Revista Internacional de Contaminación Ambiental
Not a member yet
1371 research outputs found
Sort by
LA ACTIVIDAD MINERA DEL SIGLO XX EN EL VALLE DE OAXACA: RIESGOS DE SALUD PÚBLICA DE HOY
Get PDFThe abandonment of mining is a topic that has gone unnoticed in the national debate since the mid-twentieth century, as well as in the normativity. The tailings, stacks of ground rocks that remain after the minerals of interest are extracted from the rocks, have a socio-environmental impact. However, the responsibilities of companies, the State and, in general, of civil society against the contaminating effects of tailings have not been defined. The present study evaluates the socio-environmental situation in San Jerónimo Taviche, Oaxaca, Mexico, where transnational companies generated large volumes of tailings. To evaluate the environmental part, 10 samples of water bodies and 13 soil samples were analyzed in which the concentration level of the total heavy metals (cadmium, copper, mercury, lead and zinc) was quantified by atomic absorption spectrophotometry. To evaluate the social aspects, semi-structured interviews were conducted with the miners, telesecundaria students and doctors from the health center, where the working conditions, the extraction processes of the heavy metals and the most common diseases in the miners were registered. It was found that the concentrations of some metals exceed the limits established by current Mexican normativity; in addition, interviews showed that the population is unaware of the health risks arising from the tailings. The present investigation allows understanding the vision of the sanitary and environmental risks that the abandoned tailings represent for the population.El abandono de la minería es un tema que ha pasado inadvertido tanto en el debate nacional desde mediados del siglo XX como en la normatividad. Los jales, apilamientos de rocas molidas que quedan después de que los minerales de interés son extraídos, tienen un impacto socio-ambiental. Sin embargo, no se han definido las responsabilidades de las empresas, del Estado y, en general, de la sociedad civil frente a los efectos contaminantes de los jales. El presente estudio evalúa la situación socio-ambiental en San Jerónimo Taviche, Oaxaca, México, donde empresas trasnacionales generaron grandes volúmenes de jales. Para evaluar la parte ambiental se analizaron 10 muestras de cuerpos de agua y 13 muestras de suelo en las que se cuantificó, mediante espectrofotometría de absorción atómica, el nivel de concentración de los metales pesados totales cadmio, cobre, mercurio, plomo y zinc. Para evaluar el aspecto social se realizaron entrevistas semiestructuradas a los mineros, alumnos de la telesecundaria y médicos del centro de salud, donde se registraron las condiciones laborales, los procesos de extracción de metales pesados y las enfermedades más comunes en los mineros. Se encontró que las concentraciones de algunos metales sobrepasan los límites establecidos por la normatividad mexicana vigente; además, las entrevistas muestran que las personas no conocen los riesgos ante el problema de la contaminación proveniente de los jales. La presente investigación permite entender la visión del riesgo sanitario y ambiental que representan los jales abandonados para la población
ESTADO DE LA VALORIZACIÓN DE BIORRESIDUOS DE ORIGEN RESIDENCIAL EN GRANDES CENTROS URBANOS
Get PDFIn the current study a literature review of household biowaste valorization in large urban centers of developing countries in Latin America and the Caribbean, as well as high-income countries worldwide, was performed. From the analysis of scientific and technical literature of official entities of the two evaluated contexts, 70 large urban centers (37 from Latin America and the Caribbean and 33 from high-income countries), from a total of 34 countries, were studied. The results indicated that household biowaste valorization is established in at least 27 large urban centers, three of them in Latin America and the Caribbean and 24 in high-income countries of North America, Europe, Asia and Oceania. In these, the implementation of 14 type-systems was identified. Although there are differences between the evaluated contexts, the most used treatment methods are composting and anaerobic digestion. Other methods used are thermal processing for animal food production and mechanical biological treatment with composting and with anaerobic digestion. It was evidenced that the implemented systems produce compost (mainly used in gardening and agriculture), electric power, heat, vehicular fuel and animal feed. Finally, despite the relevance of the household biowaste stream in Latin America and the Caribbean large urban centers, and the benefits of its recovery, the results of this study showed the predominance of household biowaste landfilling in this context. In consequence, it is recommended to establish the household biowaste as a priority fraction whose valorization should be the primary aim of management systems.En este estudio se revisó el estado del arte de la valorización de biorresiduos de origen residencial (BOR) en grandes centros urbanos (GCU) de países en desarrollo de América Latina y el Caribe (ALC) y países de alto ingreso económico (AIE) a nivel mundial. A partir del análisis de la literatura científica y técnica de entidades oficiales de los dos contextos evaluados, se estudiaron 70 GCU (37 de ALC y 33 de países de AIE) de 34 países. Los resultados señalaron que la valorización de los BOR es una práctica establecida en al menos 27 GCU, tres de ellos en ALC y 24 en AIE de Norteamérica, Europa, Asia y Oceanía. En éstos se identificó la implementación de 14 sistemas-tipo. Aunque con diferencias entre los contextos evaluados, los métodos de tratamiento más usados son el compostaje y la digestión anaerobia. Otros métodos utilizados son el procesamiento térmico para producción de alimentos para animales y el tratamiento mecánico biológico (TMB) con compostaje y digestión anaerobia. Se evidenció que los sistemas implementados producen compost (empleado principalmente en la jardinería y la agricultura), energía eléctrica, calor, combustible vehicular y alimentos para animales. Por último, pese a la relevancia del flujo de BOR en los GCU de ALC y los beneficios de su valorización, los resultados de este estudio evidenciaron la predominancia de la disposición final de BOR en este contexto, para el cual se recomienda establecer a los BOR como una fracción prioritaria cuya valorización debe ser la finalidad de los sistemas de gestión
MINING APPLICATIONS OF IMMOBILIZED MICROBIAL CELLS IN AN ALGINATE MATRIX: AN OVERVIEW
Get PDFImmobilized microbial cells have been used extensively in various industrial processes. However, immobilized cells have not been used widely for mining industrial applications. Cell immobilization consists of a technique by which microorganisms are confined through physical or chemical interactions in a matrix, or fixed to the surface of the immobilizing agent. In recent years, entrapment of cells within spheres of Ca2+ alginate has become the most widely used technique for immobilizing living cells. This review examines many of the scientific and technical aspects involved in using Ca2+ alginate immobilized microbial cells in mining activities, with a particular focus on the biohydrometallurgical industrial applications and processes of soil bioremediation in heavy metal contaminated mining areas, environmental recovery of atmospheric emissions containing H2S and treatment of acid mine drainage.Immobilized microbial cells have been used extensively in various industrial processes. However, immobilized cells have not been used widely for mining industrial applications. Cell immobilization consists of a technique by which microorganisms are confined through physical or chemical interactions in a matrix, or fixed to the surface of the immobilizing agent. In recent years, entrapment of cells within spheres of Ca2+ alginate has become the most widely used technique for immobilizing living cells. This review examines many of the scientific and technical aspects involved in using Ca2+ alginate immobilized microbial cells in mining activities, with a particular focus on the biohydrometallurgical industrial applications and processes of soil bioremediation in heavy metal contaminated mining areas, environmental recovery of atmospheric emissions containing H2S and treatment of acid mine drainage
VALIDACIÓN DE UNA METODOLOGÍA PARA LA DETERMINACIÓN DE As(III) Y As(V) EN AGUAS DE CONSUMO HUMANO POR CROMATOGRAFÍA DE INTERCAMBIO ANIÓNICO Y ESPECTROMETRÍA DE MASAS CON PLASMA DE ACOPLAMIENTO INDUCTIVO
Get PDFA methodology was optimized and validated for the determination of soluble and particulate arsenic (As[III] and As[V]) in drinking water using anion exchange chromatography (AEC) and inductively coupled plasma mass spectrometry (ICP-MS). The AEC optimization consisted in a laboratory simulation of the procedure to be followed in the field to evaluate the recovery of 10 mixtures of As(III) and As(V) in synthetic water. The following figures of merit were obtained in the total arsenic analysis: detection limit (LOD) of 0.1 μg/L, quantification limit (LOQ) of 0.2 μg/L, linear range between 0.1 μg/L and 300 μg/L, and coefficients of determination ≤ 0.9996. Repeatability and intermediate repeatability were evaluated with a total arsenic standard solution of 12.5 μg/L, obtaining an average repeatability of 12.6 μg/L with a standard deviation of 0.2 % and a coefficient variation of 0.2 % for n = 7, while the intermediate precision had an average of 12.6 µg/L with a standard deviation of 0.4 % and a coefficient variation of 0.3 % for n = 7.. The average recoveries in the mixtures were: total arsenic ≤ 99 %, soluble arsenic ≤ 99 % and for arsenite and arsenate ≤ 97 %.Se optimizó y validó una metodología para la determinación de arsénico soluble y particulado (As[III] y As[V]) en aguas de consumo humano (ACH) empleando cromatografía de intercambio aniónico (CIA) y espectrometría de masas con plasma de acoplamiento inductivo (ICP-MS). La optimización de CIA consistió en una simulación en el laboratorio del procedimiento a seguir en el campo, donde se evaluó la recuperación de 10 mezclas de disoluciones de As(III)/As(V) en agua sintética. Se obtuvieron las siguientes figuras de mérito en el análisis de arsénico total: límite de detección (LD) de 0.1 µg/L, límite de cuantificación (LC) de 0.2 µg/L, ámbito lineal de 0.1 µg/L a 300 µg/L y coeficientes de determinación ≤ 0.9996. La repetibilidad y repetibilidad intermedia fueron evaluadas mediante la lectura de un patrón de 12.5 µg/L de arsénico total: el promedio de repetibilidad fue de 12.6 µg/L con una desviación estándar (S0) de 0.2 µg/L y un coeficiente de variación (CV) de 0.2 % para n = 7, mientras que la repetibilidad intermedia tuvo un promedio de 12.6 µg/L con S0 = 0.4 µg/L y un CV de 0.3 % para n = 7. Las recuperaciones promedio fueron: arsénico total ≤ 99 %, arsénico soluble ≤ 99 %, y arsenito y arseniato ≤ 97 %.
ESTIMACIÓN DE LA FRACCIÓN INHALADA DE CONTAMINANTES PRIMARIOS DEL AIRE EN LA CIUDAD DE MEDELLÍN
Get PDFIntake fraction was estimated for measured pollutants in Medellín city: suspended particulates (PM10 and PM2.5), carbon monoxide (CO) and nitrogen oxides (NOx). The applicable method for primary pollutants was used, according to the existing air quality data in terms of emissions and concentrations, as a factor that can be used in the evaluation of the impact on human health due to the sources of air pollution. The data of emissions, attributable exposure concentration, amount population and breathing rates were processed for calculation. Given the importance of the spatial and temporal relationship of the variables, all data were from 2015, the last period in which the inventory of atmospheric emissions was updated. Areas of spatial representativeness were considered, obtaining cells with a CSF greater than 0.9 in Politécnico Jaime Isaza Cadavid (MED-PJIC) (PM10 and CO) and Universidad Nacional Núcleo el Volador (MED-UNNV) (PM2.5 and NOx) stations. Yearly averages of the intake fraction were: 475 and 29 ppm for PM10 and CO, respectively, at MED-PJIC station, and 151 and 64 ppm for PM2.5 and NOx, respectively, at MED-UNNV station. The intake fraction values were analyzed too by weighted respiration rates by age groups, and by hourly, daily, monthly and daily weekday averages of concentration and pollutant emission values.Se realizó la estimación de la fracción inhalada de contaminantes medidos en la ciudad de Medellín, a saber, partículas suspendidas (PM10 y PM2.5), monóxido de carbono (CO) y óxidos de nitrógeno (NOx). Se empleó el método aplicable para contaminantes de tipo primario, de acuerdo con los datos de calidad del aire existentes en términos de emisiones y concentraciones, como un factor que puede utilizarse en la evaluación del impacto de las fuentes de contaminación atmosférica en la salud humana. Para obtener el cálculo se procesaron los datos de las siguientes variables: emisiones, concentración de exposición atribuible, tamaño y tasa de respiración de la población. Dada la importancia de la relación espacial y temporal de las variables, todos los datos son de 2015, último periodo en el que se encontró actualizado el inventario de emisiones atmosféricas. Se consideró el área de representatividad espacial de las estaciones de medición de calidad del aire de la ciudad de Medellín y se obtuvieron celdas con una función de similitud de concentración (CSF, por sus siglas en inglés) mayor a 0.9 en las estaciones Politécnico Jaime Isaza Cadavid (MED-PJIC) (PM10 y CO) y Universidad Nacional Núcleo el Volador (MED-UNNV) (PM2.5 y NOx). Los promedios anuales de la fracción inhalada para estas áreas de representatividad fueron de 475 y 29 ppm para PM10 y CO, respectivamente, en la estación MED-PJIC, y de 151 y 64 ppm para PM2.5 y NOx, respectivamente, en la estación MED-UNNV. Se analizaron también los valores de la fracción inhalada utilizando las tasas ponderadas de respiración por grupos de edades, así como los promedios horarios, diarios, mensuales y para cada día de la semana de los valores de concentración y emisión de contaminantes
ASSESSMENT OF CULTURABLE BACTERIA ASSOCIATED WITH FINE PARTICULATE MATTER COLLECTED IN ANTIOQUIA COLOMBIA- SOUTH AMERICA
Get PDFIn recent years, air pollution in urban and rural environments has been increasing and is one of the factors of greatest public health concern. PM2.5 particulate matter is one of the main pollutants that deteriorate air quality. This particulate matter can carry bioaerosols as bacteria and fungi. Due to its size or aerodynamic diameter of less than 2.5 μm, it can be inhaled to the pulmonary alveoli, which is strongly associated with a rise in mortality and morbidity in exposed populations. In this research, the presence of bacteria associated with the PM2.5 fraction of particulate matter was evaluated in two urban areas (Urban-C and Urban-NW) and one rural area (Rural-N) from the Aburrá Valley (Antioquia, Colombia South America). In recent years, this region has been presenting high concentrations of PM2.5, exceeding several times the daily permissible limits (50 μg/m3) for this air pollutant. The isolation, characterization and identification of bacteria associated with PM2.5 was performed by culture-dependent techniques, molecular characterization by ribosomal intergenic spacer analysis (RISA) and 16S rDNA sequencing, respectively. The dominant phylogenetic affiliations of the bacteria were grouped into three phyla: Proteobacteria, Actinobacteria and Firmicutes. The phylum Firmicutes dominated in all sampling points with several genera such as Bacillus, Staphylococcus, Paenibacillus, Lysinibacillus, Exiguobacterium and Macrococcus. Some species of these genera have been linked to pathogenicity in plants, animals and humans. Additionally, a greater presence of possible pathogenic microorganisms in urban areas was estimated, probably influenced by the concentration of PM2.5 and environmental conditions. These results provide important information to understand the distribution and ecology of airborne bacteria and demonstrate that the atmosphere in Colombia (Aburrá Valley) harbors bacteria that are clearly an important, but understudied, component of air quality that needs to be better integrated to the public health perspective.In recent years, air pollution in urban and rural environments has been increasing and is one of the factors of greatest public health concern. PM2.5 particulate matter is one of the main pollutants that deteriorate air quality. This particulate matter can carry bioaerosols as bacteria and fungi. Due to its size or aerodynamic diameter of less than 2.5 μm, it can be inhaled to the pulmonary alveoli, which is strongly associated with a rise in mortality and morbidity in exposed populations. In this research, the presence of bacteria associated with the PM2.5 fraction of particulate matter was evaluated in two urban areas (Urban-C and Urban-NW) and one rural area (Rural-N) from the Aburrá Valley (Antioquia, Colombia South America). In recent years, this region has been presenting high concentrations of PM2.5, exceeding several times the daily permissible limits (50 μg/m3) for this air pollutant. The isolation, characterization and identification of bacteria associated with PM2.5 was performed by culture-dependent techniques, molecular characterization by ribosomal intergenic spacer analysis (RISA) and 16S rDNA sequencing, respectively. The dominant phylogenetic affiliations of the bacteria were grouped into three phyla: Proteobacteria, Actinobacteria and Firmicutes. The phylum Firmicutes dominated in all sampling points with several genera such as Bacillus, Staphylococcus, Paenibacillus, Lysinibacillus, Exiguobacterium and Macrococcus. Some species of these genera have been linked to pathogenicity in plants, animals and humans. Additionally, a greater presence of possible pathogenic microorganisms in urban areas was estimated, probably influenced by the concentration of PM2.5 and environmental conditions. These results provide important information to understand the distribution and ecology of airborne bacteria and demonstrate that the atmosphere in Colombia (Aburrá Valley) harbors bacteria that are clearly an important, but understudied, component of air quality that needs to be better integrated to the public health perspective
ESTUDIO DE LOS EFECTOS DE DIFERENTES OPCIONES DE FERTILIZACIÓN Y ROTACIONES SOBRE EL CULTIVO DE CAMELINA EN UNA REGIÓN SEMIÁRIDA DE ESPAÑA
Get PDFA study was carried out for three growing seasons on camelina (Camelina sativa L. Crantz) to evaluate its response to different fertilizers: dehydrated sewage sludge, composted sewage sludge and mineral fertilization, as well as its rotation with barley (Hordeum vulgare L.) and fallow. The camelina crop was sown in autumn and harvested in spring-summer; its germination was greater with dehydrated sewage sludge fertilization than with mineral fertilization in all seasons. The germination of the barley crop was lower with the mineral fertilization in the first growing season and with the control in the third season compared to the rest of the treatments. The development of camelina and barley was very much influenced by meteorological conditions. The last growing season had the lowest productivity due to limited rainfall and high temperature at the end of this growing season. The camelina presented the larger yields with fertilization of dehydrated sewage sludge than with control and composted sewage sludge after the first season. Barley also presented the largest productions with dehydrated sewage sludge compared to the mineral and without significant differences compared to the composted sewage sludge. After the three growing seasons, fertilizer treatments increased the amounts of nitrogen, phosphorus and potassium in the soil compared to control and organic fertilization improved soil parameters such as organic matter. The highest economic yields were for the unfertilized crop and the dehydrated sewage sludge compared to the rest of the treatments.Se realizó un estudio durante tres campañas sobre el cultivo de camelina (Camelina sativa L. Crantz) para evaluar su respuesta frente a varios tipos de fertilización: lodo deshidratado, lodo compostado y fertilización mineral. También se evaluó su rotación con el cultivo de cebada (Hordeum vulgare L.). La siembra se realizó en otoño y se la cosecha en primavera-verano. La germinación del cultivo de camelina fue mayor con la fertilización de lodo deshidratado frente a la fertilización mineral en las tres campañas. La germinación del cultivo de cebada fue menor con la fertilización mineral en la primera campaña y con el testigo en la tercera campaña frente al resto de tratamientos. El desarrollo del ciclo de ambos cultivos (camelina y cebada) estuvo muy influenciado por las condiciones meteorológicas. Se obtuvieron muy bajos rendimientos en la tercera campaña debido a baja pluviometría en primavera y altas temperaturas al final del ciclo de cultivo. La camelina presentó mayor producción con la fertilización de lodo deshidratado frente al testigo y lodo compostado tras la primera campaña. La cebada también presentó las mayores producciones con lodo deshidratado frente al mineral y sin diferencias significativas frente al lodo compostado. Tras las tres campañas agrícolas de cultivo, los tratamientos fertilizantes aumentaron las cantidades de nitrógeno, fosforo y potasio en el suelo frente al testigo y la fertilización orgánica mejoró parámetros del suelo como la materia orgánica. Los mayores rendimientos económicos fueron para el cultivo sin fertilizar y el lodo deshidratado frente al resto de tratamientos
CAMELINA (Camelina sativa L. CRANTZ) VARIETIES FOR BIODIESEL PRODUCTION. CRITERIA FOR CONVENTIONAL PLANT BREEDING
Get PDFBiodiesel and its diesel blends have been accepted worldwide as potential renewable alternative fuels to substitute petroleum diesel. Perspectives for biodiesel commercialization using Camelina sativa L. Crantz as raw material are presented in this paper. Fatty acid profiles and the morphological characterization, including production, number of seeds, thousand seed weight and fatty acid percentage were analyzed for different varieties. A further assessment, considering four parameters, viscosity, iodine value, cold filter plugging point, and cetane number, was carried out to evaluate the biodiesel quality. It was concluded that camelina varieties have a similar percentage of fatty oil content. This work shows large differences in productivity and in the selected physical and chemical properties of derived biodiesel from camelina. Results show that varieties 1072, 117 and N5 (1.9) from Camelina Company Spain could be suitable due to their high productivity (over 4.2 g per plan)t. Variety 1109 could also be used due to its low iodine value (131). Varieties 1008, 1085 and 1109 could be used due to their high cetane number (over 51). This research has identified suitable varieties for biodiesel production. Further improvement of camelina’s characteristics is needed by means of plant breeding and manipulation of culture conditions.Biodiesel and its diesel blends have been accepted worldwide as potential renewable alternative fuels to substitute petroleum diesel. Perspectives for biodiesel commercialization using Camelina sativa L. Crantz as raw material are presented in this paper. Fatty acid profiles and the morphological characterization, including production, number of seeds, thousand seed weight and fatty acid percentage were analyzed for different varieties. A further assessment, considering four parameters, viscosity, iodine value, cold filter plugging point, and cetane number, was carried out to evaluate the biodiesel quality. It was concluded that camelina varieties have a similar percentage of fatty oil content. This work shows large differences in productivity and in the selected physical and chemical properties of derived biodiesel from camelina. Results show that varieties 1072, 117 and N5 (1.9) from Camelina Company Spain could be suitable due to their high productivity (over 4.2 g per plan)t. Variety 1109 could also be used due to its low iodine value (131). Varieties 1008, 1085 and 1109 could be used due to their high cetane number (over 51). This research has identified suitable varieties for biodiesel production. Further improvement of camelina’s characteristics is needed by means of plant breeding and manipulation of culture conditions
MANUFACTURE OF LIGHTWEIGHT PREFABRICATED PANELS EMPLOYING MINE TAILINGS
Get PDFThe present study describes the incorporation of mine tailings from the silver mine La Guitarra in the manufacture of lightweight prefabricated panels (LPPs). Tailings have concentrations of heavy metals below the maximum permissible levels according to Mexican regulations. Their acidity potential (AP) of 2.22 kg of CaCO3 per tailings ton, along with their lack of neutralization potential (NP), indicates a possibility for the generation of acid mine drainage (AMD). It was reported that concrete could be employed to prevent AMD, thus we proposed to stabilize mine tailings with different concrete ratios and employ these mixtures to fabricate concrete panels. To obtain lightweight panels, a foaming agent was added to the tailings/concrete mixture. Then, a fiberglass mesh was employed to reinforce the final structure. The resulting LPPs (dimensions: 254 × 139.7 × 12.7 mm) showed a flexural strength of 5.80 ± 0.06 MPa, bulk density of 712 ± 104 kg/m3, thermal conductivity of 0.159 ± 0.004 W/m K, mass water absorption of 59 ± 10 %, and net neutralization potential (NNP = NP/AP) > 1.2. According to Mexican regulations, these LPPs are not potential generators of AMD.The present study describes the incorporation of mine tailings from the silver mine La Guitarra in the manufacture of lightweight prefabricated panels (LPPs). Tailings have concentrations of heavy metals below the maximum permissible levels according to Mexican regulations. Their acidity potential (AP) of 2.22 kg of CaCO3 per tailings ton, along with their lack of neutralization potential (NP), indicates a possibility for the generation of acid mine drainage (AMD). It was reported that concrete could be employed to prevent AMD, thus we proposed to stabilize mine tailings with different concrete ratios and employ these mixtures to fabricate concrete panels. To obtain lightweight panels, a foaming agent was added to the tailings/concrete mixture. Then, a fiberglass mesh was employed to reinforce the final structure. The resulting LPPs (dimensions: 254 × 139.7 × 12.7 mm) showed a flexural strength of 5.80 ± 0.06 MPa, bulk density of 712 ± 104 kg/m3, thermal conductivity of 0.159 ± 0.004 W/m K, mass water absorption of 59 ± 10 %, and net neutralization potential (NNP = NP/AP) > 1.2. According to Mexican regulations, these LPPs are not potential generators of AMD
ELEMENTOS POTENCIALMENTE TÓXICOS (Cd, Hg, Pb Y Zn) EN SUELOS IMPACTADOS POR PLANTA RECICLADORA DE PLOMO (ZACATECAS, MÉXICO), A UNA DÉCADA DE PARAR OPERACIONES
Get PDFCadmium (Cd), mercury (Hg), lead (Pb) and zinc (Zn) were analyzed in 75 samples of surrounding soils (7 km2) to a lead recycling plant out of operation in Fresnillo, Zacatecas, and five samples of a non-impacted soil to obtain the background regional values. Aluminum (Al) was used as a reference element for the calculation of enrichment factors (EF). A high variability was observed in the concentrations of Cd (0.02 - 9.11 μg/g), Hg (< D.L, - 2.91 μg/g), Pb (8.9 - 9216 μg/g) and Zn (31.2 - 465 μg/g). A high association was observed between Cd, Pb and Zn, but not with Al and Hg. There was an inverse association with the factory distance for the concentrations of Cd and Pb, but not for Hg and Zn. This indicates that the source of Cd and Pb was the recycling plant, while Hg and Zn may have other anthropogenic sources and/or a different behavior. Cd and Pb show a clear trend to accumulate towards the west-northwest direction. There was a significant decrease in Pb with respect to the maximum levels in 2004 (from 84 238 μg/g to 9216 μg/g) within the factory land. Even so, the FECd and FEPb varied from natural to contaminated and the contamination extends to ~ 0.5 km towards the W - NW. FEHg and FEZn were from natural to enriched levels. The high concentrations of Cd and Pb in and out of the occupied plant land make necessary the continuous monitoring of the impacted area given the potential transport of the dust to nearby populations.Se analizaron cadmio (Cd), mercurio (Hg), plomo (Pb) y zinc (Zn) en 75 muestras de suelo que circundan (7 km2) a una planta recicladora de Pb fuera de operación en Fresnillo, Zacatecas y cinco muestras de una zona no impactada para obtener los valores regionales. El aluminio (Al) fue usado como elemento de referencia para el cálculo de factores de enriquecimiento (FE). Se observó una elevada variabilidad en las concentraciones de Cd (0.02 - 9.11 µg/g), Hg (< L.D. - 2.91 µg/g), Pb (8.9 - 9216 µg/g) y Zn (31.2 - 465 µg/g). Una alta asociación fue observada entre Cd, Pb y Zn, pero no con Al y Hg. Hubo una asociación inversa con la distancia a la fundidora para las concentraciones de Cd y Pb, pero no para Hg y Zn. Esto indica que la fuente de Cd y Pb fue la planta recicladora, mientras que el Hg y el Zn pueden tener otras fuentes antrópicas o un comportamiento distinto. El Cd y el Pb muestran una clara tendencia a acumularse hacia la dirección oeste - noroeste. Hubo una significativa disminución de Pb respecto a los niveles máximos en 2004 (de 84 238 µg/g a 9216 µg/g) dentro de los terrenos de la planta. Aun así, los FECd y FEPb variaron desde naturales hasta contaminados y la contaminación se extiende a ~ 0.5 km hacia el O - NO. Los FEHg y FEZn fueron de niveles naturales a enriquecidos. Las altas concentraciones de Cd y Pb dentro y fuera del terreno ocupado por la planta hacen necesario el monitoreo continuo del área impactada, dado al transporte potencial de los polvos hacia poblaciones aledañas.