Resumen Durante las últimas décadas en Puno, Perú, la problemática de la contaminación se fue agudizando por la acción combinada del crecimiento desordenado de la población urbana, gestión deficiente de residuos sólidos, descarga de aguas servidas sin tratamiento en la bahía del lago Titicaca y prácticas de sanidad e higiene inadecuadas; situaciones que afectan severamente el ambiente y la salud humana. El objetivo del estudio fue caracterizar las actitudes y comportamientos proambientales de la población de la ciudad de Puno en relación al saneamiento, la contaminación y la gestión ambiental. La investigación es no experimental, cuantitativa, trans¬versal, descriptiva, correlacional y nivel de análisis micro. El universo de estudio fue la población mayor de 18 años del área urbana, que comprende 97.264 habitantes; la muestra, deter¬minada al azar simple, fue de 382 personas. Se aplicó un cuestionario estructurado. El análisis descriptivo, inferencial y prueba de hipótesis se realizó con el software estadístico SPSS. Los resultados señalan que las actitudes ambientales de la mayoría de la población son positivas respecto a factores y fuentes de contaminación y efectos en la salud humana; contrariamente, las prácticas ambientales son inadecuadas en gestión ambiental en el hogar y condiciones de sanidad e higiene en la vivienda. Se concluye, que la mejora sostenible de actitudes y comportamientos proambientales, demanda de una nueva política pública de educación ambiental, cuya implementación incorpore la participación efectiva de la sociedad civil con base a un sistema de incentivos.

Abstract During the last decades in Puno, Peru, the problem of contamination has worsened due to the combined action of the disorderly growth of the urban population, poor management of solid waste, discharge of untreated sewage into the bay of Lake Titicaca and practices of inadequate sanitation and hygiene, severely affecting the environment and human health. The objective of the study was to characterize the pro-environmental attitudes and behaviors of the city’s population of Puno in relation to sanitation, pollution and environmental management. The research is nonexperimental, quantitative, cross-sectional, descriptive, correlational and micro level of analysis. The universe of study was the population over 18 years of age in the urban area, which comprises 97,264 inhabitants; the sample, determined at simple random, was 382 people. A structured questionnaire was applied. Descriptive and inferential analysis and hypothesis testing were performed with SPSS statistical software. The results indicate that the environmental attitudes of the majority of the population are positive regarding factors and sources of pollution and effects on human health. On the contrary, environmental practices are inadequate in environmental management in the home and health and hygiene conditions in the home. It is concluded that the sustainable improvement of pro-environmental attitudes and behaviors demands a new public policy of environmental education, whose implementation incorporates the effective participation of civil society based on an incentive system.

Abstract The development of living beings depends on the health and chemical quality of the available water. In recent years, the importance of the environment in the spread of resistant and multi-resistant bacteria to antibiotics has been observed, a situation that has placed the problem of antibiotic resistance on a broader level and which is being studied from the perspective “One Health”. The objective of this work was to determine the presence of multi-resistant bacteria to antibiotics in irrigation water samples from the Chibunga river. Fourteen water samples of 100 mL each were collected in sterile containers and aseptically, were kept under refrigeration until analysis in the laboratory. Each sample was seeded by the surface seeding method on blood, cystine electrolyte deficient, MacConkey, Salmonella-Shigella and thiosulfate citrate bile sucrose agars, incubating in all cases at a temperature of 37 °C for a maximum time of 48 hours. The identification of bacterial colonies was carried out through physiological and biochemical tests according to the identification schemes indicated by MacFaddin. The resistance/sensitivity to antibiotics of the identified colonies was carried out by the disk diffusion method of Kirby Bauer. Two species of multi-resistant bacteria were identified, including strains of Morganella morgani and Plesiomonas shigelloides resistant to antibiotics of clinical use such as ceftazidime, aztreonam, ciprofloxacin, nalidixic acid and trimethoprim-sulfamethoxazole. The results show that the waters of Chibunga river harbor bacteria with multi-resistance to antimicrobials, representing a contamination risk of agricultural products harvested in its vicinity, as well as for the people who use these waters.

Resumen El bienestar y desarrollo de los seres vivos depende de la calidad sanitaria y química del agua disponible. En los últimos años se ha venido observando la importancia del ambiente en la diseminación de bacterias resistentes y multirresistentes a los antibióticos, situación que ha colocado la problemática de la resistencia en un plano más amplio y que se está estudiando desde la perspectiva “One Health”. En este sentido, el objetivo del presente trabajo fue determinar la presencia de bacterias multirresistentes a los antibióticos en muestras de agua de riego provenientes del río Chibunga. Se recolectaron 14 muestras de agua de un volumen de 100 mL cada una, en envases estériles y de manera aséptica, las cuales fueron conservadas bajo refrigeración hasta su análisis en el laboratorio. Cada muestra fue sembrada por el método de siembra en superficie en los agares cistina electrolito deficiente, MacConkey, Salmonella-Shigella, tiosulfato citrato bilis sacarosa y agar sangre, incubándose en todos los casos a una temperatura de 37 °C durante un tiempo máximo de 48 horas. La identificación de las colonias bacterianas se realizó mediante pruebas fisiológicas y bioquímicas de acuerdo con los esquemas de identificación indicados por MacFaddin. El perfil de susceptibilidad a los antibióticos de las colonias identificadas se realizó por el método de difusión en disco de Kirby Bauer. Se lograron identificar 2 especies de bacterias multirresistentes, entre ellas, cepas de Morganella morganii y Plesiomonas shigelloides resistentes a antibióticos de uso clínico como ceftazidima, aztreonam, ciprofloxacino, ácido nalidíxico y trimetroprim-sulfametoxazol. Los resultados muestran que las aguas del río Chibunga albergan bacterias con multirresistencia a los antimicrobianos, representando un riesgo de contaminación de los productos agrícolas cosechados en sus inmediaciones, así como para las personas que utilizan estas aguas.

Abstract The research presents a compilation of the strategies for the handling and management of mercury (Hg) carried out by Japan as a promoter and manager of the Minamata Convention. This agreement was established to reduce anthropogenic mercury emissions and prevent pollution worldwide. Article 14 of the agreement focuses on cooperation between the governments involved and provides technical assistance. That is why the activities were developed in the training course “Capacity building for the ratification and implementation of the Minamata Convention on Mercury” carried out in Japan, in which representatives from Ecuador, China, Sudan, Brazil, and Armenia. Ecuador is one of the countries that ratified this agreement in 2013, which is why it is necessary to understand the efforts developed by other countries, with a practical perspective, to know their feasibility and implementation in the long term in the national territory. This study describes the activities implemented in Japan, such as processing contaminated waste in the company Nomura Kohsan Co., Ltd. (Hokkaido), to know high-tech centers such as the National Institute for Minamata Disease (NIMD) and the Ministry of the Environment (MEGJ), and a tour of the environmental restoration project in Minamata Bay. The results demonstrate that the actions and policies adopted in Japan have considerably reduced Hg emissions, maintaining them at stable levels, which ratifies compliance with the different articles outlined in the Minamata Convention. Although efforts have been made in Ecuador to combat illegal mining where Hg and assist in mining districts, it is still among the most polluting countries in the region. Private and government entities must put effort into action plans to mitigate pollution and carry out periodic monitoring of emissions of this metal.

Resumen La investigación presenta una recopilación de las estrategias en el manejo y gestión del mercurio (Hg) que realiza Japón como promotor y gestor del Convenio de Minamata. Este acuerdo fue establecido para reducir las emisiones antropogénicas de mercurio y prevenir su polución a nivel mundial. El artículo 14 del convenio establece la cooperación entre los gobiernos involucrados y la prestación de asistencia técnica. Es por ello que las actividades se desarrollaron en el curso de capacitación “Capacity building for ratification and implementation of Minamata Convention on Mercury”, llevado a cabo en Japón, en el cual participaron representantes de Ecuador, China, Sudán, Brasil y Armenia. Ecuador es uno de los países que ratificó en el 2013 este convenio, por lo cual es necesario comprender los esfuerzos desarrollados por otros países, desde una perspectiva práctica, para poder conocer su factibilidad y ser implementadas a largo plazo en el territorio nacional. Se describen las actividades implementadas, en Japón, como la recolección y procesamiento de residuos contaminados en la empresa Nomura Kohsan Co., Ltd. (Hokkaido), visita a centros de alta tecnología como el Instituto Nacional para la Enfermedad de Minamata (NIMD) y el Ministerio del Ambiente (MEGJ), y recorrido por el proyecto de restauración ambiental en la bahía de Minamata. Los resultados demuestran que las acciones y políticas adoptadas en Japón han reducido considerablemente las emanaciones de Hg llegando a mantenerlas en niveles estables, lo que ratifica el cumplimiento de los distintos artículos expuestos en el Convenio de Minamata. A pesar de que en Ecuador se han hecho esfuerzos para mitigar el uso de Hg, aun así, se encuentra entre los principales países contaminantes de la región. Las entidades privadas y gubernamentales deben esforzarse en planes de acción para mitigar la contaminación y llevar a cabo monitoreos periódicos de las emisiones de este metal.

ABSTRACT Andean and Bolivian Indigenous Communities of Titicaca often depend on their natural resources to ensure their food security, making them especially vulnerable to environmental fluctuations and changes in the ecosystem. Under this criterion, this study applies a qualitative methodology to analyze the relationship between the food security of the communities of the Cohana Bay region (taking the Chojasivi community as a case study) and water pollution in the Katari basin. The results reveal that such contamination has generated a potential effect on access, availability, use and stability over time of the food that makes up the basic food basket of the community.

RESUMEN Las comunidades Indígenas Andino-bolivianas del Titicaca dependen a menudo de sus recursos naturales para garantizar su seguridad alimentaria, lo que las hace especialmente vulnerables a fluctuaciones ambientales y cambios en el ecosistema. Bajo ese criterio, el presente estudio aplica una metodología cualitativa para analizar la relación existente entre la seguridad alimentaria de las comunidades de la región de la bahía de Cohana (tomando como caso de estudio a la comunidad de Chojasivi) y la contaminación hídrica presente en la cuenca Katari. Los resultados revelan que dicha contaminación ha generado un efecto potencial en el acceso, disponibilidad, uso y estabilidad en el tiempo de los alimentos que componen la canasta básica de los comunarios.

Abstract The progress of economic regulation and the environmental impact of large-scale mining copper concessions are analyzed using the expo facto and correlational methodology. It was found that large-scale mining contributes 94 percent of Peru’s annual copper production; copper exports from large-scale mining and mining income are positively correlated (20002019). Given the contamination of water, air, and agricultural land and the violation of the collective rights of mining territories' inhabitants in Peru, it is necessary to implement a comprehensive mining regulation with citizen participation and insertion into sustainable development.

Resumen En esta investigación se analiza el avance de la regulación económica e impacto ambiental de las concesiones cupríferas de la gran minería, para ello se utiliza la metodología expo facto y correlacional. Se encontró que la gran minería aporta 94% de la producción anual de cobre peruano, las exportaciones de cobre de la gran minería y la renta minera están positivamente correlacionadas (2000-2019). Ante la contaminación del agua, aire, tierras agrícolas y vulneración de los derechos colectivos de los pobladores en los territorios mineros en Perú, es necesario implementar una regulación minera integral con participación ciudadana e inserción al desarrollo sustentable.

Pesticide residues and heavy metal content of cassava, yam, cocoyam, potato, water yam and carrot were evaluated by gas chromatography-mass spectrometry and atomic absorption spectroscopy. The detected pesticide residues in the samples were 2,4-dichlorophenoxyacetic acid, glyphosate, hexachlorobenzene (HCB), dichlorobiphenyl, aldrin, endosulfan, profenofos, g-chlordane, carbofuran, biphenyl, heptachlor, lindane and t-Nonachlor. The concentration of HCB ranged between 0.0799 ± 0.06 mg/kg and 0.1596 ± 0.00 mg/kg, which was greater than the permitted maximum limit of 0.5 mg/kg established by the US Environmental Protection Agency. The concentration of aldrin and profenofos detected was lower than the predetermined maximum allowed limits. Endosulfan concentrations in cocoyam (0.2500 mg/kg) and potato (0.3265 mg/kg) were higher than the limits allowed by the Canadian Department of Industrial Research. The heavy metals detected in these samples include cobalt, nickel, lead, manganese, chromium, arsenic and mercury in at least one of the samples evaluated. There was not much difference between the concentration of cobalt in yam (0.036 mg/kg) and the maximum allowed concentration (0.043 mg/kg). Lead was detected in potatoes and carrots but was below detectable concentration in cassava, yam, cocoyam and water yam. Similarly, cocoyam was found to have a significant mercury content (0.658 mg/kg), but mercury content was below detectable concentrations in cassava, yam and water yam. SIGNIFICANCE: Heavy metal pollutants and pesticide residues can impair human health, and their presence in food can cause various illnesses and health issues. It is important to prevent exposure to these contaminants and ensure that food is safe by identifying and monitoring them. Farmers may provide consumers with more assurance that their products are safe by identifying and monitoring pesticide residues and heavy metal contamination in these food crops. Overall, it is crucial to find and monitor pesticide residues and heavy metal contamination in food to safeguard customer confidence, ensure legal compliance and preserve human health.

The Southern African region contains abundant gold tailing heaps that are an environmental concern due to dust pollution and chemical contamination of nearby water bodies. Nevertheless, these heaps contain gold with potential to be extracted for financial gain. In this study, the feasibility of extraction of gold from a Witwatersrand gold tailings using glycine was investigated using a two-level full factorial design. Effects of variables such as glycine concentration at levels of 0.5-1.5 M with a solid-liquid ratio of 50-200 g/L were investigated. Although the solid-liquid ratio used in this study was below the industrial norm, it provides a starting point for investigating the applicability of this technology. To enhance the gold extraction, potassium permanganate pretreatment and copper ion addition were adopted. The results revealed that 91.4% gold extraction was achieved after 24 h pre-treatment of the tailings using 2 g/L potassium permanganate followed by subsequent leaching using 1.5 M glycine at pH 12, with 50 g/L solid-liquid ratio and 2 g/L copper ions. Statistically, the solid-liquid ratio and potassium permanganate pre-treatment of the tailings were found to be significant at 95% confidence interval, whilst interactions of copper ions and glycine concentration were significant factors. The work demonstrates that potassium permanganate pre-treatment prior to glycine leaching of low-grade secondary gold resources, such as tailings, can be beneficial. Furthermore, the methodology developed in this work provides an opportunity for further investigation of the recovery of gold hosted in complex mineralogical matrices.

Abstract Foodborne diseases cause a high burden of morbidity, with a greater occurrence in home environments. The objective of the study is to associate habits related to good hygiene practices with sociodemographic variables in a representative sample of the Chilean population. Secondary analysis study, conducted from the National Health Survey (NHS) 2016-2017, where the questions of good hygiene practices were analyzed. The sample contemplates 6,233 participants, of which 62.8% corresponds to female sex. It was identified that women have better hygiene habits in food handling compared to men. On the other hand, adults aged 45-64 years and over 65 years had better habits related to food safety than other age groups. In conclusion, sociodemographic variables such as sex, age and educational level are determining factors in good hygiene practices. The population should be educated in food handling to ensure food safety.

Resumen Las enfermedades transmitidas por los alimentos causan una alta carga de morbilidad, con una mayor ocurrencia en ambientes domiciliarios. El objetivo del estudio es asociar hábitos relacionados con buenas prácticas de higiene con variables sociodemográficas en una muestra representativa de la población chilena. Estudio de análisis secundario, realizado a partir de la Encuesta nacional de Salud (ENS) 2016-2017, donde se analizaron las preguntas de buenas prácticas de higiene. La muestra contempla 6.233 participantes, de los cuales el 62,8% corresponde a sexo femenino. Se identificó que las mujeres tienen mejores hábitos de higiene en la manipulación de alimentos respecto a los hombres. Por otro lado, los adultos entre 45-64 años y mayores a 65 años, presentan mejores hábitos relacionados con inocuidad alimentaria, en relación con otros grupos etarios. En conclusión, las variables sociodemográficas como sexo, edad, nivel educativo son determinantes en las buenas prácticas de higiene. Se debe educar a la población en la manipulación de alimentos, para garantizar la inocuidad alimentaria.

RESUMEN En la Amazonía ecuatoriana, cada día son mayores los desafíos para la identificación de especies fitorremediadoras que disminuyan la contaminación por metales pesados producto de la actividad minera. El objetivo de este trabajo fue evaluar el potencial bioacumulador de metales pesados de tres especies forestales de rápido crecimiento (Ochroma pyramidale, Piptocoma discolor y Bambusa vulgaris) en un área de extracción minera, en la comunidad Yutzupino, Napo para la restauración. Se recolectaron muestras de hoja y suelo para determinar la concentración de metales pesados (Cd, Pb, Fe y Ni), mediante espectrometría de absorción atómica y se calculó el factor de bioconcentración (FBC). Los análisis foliares mostraron que B. vulgaris presentó mayor concentración de Ni (6,89 mg kg-1) y Fe (156,33 mg kg-1) y P. discolor contenía Cd (0,35 mg kg-1) y Pb (55,67 mg kg -1). Los análisis de suelos mostraron un patrón de variación en B. vulgaris superior en Cd, Ni y Pb y en O. pyramidale para Fe. El factor de bioconcentración permitió identificar la capacidad acumuladora de las especies, lo que sugiere que P. discolor puede ser utilizada como especie fitorremediadora para sitios contaminadas por Cd y Pb, O. pyramidale para Ni y B. vulgaris para Fe.

RESUMO Na Amazônia equatoriana, os desafios para a identificação de espécies de fitorremediação para reduzir a contaminação por metais pesados provenientes de atividades de mineração aumentam a cada dia. O objetivo deste trabalho foi avaliar o potencial bioacumulativo de metais pesados de três espécies florestais de crescimento rápido (Ochroma pyramidale, Piptocoma discolor e Bambusa vulgaris) em uma área de extração de mineração na comunidade de Yutzupino, Napo, para restauração. Amostras de folhas e de solo foram coletadas para determinar a concentração de metais pesados (Cd, Pb, Fe e Ni) por espectrometria de absorção atômica e o fator de bioconcentração (BCF) foi calculado. A análise das folhas mostrou que a B. vulgaris tinha concentrações mais altas de Ni (6,89 mg kg-1) e Fe (156,33 mg kg-1) e a P. discolor continha Cd (0,35 mg kg-1) e Pb (55,67 mg kg -1). As análises do solo mostraram um padrão de variação em B. vulgaris maior em Cd, Ni e Pb e em O. pyramidale para Fe. O fator de bioconcentração identificou a capacidade de acumulação das espécies, sugerindo que P. discolor pode ser usada como uma espécie de fitorremediação para locais contaminados com Cd e Pb, O. pyramidale para Ni e B. vulgaris para Fe.

ABSTRACT In the Ecuadorian Amazon, the challenges for identifying, phytoremediation species that reduce heavy metal contamination resulting from mining activity are increasing every day. The objective of this work was to evaluate the bioaccumulator potential of heavy metals of three fast-growing forest species (Ochroma pyramidale, Piptocoma discolor and Bambusa vulgaris) in a mining extraction area, in the Yutzupino community, Napo for restoration. Leaf and soil samples were collected to determine the concentration of heavy metals (Cd, Pb, Fe and Ni) using atomic absorption spectrometry and the bioconcentration factor (BCF) was calculated. Leaf analyzes showed that B. vulgaris presented a higher concentration of Ni (6.89 mg kg-1 ) and Fe (156.33 mg kg-1 ) and P. discolor contained Cd (0.35 mg kg-1 ) and Pb (55.67 mg kg -1 ). Soil analyzes showed a pattern of variation in B. vulgaris superior in Cd, Ni and Pb and in O. pyramidale for Fe. The bioconcentration factor allowed identifying the accumulating capacity of the species, which suggests that P. discolor may be used as a phytoremediation species for sites contaminated by Cd and Pb, O. pyramidale for Ni and B. vulgaris for Fe.

Resumen: La alta demanda de materiales plásticos ha sido una tendencia post Covid-19 debido a la necesidad de materiales de protección y empaquetado para productos sanitarios y alimentarios. Sin embargo, esta situación ha agravado la problemática medioambiental asociada a la contaminación por residuos plásticos, debido a su largo tiempo de vida, por lo que en los últimos años se ha intensificado la búsqueda de alternativas de su reciclaje. De igual manera, la disposición final de los catalizadores utilizados en la petroquímica representa un importante desafío, puesto que estos terminan en vertederos, siendo un gran foco de contención por su alto contenido de metales pesados. Con este enfoque, el presente estudio tiene como objetivo la evaluación del uso de catalizadores regenerados FCC provenientes de procesos petroquímicos y su aplicación en el proceso de despolimerización mediante glicólisis del poli-(tereftalato de etileno). El catalizador fue regenerado mediante tratamiento térmico y químico, el mismo que posterior a su análisis fue evaluado en el proceso de glicólisis en cantidades del uno y dos por ciento en masa, comparándolo con otros catalizadores convencionales como el acetato de zinc y la zeolita ZSM-5 en la obtención de bis-hidroxi etilen tereftalato (BHET). Los resultados mostraron un rendimiento muy significativo comparado con los otros catalizadores, así también se demostró que la cantidad de catalizador no presenta influencia significativa en el proceso de despolimerización. Resultados que se muestran como una opción prometedora para combatir la problemática de la aglomeración de materiales plásticos.

Abstract: The high demand for plastic materials has been a post-Covid-19 trend due to the need for protective and packaging materials for sanitary and food products. However, this situation has exacerbated the environmental problem associated with plastic waste pollution, which has led to intensified efforts to find recycling alternatives in recent years. The final disposal of catalysts used in petrochemicals also represents a significant challenge, as they end up in landfills and are a major source of contamination due to their high heavy metal content. This study aims to evaluate the use of regenerated FCC catalysts from petrochemical processes in the depolymerization process of poly-(ethylene terephthalate) by glycolysis. The results showed that the regenerated catalyst had a significant performance compared to conventional catalysts such as zinc acetate and ZSM-5 zeolite in obtaining bis (hydroxyethyl terephthalate) (BHET), and the amount of catalyst did not significantly affect the depolymerization process. These results show a promising option for addressing the problem of plastic waste.

RESUMEN En la agricultura actual es necesario controlar la inocuidad de los alimentos que se producen, para ello es vital tener en cuenta los niveles de contaminación que provocan los metales pesados. Un aspecto a considerar es el estudio de calidad del suelo para conservar o mejorar su productividad, de forma que se garantice la protección ambiental, la salud humana y la seguridad alimentaria. Elementos traza en concentraciones elevadas en suelos son tóxicos alimentarios con efectos negativos sobre la salud que se manifiestan a largo plazo como resultado del consumo de aguas y alimentos contaminados. El presente trabajo plantea como objetivo: estudiar modelos matemáticos para predecir el comportamiento de las concentraciones de cobalto, plomo y zinc en un suelo agrícola, aledaño al vertimiento de residuos industriales en el municipio San José de las Lajas. Para ello se tomaron los datos de concentración de metales pesados cobalto (Co), plomo (Pb) y zinc (Zn) desde el año 2005 al año 2018 para predecir su comportamiento a partir del uso de herramientas estadístico-matemáticas hasta el año 2034. Se obtuvo que, según los modelos matemáticos obtenidos, estos suelos no deban emplearse para cultivar hortalizas con objeto de consumo, al menos hasta 10 años después de esta investigación.

ABSTRACT In current agriculture it is necessary to control the safety of the food that is produced, for this it is vital to take into account the levels of contamination caused by heavy metals. One aspect to consider is the study of soil quality to preserve or improve its productivity, in order to guarantee environmental protection, human health and food safety. Trace elements in high concentrations in soils are food toxins with negative effects on health that manifest themselves in the long term as a result of the consumption of contaminated food and water. The objective of this work is: to study mathematical models to predict the behavior of cobalt, lead and zinc concentrations in agricultural soil, adjacent to the dumping of industrial waste in the San José de las Lajas municipality. For this, the concentration data of heavy metals cobalt (Co), lead (Pb) and zinc (Zn) were taken from the year 2005 to the year 2018 to predict their behavior from the use of statistical-mathematical tools until the year 2034. It was obtained that, according to the mathematical models obtained, these soils should not be used to grow vegetables for consumption, at least until 10 years after this investigation.

As real-time air quality monitoring becomes more prevalent in US underground mines, it is important to provide the highest data reliability with the fewest possible sensors. Real-time sensors remain costly, and these costs are not exclusively financial; the time required to install, calibrate, and maintain real-time sensors poses a large barrier to widespread implementation. Current atmospheric monitoring systems typically rely on displaying point-specific values. This requires operators to infer real-time airborne contamination distributions. Monitoring and control software utilizing mine ventilation network (MVN) solvers has been implemented in limited cases because of their ability to simulate ventilation systems quickly, but these solvers use a one-dimensional representation of the mine, limiting spatial resolution of estimated distributions. Computational fluid dynamics (CFD) has likewise been considered as a means to improve spatial resolution, but processing times prevent its use as a basis for monitoring and control. For the real-time monitoring of airborne contamination distributions, we propose a spatial interpolation method that can estimate the distribution of airborne contaminants in near-real time. This method provides a middle ground between fast processing times and increased spatial resolution. With the use of a pathfinding algorithm and optimization through absolute percentage error minimization, this method outperforms spatial interpolation with a Euclidean distance. By providing contamination distribution information to operators, this method and its derivatives stand to outperform current atmospheric monitoring systems.

Flouride contamination of water is recognised as a serious challenge facing humanity. Consumption of water that contains excessive amounts of fluoride can result in fluorosis. Consequently, concerted efforts have been made to develop cheap, effective and green techniques/materials to remove fluoride from water, particularly potable water. Bone char prepared from bovine, swine, and equine bones has been used extensively in this regard, and is the most promising, cheap and green material for treating drinking water with high fluoride concentration, particularly in developing countries. However, research on bone char prepared from bones of animals in the wild, as well as those from domestic and semi-wild animals treated with antibiotics to enhance growth, has been scanty. Such research is important as the use of antibiotics may alter the composition of bones, and thus their potential as a green adsorbent to remove fluoride may be impaired. Furthermore, little attempt has been made so far to package char bones for easy application domestically, particularly in rural communities. SIGNIFICANCE: • Contamination of water by fluoride is a major problem globally. • Various techniques and materials have been employed for water defluoridation, including the use of bone char, which has several advantages. • Bone char prepared from bones of animals in the wild and those from domestic and semi-wild animals treated with antibiotics to enhance growth should be further investigated. • Cheaper and less elaborate processes and packaging are required to scale down the use of bone char at domestic level.

The genetic modification (GM) of maize to contain proteins that act to control insects has become a widespread agricultural practice. Although the reduction of insect damage to maize ears could potentially increase crop yield, rural small-scale farmers might be reluctant to buy expensive GM seed every season even when the lower fungal infection of the GM maize might also result in health benefits. This study was conducted over 5 years in three districts of northern KwaZulu-Natal, South Africa, to study the Fusarium verticillioides and F. proliferatum infection and fumonisin contamination levels in Bt maize, Roundup-Ready® maize, conventional commercial maize and traditional landrace maize planted by rural farmers following their traditional agricultural practices. Mean Fusarium infection rates varied between 3.0% and 38.3% with large standard deviations. Fusarium infection was not significantly different (p>0.05) between the various genotypes, possibly due to the wide variation in results and low sample numbers. Although the fumonisin results also showed wide variation, the trend of contamination was lower in Bt maize compared to conventional commercial genotypes. The mean fumonisin levels in Bt hybrids were mostly <300 μg/kg, ensuring a safe maize supply in populations consuming maize as a dietary staple. The wide variations in Fusarium and fumonisin levels within each district point to the influence of local agricultural practices, local environmental conditions, and seasonal variations. Reducing exposure to fumonisins in these communities requires both further attention to the possible influence of these factors, as well as the use of appropriate post-harvest strategies. SIGNIFICANCE: This study was the first in South Africa to follow rural farmers planting Bt and commercial maize hybrids as well as open-pollinated landrace maize, according to their traditional agricultural practices. The results show that in some instances the Bt maize had the lowest fumonisin levels.

INTRODUCTION: Contaminated disinfectants have been occasional vehicles of healthcare associated infections. AIMS AND OBJECTIVES: To determine the presence and level of bacterial contamination of disinfectants used to decontaminate suction devices and to assess the extent to which students comply with infection control practices. DESIGN: A two-part cross-sectional descriptive study consisting of microbiological testing of disinfectants and a questionnaire-based observation of students. METHODS: Unannounced observation of students disinfecting suction devices were recorded using a questionnaire. The process involved collecting a prepared disinfectant from a storage bin using a kitchen measuring jug. Specimens of disinfectants and swabs of jugs were collected for aerobic culture. Data pertaining to compliance with infection control practices was gathered. RESULTS: Only 33.6% of the students were observed unannounced. An overwhelming majority (84.9%) of students disinfected suction devices; 52% cleaned and disinfected the external surface of suction hoses and the spittoon bowl; 18.6% allowed the disinfectant to remain in the system long enough, and 14% advised their patients not to close their lips around the suction device. The majority of disinfectant samples (56.3%) as well jugs (55.6%) were contaminated with bacteria. CONCLUSION: Bacterial contamination of disinfectants was common in addition to poor compliance with infection control practices.