Distribution of Ultraviolet solar Radiation at Riyadh Region, Saudi Arabia

The ultraviolet UV solar radiation flux is monitored over a fixed time interval to study the daily, monthly and annual variations for a nearly one decade in Riyadh. Mathematical expressions will be presented based on a comparison between theoretical and experimental values. It is believed that the present analysis of UV radiation suggest that the environmental effects led to a better understanding of UV scattering, UV reflection, ozone and clouds layers in Riyadh and other selected areas in the mid-east region.     

Chemical Composition of Bottled Water in Saudi Arabia

Fourteen domestic and seven imported bottled water brands were analysed in Saudi Arabia for various physico-chemical water quality parameters. The results of the analysis were compared with the drinking water standards set by Saudi Arabia and World Health Organization. The levels of different physico-chemical parameters like TDS, Ca, Mg, Na, K, NO₃, Cl and SO₄ of all local and imported bottled water brands met the different drinking water standards. Fluoride was found below the Saudi Arabian Standard Organization recommended limits in two of the local brands whereas fluoride levels in all of the imported brands were below the recommended values. In one imported brand, pH was found not conforming to the recommended standards. The concentrations of trace metals in all brands were within the drinking water standards. Comparison of the study results with the reported label values indicated good agreement with stated pH values but considerable variation for Ca, Mg, and Na in the local brands and comparatively low variation in the imported brands. Low F and SO₄ variations were found in the local brands and comparatively high SO₄ variation in the imported brands.     

Metal pollution records in core sediments of some Red Sea coastal areas, Kingdom of Saudi Arabia

In the last three decades, the industrial and human activities in the coastal area of Saudi Arabia have increased dramatically and resulted in the continuous invasion of different types of pollutants including heavy metals. Seven sediment cores were collected from three major industrialized areas; Jeddah, Rabigh and Yanbu, along the coast of Saudi Arabia to determine the spatial and temporal distribution of metals and to assess the magnitude of pollution and their potential biological effects. Sediments were analyzed for texture, calcium carbonate contents, organic matter and metals (Al, Fe, Mn, Cd, Cr, Cu, Ni, Pb and Zn). Some metals like, Cr, Mn, Ni and Zn, were enriched in the upper 15 cm of core samples (recent deposition of sediments). Cadmium concentrations showed high fluctuations with depth and reverse pattern to that for Al, Fe and Mn which indicated land based sources of this element to the studied areas. Elevated concentrations of lead were recorded in the bottom layers of cores in Jeddah that indicated the most dramatic increase in usage of gasoline in early 1970s. The calculated contamination factors (CF's) were found in the following sequences: Cd > Pb > Ni > Cu > Zn > Cr > Mn for all studied areas. Results of Pollution Load Index (PLI) revealed that Jeddah is the most polluted area, followed by Rabigh while Yanbu is the least contaminated area. Except for Ni, the concentrations of most metals in the majority of sediment samples were believed to be safe for living organisms. As no data were available on the concentration of metals in core sediments in the coastal area of Saudi Arabia, the results of this study would serve as a baseline against which future anthropogenic effects can be assessed.     

Spatial distribution and metal contamination in the coastal sediments of Al-Khafji area,Arabian Gulf,Saudi Arabia

To document the spatial distribution and metal contamination in the coastal sediments of the Al-Khafji area in the northern part of the Saudi Arabian Gulf, 27 samples were collected for Al, V, Cr, Mn, Cu, Zn, Cd, Pb, Hg, Sr, As, Fe, Co, and Ni analysis using inductively coupled plasma-mass spectrometer (ICP-MS). The results revealed the following descending order of the metal concentrations: Sr > Fe > Al > As > Mn > Ni > V > Zn > Cr > Cu > Pb > Co > Hg > Cd. Average levels of enrichment factor of Sr, As, Hg, Cd, Ni, V, Cu, Co, and Pb were higher than 2 (218.10, 128.50, 80.94, 41.50, 12.31, 5.66, 2.95, 2.90, and 2.85, respectively) and that means the anthropogenic sources of these metals, while Al, Zn, Cr and Mn have enrichment factor less than 2, which implies natural sources. Average values of Sr, Hg, Cd, Cr, Ni, and As in the coastal sediments of Al-Khafji area were mostly higher than the values recorded from the background shale and earth crust and from those results along coasts of the Caspian Sea and the Mediterranean Sea. The highest levels of Cu in the northern part of the studied coastline might be due to Al-Khafji desalination plant, while levels of Al, Ni, Cr, Fe, Mn, Pb, and Zn in the central part may be a result of landfilling and industrial sewage. The highest levels of As, Cd, Co, Cu, Hg, and V in the southern part seem to be due to oil pollutants from Khafji Joint Operations (KJO). The higher values of Sr in the studied sediments in general and particularly in locality 7 could relate to the hypersalinity and aragonitic composition of the scleractinian corals abundant in that area.     

Quality assessment of various bottled waters marketed in Saudi Arabia

This study focuses on the chemical analysis of the available brands of domestic bottled water in Riyadh City, Saudi Arabia. The distribution of the chemical constituents (major, minor, and trace elements) is determined and compared with the chemical content labeled on the bottles and with drinking water standards of Saudi Arabian, World Health Organization, and U.S. Environmental Protection Agency. The obtained results indicated that except for fluoride and bromate, the concentrations of dissolved salts, soluble cations and anions, nitrate, and trace elements of most bottled waters on sale were within the permissible limits set by standards used. On the other hand, the comparison between determined and reported label values recorded a substantial variation in some parameter values. Results indicated that more than 18 % of the sampled bottled waters exceeded the allowable limits for drinking water. Generated Piper diagrams revealed that the majority of investigated waters were sodium chloride–sulfate type; however, the hydrochemical modeling indicated that all water samples were undersaturated for anhydrite, gypsum, and halite.     

Heavy metals in cooler waters in Riyadh, Saudi Arabia

Water samples were collected from 400 coolers in Riyadh area. From each cooler, one feed and one cooled water samples were collected. These samples were analyzed for trace metals like Al, Cr, Cu, Fe, Mn, Ni, Pb, and Zn by Inductively Coupled Plasma (ICP) Spectrophotometer equipped with ultrasonic nebulizer. Out of 400 coolers, water from 382 (95.50%) were found to meet World Health Organization (WHO), Saudi Arabian Standards Organization (SASO), and United States Environmental Protection Agency (USEPA) drinking water standards whereas water from 18 coolers (4.50%) were found to have elevated levels of Fe, Pb, and Ni metals. In one cooler, water was allowed to stand for 12 h and a 1 L sample collected every 2 h. All the metals mentioned above with the exception of Pb were found to increase due to standing time.     

Fluoride Content in Drinking Water Supplies of Riyadh, Saudi Arabia

Groundwater supplies about 34% ofthe total water demand for the capital city of SaudiArabia, Riyadh. The other 66% is desalinatedseawater. The fluoride level in Riyadh drinking watersupplies was evaluated. Samples were collected fromselected wells, treatment plants, desalinatedseawater, distribution network and 19 locally producedand imported bottled water. The fluoride level in theinfluent to the seven groundwater treatment plants andtheir final product water were in the range of 0.63–1.6 and 0.23–1.1 mg/L, respectively. Blending of theplants product water with the desalinated seawaterresulted in the fluoride level ranging from 0.01–0.5 mg/Lin the distribution network. Ninety percent of thesamples collected from the distribution network hadfluoride levels less than or equal to the calculatedweighted average value of 0.24 mg/L. The locallyproduced bottled waters as compared to 8 imported oneshave shown fluoride levels in the range of 0.2–0.83and 0.04–0.2 mg/L, respectively. In general, thefluoride level in Riyadh drinking water supplies isbelow the optimum recommended level of 0.7 to1.2 mg/L. It is therefore recommended thatfluoridation be considered in water treatment plants.     

Study of summer heat exposure at the ground services operations of a main international airport in Saudi Arabia

Summer heat in coastal subtropical Jeddah, augmented by heat from operating ground servicing equipment in King Abdul-Aziz International Airport (KAAIA), presents a major occupational problem to ground service operators, particularly the air traffic control coordinator (ATCC), that hinders their work efficiency and induces health disorders to them. The present study was conducted to assess the magnitude of this problem and propose heat control strategy and remedial actions for the Saudi Arabian Airlines (SAUDIA). Heat parameters including air temperature (T (a)), wet bulb temperature (T (w)), globe temperature (T (g)) and air velocity were measured around serviced planes and in other locations used by ATCC, and the WBGT and the ATCC-WBGT-TWAs were computed. Mostly all the T (a) measurements, and many T (w) measurements, were higher than T (a) and T (w) forecasted by the Presidency of Meteorology and Environment (PME) due to heat dissipated from operating vehicles and equipment in service. The measured and PME forecasted parameters have good and medium linear correlations (T (a): r (2) = 0.74 and T (w): r (2) = 0.64). The computed WBGT in the service stations around planes are considerably higher than the 25 and 27.5 degrees C recommended TLV(R) for non-acclimatized and acclimatized operators. However, the computed ATCC- WBGT-TWA levels indicate that the shift-work-schedule which was recommended to be implemented by SAUDIA has successfully reduced their heat exposure to acceptable levels, except for a very few operators (6.7% exceeding WBGT-TLV(R) of 25 degrees C and 2.2% exceeding TLV(R) of 27.5 degrees C) for whom the shift-work schedules might be corrected to achieve safe heat exposure.     

Levels of Selected Metals in Canned Fish Consumed in Kingdom of Saudi Arabia

In the present paper, seven heavy metals (Pb, Cd, Ni, Cu, Zn, Cr and Fe) in canned salmon, sardine and tuna fish were determined by using atomic absorption spectroscopy. Cadmium and lead levels were determined by graphite tube AAS whereas Ni, Cu, Cr and Fe were determined by flame AAS. Analytical results were validated by spiking the samples with various concentrations of these metals for recovery. The metal contents, expressed in μg/g, wet weight, varied depending upon the specie studied. The levels of Pb ranged from 0.03–1.20 μg-g⁻¹ with an average of 0.313 μg-g⁻¹ for salmon; 0.03–0.51 μg-g⁻¹ with an average of 0.233 μg-g⁻¹ for tuna and 0.13–1.97 μg-g⁻¹ with an average of 0.835 μg-g⁻¹ for sardines. The levels of Cd ranged from 0.02–0.38 μg-g⁻¹ with an average of 0.161 μg-g⁻¹ for salmon; 0.07–0.64 μg-g⁻¹ with an average of 0.227 μg-g⁻¹ for tuna and 0.010–0.690 μg-g⁻¹ with an average of 0.183 μg-g⁻¹ for sardines. Comparative evaluation of these metals in three varieties of fish showed that average concentration of lead in sardines is about 4 times and Ni about 3 times higher as compared to tuna. Generally, the levels of these metals follow the order sardine > salmon > tuna. The data generated in the present study compared well with the similar studies carried out in different parts of the world. The results indicate that canned fish, in general and tuna in particular, have concentrations within permissible limits of WHO/FAO levels for these heavy metals. Therefore, their contribution to the total body burden of these metals can be considered as negligibly small.     

Noise pollution in textile,printing and publishing industries in Saudi Arabia

A study of 20 factories belonging to textile, printing, publishing and paper products industries in Jeddah was conducted.Data on Leq, Maximum and Minimum SPL at different octave bands, as well as dBA, were collected. It has been found that textile,publishing and paper products industries are the most noisy industries. The paper is concluded with suitable recommendationfor noise control and worker protection.     

Interspecific and locational differences in metal levels in edible fish tissue from Saudi Arabia

Metal levels in fish have been extensively studied, but little data currently exists for the Middle East. We examined the levels of metals and metalloids (aluminum, arsenic, copper, manganese, selenium, zinc, and mercury) in the flesh of 13 fish species collected from three fishing sites and a local fish market in Jeddah, Saudi Arabia. We tested the following null hypotheses: (1) there are no interspecific differences in metal levels, (2) there are no differences in metal levels in fishes between market and fishing sites, (3) there are no size-related differences in metal levels, and (4) there are no differences in selenium:mercury molar ratio among different fish species. There were significant interspecific differences in concentrations for all metals. There was an order of magnitude difference in the levels of aluminum, arsenic, mercury, manganese, and selenium, indicating wide variation in potential effects on the fish themselves and on their predators. Fishes from Area II, close to a large commercial port, had the highest levels of arsenic, mercury, and selenium, followed by market fishes. Mercury was positively correlated with body size in 6 of the 13 fish species examined. Mercury was correlated positively with arsenic and selenium, but negatively with aluminum, cobalt, copper, manganese, and zinc. Selenium:mercury molar ratios varied significantly among species, with Carangoides bajad, Cephalopholis argus, Variola louti, and Ephinephelus tauvina having ratios below 10:1. These findings can be used in risk assessments, design of mercury reduction plans, development of fish advisories to protect public health, and future management decision-making.     

Major ion chemistry and weathering processes in the Midyan Basin, northwestern Saudi Arabia

Chemical characteristics of 72 groundwater samples collected from Midyan Basin have been studied to evaluate major ion chemistry together with the geochemical and weathering processes controlling the water composition. Water chemistry of the study area is mainly dominated by Na, Ca, SO₄, and Cl. The molar ratios of (Ca?+?Mg)/total cations, (Na?+?K)/total cations, (Ca?+?Mg)/(Na?+?K), (Ca?+?Mg)/(HCO₃?+?SO₄), (Ca?+?Mg)/HCO₃, and Na/Cl reveal that water chemistry of the Midyan Basin is controlled by evaporite dissolution (gypsum and/or anhydrite, and halite), silicate weathering, and minor contribution of carbonate weathering. The studied groundwater samples are largely undersaturated with respect to dolomite, gypsum, and anhydrite. These waters are capable of dissolving more of these minerals under suitable physicochemical conditions.     

Uranium bioassay and radioactive dust measurements at some uranium processing sites in Egypt--health effects

The safety of radiation workers in the uranium mining industry requires close and continuous monitoring of their working conditions. In this study, external radiation surveillance, radioactive dust monitoring and the bioassay of uranium were carried out in some processing sites. As dust represents one of the most important sources of radiation exposure in mills and mines, dust monitoring and bioassays were performed for a sample of workers on the production lines. The concentration of uranium in air ranged from 22.6 x 10(-7) to 11.1 x 10(-5) Bq cm-3, and the exposure levels ranged from 1 to 80 microSv h-1. Laser fluorimetric determination of uranium in urine samples showed concentrations in the range 8.4-29.2 micrograms L-1. Renal function parameters, such as serum creatinine and urea, and hematological parameters were determined in an attempt to correlate them with radiation exposure and the health status of the workers. Urine specimens collected from workers at the ore crushing and separation site showed elevated concentrations of uranium (up to 29.2 micrograms L-1) and a strong correlation between these concentrations and the registered serum creatinine. The mean uranium excretion in the investigated group was more than 20 times the occupational exposure decision level for urine uranium of 0.8 microgram L-1.     

Quality comparison of tap water vs. bottled water in the industrial city of Yanbu (Saudi Arabia)

The objective of this study was to determine the relative influence of reach-specific habitat variables and geographic location on benthic invertebrate assemblages within six ecoregions across the Western USA. This study included 417 sites from six ecoregions. A total of 301 taxa were collected with the highest richness associated with ecoregions dominated by streams with coarse substrate (19-29 taxa per site). Lowest richness (seven to eight taxa per site) was associated with ecoregions dominated by fine-grain substrate. Principle component analysis (PCA) on reach-scale habitat separated the six ecoregions into those in high-gradient mountainous areas (Coast Range, Cascades, and Southern Rockies) and those in lower-gradient ecoregions (Central Great Plains and Central California Valley). Nonmetric multidimensional scaling (NMS) models performed best in ecoregions dominated by coarse-grain substrate and high taxa richness, along with coarse-grain substrates sites combined from multiple ecoregions regardless of location. In contrast, ecoregions or site combinations dominated by fine-grain substrate had poor model performance (high stress). Four NMS models showed that geographic location (i.e. latitude and longitude) was important for: (1) all ecoregions combined, (2) all sites dominated by coarse-grain sub strate combined, (3) Cascades Ecoregion, and (4) Columbia Ecoregion. Local factors (i.e. substrate or water temperature) seem to be overriding factors controlling invertebrate composition across the West, regardless of geographic location.     

Change of atmospheric condition in an urbanized area of Japan from the viewpoint of rainfall intensity

The atmospheric condition in an urbanized area of Japan was examined from the viewpoint of a 14-year trend in the rainfall intensity. To cancel the wide-area meteorological phenomena such as a typhoon and a front, the rainfall datasets obtained not only in an urban area but also in a rural area was studied. The rainfall datasets collected on a 0.5 mm rainfall basis was used. The rainfall intensity dominantly increased in urban area, while that in rural area neither increased nor decreased. An increasing trend was clearly observed for rainfall with precipitation amounts of 5 and 10 mm. Rainfall with precipitation amounts of 15 and 20 mm showed neither an increasing nor a decreasing trend. The results of this study show that there is a high probability of a connection between the urbanization and the change of rainfall intensity.