34 research outputs found
Heavy metals as an indicator of ecological impact of a fragmented land uses, San Luis Potosi, Mexico
La necesidad de estudiar la presencia
de metales pesados en el suelo radica en su
impacto como indicador de contaminación
ambiental. Se determinó la presencia de Cu,
Zn, Pb y Cd en suelos donde se distribuyen
especies vegetales en un corredor ecológico.
Entre los municipios de Soledad de Graciano
Sánchez y San Luis Potosí (México) fueron
establecidos 30 puntos distribuidos en cinco
prácticas dominantes de usos de suelo:
agropecuario, residencial rural, comercio y
servicios, residencial urbano y minero. Los
muestreos se realizaron en cuatro épocas
durante 2009 y 2010 (verano, otoño, invierno y
primavera). Se encontró un efecto significativo
del uso del suelo en cuanto a los niveles de
Cu (p = 0,000), Pb (p = 0,043) y Cd (p = 0,010).
En el caso del Zn, el uso del suelo (p = 0,000)
y la estación (p = 0,059) fueron significativos.
El uso del suelo minero mostró las mayores
concentraciones de metales y el agrícola las
menores. Los niveles de los cuatro metales se
encuentran en el rango marcado como alto por
la EPA y por otras fuentes técnicas. En el caso
de Pb y Cd no rebasan los estándares NOM-147-
SEMARNAT-SSA1. Estos resultados reflejan
el potencial indicativo del uso del suelo en la
evaluación de la calidad ambiental, sin embargo,
se requiere continuar con un monitoreo de
metales pesados en la zona.The need to study the presence of heavy
metals in the soil lies on their impact as a indicator
of environmental pollution. Therefore, it was
determined the presence of Cu, Zn, Pb and Cd
in soils where plant species were distributed in
an ecological corridor. Among the municipalities
of Soledad Graciano Sanchez and San Luis
Potosi (Mexico), 30 points were established,
distributed in five land uses: agricultural , rural
residential, trade and services, urban residential
and mining. Sampling was conducted from
2009 to 2010 (summer, fall, winter and spring).
A significant effect of land use was found in
terms of Cu (p = 0.000), Pb (p = 0.043) and
Cd (p = 0.010). In the case of Zn both the land
use (p = 0.000) and season (p = 0.059) had
significant effects. It is emphasized that mining
land use presented the highest concentrations
of the studied metals and agricultural land use
the lowest. The levels of four metals are in the
range marked like high by the EPA and other
technical sources. The levels of Pb and Cd do not
exceed the NOM-147-SEMARNAT-SSA1. These
results reflect the indicative potential of the soil
and its consideration for future to evaluate the
habitat of plant species. These results reflect the
potential indicative land use in the assessment
of environmental quality, however, requires
continued monitoring of heavy metals in the area.Fil: Alcalá Jáuregui, Jorge.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Ávila Castorena, Cecilia.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Rodríguez Ortíz, Juan C..
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Hernández Montoya, Alejandra.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Beltrán Morales, F. Alfredo.
Universidad Autónoma de Baja California Sur (México)Fil: Rodríguez Fuentes, Humberto.
Universidad Autónoma de Nuevo León (México). Facultad de Agronomía.Fil: Loya Ramírez, J. Guadalupe.
Universidad Autónoma de Baja California Sur (México
Vegetative as bioindicators of heavy metals in a semiarid system
Evaluar la contaminación por metales
pesados en los ecosistemas permite conocer la
capacidad bioindicativa de especies vegetativas.
El objetivo fue determinar la concentración
de metales pesados en Prosopis laevigata,
Acacia spp. y Schinus molle bajo el efecto de
usos suelo y temporalidad. El área se sitúa en
la colindancia de los Municipios de Soledad
de Graciano Sánchez y San Luis Potosí
fragmentada por usos de suelo: agropecuario,
comercio y servicios, residencial urbano y
minero. Fueron tomadas muestras de hojas de
las tres especies en las estaciones de verano,
otoño, invierno y primavera y se evaluó la
concentración de metales pesados a través de
la técnica de ICP-MS. Los análisis estadísticos
indicaron niveles de Aluminio (Al) > Cinc (Zn) >
Plomo (Pb) > Cobre (Cu) > Titanio (Ti) >
Vanadio (V) > Arsénico (As) > Cromo (Cr) >
Cadmio (Cd) > Cobalto (Co). Los elementos
Al, As, Cd, Cr, Pb y Ti presentaron niveles por
encima del umbral normal en vegetación. El
uso de suelo tuvo efecto significativo con Al,
Ti, Cd, As y Pb; los árboles ubicados en los
usos de suelo minero, comercio y servicios
tuvieron la mayor concentración. La especie
tuvo efecto significativo con Al y Pb siendo
Acacia spp. el que presentó la mayor capacidad
de acumulación. La temporada del año impactó
significativamente en la acumulación de As, Cd,
Co, Cu, Cr y Ti en las tres especies. La dinámica
antropogénica de los diferentes usos de suelo
genera partículas y residuos con metales
pesados impactando en la disponibilidad
y acumulación en las especies evaluadas.
Se contribuye a evaluar el impacto ambiental
en el sistema fragmentado recomendando dar
continuidad a este tipo de estudios.The evaluation of pollution by heavy metals
on ecosystems can determine the bioindicative
capacity of plant species. The presence of
heavy metals was determined in Prosopis
laevigata, Acacia spp. and Schinus molle under
the effect of different of land uses and seasons.
The area is located near of the municipalities
of Soledad de Graciano Sánchez and San
Luis Potosi which has fragmented land use
such as: agriculture, commercial and services,
urban residential and mining. Samples were
taken from leaves of the three species during
summer, autumn, winter and spring to assess
the concentrations of heavy metals through
the technique of ICP-MS. Statistical analyzes
showed levels of Aluminum (Al) > Zinc (Zn)
> Lead (Pb) > Copper (Cu) > Titanium (Ti) >
Vanadium (V) > Arsenic (As) > Chromium (Cr)
> Cadmium (Cd) > Cobalt (Co). The elements
Al, As, Cd, Cr, Pb and Ti had levels above the
normal threshold in vegetation. Land use had a
significant effect with Al, Ti, Cd, As and Pb having
the trees being located in the land with mining
and commercial and services use the greater
concentrations. The species had a significant
effect on Al and Pb with Acacia spp., having
the largest storage capacity. The season of the
year significantly impacted the accumulation of
As, Cd, Co, Cu, Cr and Ti in the three species.
The anthropogenic dynamics of different land
uses generated waste particles and residues
of heavy metals, impacting the availability and
accumulation in the species evaluated. This
study contribute to evaluate the environmental
impact in the system with a fragmented land
use and the continuation of this type of studies
is recommended.Fil: Alcalá Jáuregui, Jorge.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Rodríguez Ortíz, Juan C..
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Villaseñor Zuñiga, María Elena.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Hernández Montoya, Alejandra.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: García Arreola, María Elena.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Beltrán Morales, F. Alfredo.
Universidad Autónoma de Baja California Sur (México)Fil: Rodríguez Fuentes, Humberto.
Universidad Autónoma de Nuevo León (México). Facultad de Agronomía
Contaminación por metales pesados en sedimentos de un área ribereña en San Luis Paotosí, México
The aim of this study was to determine the presence of heavy metal in sediments of a fragmented riparian area, as an indicator of environmental pollution in San Luis Potosi, Mexico. Eleven sampling points, including four different land uses were established: Pond, Agriculture, Livestock and Rural Settlement. Sediment samples were taken during the seasons of spring, summer and autumn 2010, and winter 2011. The technique of ICP-MS was used to determine Pb, Cd, Cu, and Zn data analysis was performed with Minitab®. Land use has an effect on the accumulation of Cu, Zn and Cd, with the agricultural area containing the highest concentrations. The season was a significant factor for concentrations of Zn, Cd and Pb, emphasizing spring 2010 and autumn 2010, respectively. Significant correlations were found between Cu-Zn (r = 0.746), Pb-Cu (r = 0.635) and Cd-Zn (r = 0.720). The normal limits of Cu, Cd, Zn and Pb in sediments established by the Canadian Environmental Quality Guidelines were exceeded. By using other scientific and technical sources, maximum levels of Cu, Cd and Pb were defined with a condition of high pollution. This condition is attributed to the land use change dynamics, to wastewater discharges, and urban, agricultural and livestock wastes. Thus, a further environmental assessment is recomended for the study area.Se determinó la presencia de metales pesados en sedimentos de un sistema ribereño fragmentado por usos de suelo como indicador de contaminación ambiental en San Luis Potosí, México. Se establecieron once puntos de muestreo considerando los usos de suelo: Estanque, agrícola, Asentamiento rural y Ganadero. Durante las estaciones de primavera, verano y otoño de 2010 e invierno 2011, se tomaron muestras de sedimentos. Se utilizó la técnica de ICP-MS para determinar Pb, Cd, Cu and Zn y los datos fueron analizados en Minitab®. El uso de suelo incide en la acumulación de Cu, Zn y Cd, siendo la zona agrícola la que cuenta con mayores concentraciones. La estación fue significativa respecto de las concentraciones de Zn, Cd y Pb, destacando primavera 2010 y otoño 2010 respectivamente. Asimismo, fueron encontradas correlaciones significativas entre Cu-Zn (r = 0,746), Pb-Cu (r = 0,635) y Cd-Zn (r = 0,720). Los límites normales de Cu, Cd, Zn y Pb en sedimentos establecidos por la Canadian Environmental Quality Guidelines fueron rebasados. Con otras fuentes se definieron que los niveles máximos de Cu, Cd y Pb presentaron una condición alta de contaminación. Esta condición es atribuida a la dinámica de usos de suelo, descargas de aguas residuales, desechos sólidos urbanos, agrícolas y ganaderos, recomendándose continuar su evaluación ambiental
Metallic elements in foliar material and fruits of three tree species as bioindicators
This study aimed to determine the presence of metal elements in fruits and leaves of three tree species as bioindicators in San Luis Potosi, Mexico. Ninety fruit and 90 leaf samples (30 per tree species) were collected at five sites (agricultural, suburban, commercial and services, urban, and mining), using the site and the presence of P. laevigata, S. molle, and A. farnesiana as references. Total concentrations of 13 metal elements were determined using an inductively coupled plasma mass spectrometer (ICP-MS). The species were significantly affected by Co, As, and Pb (ANOVA, p≤0.05). Considering the land use and the species, the contents determined in the leaves and fruits of the three species had sufficient and phytotoxic contents of Al, Cd, Co, Ni, Mn, Ti, and Cr, and excessive ranges with the possible phytotoxic effect of As, Cu, Pb, Zn, V, and Fe. The A. farnesiana had the highest concentrations of 12 heavy metals analyzed (HM). The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%, with V, As, and Cr being prominent. The functionality of these tree species as phytoremediators and bioindicators is reviewed to evaluate environmental impacts on land use.
Highlights
Tree species represent a potential bioindicator for studying environmental pollutants due to their ability to accumulate heavy metals.
The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%
The contents determined in the leaves and fruits of the three species trees had sufficient and phytotoxic HM contents.
The tree species have phytoremediators capacity to evaluate environmental impacts and environmental contamination of land use.This study aimed to determine the presence of metal elements in fruits and leaves of three tree species as bioindicators in San Luis Potosi, Mexico. Ninety fruit and 90 leaf samples (30 per tree species) were collected at five sites (agricultural, suburban, commercial and services, urban, and mining), using the site and the presence of P. laevigata, S. molle, and A. farnesiana as references. Total concentrations of 13 metal elements were determined using an inductively coupled plasma mass spectrometer (ICP-MS). The species were significantly affected by Co, As, and Pb (ANOVA, p≤0.05). Considering the land use and the species, the contents determined in the leaves and fruits of the three species had sufficient and phytotoxic contents of Al, Cd, Co, Ni, Mn, Ti, and Cr, and excessive ranges with the possible phytotoxic effect of As, Cu, Pb, Zn, V, and Fe. The A. farnesiana had the highest concentrations of 12 heavy metals analyzed (HM). The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%, with V, As, and Cr being prominent. The functionality of these tree species as phytoremediators and bioindicators is reviewed to evaluate environmental impacts on land use.
Highlights
Tree species represent a potential bioindicator for studying environmental pollutants due to their ability to accumulate heavy metals.
The variation in total metal concentrations between leaves and fruits ranged from 84.70 to 99.06%
The contents determined in the leaves and fruits of the three species trees had sufficient and phytotoxic HM contents.
The tree species have phytoremediators capacity to evaluate environmental impacts and environmental contamination of land use
Indicators of restoration strategies in land uses: metallic and non-metallic elements
Land management practices can have an impact on the environmental quality of soil and contribute to identifying the source of its pollution. The objective of this study was to determine presence of metallic and non-metallic elements as indicators of land use impact (livestock management, restoration strategies and without management practices) in the Monte Caldera communal lands located in Cerro de San Pedro, San Luis Potosi, Mexico. Eighteen samples were collected at depths of 0-10 cm and 10-20 cm for each land use. Total concentrations of Zr, Sr, U, Th, Pb, As, Rb, Cr, V, Ti, Zn, and Cu were determined by X-ray fluorescence. Mean concentrations ranged in the following order: Ti>Zr>Rb>V>Sr>Zn>Cr>Pb> Cu>Th>U>As, with concentrations for Ti, Cr, Th, U and As exceeding technical reference values for phytotoxic soils. Significant differences were evidenced by ANOVA between land use (Th, Pb, Rb, Cu) and soil depth (U, Pb, and As). Land use practices associated with restoration resulted in a positive environmental impact. These findings underscore the need to conduct follow-up studies in the area and further examine the relationship of such practices with other environmental factors.
Highlights:
Soil management practices can affect the environmental quality of this resource and help diagnose the source of its contamination.
It is necessary to evaluate the Impact of land use on livestock management, restoration strategies, and without management or conservation areas.
By X-ray fluorescence technique the total concentration of Zr, Sr, U, Th, Pb, As, Rb, Cr, V, Ti, Zn, and Cu was determined.
Ti, Cr, Th, U and As exceed the technical reference values for consideration as phytotoxic in soils.
Land use associated with reclamation practices is an indicator of a positive influence on improving soil quality.Land management practices can have an impact on the environmental quality of soil and contribute to identifying the source of its pollution. The objective of this study was to determine presence of metallic and non-metallic elements as indicators of land use impact (livestock management, restoration strategies and without management practices) in the Monte Caldera communal lands located in Cerro de San Pedro, San Luis Potosi, Mexico. Eighteen samples were collected at depths of 0-10 cm and 10-20 cm for each land use. Total concentrations of Zr, Sr, U, Th, Pb, As, Rb, Cr, V, Ti, Zn, and Cu were determined by X-ray fluorescence. Mean concentrations ranged in the following order: Ti>Zr>Rb>V>Sr>Zn>Cr>Pb> Cu>Th>U>As, with concentrations for Ti, Cr, Th, U and As exceeding technical reference values for phytotoxic soils. Significant differences were evidenced by ANOVA between land use (Th, Pb, Rb, Cu) and soil depth (U, Pb, and As). Land use practices associated with restoration resulted in a positive environmental impact. These findings underscore the need to conduct follow-up studies in the area and further examine the relationship of such practices with other environmental factors.
Highlights:
Soil management practices can affect the environmental quality of this resource and help diagnose the source of its contamination.
It is necessary to evaluate the Impact of land use on livestock management, restoration strategies, and without management or conservation areas.
By X-ray fluorescence technique the total concentration of Zr, Sr, U, Th, Pb, As, Rb, Cr, V, Ti, Zn, and Cu was determined.
Ti, Cr, Th, U and As exceed the technical reference values for consideration as phytotoxic in soils.
Land use associated with reclamation practices is an indicator of a positive influence on improving soil quality
Metales pesados en polvo atmosférico depositado en hojas de Acacia farnesiana (Fabaceae) y Prosopis laevigata (Fabaceae)
Atmospheric dust establishes an element of study to know the distribution of
pollutant particles such as heavy metals and their effects on ecological systems. The
objective was to determine the elemental composition of particles deposited in two
species of trees as an indicator of environmental impact in San Luis Potosí, México. The
distribution of Acacia farnesiana and Prosopis laevigata trees was taken into account
in five soil uses to collect leaf material and extract atmospheric dust during the spring
and summer seasons, determining the concentration of heavy metals using the ICP-MS
technique. The results indicated the presence of Al> Cu> Zn> Pb> V> As> Ni> Cd> Ti>
Cr> Co. Correlations with values of r2> 0.90 were presented between V-Ti, Ni-V, Ni-Ti,
Al-Ti and Cr-V. The species factor conditioned the concentrations of Al, Ti, V, Cr, Ni and
Zn mainly in the particles deposited in Prosopis leaves. Particles of nine elements were
conditioned by the activities of the five land uses, where the use of mineral soil affected
by the presence of Al, Cd, Co, Pb, Cu and Zn. Concentrations of Cd were 6.2 times higher
in the use of mining soil than in the agricultural sector; 5.9 and 5.4 times the concentrations
of Co and Pb in the use of mining soil with respect to the trade and service respectively.
The season had only significant effects on Cr and Pb particles. This study indicates
the existence of pollutants that can affect ecological systems so it falls within the context
of continued evaluation of environmental impacts.El polvo atmosférico se establece como elemento de estudio para conocer la
distribución de partículas contaminantes, como son los metales pesados y sus efectos
sobre los sistemas ecológicos. El objetivo fue determinar la composición elemental de
las partículas depositadas en dos especies de árboles como un indicador de impacto
ambiental en San Luis Potosí, México. La distribución de los árboles de Acacia farnesiana
y Prosopis laevigata se tomó en cuenta en cinco usos del suelo para recolectar
material foliar y extraer el polvo atmosférico durante la primavera y el verano, determinando
la concentración de metales pesados utilizando la técnica ICP-MS. Los resultados
indicaron la presencia de Al> Cu> Zn> Pb> V> As> Ni> Cd> Ti> Cr> Co. Se presentaron
correlaciones con valores de r2> 0,90 entre V-Ti, Ni-V, Ni-Ti, Al-Ti y Cr-V. El factor especie
condicionó las concentraciones de Al, Ti, V, Cr, Ni y Zn principalmente en las partículas
depositadas en las hojas de Prosopis. Las partículas de nueve elementos fueron condicionadas
por las actividades de los cinco usos de la tierra, donde el uso del suelo mineral
se vio afectado por la presencia de Al, Cd, Co, Pb, Cu y Zn. Las concentraciones de Cd
fueron 6,2 veces más altas en el uso de suelo minero que en el sector agrícola; 5,9 y 5,4
veces las concentraciones de Co y Pb en el uso del suelo minero con respecto al comercio
y al servicio, respectivamente. La temporada solo tuvo efectos significativos sobre las
partículas de Cr y Pb. Este estudio indica la existencia de contaminantes que pueden
afectar los sistemas ecológicos, por lo que entran en el contexto de la evaluación de los
impactos ambientales.Fil: Jorge Alcalá Jáuregui.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Juan C. Rodríguez Ortiz.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Alejandra Hernández Montoya.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: María Flavia Filippini.
Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Eduardo Martinez Carretero.
Instituto Argentino de Investigaciones de las Zonas Áridas Fil: Paola Elizabeth Díaz Flores.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Ángel Natanael Rojas Velázquez.
Universidad Autónoma de San Luis Potosí. Facultad de AgronomíaFil: Humberto Rodríguez-Fuentes.
Universidad Autónoma de Nuevo León (México). Facultad de Agronomía.Fil: Félix Alfredo Beltrán Morales.
Universidad Autónoma de Baja California Sur (México
Use of a micro title plate dilution assay to measure activity of antifungal compounds against mycosphaerella fijiensis, morelet.
Black Sigatoka, caused by the fungus Mycosphaerella fijiensis is the most important disease in banana plantations. The fungus is controlled mainly by fungicide applications with an annual cost of about 350 million dollars in Latin and Central America. Due to the appearance of resistant strains and to the economical and environmental impact caused by the extensive use of fungicides, accurate methods are necessary for monitoring the fungal sensitivity to these agents. In this paper we describe the standarization of a method basedmon microplate dilutions that measures IC50 of different antifungal compounds against single ascospore cultures of M. fijiensis. The method was used to measure the sensitivity of 30 strains collected from different regions in Colombia against Propiconazol, Benomyl and Azoxystrobin. Used at a larger scale, this method could be useful to monitor M. fijiensis sensitivity against fungicides and to search for new compounds with activity against the fungus
Metales pesados como indicador de impacto de un sistema ecológico fragmentado por usos de suelo, San Luis Potosí, México
La necesidad de estudiar la presenciade metales pesados en el suelo radica en suimpacto como indicador de contaminaciónambiental. Se determinó la presencia de Cu,Zn, Pb y Cd en suelos donde se distribuyenespecies vegetales en un corredor ecológico.Entre los municipios de Soledad de Graciano Sánchez y San Luis Potosí (México) fueron establecidos 30 puntos distribuidos en cinco prácticas dominantes de usos de suelo: agropecuario, residencial rural, comercio y servicios, residencial urbano y minero. Los muestreos se realizaron en cuatro épocas durante 2009 y 2010 (verano, otoño, invierno y primavera). Se encontró un efecto significativo del uso del suelo en cuanto a los niveles de Cu (p = 0,000), Pb (p = 0,043) y Cd (p = 0,010). En el caso del Zn, el uso del suelo (p = 0,000) y la estación (p = 0,059) fueron significativos. El uso del suelo minero mostró las mayores concentraciones de metales y el agrícola las menores. Los niveles de los cuatro metales se encuentran en el rango marcado como alto por la EPA y por otras fuentes técnicas. En el caso de Pb y Cd no rebasan los estándares NOM-147- SEMARNAT-SSA1. Estos resultados reflejan el potencial indicativo del uso del suelo en la evaluación de la calidad ambiental, sin embargo, se requiere continuar con un monitoreo de metales pesados en la zona.La necesidad de estudiar la presenciade metales pesados en el suelo radica en suimpacto como indicador de contaminaciónambiental. Se determinó la presencia de Cu,Zn, Pb y Cd en suelos donde se distribuyenespecies vegetales en un corredor ecológico.Entre los municipios de Soledad de Graciano Sánchez y San Luis Potosí (México) fueron establecidos 30 puntos distribuidos en cinco prácticas dominantes de usos de suelo: agropecuario, residencial rural, comercio y servicios, residencial urbano y minero. Los muestreos se realizaron en cuatro épocas durante 2009 y 2010 (verano, otoño, invierno y primavera). Se encontró un efecto significativo del uso del suelo en cuanto a los niveles de Cu (p = 0,000), Pb (p = 0,043) y Cd (p = 0,010). En el caso del Zn, el uso del suelo (p = 0,000) y la estación (p = 0,059) fueron significativos. El uso del suelo minero mostró las mayores concentraciones de metales y el agrícola las menores. Los niveles de los cuatro metales se encuentran en el rango marcado como alto por la EPA y por otras fuentes técnicas. En el caso de Pb y Cd no rebasan los estándares NOM-147- SEMARNAT-SSA1. Estos resultados reflejan el potencial indicativo del uso del suelo en la evaluación de la calidad ambiental, sin embargo, se requiere continuar con un monitoreo de metales pesados en la zona
Vegetación bioindicadora de metales pesados en un sistema semiárido
The evaluation of pollution by heavy metals on ecosystems can determine the bioindicative capacity of plant species. The presence of heavy metals was determined in Prosopis laevigata, Acacia spp. and Schinus molle under the effect of different of land uses and seasons. The area is located near of the municipalities of Soledad de Graciano Sánchez and San Luis Potosi which has fragmented land use such as: agriculture, commercial and services, urban residential and mining. Samples were taken from leaves of the three species during summer, autumn, winter and spring to assess the concentrations of heavy metals through the technique of ICP-MS. Statistical analyzes showed levels of Aluminum (Al) > Zinc (Zn) > Lead (Pb) > Copper (Cu) > Titanium (Ti) > Vanadium (V) > Arsenic (As) > Chromium (Cr) > Cadmium (Cd) > Cobalt (Co). The elements Al, As, Cd, Cr, Pb and Ti had levels above the normal threshold in vegetation. Land use had a significant effect with Al, Ti, Cd, As and Pb having the trees being located in the land with mining and commercial and services use the greater concentrations. The species had a significant effect on Al and Pb with Acacia spp., having the largest storage capacity. The season of the year significantly impacted the accumulation of As, Cd, Co, Cu, Cr and Ti in the three species. The anthropogenic dynamics of different land uses generated waste particles and residues of heavy metals, impacting the availability and accumulation in the species evaluated. This study contribute to evaluate the environmental impact in the system with a fragmented land use and the continuation of this type of studies is recommended.Evaluar la contaminación por metales pesados en los ecosistemas permite conocer la capacidad bioindicativa de especies vegetativas. El objetivo fue determinar la concentración de metales pesados en Prosopis laevigata, Acacia spp. y Schinus molle bajo el efecto de usos suelo y temporalidad. El área se sitúa en la colindancia de los Municipios de Soledad de Graciano Sánchez y San Luis Potosí fragmentada por usos de suelo: agropecuario, comercio y servicios, residencial urbano y minero. Fueron tomadas muestras de hojas de las tres especies en las estaciones de verano, otoño, invierno y primavera y se evaluó la concentración de metales pesados a través de la técnica de ICP-MS. Los análisis estadísticos indicaron niveles de Aluminio (Al) > Cinc (Zn) > Plomo (Pb) > Cobre (Cu) > Titanio (Ti) > Vanadio (V) > Arsénico (As) > Cromo (Cr) > Cadmio (Cd) > Cobalto (Co). Los elementos Al, As, Cd, Cr, Pb y Ti presentaron niveles por encima del umbral normal en vegetación. El uso de suelo tuvo efecto significativo con Al, Ti, Cd, As y Pb; los árboles ubicados en los usos de suelo minero, comercio y servicios tuvieron la mayor concentración. La especie tuvo efecto significativo con Al y Pb siendo Acacia spp. el que presentó la mayor capacidad de acumulación. La temporada del año impactó significativamente en la acumulación de As, Cd, Co, Cu, Cr y Ti en las tres especies. La dinámica antropogénica de los diferentes usos de suelo genera partículas y residuos con metales pesados impactando en la disponibilidad y acumulación en las especies evaluadas. Se contribuye a evaluar el impacto ambiental en el sistema fragmentado recomendando dar continuidad a este tipo de estudios
<em>In vitro</em> Evaluation of the Phagocytosis Activity of Neutrophils and Characterization of <em>Staphylococcus aureus</em> Mastitis in Dairy Cows of Small Family Farms
A total of 269 cows in small family herds in the central region of México from different municipalities of México State were studied. Composed milk samples were obtained to detect subclinical mastitis and S. aureus infection and for characterization of phenotypes as follows: biotypes, capsular exopolysaccharide 5 and 8, ORSA/MRSA and MRSA strains; and in vitro phagocytosis neutrophil activity and apoptosis by S. aureus serotype 5. Results were evaluated by estimating proportions and chi-square test (p < 0.05). The microbial isolation rate was 46%; S. aureus isolation rate was 23.4–21.0% among cow herds; 39% of microbial isolates were in 1500–2500 cells/mL, with Wisconsin test. The phenotypes of S. aureus were: biotypes A and C are identified frequently that produce alpha and beta-hemolysin toxins, and a smaller proportion other hemolysins types. S. aureus isolates capsular serotypes 5 and 8 show differences in the in vitro neutrophil phagocytosis activity and apoptosis. The ORSA/MRSA isolates show that MRSA strains? mec A gene was confirmed by PCR. The S. aureus infection level in the dairy cow herds shows a wide municipal distribution, identifying different S. aureus pathotypes enclosed to virulence factors and MRSA to establish a potential health risk in small dairy cow herds in México