Arsenic and mercury exposure in different insect trophic guilds from mercury mining areas in Mexico.

The exposure to arsenic and mercury in various insect trophic guilds from two mercury mining sites in Mexico was assessed. The two study sites were La Laja (LL) and La Soledad (LS) mines. Additionally, a reference site (LSR) was evaluated for LS. The terrestrial ecosystem was studied at LL, whereas both the terrestrial ecosystem and a stream called El Cedral (EC) were assessed at LS. The study sites are situated in the Biosphere Reserve Sierra Gorda (BRSG). Mercury vapor concentrations were measured with a portable analyzer, and concentrations of arsenic and mercury in environmental and biological samples were determined through atomic absorption spectrophotometry. Both pollutants were detected in all terrestrial ecosystem components (soil, air, leaves, flowers, and insects) from the two mines. The insect trophic guilds exposed included pollinivores, rhizophages, predators, coprophages, and necrophages. In LS, insects accumulated arsenic at levels 29 to 80 times higher than those found in specimens from LSR, and 10 to 46 times higher than those from LL. Similarly, mercury exposure in LS was 13 to 62 times higher than LSR, and 15 to 54 times higher than in LL. The analysis of insect exposure routes indicated potential exposure through air, soil, leaves, flowers, animal prey, carrion, and excrement. Water and sediment from EC exhibited high levels of arsenic and mercury compared to reference values, and predatory aquatic insects were exposed to both pollutants. In conclusion, insects from mercury mining sites in the BRSG are at risk.

Serum levels of inflammatory cytokines in mercury mining workers in a precarious situation: A preliminary study.

Mercury is a ubiquitous environmental xenobiotic; the primary sources of exposure to this metal are artisanal gold mining and the direct production of mercury. In Mexico, artisanal mercury mining continues to be an important activity in different regions of the country. Exposure to mercury vapors releases can have severe health impacts, including immunotoxic effects such as alterations in cytokine profiling. Therefore, in the present work, we evaluated the inflammatory cytokines profile in the blood serum of miners exposed to mercury. A cross-sectional observational study was performed on 27 mining workers (exposed group) and 20 control subjects (nonexposed group) from central Mexico. The mercury urine concentration (U-Hg) was determined by atomic absorption spectrometry, and IL-2, IL-6, IL-8, IL-10, and TNF-α were measured using a Multiplex Assay. The results showed that the U-Hg in the miners had a median value of 552.70 µg/g creatinine. All cytokines showed a significant increase in the miner group compared with the control group, except for TNF-α. In addition, we observed a positive correlation between U-Hg concentration and cytokine levels. In conclusion, mercury exposure correlated with cytokine levels (considered acute inflammatory marker) in miners; therefore, workers exposed to this metal show an acute systemic inflammation that could lead to alterations in other organs and systems.

The Use of the Oxygenation Stretch Index to Predict Outcomes in Mechanically Ventilated Patients With COVID-19 ARDS.

BACKGROUND: In ARDS caused by COVID-19 pneumonia, appropriate adjustment of physiologic parameters based on lung stretch or oxygenation may optimize the ventilatory strategy. This study aims to describe the prognostic performance on 60-d mortality of single and composite respiratory variables in subjects with COVID-19 ARDS who are on mechanical ventilation with a lung-protective strategy, including the oxygenation stretch index combining oxygenation and driving pressure (ΔP). METHODS: This single-center observational cohort study enrolled 166 subjects on mechanical ventilation and diagnosed with COVID-19 ARDS. We evaluated their clinical and physiologic characteristics. The primary study outcome was 60-d mortality. Prognostic factors were evaluated through receiver operating characteristic analysis, Cox proportional hazards regression model, and Kaplan-Meier survival curves. RESULTS: Mortality at day 60 was 18.1%, and hospital mortality was 22.9%. Oxygenation, ΔP, and composite variables were tested: oxygenation stretch index ([Formula: see text]/[Formula: see text] divided by ΔP) and ΔP × 4 + breathing frequency (f) (ΔP × 4 + f). At both day 1 and day 2 after inclusion, the oxygenation stretch index had the best area under the receiver operating characteristic curve (oxygenation stretch index on day 1 0.76 (95% CI 0.67-0.84) and on day 2 0.83 (95% CI 0.76-0.91) to predict 60-d mortality, although without significant difference from other indexes. In multivariable Cox regression, ΔP, [Formula: see text]/[Formula: see text], ΔP × 4 + f, and oxygenation stretch index were all associated with 60-d mortality. When dichotomizing the variables, ΔP ≥ 14, [Formula: see text]/[Formula: see text] ≤ 152 mm Hg, ΔP × 4 + f ≥ 80, and oxygenation stretch index < 7.7 showed lower 60-d survival probability. At day 2, after optimization of ventilatory settings, the subjects who persisted with the worse cutoff values for the oxygenation stretch index showed a lower probability of survival at 60 d compared with day 1; this was not the case for other parameters. CONCLUSIONS: The oxygenation stretch index, which combines [Formula: see text]/[Formula: see text] and ΔP, is associated with mortality and may be useful to predict clinical outcomes in COVID-19 ARDS.

Health effects of informal precarious workers in occupational environments with high exposure to pollutants.

The aim is to investigate and describe the health conditions of workers who are employed in precarious work settings in Mexico. Specifically, the study aims to provide insight on the health status of workers who are vulnerable due to the informal nature of their employment. Through the evaluation of three different scenarios of precarious employment (n = 110), including workers in mercury miner (workers A), brick-kilns (workers B), and quarries workers (workers C). The study analyzes clinical parameters to determine the workers' renal health condition and assesses their pulmonary function using spirometry. Multivariate analyses and Spearman correlation are performed to determine the contribution of length of service to workers' health parameters. Workers B have the highest incidence of clinical health alterations, with the highest BMI and prediabetes/diabetes index, albumin creatinine ratio, and eGFR. Moreover, pulmonary function parameters show a decrease in %FEV1/FVC in workers B and C compared to workers A, while workers A demonstrate a more significant decrease in %FEV1. Additionally, a negative correlation is observed between the length of service in precarious work settings and lung parameters (r = -0.538, p < 0.001). In conclusion, this study highlights the need to address the issue of precarious employment in Mexico by improving working conditions, access to healthcare and promoting social protection for workers, which can reduce the number of work-related illnesses and deaths and ensure the safety and health of workers.

[CRCP units: a strategy to assess health risks in children in contaminated communitiesUnidades RISC: uma estratégia para avaliar os riscos de saúde na população infantil de comunidades contaminadas]. / Unidades RISC: una estrategia para evaluar riesgos de salud en la población infantil de comunidades contaminadas.

Humanitarian crises can occur in places affected by chemical, physical, biological, and social threats, especially when these threats interact with each other and cause a syndemic. In order to avoid crises in these places, it is necessary to introduce mitigation measures that we have framed as "humanitarian scenarios". Due to their nature, implementation of these interventions requires the creation of multidisciplinary operational groups with a work strategy that integrates them into the affected community. In the case of the child population, the operational group was called the 'childhood risks in contaminated places' (CRCP) unit; contaminated places meaning localities impacted by chemical, physical, or biological threats. The strategy has six phases: (i) planning the survey and site visit; (ii) community involvement in identifying threats, vulnerabilities, and routes of exposure (the path of pollutants from their source to the receiving population), and in preparing joint work for the subsequent phases; iii) prioritization of risks identified through environmental monitoring and use of biomarkers of exposure and effects; iv) risk prevention through the creation of various 'capacities and alternatives for the prevention of syndemic threats'; (v) advocacy to implement these capacities and alternatives through risk communication and local training; and (vi) protection through measures that include telehealth, social progress, and innovation to improve health coverage. The strategy has been implemented in different contexts, and in some of them it has been enriched by analysis of respect for human rights.

Crises humanitárias podem ocorrer em locais afetados por ameaças químicas, físicas, biológicas e sociais, principalmente quando essas ameaças interagem entre si e causam uma sindemia. Para evitar as crises, é necessário introduzir nesses locais medidas de mitigação que enquadramos no termo "cenários humanitários". Por sua natureza, a implementação de tais ações de intervenção exige a formação de grupos operacionais multidisciplinares e de uma estratégia de trabalho que permita integrá-los à comunidade afetada. No caso da população infantil, o grupo operacional recebeu o nome de Unidade de Riscos Infantis em Áreas Contaminadas (na sigla em espanhol, RISC), ou seja, em locais impactados por ameaças químicas, físicas ou biológicas. A estratégia consiste nas seis fases a seguir: i) planejamento para o estudo e visita ao local; ii) participação da comunidade para identificar ameaças, vulnerabilidades e rotas de exposição (caminho que os contaminantes devem seguir desde a sua fonte até a população receptora), bem como para o trabalho conjunto nas fases seguintes; iii) priorização dos riscos identificados por meio do monitoramento ambiental e uso de biomarcadores de exposição e efeitos; iv) prevenção de riscos por meio da criação de diversas capacidades e alternativas para a prevenção diante de ameaças sindêmicas (CAPAS); v) promoção da implantação das CAPAS por meio da comunicação de riscos e capacitação local; e vi) proteção com medidas que incluem propostas de telessaúde, progresso social e inovação para melhorar a cobertura de saúde. A estratégia foi aplicada em diferentes contextos, em alguns dos quais foi enriquecida com uma análise do respeito pelos direitos humanos.

Unidades RISC: una estrategia para evaluar riesgos de salud en la población infantil de comunidades contaminadas

[RESUMEN]. Las crisis humanitarias pueden presentarse en sitios afectados por amenazas químicas, físicas, biológicas y sociales, sobre todo cuando estas amenazas interaccionan entre sí y causan una sindemia. A fin de evitar las crisis, en estos sitios se hace necesario introducir medidas de mitigación que hemos enmarcado bajo el término de “escenarios humanitarios”. Debido a su naturaleza, la implementación de dichas acciones de intervención requiere de la conformación de grupos operativos multidisciplinarios y de una estrategia de trabajo que permita integrarlos con la comunidad afectada. En el caso de la población infantil, el grupo ope- rativo recibió el nombre de unidad de riesgos infantiles en sitios contaminados (RISC), es decir, en localidades impactadas por amenazas químicas, físicas o biológicas. La estrategia consta de las siguientes seis fases: i) planificación para el estudio y la visita al sitio; ii) participación de la comunidad para identificar amena- zas, vulnerabilidades y rutas de exposición (el camino que deben seguir los contaminantes desde su fuente hasta la población receptora), así como para el trabajo conjunto en las siguientes fases; iii) priorización de riesgos identificados mediante el monitoreo ambiental y uso de biomarcadores de exposición y efectos; iv) prevención de riesgos a través de la creación de diversas capacidades y alternativas para la prevención ante amenazas sindémicas (CAPAS); v) promoción para implementar las CAPAS mediante la comunicación de riesgos y la capacitación local; y vi) protección con medidas que incluyen propuestas de telesalud, progreso social e innovación para mejorar la cobertura sanitaria. La estrategia ha sido aplicada en diferentes contextos, en algunos de los cuales, ha sido enriquecida con el análisis del respeto de los derechos humanos.

[ABSTRACT]. Humanitarian crises can occur in places affected by chemical, physical, biological, and social threats, espe- cially when these threats interact with each other and cause a syndemic. In order to avoid crises in these places, it is necessary to introduce mitigation measures that we have framed as "humanitarian scenarios". Due to their nature, implementation of these interventions requires the creation of multidisciplinary operational groups with a work strategy that integrates them into the affected community. In the case of the child popula- tion, the operational group was called the ‘childhood risks in contaminated places’ (CRCP) unit; contaminated places meaning localities impacted by chemical, physical, or biological threats. The strategy has six phases: (i) planning the survey and site visit; (ii) community involvement in identifying threats, vulnerabilities, and routes of exposure (the path of pollutants from their source to the receiving population), and in preparing joint work for the subsequent phases; iii) prioritization of risks identified through environmental monitoring and use of bio- markers of exposure and effects; iv) risk prevention through the creation of various ‘capacities and alternatives for the prevention of syndemic threats’; (v) advocacy to implement these capacities and alternatives through risk communication and local training; and (vi) protection through measures that include telehealth, social pro- gress, and innovation to improve health coverage. The strategy has been implemented in different contexts, and in some of them it has been enriched by analysis of respect for human rights.

[RESUMO]. Crises humanitárias podem ocorrer em locais afetados por ameaças químicas, físicas, biológicas e sociais, principalmente quando essas ameaças interagem entre si e causam uma sindemia. Para evitar as crises, é necessário introduzir nesses locais medidas de mitigação que enquadramos no termo “cenários huma- nitários”. Por sua natureza, a implementação de tais ações de intervenção exige a formação de grupos operacionais multidisciplinares e de uma estratégia de trabalho que permita integrá-los à comunidade afe- tada. No caso da população infantil, o grupo operacional recebeu o nome de Unidade de Riscos Infantis em Áreas Contaminadas (na sigla em espanhol, RISC), ou seja, em locais impactados por ameaças químicas, físicas ou biológicas. A estratégia consiste nas seis fases a seguir: i) planejamento para o estudo e visita ao local; ii) participação da comunidade para identificar ameaças, vulnerabilidades e rotas de exposição (caminho que os contaminantes devem seguir desde a sua fonte até a população receptora), bem como para o trabalho conjunto nas fases seguintes; iii) priorização dos riscos identificados por meio do monitoramento ambiental e uso de biomarcadores de exposição e efeitos; iv) prevenção de riscos por meio da criação de diversas capacidades e alternativas para a prevenção diante de ameaças sindêmicas (CAPAS); v) promoção da implantação das CAPAS por meio da comunicação de riscos e capacitação local; e vi) proteção com medi- das que incluem propostas de telessaúde, progresso social e inovação para melhorar a cobertura de saúde. A estratégia foi aplicada em diferentes contextos, em alguns dos quais foi enriquecida com uma análise do respeito pelos direitos humanos.

Assessment of inflammatory cytokines in exhaled breath condensate and exposure to mixtures of organic pollutants in brick workers.

Brick production causes a lot of pollution in the form of dust, fumes, and toxic substances. Therefore, brick workers are highly exposed to pollutants and present a high risk of developing respiratory diseases. The objective of this research was to determine the exposure to polycyclic aromatic hydrocarbons (PAHs) and toluene in urine and evaluate the effects on health using markers of oxidative stress in exhaled breath condensate (EBC) as well as the exposure to pollutants in suspended particles of the studied area. Exposure to PAHs and toluene was evaluated using hydroxylated markers (OH) of PAHs and hippuric acid in urine, respectively. Cytokines like TNF-α, INF-y, IL-2, IL-4, IL-6, IL-8, IL-10 y GMCSF in EBC were also evaluated. PM2.5 particles were measured during an 8-h work shift. The results in brick workers presented a total OH-PAHs concentration of 97.3 µg/L and hippuric acid concentration of 0.2 g/L. The environmental concentrations of suspended particles were found within a range of 41.67-3541.6 µg/m3. The median of cytokines oscillated between 11.8 pg/mL to 1041 pg/mL. In conclusion, these results are similar to those of occupations in which there is high exposure to pollutants and populations with lung diseases. For that reason, the brick production sector requires prevention and control strategies against the pollutants emitted.

Unidades RISC: una estrategia para evaluar riesgos de salud en la población infantil de comunidades contaminadas / CRCP units: a strategy to assess health risks in children in contaminated communities / Unidades RISC: uma estratégia para avaliar os riscos de saúde na população infantil de comunidades contaminadas

RESUMEN Las crisis humanitarias pueden presentarse en sitios afectados por amenazas químicas, físicas, biológicas y sociales, sobre todo cuando estas amenazas interaccionan entre sí y causan una sindemia. A fin de evitar las crisis, en estos sitios se hace necesario introducir medidas de mitigación que hemos enmarcado bajo el término de "escenarios humanitarios". Debido a su naturaleza, la implementación de dichas acciones de intervención requiere de la conformación de grupos operativos multidisciplinarios y de una estrategia de trabajo que permita integrarlos con la comunidad afectada. En el caso de la población infantil, el grupo operativo recibió el nombre de unidad de riesgos infantiles en sitios contaminados (RISC), es decir, en localidades impactadas por amenazas químicas, físicas o biológicas. La estrategia consta de las siguientes seis fases: i) planificación para el estudio y la visita al sitio; ii) participación de la comunidad para identificar amenazas, vulnerabilidades y rutas de exposición (el camino que deben seguir los contaminantes desde su fuente hasta la población receptora), así como para el trabajo conjunto en las siguientes fases; iii) priorización de riesgos identificados mediante el monitoreo ambiental y uso de biomarcadores de exposición y efectos; iv) prevención de riesgos a través de la creación de diversas capacidades y alternativas para la prevención ante amenazas sindémicas (CAPAS); v) promoción para implementar las CAPAS mediante la comunicación de riesgos y la capacitación local; y vi) protección con medidas que incluyen propuestas de telesalud, progreso social e innovación para mejorar la cobertura sanitaria. La estrategia ha sido aplicada en diferentes contextos, en algunos de los cuales, ha sido enriquecida con el análisis del respeto de los derechos humanos.

ABSTRACT Humanitarian crises can occur in places affected by chemical, physical, biological, and social threats, especially when these threats interact with each other and cause a syndemic. In order to avoid crises in these places, it is necessary to introduce mitigation measures that we have framed as "humanitarian scenarios". Due to their nature, implementation of these interventions requires the creation of multidisciplinary operational groups with a work strategy that integrates them into the affected community. In the case of the child population, the operational group was called the 'childhood risks in contaminated places' (CRCP) unit; contaminated places meaning localities impacted by chemical, physical, or biological threats. The strategy has six phases: (i) planning the survey and site visit; (ii) community involvement in identifying threats, vulnerabilities, and routes of exposure (the path of pollutants from their source to the receiving population), and in preparing joint work for the subsequent phases; iii) prioritization of risks identified through environmental monitoring and use of biomarkers of exposure and effects; iv) risk prevention through the creation of various 'capacities and alternatives for the prevention of syndemic threats'; (v) advocacy to implement these capacities and alternatives through risk communication and local training; and (vi) protection through measures that include telehealth, social progress, and innovation to improve health coverage. The strategy has been implemented in different contexts, and in some of them it has been enriched by analysis of respect for human rights.

RESUMO Crises humanitárias podem ocorrer em locais afetados por ameaças químicas, físicas, biológicas e sociais, principalmente quando essas ameaças interagem entre si e causam uma sindemia. Para evitar as crises, é necessário introduzir nesses locais medidas de mitigação que enquadramos no termo "cenários humanitários". Por sua natureza, a implementação de tais ações de intervenção exige a formação de grupos operacionais multidisciplinares e de uma estratégia de trabalho que permita integrá-los à comunidade afetada. No caso da população infantil, o grupo operacional recebeu o nome de Unidade de Riscos Infantis em Áreas Contaminadas (na sigla em espanhol, RISC), ou seja, em locais impactados por ameaças químicas, físicas ou biológicas. A estratégia consiste nas seis fases a seguir: i) planejamento para o estudo e visita ao local; ii) participação da comunidade para identificar ameaças, vulnerabilidades e rotas de exposição (caminho que os contaminantes devem seguir desde a sua fonte até a população receptora), bem como para o trabalho conjunto nas fases seguintes; iii) priorização dos riscos identificados por meio do monitoramento ambiental e uso de biomarcadores de exposição e efeitos; iv) prevenção de riscos por meio da criação de diversas capacidades e alternativas para a prevenção diante de ameaças sindêmicas (CAPAS); v) promoção da implantação das CAPAS por meio da comunicação de riscos e capacitação local; e vi) proteção com medidas que incluem propostas de telessaúde, progresso social e inovação para melhorar a cobertura de saúde. A estratégia foi aplicada em diferentes contextos, em alguns dos quais foi enriquecida com uma análise do respeito pelos direitos humanos.

Caracterización y biomonitoreo de contaminantes orgánicos e inorgánicos en una zona ladrillera de San Luis Potosí / Characterization and biomonitoring of organic and inorganic contaminants in a brick-making area of San Luis Potosí

Resumen El sector ladrillero se caracteriza por la elaboración del ladrillo de forma artesanal donde utilizan técnicas rudimentarias, hornos de baja tecnología y diversos combustibles de poca calidad generando humos negros con gran cantidad de contaminantes. Por lo que el objetivo de este estudio fue caracterizar los metales en suelo, HAPs en aire y biomonitoreo de HAPs en trabajadores de la zona ladrillera "Las Terceras" San Luis Potosí, México. Con el fin de conocer la exposición laboral se determinó la concentración de HAPs en partículas PM10, se caracterizó el suelo de la zona de trabajo y se realizó un biomonitoreo de me-tabolitos hidroxilados HAPs (OH-HAPs) en orina de los trabajadores. En aire se encontraron 14 de los 16 HAPs prioritarios por la Agencia de Protección Ambiental en la fracción de PM10, con una concentración media de 5293,05 gg/m3 (3,11-10510,81). Los resultados del análisis químico de los polvos mostraron que están constituidos principalmente de cuarzo (SiO2) y arcillas (SiAlOx) con presencia de óxidos de Fe-Ti, fosfatos de tierras raras (Lantano, Cerio, Neodimio Torio), silicatos de zirconio, sulfatos de bario, óxidos de zinc. En el biomonitoreo participaron 42 trabajadores ladrilleros, los resultados de la exposición a OH-HAPs en orina demostraron la media total de los OH-HAPs de 15,7 (6,92-195) ng/ml. Estos resultados muestran que el monitoreo ocupa-cional de las zonas ladrilleras es importante debido al escenario de riesgo y a las condiciones precarias de este trabajo, además de la alta exposición a contaminantes que afectan la salud de los trabajadores y sus familias, así como la propuesta de estrategias que ayuden a minimizar los impactos ambientales y prevenir los efectos en salud de las poblaciones.

Abstract The brick-making sector is characterized by artisanal brick production using rudimentary techniques, low-tech kilns and various low-quality fuels that generate black fumes with a large amount of pollutants. Therefore, the objective of this study was to characterize metals in soil, PAHs in air and biomonitoring of PAHs in workers of the "Las Terceras" brick area in San Luis Potosí, Mexico. In order to know the occupational exposure, the concentration of PAHs in PM10 particles was determined, the soil of the work area was characterized and a biomonitoring of hydroxylated PAH metabolites (OH-HAPs) in the urine of the workers was carried out. In air, 14 of the 16 PAHs prioritized by the Environmental Protection Agency were found in the PM10 fraction, with an average concentration of 5293.05 gg/m3 (3.11-10510.81). The results of the chemical analysis of the dusts showed that they are mainly constituted of quartz (SiO2) and clays (SiAlOx) with presence of Fe-Ti oxides, rare earth phosphates (Lanthanum, Cerium, Neodymium Thorium), zirconium silicates, barium sulfates, zinc oxides. The biomonitoring involved 42 brick workers, the results of OH-HAPs exposure in urine showed the mean total OH-HAPs of 15.7 (6.92-195) ng/ml. These results show that occupational moni-toring of brick-making areas is important due to the risk scenario and the precarious conditions of this work, in addition to the high exposure to pollutants that affect the health of workers and their families, as well as the proposal of strategies that help minimize environmental impacts and prevent health effects on populations.

Evaluation of cytokines in exhaled breath condensate in an occupationally exposed population to pneumotoxic pollutants.

The quarrying is considered a precarious occupation with high toxicity, is an informal economic activity that employs low technology, limited protection, and poses a risk to workers and their families. In quarrying, silica dust is generated and there is also occupational exposure to significant mixtures of pneumotoxic pollutants, including mineral dust (crystalline silica, carbon or cement, polycyclic aromatic hydrocarbons (PAHs), solvents, and others, which are aggravated by the lack of use of protective equipment, causing irreversible damage to the worker's respiratory health. Thus, the objective of this work focused on the evaluation of the respiratory health of artisan stonemasons in San Luis Potosí, Mexico through the study of exhaled breath condensate (EBC) (pH, pro-inflammatory cytokines) as well as the study of the exposure to pollutants present in the work area (PAHs, toluene, and 2.5 µm particulate matter) through biomarkers of exposure (hippuric acid and hydroxylated metabolites of PAHs). The results show the presence of crystalline SiO2 in 100% of the samples analyzed; the PM2.5 concentrations were 5 to 10 times the permitted levels. Regarding exposure to PAHs, all the stonemasons presented urine concentrations of at least 5 of the OH-PAHs evaluated; 9-OH-FLU occurred at higher concentrations of 171.2 (122.7-279.4) µg L-1; hippuric acid, which was present in 100% of the workers evaluated in concentrations of 283.4 (27.72-1119) mg L-1, 100% of which were above the values established for occupational scenarios. The pH values obtained for the EBC samples were presented at an average of 7.07 (6.33-7.66). Pro-inflammatory cytokines were present in 86.1% of the study population. The cytokine that was found in higher concentrations was IL-2, with a mean of 178.01 pg mL-1 and 3124.01 pg mL-1 for the pH < 7 and pH > 7 groups, respectively. Some correlations between the cytokines and the exposure biomarkers were presented. Stonemasons are highly exposed to pneumotoxic pollutants and markers of inflammation at the pulmonary level; in addition, a high risk of developing silicosis. Quarrying should be addressed as a carcinogenic activity, which would imply the design of monitoring and control strategies for these pollutants that our country currently lacks, particularly in precarious occupations. It is necessary to develop strategies to protect the health of precarious workers.

Sequential lateral positioning as a new lung recruitment maneuver: an exploratory study in early mechanically ventilated Covid-19 ARDS patients.

BACKGROUND: A sequential change in body position from supine-to-both lateral positions under constant ventilatory settings could be used as a postural recruitment maneuver in case of acute respiratory distress syndrome (ARDS), provided that sufficient positive end-expiratory pressure (PEEP) prevents derecruitment. This study aims to evaluate the feasibility and physiological effects of a sequential postural recruitment maneuver in early mechanically ventilated COVID-19 ARDS patients. METHODS: A cohort of 15 patients receiving lung-protective mechanical ventilation in volume-controlled with PEEP based on recruitability were prospectively enrolled and evaluated in five sequentially applied positions for 30 min each: Supine-baseline; Lateral-1st side; 2nd Supine; Lateral-2nd side; Supine-final. PEEP level was selected using the recruitment-to-inflation ratio (R/I ratio) based on which patients received PEEP 12 cmH2O for R/I ratio ≤ 0.5 or PEEP 15 cmH2O for R/I ratio > 0.5. At the end of each period, we measured respiratory mechanics, arterial blood gases, lung ultrasound aeration, end-expiratory lung impedance (EELI), and regional distribution of ventilation and perfusion using electric impedance tomography (EIT). RESULTS: Comparing supine baseline and final, respiratory compliance (29 ± 9 vs 32 ± 8 mL/cmH2O; p < 0.01) and PaO2/FIO2 ratio (138 ± 36 vs 164 ± 46 mmHg; p < 0.01) increased, while driving pressure (13 ± 2 vs 11 ± 2 cmH2O; p < 0.01) and lung ultrasound consolidation score decreased [5 (4-5) vs 2 (1-4); p < 0.01]. EELI decreased ventrally (218 ± 205 mL; p < 0.01) and increased dorsally (192 ± 475 mL; p = 0.02), while regional compliance increased in both ventral (11.5 ± 0.7 vs 12.9 ± 0.8 mL/cmH2O; p < 0.01) and dorsal regions (17.1 ± 1.8 vs 18.8 ± 1.8 mL/cmH2O; p < 0.01). Dorsal distribution of perfusion increased (64.8 ± 7.3% vs 66.3 ± 7.2%; p = 0.01). CONCLUSIONS: Without increasing airway pressure, a sequential postural recruitment maneuver improves global and regional respiratory mechanics and gas exchange along with a redistribution of EELI from ventral to dorsal lung areas and less consolidation. Trial registration ClinicalTrials.gov, NCT04475068. Registered 17 July 2020, https://clinicaltrials.gov/ct2/show/NCT04475068.

A preliminary study on health impacts of Mexican mercury mining workers in a context of precarious employment.

Mercury mining is one of the main sources of mercury (Hg) release into the environment, causing serious impacts on human health and the environment. Workers in these mines are employed informally and precariously and therefore lack labor rights such as social security. The objective of the study is to make visible the exposure to environmental contaminants and the health of workers in mercury mines. An environmental assessment was conducted to determine workers' exposure to contaminants; urine samples were obtained to measure exposure to mercury and arsenic, and blood samples were obtained for lead and cadmium. Clinical parameters were also evaluated. Concentrations of Hg, As and Pb were determined in soil, 279.4 mg/kg (24.4-788.5), 14.7 mg/kg (9.5-20.3) and 1.4 mg/kg (1-2.8), respectively. The exposure results for mercury were 551 µg/g creatinine, for arsenic 50 µg/L and for lead 4.7 µg/dL. Cd-B was not found. In addition, 17.6 % of the workers had diabetes and 17.6 % had renal disorders. Principal Component Regression was performed obtaining an r2 of 0.86 for glomerular filtration rate and 0.54 for albumin creatinine ratio using clinical, occupational, and metal exposure variables. Exposure to Hg in this type of mine is not exclusive, so there is a cumulative risk of chronic exposure to different environmental pollutants directly impacting the health of workers. It is necessary to implement health strategies and different work opportunities for these workers.

Assessment of biomarkers of early kidney damage and exposure to pollutants in artisanal mercury mining workers from Mexico.

Artisanal mercury mining (AMM) is an informal economic activity that employs low technology and limited protection, and poses a risk to workers and their families; due to the extraction process, these scenarios involve exposure to complex mixtures of pollutants that synergistically aggravate the health of miners and people living near the site. Although mercury is the predominant pollutant, there are others such as polycyclic aromatic hydrocarbons (PAHs), toluene, arsenic, and lead which have been classified as nephrotoxic pollutants. Therefore, the purpose of this research was to evaluate the association between exposure to a complex mixture of pollutants (mercury, lead, arsenic, PAHs, and toluene) and kidney damage in artisanal Hg mining workers through early kidney damage proteins (KIM-1, OPN, RBP-4, NGAL, and Cys-C). The results demonstrate the presence of OH-PAHs at concentrations of 9.21 (6.57-80.63) µg/L, hippuric acid as a biomarker of exposure to toluene, As and Pb (655. 1 (203.8-1231) mg/L, 24.05 (1.24-42.98) g/g creatinine, and 4.74 (2.71-8.14) g/dL, respectively), and urinary Hg (503.4 (177.9-878.7) g/g creatinine) in the study population. As well as biomarkers of kidney damage, NGAL and RPB-4 were found in 100% of the samples, KIM-1 and Cys-C in 44.1%, and OPN in 41% of the miners. Significant correlations were found between several of the evaluated pollutants and early kidney damage proteins. Our results demonstrate the application of the early kidney damage biomarkers for the assessment of damage caused by the exposure to mixtures of pollutants and, therefore, the urgent need for monitoring in AMM areas.

Antiviral capacity of polypropylene/(1-Hexadecyl) trimethyl-ammonium bromide composites against COVID-19.

During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, scientists from different areas are looking for alternatives to fight it. SARS-CoV-2, the cause of the infectious respiratory disease COVID-19, is mainly transmitted through direct or indirect contact with infected respiratory droplets. The integrity of the virus structure is crucial for its viability to attack human cells. Quaternary ammonium salts are characterized by having antiviral capabilities which alter or destroy the structure of the viral capsid. In this work, polypropylene (PP)/(1-Hexadecyl) trimethyl-ammonium bromide (CTAB) composites have been prepared in order to create an antiviral material. The composites were melt processed and blown to produce thin films. The CTAB content on the antiviral effect was evaluated using antibodies and serum from infected patients with the SARS-CoV-2 virus. In addition, the mechanical and thermal properties of blown films were investigated, and CTAB release kinetics from the films was followed by UV-Vis. The results indicate that the virus tends to remain less on the polymer surface by increasing the amount of CTAB in the PP matrix.

Evaluation of respiratory function and biomarkers of exposure to mixtures of pollutants in brick-kilns workers from a marginalized urban area in Mexico.

Brick-kilns are polluted environments due to the use of low-quality technologies and fuels, which generates black fumes with a large number of pollutants. The objective of this research was to analyze environmental exposure and biomarkers of exposure to polycyclic aromatic hydrocarbons, metals, and respiratory health in brickmakers to assess the baseline state of contamination in a brick-kiln area of San Luis Potosi, Mexico. Lead was quantified in soil and particulate matter of 2.5 µm (PM2.5) and 10 µm (PM10) in brick-kiln areas. In brickmakers, lead was evaluated in whole blood and 10 hydroxylated metabolites of polycyclic aromatic hydrocarbons were determined in urine. Respiratory health was assessed by spirometry, exhaled breath condensate, and a COPD-PS questionnaire. Data association was performed by Spearman correlation. Environmental concentrations and biomarkers of exposure are presented as medians, for lead, it was 60.4 mg/kg, for PM10, it was 2663.1 µg/m3, and for PM2.5, it was 166.6 µg/m3. For blood lead, it was 1.06 µg/dL, and the summed concentration of OH-PAHs in urine was 16.1 µg/L. Spirometry values were 2.8 ± 0.6 L and 2.9 ± 1.3 L/s FEV1 and FEV 25-75 respectively. The correlation results indicate that the older the age of the workers is and the extensive period they have been working, their lung function is affected the most. The health vulnerability present in these occupational activities is high, so it is necessary to make visible, address these economic activities in Mexico, and apply surveillance systems based on the health of the worker.

Holistic health risk assessment in an artisanal mercury mining region in Mexico.

Mexico is one of the world's leading mercury producers and exporters. However, mercury mining is carried out using artisanal procedures, which highly impact ecosystems. In the municipality of Pinal de Amoles, Queretaro, Mexico, artisanal mercury mining (AMM) is practiced in a region that has been categorized as a Biosphere Reserve. Therefore, a holistic health risk assessment for mercury was performed in the region, including environmental monitoring (air, water, and soil) and mercury exposure in both humans (children, women, and miners) and biota (plants, rodents, and worms). The atmospheric mercury determination was carried out using the JEROME® J405 analyzer, whereas total mercury in environmental and biological samples was determined by atomic absorption spectrophotometry/cold vapor. Results showed that mercury concentrations in the environmental and biological matrices exceeded their respective reference values. These results demonstrate the direct influence of AMM in the increasing levels of mercury in all the components of the studied ecosystem. Therefore, comprehensive intervention strategies must be implemented to reduce and prevent human health and ecological risks due to the presence of mercury. In this regard, the Minamata Convention for mercury control should include biomonitoring programs not only for humans but also for critical ecological receptors in polluted ecosystems.

Health Sentinel: A mobile crowdsourcing platform for self-reported surveys provides early detection of COVID-19 clusters in San Luis Potosí, Mexico.

BACKGROUND: The Health Sentinel (Centinela de la Salud, CDS), a mobile crowdsourcing platform that includes the CDS app, was deployed to assess its utility as a tool for COVID-19 surveillance in San Luis Potosí, Mexico. METHODS: The CDS app allowed anonymized individual surveys of demographic features and COVID-19 risk of transmission and exacerbation factors from users of the San Luis Potosí Metropolitan Area (SLPMA). The platform's data processing pipeline computed and geolocalized the risk index of each user and enabled the analysis of the variables and their association. Point process analysis identified geographic clustering patterns of users at risk and these were compared with the patterns of COVID-19 cases confirmed by the State Health Services. RESULTS: A total of 1554 COVID-19 surveys were administered through the CDS app. Among the respondents, 50.4 % were men and 49.6 % women, with an average age of 33.5 years. Overall risk index frequencies were, in descending order: no-risk 77.8 %, low risk 10.6 %, respiratory symptoms 6.7 %, medium risk 1.4 %, high risk 2.0 %, very high risk 1.5 %. Comorbidity was the most frequent vulnerability category (32.4 %), followed by the inability to keep home lockdown (19.2 %). Statistically significant risk clusters identified at a spatial scale between 5 and 730 m coincided with those in neighborhoods containing substantial numbers of confirmed COVID-19 cases. CONCLUSIONS: The CDS platform enables the analysis of the sociodemographic features and spatial distribution of individual risk indexes of COVID-19 transmission and exacerbation. It is a useful epidemiological surveillance and early detection tool because it identifies statistically significant and consistent risk clusters in neighborhoods with a substantial number of confirmed COVID-19 cases.

A review of Environmental risks and vulnerability factors of indigenous populations from Latin America and the Caribbean in the face of the COVID-19.

Latin America and the Caribbean (LAC) was declared a new epicentre of the coronavirus pandemic by the World Health Organization (WHO) on 22 May 2020. As of 13 January 2021, the numbers of deaths and cases caused by COVID-19 in LAC reported are 552,000 and 17'485,000 respectively. LAC concentrates the largest percentage of indigenous populations throughout the world. In this region, poverty is persistent and particularly rural indigenous peoples hold the steepest barriers to health services and experience profound discrimination based on ethnicity, poverty, and language, compared to their non-indigenous counterparts. The information regarding the health of indigenous populations, in general, is scarce, and this problem is aggravated in the face of the COVID-19 pandemic. Therefore, the main objective of this work is to address the overall scenario of indigenous peoples in the Latin American and Caribbean region from March 2020 to January 2021, in this manner gathering information regarding health problems, economic, social, cultural and environmental factors that make indigenous populations in LAC particularly vulnerable to serious health effects from the COVID-19 pandemic, as well as compiling the mitigation strategies implemented in indigenous communities.

Comparative analysis of chemical breath-prints through olfactory technology for the discrimination between SARS-CoV-2 infected patients and controls.

BACKGROUND: We identified a global chemical pattern of volatile organic compounds in exhaled breath capable of discriminating between COVID-19 patients and controls (without infection) using an electronic nose. METHODS: The study focused on 42 SARS-CoV-2 RT-qPCR positive subjects as well as 42 negative subjects. Principal component analysis indicated a separation of the study groups and provides a cumulative percentage of explanation of the variation of 98.3%. RESULTS: The canonical analysis of principal coordinates model shows a separation by the first canonical axis CAP1 (r2 = 0.939 and 95.23% of correct classification rate), the cut-off point of 0.0089; 100% sensitivity (CI 95%:91.5-100%) and 97.6% specificity (CI 95%:87.4-99.9%). The predictive model usefulness was tested on 30 open population subjects without prior knowledge of SARS-CoV-2 RT-qPCR status. Of these 3 subjects exhibited COVID-19 suggestive breath profiles, all asymptomatic at the time, two of which were later shown to be SARS-CoV-2 RT-qPCR positive. An additional subject had a borderline breath profile and SARS-CoV-2 RT-qPCR positive. The remaining 27 subjects exhibited healthy breath profiles as well as SARS-CoV-2 RT-qPCR test results. CONCLUSIONS: In all, the use of olfactory technologies in communities with high transmission rates as well as in resource-limited settings where targeted sampling is not viable represents a practical COVID-19 screening approach capable of promptly identifying COVID-19 suspect patients and providing useful epidemiological information to guide community health strategies in the context of COVID-19.