Tiem and space variations of sulfur dioxide concentrations in the metropolitan area of Mexico City

1990 ◽  
Vol 29 (3) ◽  
pp. 137-147
Author(s):  
H. Bravo A ◽  
R. Torres J.
Keyword(s):  
Sulfur Dioxide ◽  
Mexico City ◽  
Metropolitan Area ◽  
La Red

Se analizan las variaciones espaciales y temporales del bióxido de azufre (SO2) en la atmósfera de la Zona Metropolitana de la Ciudad de M{exico (ZMCM) para varios períodos de 1986 a 1989. Se utilizan mediciones horarias registradas por la red de monitoreo gubernamental (SEDUE) y por la estación de monitoreo del Centro de Ciencias de la Atmósfera, UNAM. El análisis cubre los siguientes aspectos: variaciones espaciales y temporales de SO2 en base anual estacional, mensual, semanal y horaria. Se incluye un an{alisis y discusi{on de la tendencia invernal del SO2 en la zona Sur de fuentes emisoras en la ZMCM.El análisis anual señala que las mayores concentraciones se presentan al norte de la ZMCM, donde se localiza la zona industrial, disminuyendo la concentrancion del SO2 en la dirección del viento dominante. La norma primaria de calidad del aire del EPA para SO2 de 30 ppb es rebasada en la mayor parte de la ZMCM. Los meses invernales presentan el mayor problema en toda el área urbana. El ciclo semanal indica que en los días laborales los niveles de SO2 son significativamente mayores comparados con los presentes en los días de descanso conforme a la cercanía de a la zona industrial. El cliclo diurno señala que la concentración pico de SO2 varía en tiempo y distancia de las fuentes emisoras de ZMCM.La tendencia de concentración del SO2 en el campus de la universidad de México indica que el problema es creciente desde 1986, en contra de loq eu previamente han señalado diversos organismos públicos en México.

scholarly journals A Health Risk Assessment of Lead and Other Metals in Pharmaceutical Herbal Products and Dietary Supplements Containing Ginkgo biloba in the Mexico City Metropolitan Area

2021 ◽  
Vol 18 (16) ◽  
pp. 8285
Author(s):  
Patricia Rojas ◽  
Elizabeth Ruiz-Sánchez ◽  
Camilo Ríos ◽  
Ángel Ruiz-Chow ◽  
Aldo A. Reséndiz-Albor
Keyword(s):  
Health Risk ◽  
Dietary Supplements ◽  
Mexico City ◽  
Metropolitan Area ◽  
Ginkgo Biloba ◽  
Graphite Furnace ◽  
Human Health Risk ◽  
Daily Intake ◽  
Herbal Remedies ◽  
Herbal Products

The use of the medicinal plant Ginkgo biloba has increased worldwide. However, G. biloba is capable of assimilating both essential and toxic metals, and the ingestion of contaminated products can cause damage to health. The aim of this study was to investigate the safety of manganese (Mn), copper (Cu), lead (Pb), arsenic (As), and cadmium (Cd) in 26 items containing Ginkgo biloba (pharmaceutical herbal products, dietary supplements, and traditional herbal remedies) purchased in the metropolitan area of Mexico City. Metal analysis was performed using a graphite furnace atomic absorption spectrometer. All of the products were contaminated with Pb, 54% of them with As, and 81% with Cd. The lowest values of Pb, As, and Cd were detected in pharmaceutical herbal products > dietary supplements > traditional herbal remedies. The daily intake dose (DID) of pharmaceutical herbal products was within the established limits for the five metals. Dietary supplements and traditional herbal remedies exceeded the DID limits for Pb. The hazard quotients estimation and non-carcinogenic cumulative hazard estimation index for Mn, As, and Cd indicated no human health risk. Our results suggest that products containing G. biloba for sale in Mexico are not a health risk.

Fuel-based motor vehicle emission inventory for the metropolitan area of Mexico city

2005 ◽  
Vol 39 (5) ◽  
pp. 931-940 ◽  
Author(s):  
I. Schifter ◽  
L. Díaz ◽  
V. Múgica ◽  
E. López-Salinas
Keyword(s):  
Mexico City ◽  
Metropolitan Area ◽  
Emission Inventory ◽  
Motor Vehicle ◽  
Vehicle Emission

Indicators of environmental contamination by heavy metals in leaves of Taraxacum officinale in two zones of the metropolitan area of Mexico City

2017 ◽  
Vol 25 (5) ◽  
pp. 4739-4749 ◽  
Author(s):  
Sandra Gómez-Arroyo ◽  
Arisbel Barba-García ◽  
Francisco Arenas-Huertero ◽  
Josefina Cortés-Eslava ◽  
Michel Grutter de la Mora ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Mexico City ◽  
Metropolitan Area ◽  
Environmental Contamination ◽  
Taraxacum Officinale

Impact of sulfur-in-gasoline on motor vehicle emissions in the metropolitan area of Mexico City☆

Fuel ◽  
2003 ◽  
Vol 82 (13) ◽  
pp. 1605-1612 ◽  
Author(s):  
I Schifter ◽  
L Dı́az ◽  
M Vera ◽  
E Guzmán ◽  
E López-Salinas
Keyword(s):  
Mexico City ◽  
Metropolitan Area ◽  
Vehicle Emissions ◽  
Motor Vehicle ◽  
Motor Vehicle Emissions

scholarly journals In situ measurements of speciated atmospheric mercury and the identification of source regions in the Mexico City Metropolitan Area

2009 ◽  
Vol 9 (1) ◽  
pp. 207-220 ◽  
Author(s):  
A. P. Rutter ◽  
D. C. Snyder ◽  
E. A. Stone ◽  
J. J. Schauer ◽  
R. Gonzalez-Abraham ◽  
...  
Keyword(s):  
Point Source ◽  
Mexico City ◽  
Metropolitan Area ◽  
Atmospheric Mercury ◽  
Point Sources ◽  
Rural Site ◽  
Urban Site ◽  
Trajectory Data ◽  
Source Regions ◽  
Rural Sites

Abstract. In order to expand the currently limited understanding of atmospheric mercury source-receptor relationships in the Mexico City Metropolitan Area, real time measurements of atmospheric mercury were made at a downtown urban site, and a rural site on the outskirts of Mexico City, during March 2006. Numerous short-lived increases in particulate mercury (PHg) and reactive gaseous mercury (RGM) concentrations were observed at the urban site during the 17 day study, and less frequent increases in gaseous elemental mercury (GEM) concentrations were measured at both the urban and rural sites. The episodic increases observed were attributed to plume impacts from industrial point source emissions in and around Mexico City. Average concentrations and standard deviations measured during the study were as follows: i) urban site; PHg=187±300 pg m−3, RGM=62±64 pg m−3, GEM=7.2±4.8 ng m−3, and; ii) rural site; GEM=5.0±2.8 ng m−3. Several source regions of atmospheric mercury to the urban and rural sites were determined using Concentration Field Analysis, in which atmospheric mercury measurements were combined with back trajectory data to determine source regions. Only some source regions correlated to mercury emission sources listed in the Federal Pollutant Release and Transfer Register, leaving the rest unaccounted for. Contributions of anthropogenic mercury point sources in and around Mexico City to concentration averages measured at the urban site during the study were estimated to be: 93±3% of reactive mercury (PHg and RGM), and; 81±0.4% of GEM. Point source contributions to GEM measured at the rural site were 72±1%. GEM and reactive mercury (PHg+RGM) were not found to correlate with biomass burning at either of the measurement sites.

scholarly journals Warm Spells and Climate Risk to Human Health in the Mexico City Metropolitan Area

2020 ◽  
Vol 12 (3) ◽  
pp. 351-365
Author(s):  
Nuria Vargas ◽  
Víctor Magaña
Keyword(s):  
Mexico City ◽  
Metropolitan Area ◽  
Urban Expansion ◽  
Threshold Value ◽  
Early Warning Systems ◽  
Natural Vegetation ◽  
Mitigation Strategies ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
Canopy Layer

AbstractDuring the second half of the twentieth century, rapid demographic growth and urban expansion led to the development of the Mexico City metropolitan area (MCMA) urban heat island (UHI). The thermal gradient between rural and urban regions is used to define the UHI in the transition zone along the 26°C isotherm of mean maximum temperature. As the MCMA expands, more natural vegetation is replaced with urbanization, and the spatial extent of the 26°C isotherm grows. The loss of natural vegetation, in a densely populated region of Mexico, leads to the formation of a canopy-layer UHI. The intensification of the MCMA UHI results in an increase in the frequency of daily maximum temperatures above 30°C (above 26°C on a weekly average), a threshold value that constitutes a natural hazard. Warm-spell occurrences are related to an increase in the number of acute diarrhea diseases (ADD), mainly in zones of the MCMA where the socioeconomic and environmental conditions are low (e.g., insufficient access to potable water). Vulnerable people are mostly located in new settlements along the periphery of the MCMA, where large numbers of hospital discharges due to ADD are reported. The combined effect of more frequent warm spells and increasing vulnerability results in higher levels of risk of suffering this type of health problem, mainly during the warmest part of the year. This analysis may serve to develop UHI mitigation strategies and early warning systems to manage high levels of ADD risk during warm spells.

Prenatal exposure to particulate matter and ozone: Bulky DNA adducts, plasma isoprostanes, allele risk variants, and neonate susceptibility in the Mexico City Metropolitan Area

2019 ◽  
Vol 60 (5) ◽  
pp. 428-442 ◽  
Author(s):  
Jorge A. Maciel‐Ruiz ◽  
Cristina López‐Rivera ◽  
Rogelio Robles‐Morales ◽  
Maria G. Veloz‐Martínez ◽  
Raquel López‐Arellano ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Mexico City ◽  
Prenatal Exposure ◽  
Dna Adducts ◽  
Metropolitan Area ◽  
Risk Variants ◽  
Bulky Dna Adducts
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