Resumo A contaminação dos recursos naturais com metais pesados liberados pelas siderúrgicas é a principal causa da poluição do solo e da água no Dargai Malakand, localizado no lado norte do Paquistão. Portanto, o presente estudo teve como objetivo determinar o teor de metais pesados em amostras de solo e água desta área. O cultivo de plantas silvestres (nove plantas nativas: Pteris vittata, Populus nigra, Eucalyptus camaldulensis, Persicaria maculosa, Arundo donax, Xanthium strumarium, Verbascum thapsus, Ricinus communis e Parthenium hysterophorus) foi testado quanto às suas capacidades de fitorremediação, que é um meio ambiente, geralmente utilizado, e abordagem de baixo custo para eliminar metais pesados de solos e águas poluídas. Amostras de solo, água e efluentes foram retiradas dos locais contaminados de sete siderúrgicas no distrito de Dargai, Malakand, e submetidas à análise de metais pesados. Com base no fator de bioconcentração (BCF) e fator de translocação (TF) calculados, o maior BCF para zinco foi registrado para as raízes de Pteris vittata (3,93), enquanto o menor valor foi observado para as folhas de Verbascum thapsus (0,306). A raiz de Pteris vittata apresentou o maior BCF para ferro (1,618), enquanto as folhas de Ricinus communis apresentaram o menor (0,023). O maior valor de BCF para cromo foi maior para raízes de Populus nigra (0,717), enquanto o menor valor foi registrado para folhas de Persicaria maculosa (0,031). Para os metais selecionados, Fe, Zn e Cr, os maiores TF foram registrados para Pteris vittata (0,988), Verbascum thapsus (0,944) e Xanthium strumairum (0,968), respectivamente. Portanto, recomenda-se que essas plantas sejam cultivadas próximas a siderúrgicas para recuperar metais pesados de efluentes industriais, solo poluído e água poluída.

Abstract The contamination of natural resources with heavy metals released from steel mills is the primary cause of soil and water pollution in the Dargai Malakand, located on the northern side of Pakistan. Therefore, the present study was aimed to determine the level of heavy metals in soil and water samples of this area. The wild plant growing (nine native plants: Pteris vittata, Populus nigra, Eucalyptus camaldulensis, Persicaria maculosa, Arundo donax, Xanthium strumarium, Verbascum thapsus, Ricinus communis and Parthenium hysterophorus) there were then tested for their phytoremediation capabilities which is an environmentally friendly, generally utilized, and low-cost approach to eliminate heavy metals from polluted soils and water. Soil, water, and effluent samples were taken from the contaminated sites of seven steel mills in Dargai District Malakand and subjected to heavy metals analysis. Based on bioconcentration factor (BCF) and translocation factor (TF) calculated, The highest BCF for zinc was recorded for Pteris vittata roots (3.93), while the lowest value was observed for Verbascum thapsus leaves (0.306). Pteris vittata root showed the highest BCF for iron (1.618), while Ricinus communis leaves showed the lowest (0.023). The highest BCF value for chromium was highest for Populus nigra roots (0.717), while the lowest value was recorded for Persicaria maculosa leaves (0.031). For the selected metals; Fe, Zn and Cr the highest TF were recorded for Pteris vittata (0.988), Verbascum thapsus (0.944) and Xanthium strumairum (0.968) respectively. Therefore, it is recommended that these plants should be grown near to steel mills to reclaim heavy metals from industrial effluent, polluted soil as well as from polluted water.

As an example of a developing megacity the Greater Cairo (GC) area in Egypt has been evaluated with respect to atmospheric particulate matter (PM) and lead (Pb). Particulate matter was collected during 2001-2002 in the two size fractions PM2 5 and PM10 at 17 sites representing different activities (industrial, urban, residential and background condition). The PM concentrations were generally high, with yearly average PM2.5 and PM10 values of 85 ± 12 and 170 ± 25 µg/m-3, respectively. On an annual scale, the high PM levels were due to many sources that included traffic, waste burning and wind blown dust particles emitted from the desert outside GC and the Moqattam hill inside GC. On a seasonal scale, the PM concentrations were highest in the industrial sector during spring, the dusty season, due to the combined effect of dust storm events and anthropogenic emissions over GC. The lowest seasonal concentrations were recorded in the summer season at the background sites. There was a marked increase in PM levels during the period October to December due to burning of waste from harvested rice in the agriculture area in the Nile Delta (north of Cairo). The highest PM2.5/PM10 ratio was recorded in the urban sector (0.59) while the lowest ratio was recorded in the residential sector (0.32). The PM2.5 and PM10 samples were also analyzed for Pb in order to address the influence of different emission sources. The monthly average concentrations of Pb in both PM2.5 (Pb2.5) and PM10 (Pb10) varied between 0.4 and 1.8 ± µg m-3 at the non industrial sites. The concentrations were significantly higher in the industrial areas, where concentration up to a maximum of 16 ± g m-3 could be observed. Both the high lead and PM concentrations measured are contributing to local environmental pollution. GC is subjected to high concentrations of particulates most of the year. There is no annual limit for PM10 concentrations in the Egyptian law of environment, but comparing to the 24 hour average, PM10 is representing health risks on the long-term that will give both regionally and globally environmental effects. High volume samplers measuring PM10 as daily average shows that the air quality limit value has been exceeded at sites Heliopolis (35), Maadi (6) and 6th October (13) during 60.47, 79.07, and 62.96% of the measuring period of 2001, and at Shoubra El-Kheima (20), El-Qolaly Sq (1), and Abbasiya (36) during 100.0, 91.7, and 89.8% of the measuring period of 2002. Thus, the evaluation of the data presented in this paper will serve as a basis for future regional and global modelling and source apportionment.

Como ejemplo de una mega ciudad en desarrollo se evaluó el área del Gran Cairo, Egipto (GC) en relación con las partículas (PM) y el plomo (Pb) atmosféricos. Las partículas se colectaron durante 2001-2002 en dos tamaños de fracción, PM2.5 y PM10 de 17 sitios representativos de diferentes características (industriales, urbanas, residenciales y ambiente no alterado). Las concentraciones de partículas fueron en general altas, con promedios anuales de 85 ± 12 ug m-3 para PM2.5 y de 170 ± 25 para PM10. En una escala anual, los niveles elevados de PM se deben a varias fuentes que incluyen el tráfico, la incineración de desechos, partículas de polvo transportadas por el viento desde el desierto fuera del GC, y dentro del GC desde la colina Moqattam. En una escala estacional, las concentraciones de PM son más elevadas en el sector industrial durante la primavera, la estación polvosa, debido al efecto combinado de las tormentas de polvo y las emisiones antrópicas en el GC. Las concentraciones estacionales más bajas se registraron en el verano en los sitios no alterados. Hubo un incremento notable en los niveles de PM durante el periodo de octubre a diciembre debido a la incineración de desechos de las cosechas de arroz en el área del delta del Nilo (al norte del Cairo). La relación PM2.5/PM10 más alta (0.59) que se registró corresponde al sector urbano, mientras que la más baja (0.32) es del sector residencial. Las muestras de PM2.5 y PM10 también se analizaron para Pb con el fin de determinar la influencia de diferentes fuentes de emisión. Las concentraciones promedio mensuales de Pb en PM2.5 (Pb2.5) y PM10 (Pb10) variaron entre 0.4 y 1.8 µg m-3 en los sitios no industriales. Las concentraciones fueron significativamente mayores en las áreas industriales, en las que se observó un máximo de 16 µg m-3. Las concentraciones elevadas de Pb y PM determinadas contribuyen a la contaminación ambiental local. El GC está sujeto a concentraciones elevadas de partículas durante todo el año. No hay un límite anual para las concentraciones de PM10 en la ley ambiental egipcia, pero al compararlas con los promedios de 24 h, las PM10 representan riesgos de largo plazo a la salud ya que tienen efectos ambientales locales y regionales. Los muestreos de alto volumen de PM10 considerados como promedios diarios muestran que los límites de calidad del aire se excedieron 60.47, 79.07 y 62.96 % en los sitios Heliopolis (35), Maadi (6) y 6 de Octubre (13) durante el periodo de medición de 2001 y 100, 91.7 y 89.8 % en Shoubra El-Kheima (20), El-Qolay Sq (1) y Abbasiya (36) durante el periodo de 2002. La evaluación de los datos presentados en este trabajo servirá como base para futuras modelaciones regionales y globales y para la clasificación de las fuentes.

We have established a relationship between net longwave radiation and planetary albedo at the surface and at the top of the atmosphere. It was found that there is an inverse relationship between the longwave radiation and the planetary albedo at both the surface and the top of the atmosphere. Latitudinal changes were also found to be a significant factor in addition to the seasonal one in the behavior of this relationship. This type of relationship can be helpful in understanding the climate cycle and explain many radiation budget problems.

Hemos establecido una relación entre la radiación de onda larga neta y el albedo planetario en la superficie y en la alta atmósfera. Se encontró que hay una relación inversa entre la radiación de onda larga y el albedo planeterio, tanto en la superficie como en la alta atmósfera. Cambios latitudinales también fueron encontrados como un factor significativo, en adición al estacional en el comportamiento de esta relación. Este tipo de relación puede ayudar a entender los ciclos climáticos y explicar muchos problemas de balance de radiación.

Ultrasonography can reveal most of the manifestations of portal hypertension complicating hepatosplenic, schistosomiasis. However, direct demonstration of gastroesophageal varices by ultrasonography is still very difficult. An attempt was done to correlate sonographic features of portal hypertension with the degree of fibrosis to screen patients having varices and predicting their chance of bleeding. The results obtained were found to be consistent with the esophagogastric endoscopy and with history of hematemesis. Four parameters were used, size of spleen, degree of periportal fibrosis, presence of collaterals and portal vein diameter. A pilot field survey was also done adopting the same principle.