Refinar búsqueda
Resultados 1-10 de 10
Source apportionments of ambient fine particulate matter in Israeli, Jordanian, and Palestinian cities
2017
Heo, Jongbae | Wu, Bo | Abdeen, Ziad | Qasrawi, Radwan | Sarnat, Jeremy A. | Sharf, Geula | Shpund, Kobby | Schauer, James J.
This manuscript evaluates spatial and temporal variations of source contributions to ambient fine particulate matter (PM2.5) in Israeli, Jordanian, and Palestinian cities. Twenty-four hour integrated PM2.5 samples were collected every six days over a 1-year period (January to December 2007) in four cities in Israel (West Jerusalem, Eilat, Tel Aviv, and Haifa), four cities in Jordan (Amman, Aqaba, Rahma, and Zarka), and three cities in Palestine (Nablus, East Jerusalem, and Hebron). The PM2.5 samples were analyzed for major chemical components, including organic carbon and elemental carbon, ions, and metals, and the results were used in a positive matrix factorization (PMF) model to estimate source contributions to PM2.5 mass. Nine sources, including secondary sulfate, secondary nitrate, mobile, industrial lead sources, dust, construction dust, biomass burning, fuel oil combustion and sea salt, were identified across the sampling sites. Secondary sulfate was the dominant source, contributing 35% of the total PM2.5 mass, and it showed relatively homogeneous temporal trends of daily source contribution in the study area. Mobile sources were found to be the second greatest contributor to PM2.5 mass in the large metropolitan cities, such as Tel Aviv, Hebron, and West and East Jerusalem. Other sources (i.e. industrial lead sources, construction dust, and fuel oil combustion) were closely related to local emissions within individual cities. This study demonstrates how international cooperation can facilitate air pollution studies that address regional air pollution issues and the incremental differences across cities in a common airshed. It also provides a model to study air pollution in regions with limited air quality monitoring capacity that have persistent and emerging air quality problems, such as Africa, South Asia and Central America.
Mostrar más [+] Menos [-]What nutrient sources support anomalous growth and the recent sargassum mass stranding on Caribbean beaches? A review
2019
Oviatt, Candace A. | Huizenga, Kristin | Rogers, Caroline S. | Miller, W Jeff
Since 2011, tropical beaches from Africa to Brazil, Central America, and the Caribbean have been inundated by tons of sargassum seaweed from a new equatorial source of pelagic sargassum in the Atlantic. In recent years the extraordinary accumulations of sargassum make this a nuisance algal bloom for tropical coasts. In 2018 satellite data indicated floating mats of sargassum that extended throughout the Caribbean to the northeast coast of Brazil with the highest percent coverage over the water yet recorded. A literature review suggests that Atlantic equatorial recirculation of seaweed mats combined with nutrients from several possible sources may be stimulating the growth and accumulations of sargassum. In the western equatorial recirculation area, new nutrient sources may include Amazon River floods and hurricanes; in the eastern equatorial recirculation area, nutrient sources that could sustain the sargassum blooms include coastal upwelling and Congo River freshwater and nutrients.
Mostrar más [+] Menos [-]An overview of plastic straw policies in the Americas
2021
Neto, Arnaldo Mailes | Gomes, Thiago Santiago | Pertel, Mônica | Vieira, Louise A.V.P. | Pacheco, Elen B.A.V.
Although plastic straws account for a small fraction of urban residue, they are also found in marine and coastal waste, raising concerns in the community and resulting in policies to curb or ban improper disposal. These policies are still little documented and discussed in the scientific literature. This review article aims at surveying, categorizing and analyzing existing regulations on the American continent (North, Central and South America and the Caribbean). The regulations were analyzed in terms of straw bans; obligations regarding the type of raw material used in manufacturing; accessibility-related exceptions to bans; and the adoption of environmental education measures. A total of 363 regulations enacted in 62.8% of American countries were examined, 37% of which need technical standards to support their requirements. In Central America and the Caribbean, it is primarily the regulations that provide environmental education. Locations with a strong beach tourism economy have enacted plastic straw regulations.
Mostrar más [+] Menos [-]Metals and metalloids in whole blood and tissues of Olive Ridley turtles (Lepidochelys olivacea) from La Escobilla Beach (Oaxaca, Mexico)
2014
Cortés-Gómez, Adriana A. | Fuentes-Mascorro, Gisela | Romero, Diego
Concentrations of eight metals and metalloids (Pb, Cd, Cu, Zn, Mn, Se, Ni and As) were evaluated from 41 nesting females (blood) and 13 dead (tissues) Olive Ridley turtles (Lepidochelys olivacea), a species classified as vulnerable and also listed in Appendix I of the Convention of International Trade in Endangered Species (CITES). The mean blood, liver and kidney lead concentration were 0.02±0.01, 0.11±0.08 and 0.06±0.03μgg−1 ww respectively, values lower than other turtle species and locations, which it could be due to the gradual disuse of leaded gasoline in Mexico and Central America since the 1990s. Mean concentration of cadmium was 0.17±0.08 (blood), 82.88±36.65 (liver) and 150.88±110.99μgg−1 (kidney). To our knowledge, the mean renal cadmium levels found is the highest ever reported worldwide for any sea turtle species, while other six elements showed a concentration similar to other studies in sea turtles.
Mostrar más [+] Menos [-]Chronic kidney disease of unknown etiology in India: a comparative study with Mesoamerican and Sri Lankan nephropathy
2022
Jolly, Aleeta Maria | Thomas, Jaya
Chronic kidney disease of unknown etiology [CKDu] is a condition characterized by decline in kidney function and is not associated with diabetic nephropathy or hypertensive nephropathy. In this review, we have done a detailed literature analysis on CKDu in India, and then had a comparison with that of Mesoamerica and Sri Lanka. In India, CKDu became the second most common type of CKD after diabetic nephropathy. Silica was seen in the groundwater of both India and Sri Lanka, whereas in Mesoamerica silica exposure through particulate matter was seen among CKDu communities. DDE is a common agrochemical seen in both India and Sri Lanka. The risk factors vary from region to region and it is important to categorize CKDu population based on the risk factors to avoid misinterpretation of the condition as non-CKDu category and to evade further complications. More studies have to be conducted to reveal the detailed pathophysiological mechanisms and its relation with irrational exploitation of environmental resources.
Mostrar más [+] Menos [-]Mollusc and sediment contaminant levels and trends in south Florida coastal waters
1997
Cantillo, A.Y. | Lauenstein, G.G. | O'Connor, T.P. (Office of Ocean Resources, Conservation and Assessment, NO AA/National Ocean Service, 1305 East West Hwy, Silver Spring, MD 20910 (USA))
Trace organic contamination in the Americas: an overview of the US National Status and Trends and the International 'Mussel Watch' programmes
1995
Sericano, J.L. | Wade, T.L. | Jackson, T.J. | Brooks, J.M. | Tripp, B.W. | Farrington, J.W. | Mee, L.D. | Readmann, J.W. | Villeneuve, J.P. | Goldberg, E.D. (Geochemical and Environmental Research Group, College of Geosciences and Maritime Studies, Texas AandM University, College Station, TX 77845 (USA))
Persistent organophosphorus pesticides in tropical marine environments
1992
Readman, J.W. | Kwong, L.L.W. | Mee, L.D. | Bartocci, J. | Nilve, G. | Rodriguez-Solano, J.A. | Gonzalez-Farias, F. (International Atomic Energy Agency, Marine Environment Laboratory, PO Box 800, MC-98012 (Monaco))
The impact of biomass burning emissions on protected natural areas in central and southern Mexico
2021
Trujano-Jiménez, Fabiola | Ríos, Blanca | Jaramillo S., Alejandro (Jaramillo Sánchez) | Ladino, Luis A. | Raga, Graciela B.
Biomass burning from grassland, forests, and agricultural waste results in large amounts of gases and particles emitted to the atmosphere, which affect air quality, population health, crop development, and natural vegetation. Regional atmospheric circulations can transport those plumes of pollutants over hundreds of kilometers, affecting vulnerable environments such as those considered protected natural areas (PNAs). This study evaluates the spatiotemporal distribution of active fires detected, and associated emissions, in central and southern Mexico from satellite data between March and June 2017, to assess the impact of the smoke plumes on protected ecosystems. The arrival of smoke plumes to selected PNAs (both near large urban centers and in remote areas) is assessed using airmass forward trajectories from selected emission sources. The spatial distribution of the remotely derived aerosol optical depth confirms the regional impact of particle emissions from the observed fires on PNAs, particularly in central Mexico. The identified areas of high fire density are also associated with large coarse particle concentrations at the surface. Moreover, there is a significant contribution of organic carbon to the total coarse particle mass, 60% on average. Finally, while most of the impact in ambient pollution is observed in PNAs located close to the regions with active fires in southern Mexico and Central America, the long-range transport of smoke plumes reaching the USA was also confirmed.
Mostrar más [+] Menos [-]Crayfishes (Astacidae) of North and Middle America
1972
Hobbs, Horton H. (Horton Holcombe)