Estudios de contaminación ambiental en La Habana mediante técnicas nucleares y conexas / Assessment of environmental pollution in Havana city using nuclear and related techniques

RESUMEN Se resumen las diferentes experiencias en la aplicación de las técnicas nucleares y conexas en el estudio de diversos problemas ambientales de la Ciudad de La Habana. El análisis medioambiental mediante las técnicas de Análisis por Activación Neutrónica (AAN) y Gamma (AAG), Fluorescencia de Rayos X (FRX), Espectrometría por Absorción Atómica (EAA) y por Inducción de plasma acoplado (ICP), así como la Espectrometría Gamma de Bajo Fondo (EGBF), han permitido obtener información muy relevante sobre el comportamiento de los metales pesados, antibióticos y radionúclidos en los sedimentos marinos y fluviales, suelos urbanos y agrícolas, aguas, arenas de balnearios, polvos urbanos y productos de la agricultura urbana de la ciudad de La Habana.

ABSTRACT Various nuclear and related analytical techniques applied to study different environmental problems in Havana city are presented. The environmental analysis by means of Neutron and Gamma Activation analyses, X-ray Fluorescence Atomic Abortion and Induced Coupled Plasma spectroscopies and Low Background , Gamma Spectrometry, have allowed to obtain important information about the behavior of heavy metals, antibiotics and radionuclides in sediments, urban and agricultural soils, waters, beach sands, urban dusts and agricultural products farmed in the Havana city.

Assessment of heavy metal content in urban agricultural soils from the surrounding of steel-smelter plant using X-ray fluorescenc / Estudio del contenido de metales pesados en suelos urbanos agrícolas adyacentes a una planta de acero mediante fluorescencia de rayos X

Concentrations of Cr, Co, Ni, Cu, Zn and Pb in the topsoils (0-10 cm) from ten farms located in the vicinity of a steel-smelter plant at Cotorro (Havana, Cuba) were measured by X-ray fluorescence analysis. The concentration ranges of Cr, Co, Ni, Cu, Zn and Pb were 54-186, 15-39, 19-137, 50-945, 91-7739 and 21-731 dry weight respectively. The metal mean contents in the farm topsoil samples were compared with metal contents reported for soils from the vicinity of other smelters worldwide. The Metal-to-Iron normalisation and estimation of the integral pollution indexes allowed observing that most metal polluted soils are from those farms, and that their location coincide with the prevalent wind direction in the studied area. The enrichment index values show that metal concentrations in soils from these farms are above the permissible levels for urban agriculture.

Se determinan por fluorescencia de rayos X las concentraciones de Cr, Co, Ni, Cu, Zn y Pb en los suelos superficiales (0-10 cm) de 10 granjas agrícolas, localizadas en la vecindad de la planta de acero del Cotorro (La Habana, Cuba). Los rangos de concentraciones de Cr, Co, Ni, Cu, Zn y Pb fueron de 54-186, 15-39, 19-137, 50-945, 91-7739 y 21-731 de peso seco respectivamente. Los contenidos medios de metales pesados en los suelos superficiales de las granjas se comparan con los niveles de metales pesados reportados en la literatura para suelos adyacentes a plantas de acero. La normalización de los metales al hierro y la estimación del los índices de polución integral, permitió determinar que los suelos contaminados por metales pesados fueron aquellos, cuya ubicación coincide con la dirección predominante de los vientos en la zona estudiada. Los valores delíndice de enriquecimiento mostraron que las concentraciones de metales pesados en los suelos de esas granjas, superan los niveles permisibles para la agricultura urbana.

Occurrence and Source Appraisal of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Waters of the Almendares River, Cuba.

In this work, 14 polycyclic aromatic hydrocarbons (PAHs) included in the United States Environmental Protection Agency pollutant priority list were analyzed in the surface water of the upper urbanized part of Almendares River, the most important water course in Havana, Cuba. Surface water from five sampling sites was collected at the end of dry season and analyzed by high-performance liquid chromatography-fluorescence detection method after solid phase extraction procedure. Total PAHs concentrations varied from 836 to 15 811 ng L(-1) with a geometric mean value of 2512 ng L(-1). PAH typology was dominated by low molecular-weight PAHs (2- to 3-ring components). Pollutant source appraisal was determined by diagnostic ratios method in five sampling sites. Factor analysis of normalized samples was used to concentration identified two factors as the main significant pollutant sources and to cluster similar sampling sites corresponding to petrogenic and combustion inputs, respectively. Ecological risks were considered. For animal aquatic life, acute toxicity values exceed the permissible values in the more-polluted sampling sites.

Seasonal variations in antibiotic resistance gene transport in the almendares river, havana, cuba.

Numerous studies have quantified antibiotic resistance genes (ARG) in rivers and streams around the world, and significant relationships have been shown that relate different pollutant outputs and increased local ARG levels. However, most studies have not considered ambient flow conditions, which can vary dramatically especially in tropical countries. Here, ARG were quantified in water column and sediment samples during the dry- and wet-seasons to assess how seasonal and other factors influence ARG transport down the Almendares River (Havana, Cuba). Eight locations were sampled and stream flow estimated during both seasons; qPCR was used to quantify four tetracycline, two erythromycin, and three beta-lactam resistance genes. ARG concentrations were higher in wet-season versus dry-season samples, which combined with higher flows, indicated much greater ARG transport downstream during the wet-season. However, water column ARG levels were more spatially variable in the dry-season than the wet-season, with the proximity of waste outfalls strongly influencing local ARG levels. Results confirm that dry-season sampling provides a useful picture of the impact of individual waste inputs on local stream ARG levels, whereas the majority of ARGs in this tropical river were transported downstream during the wet-season, possibly due to re-entrainment of ARG from sediments.

Evaluación de riesgos a la salud por exposición a metales pesados en cercanías de sitios potencialmente peligrosos con actividad agrícola / Evaluation of health risks by exposure to heavy metals near to hazardous sites with agricultural activity

La presencia de ciertos elementos químicos en el medio ambiente, como los metales pesados (cadmio, plomo, cobre, mercurio, etc.), son consecuencia de su presencia espontánea en la naturaleza o de la actividad humana que incide directamente en los posibles riesgos químicos que su presencia puede generar para la salud humana. En los alimentos de origen vegetal, estos contaminantes pueden ser incorporados mediante técnicas de tratamientos de los cultivos o de tipo medioambiental, que inciden sobre la seguridad de los mismos. El objetivo de este trabajo consiste en evaluar los riesgos a la salud en productores agrícolas y sus familiares por exposición a metales pesados, ubicados en unidades agrícolas en las cercanías del vertedero provincial de la calle 100 en la ciudad de La Habana. Los valores de concentración de metales tóxicos ( Cd, Cu, Zn y Pb) obtenidos en las muestras ambientales (suelos y hortalizas), se emplearon para realizar la evaluación del riesgo para la salud humana por concepto de ingestión de metales pesados en los trabajadores agrícolas y sus familiares. Además, se realizó la evaluación por concepto de ingestión de metales pesados presentes en los aditivos agrícolas que aplicaban los trabajadores del área para fomentar la producción de hortalizas. De forma general, se determinó la no existencia de riesgo a la salud por concepto de ingestión de metales pesados para los niños y trabajadores agrícolas del área en estudio(AU)

Evaluación de la incorporación de metales pesados al agroecosistema. Rol de las prácticas productivas ejecutadas por los trabajadores agrícolas / Evaluating the incorporation of heavy metals to agroecosystem. Role of the productive practices executed by agricultural workers

Los riesgos a la salud asociados al trabajo agrícola son cada vez mayores y dependen del uso de tecnologías y sustancias químicas con mayor frecuencia e intensidad. El desarrollo agrícola urbano constituye un reto para productores e investigadores. Esta actividad productiva se desarrolla con la finalidad de obtener producciones más sostenibles, pero ejecutadas en escenarios peligrosos, donde es posible la presencia de contaminantes de diferente naturaleza y su posible paso a los humanos a través de rutas y vías diferentes. Los metales pesados son, entre otros, contaminantes de interés vinculados a la práctica agrícola y constituyen factores de riesgo a la salud a tener en cuenta para el manejo de agroecosistemas. El análisis ponderado de factores vinculados a las prácticas productivas de los trabajadores agrícolas de sitios agrícolas urbanos, así como de los antecedentes analíticos medioambientales y las características de los escenarios productivos con el empleo de los criterios de grupos de expertos, es una herramienta válida para acometer investigaciones de campo por su capacidad de enfocar prioridades en el hallazgo de resultados de interés aplicando métodos cualitativos de análisis. Se determinó que factores como el historial de uso del suelo, la aplicación de fertilizantes, la aplicación de abonos y productos sanitarios respectivamente constituyeron los factores más importantes a tener en cuenta para el manejo de los agroecosistemas en estudio y para prevenir riesgos de salud relacionados con la presencia de metales pesados(AU)

Antibiotic resistance gene abundances associated with waste discharges to the Almendares River near Havana, Cuba.

Considerable debate exists over the primary cause of increased antibiotic resistance (AR) worldwide. Evidence suggests increasing AR results from overuse of antibiotics in medicine and therapeutic and nontherapeutic applications in agriculture. However, pollution also can influence environmental AR, particularly associated with heavy metal, pharmaceutical, and other waste releases, although the relative scale of the "pollution" contribution is poorly defined, which restricts targeted mitigation efforts. The question is "where to study and quantify AR from pollution versus other causes to best understand the pollution effect". One useful site is Cuba because industrial pollution broadly exists; antibiotics are used sparingly in medicine and agriculture; and multiresistant bacterial infections are increasing in clinical settings without explanation. Within this context, we quantified 13 antibiotic resistance genes (ARG; indicators of AR potential), 6 heavy metals, 3 antibiotics, and 17 other organic pollutants at 8 locations along the Almendares River in western Havana at sites bracketing known waste discharge points, including a large solid waste landfill and various pharmaceutical factories. Significant correlations (p < 0.05) were found between sediment ARG levels, especially for tetracyclines and ß-lactams (e.g., tet(M), tet(O), tet(Q), tet(W), bla(OXA)), and sediment Cu and water column ampicillin levels in the river. Further, sediment ARG levels increased by up to 3 orders of magnitude downstream of the pharmaceutical factories and were highest where human population densities also were high. Although explicit links are not shown, results suggest that pollution has increased background AR levels in a setting where other causes of AR are less prevalent.

Assessment of heavy metal levels in Almendares River sediments--Havana City, Cuba.

The Almendares River watershed covers a large portion of Havana, Cuba and is centrally important to both recreational and other activities in the region. In order to assess current water quality conditions prior to planned remediation efforts, the spatial distribution of six heavy metals and other compounds were determined in river sediments at fifteen sampling stations in the watershed. Metal concentrations in sediments ranged from 86.1 to 708.8 for Zn, 39.3 to 189.0 for Pb, 71.6 to 420.8 for Cu, 84.4 to 209.7 Cr, 1.5 to 23.4 for Co, and 1.0 to 4.3 for Cd microg/g dry weight sediment. Calculated enrichment factors (EF; measured metal versus background mineral conditions) were almost always greater than 1.0, suggesting significant anthropogenic impact on metal levels in the river. The highest EF values were seen immediately below Cotorro (EF>10 for Pb, Cu, and Cd), a suburban town that has an active secondary smelter, and below the largest municipal landfill in Havana (EF>10 for Pb, Cu, Cd, and Zn). Further, three sampling stations had multiple metals at concentrations higher than probable effects concentrations (PEC), implying possible local ecotoxicological impacts. Finally, sequential extractions of the sediments indicated that heavy metals were largely associated with the organic fraction, and it was estimated that up to 62% of metals in the sediments would be susceptible to release back into the water column if hydraulic or other changes occurred in the river. These data are being used to prioritize decisions related to the remediation of the river system.