on pitch judgments; these results suggest that vertical visual stimuli are processed automatically, while the effects of horizontal visual stimuli are decisional and require a compatible response orientation. Based on these findings, we propose an effect we call the ROMPR effect: response orientation modulates pitch-space relationships. Unexpectedly, non-musicians demonstrated significant ROMPR effects while trained musicians did not. We suggest that non-musicians are more likely to use visual information when making spatial location judgments of pitch: unlike musicians, they have not been trained to rely exclusively on auditory information during pitch processing. We also discuss alternative explanations of the data: namely, that there is a need to disambiguate audiovisual congruency from visual-response congruency with modulations of experimental design.

Evaluating the mental health and well-being of Canadian healthcare workers during the COVID-19 outbreak.

During the COVID-19 pandemic, healthcare systems have been under extreme levels of stress due to increases in patient distress and patient deaths. While additional research and public health funding initiatives can alleviate these systemic issues, it is also important to consider the ongoing mental health and well-being of professionals working in healthcare. By surveying healthcare workers working in Canada during the COVID-19 pandemic, we found that there was an elevated level of depressive symptomatology in that population. We also found that when employees were provided with accurate and timely information about the pandemic, and additional protective measures in the workplace, they were less likely to report negative effects on well-being. We recommend that healthcare employers take these steps, as well as providing targeted mental health interventions, in order to maintain the mental health of their employees, which in turn will provide better healthcare at the population level.

Coastline variability of several Latin American cities alongside Pacific Ocean due to the unusual "Sea Swell" events of 2015.

This study aims to report the short-term coastline dynamics and inundation limits of coastal cities along the Eastern Pacific due to the sea swell events that occurred during April to May 2015. The multi-temporal satellite datasets from Landsat such as Enhanced Thematic Mapper (L7 ETM+) and Operational Land Imager/Thermal Infrared Sensor (L8 OLI/TIRS) of different periods before and after the swell events were used to identify the shoreline changes. The satellite images were pre-processed using ERDAS imagine 9.2, and the coastline was digitized in ArcGIS 10.4.1 for ten cities spread across from Mexico to Chile (in Pacific coast) using the spectral water indices, and the shoreline change rate and erosion/accretion pattern at each transect were estimated using the statistical parameters embedded in Digital Shoreline Analysis System (DSAS). The maximum erosion and accretion were observed in El Salvador (268 m) and Huatulco (Mexico) (115 m), respectively. Likewise, the maximum inundation was observed in El Salvador with 268 m and Acapulco (Mexico) with 254 m, and the tide gauge data suggest a possible relation to the bathymetry and the geomorphological conditions of the coast. Overall, the results indicate that the Eastern Pacific Ocean side sea swell events has led to extreme coastal flooding in recent years due to the increase in the mean sea level and the unpredictable variation in El Niño/Southern Oscillation events. Graphical abstract.

Evaluation of climate change adaptation in the energy generation sector in Colombia via a composite index - A monitoring tool for government policies and actions.

The aim of the article is to evaluate the national adaptation to climate change in the energy generation sector in Colombia via a composite index. To build an index, a framework by stages is used, which includes the definition of the main concepts that supports the measurements; the selection of the relevant indicators using a subject matter experts; standardization of the indicators using a mathematic formula regarding the relationship between the variables that represent the adaptation to climate change; and establishment of the weights using an analytic hierarchical process of paired comparisons and the aggregation of indicators to obtain the following three sub-indexes: reactive adaptation, wherein the replacement of hydraulic energy by thermal energy is evaluated; anticipatory adaptation, which measures the gap between the generation of total energy and the demand of the national energy system; and planned adaptation, which considers indicators such as the sectoral plan for adapting to climate change, the law of alternative energies, and the generation of alternative energies as a percentage of generation capacity. By adding these sub-indices, the climate change adaptation index (CCAI) is obtained. The results of CCAI show that progress was made from a reactive adaptation scenario in which the system vulnerability was high to an anticipatory adaptation scenario wherein the vulnerability was average, indicating that the foundations for this sector to build a planned adaptation are currently being laid.

Trace elements in marine organisms of Magdalena Bay, Pacific Coast of Mexico: Bioaccumulation in a pristine environment.

Trace element (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd, As, Hg) concentrations were assessed in marine organisms (n = 52) sampled from the Magdalena Bay lagoon complex in Baja California Sur, Mexico, a pristine marine environment. The overall trend of metal concentrations (dry weight) in the organisms was found to be Fe > Zn > Cd > Cu > Mn > Pb > As > Hg > Ni > Cr > Co. Bivalve mollusks (53.83 mg kg-1) contained twofold higher levels of metals than the finfishes (20.77 mg kg-1). Calculated BioConcentration Factor (BCF) values showed that dissolved Mn is readily bioavailable to the organisms, whereas Biota Sediment Accumulation Factor (BSAF) indicated high values for Zn, Cu and Cd. Cd and As levels were observed to be increasing with the trophic levels. Toxic elements, namely Pb, Cd and As in the studied fish species were found to be higher than the values recommended for human seafood consumption. The study provides a comprehensive baseline report on trace element bioaccumulation in several marine organisms that will aid in developing effective conservation strategies of the highly biodiverse lagoon complex.

Heavy metals in the volcanic and peri-urban terrain watershed of the River Yautepec, Mexico.

Thirty-four water samples were collected all along the course of River Yautepec, Morelos State, Central Mexico, in three different zones based on the physical and anthropogenic setting. In situ measurements of physical characteristics (temperature, pH, conductivity, and turbidity) were also performed at each sampling station. Likewise, total/dissolved metal concentrations (Fe, Mn, Cr, Cu, Ni, Pb, Zn, Cd, As, and Pb) were determined using an atomic absorption spectrophotometer. Located in a peri-urban and volcanic zone of Central Mexico, the river system presented impacts of both natural and anthropogenic activities. Results revealed differences in pH values (6.7-8.23) in all the three zones probably due to the influences of volcanic ash and local geological formations, whereas conductivity levels (635-1098 µs/cm) were high indicating the effect of agricultural and industrial activities. The relative order of the concentrations of metals in both the total and dissolved fractions was observed to be in the following order: zone I, Fe > Zn > Mn > Cu > Pb > Ni > Cr > As > Cd > Hg; zone II, Fe > Zn > Pb > Ni > Mn > Cu > Cr > Cd > As > Hg; zone III, Fe > Pb > Zn > Mn > Ni > Cu > As > Cd > Cr > Hg. Calculated heavy metal evaluation index (HEI) values indicated less contamination. However, concentrations of Fe and Pb were observed to be higher than the permissible limits set forth by the Mexican government for human consumption. Henceforth, the prerequisite for maintaining and improving the health of a river system depends on continuous long-term monitoring of the dynamic ecosystem for sustainable management.

Mercury levels in human population from a mining district in Western Colombia.

A biomonitoring study was carried out to examine the adverse impacts of total mercury in the blood (HgB), urine (HgU) and human scalp hair (HgH) on the residents of a mining district in Colombia. Representative biological samples (scalp hair, urine and blood) were collected from volunteered participants (n=63) to estimate the exposure levels of THg using a Direct mercury analyzer. The geometric mean of THg concentrations in the hair, urine and blood of males were 15.98µg/g, 23.89µg/L and 11.29µg/L respectively, whereas the females presented values of 8.55µg/g, 5.37µg/L and 8.80µg/L. Chronic urinary Hg (HgU) levels observed in male workers (32.53µg/L) are attributed to their long termed exposures to inorganic and metallic mercury from gold panning activities. On an average, the levels of THg are increasing from blood (10.05µg/L) to hair (12.27µg/g) to urine (14.63µg/L). Significant positive correlation was found between hair and blood urinary levels in both male and female individuals. Thus the present biomonitoring investigation to evaluate the Hg levels and associated health issues would positively form a framework for further developmental plans and policies in building an ecofriendly ecosystem.

Effects of vocal training in a musicophile with congenital amusia.

Congenital amusia is a condition in which an individual suffers from a deficit of musical pitch perception and production. Individuals suffering from congenital amusia generally tend to abstain from musical activities. Here, we present the unique case of Tim Falconer, a self-described musicophile who also suffers from congenital amusia. We describe and assess Tim's attempts to train himself out of amusia through a self-imposed 18-month program of formal vocal training and practice. We tested Tim with respect to music perception and vocal production across seven sessions including pre- and post-training assessments. We also obtained diffusion-weighted images of his brain to assess connectivity between auditory and motor planning areas via the arcuate fasciculus (AF). Tim's behavioral and brain data were compared to that of normal and amusic controls. While Tim showed temporary gains in his singing ability, he did not reach normal levels, and these gains faded when he was not engaged in regular lessons and practice. Tim did show some sustained gains with respect to the perception of musical rhythm and meter. We propose that Tim's lack of improvement in pitch perception and production tasks is due to long-standing and likely irreversible reduction in connectivity along the AF fiber tract.

Bioaccumulation of metals in fish species from water and sediments in macrotidal Ennore creek, Chennai, SE coast of India: A metropolitan city effect.

Accumulation of trace metals (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd) were investigated in water, sediment (n=20) along with six fish of diverse feeding guilds (Sillago sihama, Liza parsia, Etroplus suratensis, Oreochromis mossambicus, Arius parkii and Gerres oyena) from the Ennore creek, northern part of Chennai metropolitan megacity, southeast coast of India. Dissolved trace metals (DTMs) in surface water samples and total trace metals (TTMs) in surface sediments (top 0-10cm) indicate that concentration pattern of metals was higher in the discharge point of the river/channels entering the main creek. The maximum mean values of DTMs exhibited the following decreasing order (expressed in µg/L): Fe (1698)>Mn (24)>Zn (14.50)>Pb (13.89)>Ni (6.73)>Cu (3.53)>Co (3.04)>Cr (2.01) whereas the trend is somewhat different in sediments (µgg(-1)): Fe (4300)>Mn (640)>Cr (383)>Zn (155)>Cu (102)>Ni (35)>Pb (32)>Cd (0.51) are mainly due to the industrial complexes right on the banks of the river/channels. Species-specific heterogeneous patterns of tissue metal loads were apparent and the overall metal enrichment exhibited the following decreasing order (expressed in µgg(-1)): Cu (7.33)>Fe (6.53)>Zn (4.91)>Cr (1.67)>Pb (1.33)>Ni (0.44)>Mn (0.43)>Co (0.36)>Cd (0.11). This indicates that metals are absorbed onto the different organs, which is also endorsed by the calculated values of bioaccumulation factor (BAFs) (avg. muscle 117, gill 126, liver 123, intestine 118) in fishes. The high calculated biota sediment accumulation factor (BSAF) (0.437) for the species Arius parkii is considered to be a potential bioindicator in this region. The enrichment of trace metals is also supported by the association of metals in water, sediments and different body organs (muscle, gill, liver, intestine) of fish samples. Comparative studies with other coastal regions indicate considerable enrichment of DTMs & TTMs in sediments as well as in various organs of fish samples. Holistic spatial, temporal monitoring and comprehensive regional strategies are required to prevent health risks and ensure nutritional safety conditions.

Accumulation of Trace Metals by Mangrove Plants in Indian Sundarban Wetland: Prospects for Phytoremediation.

The work investigates on the potential of ten mangrove species for absorption, accumulation and partitioning of trace metal(loid)s in individual plant tissues (leaves, bark and root/pneumatophore) at two study sites of Indian Sundarban Wetland. The metal(loid) concentration in host sediments and their geochemical characteristics were also considered. Mangrove sediments showed unique potential in many- fold increase for most metal(loid)s than plant tissues due to their inherent physicochemical properties. The ranges of concentration of trace metal(loid)s for As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn in plant tissue were 0.006-0.31, 0.02-2.97, 0.10-4.80, 0.13-6.49, 4.46-48.30, 9.2-938.1, 0.02-0.13, 9.8-1726, 11-5.41, 0.04-7.64, 3.81-52.20 µg g (-1)respectively. The bio- concentration factor (BCF) showed its maximum value (15.5) in Excoecaria agallocha for Cd, suggesting that it can be considered as a high-efficient plant for heavy metal bioaccumulation. Among all metals, Cd and Zn were highly bioaccumulated in E. agallocha (2.97 and 52.2 µg g (-1) respectively. Our findings suggest that the species may be classified as efficient metal trap for Cd in aerial parts, as indicated by higher metal accumulation in the leaves combined with BCF and translocation factor (TF) values.

Metal enrichment of soils following the April 2012-2013 eruptive activity of the Popocatépetl volcano, Puebla, Mexico.

We analyzed the total (Zn, Pb, Ni, Hg, Cr, Cd, Cu, As) and partially leachable metals (PLMs) in 25 ash and soil samples from recent (2012-2013) eruptions of the Popocatépetl Volcano in Central Mexico. More recent ash and soil samples from volcanic activity in 2012-2013 had higher metal concentrations than older samples from eruptions in 1997 suggesting that the naturally highly volatile and mobile metals leach into nearby fresh water sources. The higher proportions of As (74.72%), Zn (44.64%), Cu (42.50%), and Hg (32.86%) reflect not only their considerable mobility but also the fact that they are dissolved and accumulated quickly following an eruption. Comparison of our concentration patterns with sediment quality guidelines indicates that the Cu, Cd, Cr, Hg, Ni, and Pb concentrations are higher than permissible limits; this situation must be monitored closely as these concentrations may reach lethal levels in the future.

Characterization of As and trace metals embedded in PM10 particles in Puebla City, México.

Forty-eight air-filter samples (PM10) were analysed to identify the concentration level of partially leached metals (PLMs; As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and V) from Puebla City, México. Samples were collected during 2008 from four monitoring sites: (1) Tecnológico (TEC), (2) Ninfas (NIN), (3) Hermanos Serdán (HS) and (4) Agua Santa (AS). The results indicate that in TEC, As (avg. 424 ng m(-3)), V (avg. 19.2 ng m(-3)), Fe (avg. 1,202 ng m(-3)), Cu (avg. 86.6 ng m(-3)), Cr (41.9 ng m(-3)) and Ni (18.6 ng m(-3)) are on the higher side than other populated regions around the world. The enrichment of PLMs is due to the industrial complexes generating huge dust particles involving various operations. The results are supported by the correlation of metals (Mn, Cd and Co) with Fe indicating its anthropogenic origin and likewise, As with Cd, Co, Fe, Mn, Pb and V. The separate cluster of As, Fe and Mn clearly signifies that it is due to continuous eruption of fumaroles from the active volcano Popocatépetl in the region.

Speciation of selected heavy metals geochemistry in surface sediments from Tirumalairajan river estuary, east coast of India.

Surface sediment samples from the Tirumalairajan river estuary were studied for grain size pattern, organic matter, and heavy metals (Fe, Mn, Zn, and Pb) using the sequential and bulk metal extraction methods to evaluate metal behavior. Ten surface sediment samples were collected during the monsoon and summer seasons of the year 2009. The observed orders of concentrations of heavy metals in the sediments were as follows: Fe > Mn > Zn > Pb. The results obtained from sequential extraction showed that, among the metals studied, a larger portion of the metals were associated with the residual phase, although they are available in other fractions. The low concentration of metals available in bioavailable phases indicated that the sediments of Tirumalairajan river estuary were relatively unpolluted. Correlation analysis was also carried out to understand the associations of metals in different phases with sand, silt, clay, and organic matter. To understand the risk of heavy metals to sediment-dwelling organisms, the data were compared with risk assessment code and sediment quality values using the screening quick reference table. The main source of metals to the estuary is from the irrigation field and its associated activities in the study area.

First account of microplastics in pelagic sporting dolphinfish from the eastern Mexican coast of Baja California Sur.

This study is a baseline data on the presence of MPs from the gastro-intestinal tracts (GITs) in Coryphaena hippurus Linnaeus, from eastern Baja California Sur, México. 878 MPs items (in %) of fibers (29%), fragments (68%) and films (1.3%) were detected from 51 GITs of Coryphaena hippurus. Transparent, white, blue and black were the prevalent colours. Morphological features observed through SEM analysis, the presence of heavily weathered MPs is due to the mechanical, microbiological and chemical weathering process. PP (29%), Nylon (29%), PS (17%), PE (11%), PET (6%) and HDPE (8%) presence indicates their source from regional anthropogenic stress. Trophic level transition is enforced by polymer derivative, permitting the sinking behavior of MPs and increased ingestion probability. Fishes were classified as slim despite their higher feeding capabilities and ingested MPs indicates a relationship with environmental contaminants. Current study emphasizes the health risk linked to biological aspects of MPs ingestion.

Spatiotemporal trends and characteristics of microplastic contamination in a large river-dominated estuary.

Microplastic (MP) pollution is a major global issue that poses serious threats to aquatic organisms. Although research on MP pollution has been extensive, the relationship between MPs and water quality parameters in estuarine water systems is unclear. This work studied the spatiotemporal distribution and characteristics of MPs in the Karnaphuli River estuary, Bangladesh. MP abundance was calculated by towing with a plankton net (300 µm mesh size) at three river gradients (up-, mid- and downstream) and the association between physicochemical parameters of water (temperature, pH, salinity, electrical conductivity, total dissolved solids, and dissolved oxygen) and MP distribution patterns was also investigated. Mean MP abundance in water was higher during the wet season (April) (4.33 ± 2.45 items per m3) compared to the dry season (September) (3.65 ± 2.54 items per m3). In descending order, the highest MP abundance was observed downstream (6.60 items per m3) > midstream (3.15 items per m3) > upstream (2.22 items per m3). pH during the wet season (April) and temperature during the dry season (September) were key physicochemical parameters that correlated with river MP abundance (r = -0.74 and 0.74 respectively). Indicating that if the Karnaphuli River water has low pH or high temperature, there is likely to be high MPs present in the water. Most MP particles were film-shaped, white in color, and 1-5 mm in size. Of the six polymers detected, polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), and cellulose were predominant, comprising roughly 17-19% each. These results can be used to model MP transport in the freshwater ecosystem of the Karnaphuli River estuary in Bangladesh to help develop future mitigation strategies.

Autoclave decomposition method for metals in soils and sediments.

Leaching of partially leached metals (Fe, Mn, Cd, Co, Cu, Ni, Pb, and Zn) was done using autoclave technique which was modified based on EPA 3051A digestion technique. The autoclave method was developed as an alternative to the regular digestion procedure passed the safety norms for partial extraction of metals in polytetrafluoroethylene (PFA vessel) with a low constant temperature (119.5° ± 1.5°C) and the recovery of elements were also precise. The autoclave method was also validated using two Standard Reference Materials (SRMs: Loam Soil B and Loam Soil D) and the recoveries were equally superior to the traditionally established digestion methods. Application of the autoclave was samples from different natural environments (beach, mangrove, river, and city soil) to reproduce the recovery of elements during subsequent analysis.

Mercury pollution on tourist beaches in Durban, South Africa: A chemometric analysis of exposure and human health.

Mercury (Hg) is a global pollutant that is a major public health concern due to its mobility, stability and toxicity behavior in the environment. In this study Hg concentrations were determined in beach sediment samples (n = 43) collected from the South Durban Coast, South Africa. A human health risk assessment was also carried out to comprehend the potential health effects of incidental ingestion/direct contact with contaminated sediments in a recreational setting. Hg concentrations ranged between 0.62 and 4.88 mg kg-1 dw., exceeding all background and regulatory limits. Numerical values of calculated exposure pathways represented dermal contact with the sediments as one of the potential paths in both adults and children. Hazard Index (HI) values were found to be less than unity signifying no adverse health effects. This study validates the critical need for long-term monitoring of Hg in various scenarios in order to incorporate better public health management strategies.

Seasonal tendencies of microplastics around coral reefs in selected Marine Protected National Parks of Gulf of California, Mexico.

This study focuses on the presence of MPs in the sediment beds around coral reefs of MPNPs in Baja California Sur, México. Based on seasonal sampling results, comparison of MPs from Cabo Pulmo (avg. 680.25 items/100 g-1 d.w) recorded higher values than Espiritu Santo Island (avg. 321.75 items/100 g-1 d.w) from backshore/foreshore regions. Fibrous MPs are the dominant morphotypes followed by fragments and spheres. SEM/EDS analysis revealed that the MPs are altered texturally in surface and is bioavailable to marine organisms independent of size/shape. FTIR analysis indicate different polymers (in %) in the form of PP (70), PET (65), HDPE (59), LDPE (50), PS (30), PC (18), PU (10) and RYN (10). Most of the MPs are secondary in origin resulting from man-made and tourist's activities controlled by wave transportation and tidal currents. Existence of MPs in sediment beds around the coral reefs signals the ways for future investigations.