Marrakech City Research Articles

STATE OF AMBIENT AIR QUALITY IN MARRAKECH CITY (MOROCCO) OVER THE PERIOD 2009 – 2012

The strong urbanization and the socio-economic development of a city cause serious effects on its environment and its population; our study focuses on the air quality of Marrakech city in Morocco, it’s the first integral study done for that city. We will give a synthesis of air pollutants measurement results; conducted in the city over the period 2009-2012; in order to determine the spatial and temporal variations of major pollutants (NOx; SO2; O3; PM10) measured at the air quality monitoring stations; as well as the weather parameters which are essential to understand the dispersion of this pollution. The results showed that the NOx levels are depending on the local emissions density and the nature of the road network. The concentrations of SO2 are low compared to the admitted Emission Limit values (ELV); this is owing to the weak industrial activity of the city and the use of less polluting fuel (350 ppm diesel).As of particles (PM10); related to road traffic; industry and natural sources; their levels exceed the thresholds limits over all sites. The city is also subject to photochemical pollution mainly due to its geographical location (strong sunlight). During the spring and the summer; the concentrations of O3 reaches an alarming levels with significant overshoot periods of the permitted limits. This study allows us to establish a first approach on the state of the air quality of Marrakech without assessing the contribution of each source; which requires a further study to identify the phenomenon.

English

Heavy metal pollution is one of the most important problems in Morocco and causes serious effects to humans and animals. The aim of the present study was to evaluate the spatial distribution of heavy metals in Draa Lasfar mine area in Marrakech city and understand the characteristics of the pollution generated by this mine activity. A total of 120 soil samples were collected from Ouled Bou Aicha and Tazakourte along with two soil control samples. The edaphologic soil parameters pH and electrical conductivity (EC) and carbonate content were measured according to standard methods, whilst heavy metals concentration was done by atomic absorption spectroscopy (AAS). Contamination factors (CF) and pollution index (IP) were calculated in order to estimate the anthropogenic contribution of target pollutants determining As, Se, Pb and Zn as the main pollutants in this region. The results show that the polluted areas at the vicinity of the mine, especially two rural communities (Ouled Bou Aicha and Tazakourte) of about 5790 ha, is probably linked to increasing mine activities and the lack of appropriate measures to counteract its effects causing a progressive pollution of soil with heavy metal emissions in this studied region. Key words: Contamination, heavy metals, soils, mine area, mine tailings, Marrakech – Morocco.

A survey of wastewaters generated by a hospital in Marrakech city and their characterization

In Morocco, few studies focus on hospital wastewaters. This study is among the first studies on this subject because of its paramount interest to show the necessity of treating these effluents before discharging. This study focuses on the characterization of wastewaters from the University Hospital Centre (Mohammed VI) in Marrakech. This hospital has medical and surgical missions with a capacity of 409 beds. Its water consumption is estimated to 425 m3/d at the rate of 1.04 m3/d/bed with a rate of 1.63–12.67 m3/h. To assess the pollution degree of effluents generated by the hospital, we started with a survey of the different products used in every department of the hospital followed by sampling of different types of wastewaters and their fate in this hospital. Then we conducted a physicochemical and biological characterization of the samples. The investigation revealed that the various hospital departments used several chemicals including detergents, disinfectants used frequently in hospitals. These products are mainly recommended in the cleaning and maintenance of premises and represent 70% of the whole used chemicals. Around 30% of the products are pre-disinfectants and sanitizers such as glutaraldehyde (at concentration 2%). The annual consumption of medicines and drugs within the studied hospital are anesthetics and β-blockers that represent 37% of the total consumed drugs in the studied hospital. Antibiotics, gastro-entero-hepatology, and anti-inflammatory drugs represent 14, 9, and 7%, respectively. Other drugs used for different therapeutic classes represent 33%. From the total reported cases of hospital infections, 29% are died. This shows the risk of potential pathogens load in the hospital effluents. The physicochemical characterization of the effluents of each service revealed that they are heavily loaded with organic matter: 2,641 mg/L of COD, 910 mg/L BOD5, and 1,490 mg/L TSS. These levels exceed far the levels recommended by the Moroccan discharge standards. Total phosphorus; orthophosphates and Kjeldahl Total Nitrogen are, respectively, in the range of 8.02 mgP/L, 3.55 mgP/L, and 197.14 mgN/L. The heavy metals content are low except for copper (2.84 mg/L) and iron (3.38 mg/L), which are very high. Bacteriological characterization shows that fecal coliforms reached 108 CFU/100 mL. These effluents also contain pathogens responsible for nosocomial infections. Among these pathogens, Pseudomonas aeruginosa and Staphylococcus aureus are detected with suspected Salmonella and Vibrio. The COD/BOD5 ratio is around 2.9, value indicating that the hospital effluents are biodegradables by selected strains. Furthermore, it is essential to apply an adequate treatment to this hospital wastewaters because of their bacterial load pathogenicity that may have an adverse impact on the health of the population and the risk of epidemic diseases spread.

English

Mining activity is one of the most important sources of heavy metals in the environment. In Marrakech region, functioning or abandoned mines represent a great hazard due to huge amounts of waste deposited in waste dumps and tailings often with high concentration of heavy metals pollution. In this study, the chemical forms of four heavy metals in mine tailings of Draa Lasfar in north-west of Marrakech city (Morocco) were studied by determining of four metals (Cd, Cu, Pb, and Zn) using standard solvent extraction and atomic absorption spectrophotometric techniques. The chemical pools of the metals indicated that the metals were distributed into six fractions with most of the metals residing in the non-residual fractions, suggesting how readily the metals are released into the environment. Results showed Cd and Cu were predominantly associated with short-term mobile fraction (F1 and F2) while Pb was largely associated with long-term mobile fraction (F3, F4 and F5) and Zn was essentially bound to Fe–Mn oxide phase (F4). Key words: Heavy metal contamination, mining activity, sequential extraction, mine tailings, Marrakech – Morocco.

Speciation of four heavy metals in agricultural soils around DraaLasfarmine area in Marrakech (Morocco)

This study was carried out to 1. determine spatial variations of heavy metal deposition in agricultural soils of two rural communities (OuledBouAicha and Tazakourte) of about 5790 ha in a mining area near Marrakech city in Morocco; 2. to assess the extent of metallic pollution generated by the mining activity and; 3. to identify the key mechanism responsible for this contamination and its relation to mining activity. Soil pollution assessment was carried out on one hand by measurement of the total metal concentration and on the other hand by studying four heavy metals speciation of the studied soils. The chemical forms of four heavy metals in soils around DraaLasfar mine were studied by determining soil Cd, Cu, Pb and Zn species using standard solvent extraction and Atomic Absorption Spectrophotometric techniques. The chemical pools of the metals indicated that the metals were distributed into six fractions with most of them residing in the non-residual fractions thus suggesting how readily the metals are released into the environment. Considering that the metals occur in the most available forms, we suggested that it is most likely that the metals must have been derived from anthropogenic sources especially from the mining activity in the studied region.

Don d’organes issus de donneurs décédés et population marocaine

IntroductionMorocco stays far behind other countries in the domain of organ donation and transplantation. Improving the knowledge of Moroccan students, about organ donation and transplantation, can be a key factor in the development of transplant activity. The aim of this study is to evaluate the knowledge, attitudes and beliefs of students concerning organ donation and transplantation. Materials and methodsThe opinion survey was conducted in Marrakech city, with four high education structures with a pre-established questionnaire. The survey questions answered four main themes, which are: the evaluation of knowledge, the opinion and attitude of citizen, the explanation of refusal and the propositions to encourage organ donation in Morocco. ResultsHundred percent of surveyed subjects answered the questionnaire. Among them, 40.3% were men. The middle age was 21.5 years. Out of 503 surveyed students, 89.4% were aware of organ transplant in Morocco. A quarter of students believed that removal and transplant acts were realized just in public health establishments, which have the authorization. Two persons out of 3 were able to identify transplantable organs and tissues. More than half accepted to donate their organs after death. The religious reason was in the head list of refusal determinants of organ donation after death, with a prevalence of 39.7%. ConclusionYoung Moroccans have limited knowledge relating to organ donation. The development of this therapy needs to establish an adequate project of information and motivation of general population.

Female lung cancer in Marrakech

Background: To evaluate the epidemiological aspect of lung cancer in women in Marrakech city in Morocco. Methods: This is a retrospective study conducted between 2003 and 2009 in the Department of Oncology-Radiotherapy, University Hospital Mohamed VI Marrakech. Results: Twenty nine women with lung cancer were unrolled (9% of all lung cancer). The average age was 55.7 ± 12 years. Only twenty percent of our patients were smokers while 38% reported a greater or lesser exposure to passive smoking. Ninety percent of patients were housewives and 62% were from rural areas and all reported massive exposure to smoke from cooking fuels which was mainly charcoal. Squamous cell carcinoma represents 67% of cases. Tumors were diagnosed at advanced stages II/IV in 81% of cases. Eight patients received neo-adjuvant chemotherapy followed by radio-chemotherapy combination and palliative chemotherapy has been indicated in twelve patients. Nine patients received best supportive care. Average follow-up was of twelve months. Fourteen patients were lost to follow-up. Among fifteen evaluable patients, response was noted in seven patients, stabilization in four patients and progression in four patients. Conclusion: Female lung cancer is a relatively rare condition in Marrakech, Morocco. Although the role of smoking in the pathogenesis of lung cancer is clearly established; there are other risk factors including hormones that make women more susceptible to carcinogens of tobacco. Other geographical and environmental factors could be incriminated including domestic smoke exposure especially in our context.

In search of enteroviruses in water media in Marrakech

Enteroviruses are among the most common viruses infecting the human intestine; they are very widespread in nature and resistant to external agents. They are eliminated in the faeces and contaminate water and food. These viruses cause various clinical syndromes and constitute a big public health problem. The aim of our study was to search for enteroviruses in the water samples. For this, a total of 225 L of tap water coming from the national network office for drinking water (ONEP) and 18 samples of waste water originating from Marrakech city were studied. These samples were concentrated, treated with polyethylene glycol 6000 and then analyzed by RT-PCR. Only two samples were found to be positive for enteroviruses by RT-PCR among the 18 waste water samples analyzed, which gave a rate of 11.11%. On the other hand, no positive samples were found in the tap water. This study made it possible on the one hand to apply for the first time RT-PCR for the detection of enteroviruses in water samples originating from Marrakech city, and on the other hand to show that tap water of this city does not present any risk of contamination by this type of germ. Key words: Drinking water, waste water, enterovirus, RT-PCR, Marrakech.

Phlebotomine sandflies (Diptera: Psychodidae) of southern Morocco: results of entomological surveys along the Marrakech–Ouarzazat and Marrakech–Azilal roads

Since the 1970s, Azilal and Ouarzazat have been the main foci for human cutaneous leishmaniasis (CL) in Morocco. The sandflies along the main roads linking these two foci to Marrakech city, which is considered to be an area at risk of CL, were recently surveyed. Among the 872 sandflies collected, in June 2005, on the Marrakech-Ouarzazat road, Sergentomyia fallax was the most common species (36.1%), followed by Phlebotomus sergenti (21.1%), P. papatasi (14.2%), S. minuta (11.7%), P. longicuspis (5.5%), P. alexandri (5.4%), P. perniciosus (4.1%), P. ariasi (0.9%), S. africana (0.6%) and S. dreyfussi (0.3%). On the Marrakech-Azilal road, however, S. minuta was by far the most prevalent species (63.5% of the 1983 sandflies that were collected in August 2006), followed by S. fallax (12.9%), P. perniciosus (12.4%), P. sergenti (4.0%), P. longicuspis (3.0%), P. papatasi (2.8%), S. dreyfussi (1.1%) and P. alexandri (0.2%). The distribution of potential vectors along the two transects, according to altitude and bioclimate, was explored.

Combining a large aperture scintillometer and estimates of available energy to derive evapotranspiration over several agricultural fields in a semi-arid region

The objective of the present study was to investigate the potential of a large aperture scintillometer (LAS) combined with a simple available energy model to estimate area-averaged latent heat flux in difficult environmental conditions. The difficulties are related to the sparseness of the vegetation, the heterogeneity of the soil characteristics, and, most importantly, the heterogeneity in terms of soil moisture induced by the “flood irrigation” method. In this context, three sites (Agdal, R3 and Sâada) in the Tensift Al Haouz plain (region of Marrakech city, central Morocco) have been equipped with a LAS and eddy covariance (EC) system (local scale measurements). Agdal and R3 are a flood-irrigated olive yard and wheat field, respectively. Sâada is a drip-irrigated orange orchard. Due to the irrigation method applied, the Agdal and R3 sites shifted from being almost homogeneous between two irrigations (dry conditions) and completely heterogeneous during the irrigation events (large variability of soil moisture along the site), while Sâada was always heterogeneous, at least at the scintillometer footprint scale. Consequently, the comparison between the sensible heat fluxes derived from both LAS and EC showed a large scatter during the irrigation events, while a good correspondence was found in between two irrigations. It was also found that combining LAS and an estimate of the available energy (using a simple model) can provide reasonable large-scale evapotransipration estimates, which are of prime interest for irrigation management.

Numerical analysis of a coupled solar collector latent heat storage unit using various phase change materials for heating the water

A theoretical model based on the energy equations was developed to predict the thermal behaviour and performance of a solar latent heat storage unit (LHSU) consisting of a series of identical tubes embedded in the phase change material (PCM). During charging mode, a heat transfer fluid (hot water) from the solar collector passes through the tubes and transfers the collecting heat of solar radiation to the PCM. The heat stored in the liquid PCM is next transferred to water during discharging mode to produce heating water. A simulation program based on the finite volume approach was also developed to numerically evaluate the thermal performance of the LHSU. The model was first validated by comparing the results of numerical simulations to the experimental data. A series of numerical simulations were conducted for three kinds of PCM ( n-octadecane, Paraffin wax and Stearic acid) to find the optimum design for a given summer climatic conditions of Marrakech city: solar radiation and ambient temperature. Optimization of the LHSU involves determination of the mass of the PCM, the number of tubes, and the flow rate water in solar collector that maximise the thermal storage efficiency. Several simulations were also made to study the effect of the flow rate water on its outlet temperature, during the discharging mode.

Aerosol columnar characterization in Morocco: ELT prospect

The work presented in this paper focuses on site testing in terms of aerosol loadings where ground based measurements are essential. In our case they are materialized by the aerosol optical thickness (AOT) and are provided by the Aerosol Robotic Network (AERONET) network from four stations, Dakhla and Marrakech in Morocco and Santa-Cruz and Izana in the Canary Islands. To fully scan all the area of the Moroccan territories, satellite measurements are certainly the most efficient way. We used the most popular and reliable products. Total ozone mapping spectrometer (TOMS) aerosol index (AI) provided by both TOMS Earth Probe and TOMS ozone monitoring instrument (OMI) along with aerosol optical thicknesses provided by moderate resolution imaging spectroradiometer (MODIS) and multiangle imaging spectroradiometer (MISR) instruments, onboard Terra platform. The idea is to compare sensing capabilities of each instrument in the region under study, in order to know which is suitable for a given place and when. For that purpose linear regression analysis were performed between satellite data and AERONET observations. Good correlations were observed with the Pearson correlation coefficient, R, varying from 0.68 to 0.92 for MODIS, MISR and TOMS OMI. However for TOMS EP the correlations are fairly poor (from 0.54 to 0.74). A ten years analysis of the TOMS EP index has been performed with a calibration of the aerosol index into TOMS retrieved aerosol optical thickness in the area of interest (Morocco and Canary Islands) and an inter-comparison with the other products was achieved. In the frame of the extremely large telescope (ELT) project prospect, once the appropriate satellite instrument have been chosen and the area scanned, the next step would be to scan aerosol loadings at higher altitude locations. Since vertical distribution of aerosol optical thickness and microphysical properties are not well understood and modelized, we used the relationships related to Izana (Izana’s altitude is 2367 m), as a first attempt, to extrapolate the aerosol optical thickness at higher locations in the Moroccan mountains. Izana and Santa-Cruz very close to each other (30 km) are located in the same satellite pixel and then have the same satellite (AOT) or (AI) whereas AERONET gives very distinct aerosol optical depths. A good linear correlation ( R = 0.92) has been observed between the AERONET aerosol optical depths at Izana and Santa-Cruz. The seasonal correlation coefficients are 0.85 for winter, 0.87 for spring, 0.91 for summer and 0.87 for autumn The ratio AOD Santa-Cruz/AOD Izana has a seasonal behavior, reaches the average of 4.5 in winter and 2 in summer time and the subtraction of the aerosol optical thicknesses has an average of 1.3. Finally we retrieved the aerosol optical thickness at Oukaimeden: a Moroccan observatory located at 2700 m above sea level, and about 70 km from Marrakech city. We then converted the aerosol optical depth into astronomical light extinction and compare with previous records measured at the observatory.

Seasonal fluctuations of phlebotomine sand fly populations (Diptera: Psychodidae) in the urban area of Marrakech, Morocco

Phlebotomine sand flies (Diptera: Psychodidae) were collected continuously, using sticky traps, during 1 year from October 2002 to September 2003, in an urban area of Marrakech city (Morocco). A total of 3277 specimens were collected belonging to five species. Phlebotomus ( Phlebotomus) papatasi (54.6%) is the predominant species followed by Sergentomyia ( Sergentomyia) minuta (20%), S. ( S.) fallax (11.3%), P. ( Paraphlebotomus) sergenti (10.3%) and P. ( Larroussius) longicuspis (3.8%). Data analyses showed a mono-modal annual pattern for P. sergenti and a bi-modal one for the other species. P. papatasi, the proven vector of Leishmania major in Morocco, was active throughout the year. This species did not diapause in this region. P. papatasi population peaked in June and November, which relating to the periods of risk in this area. Its preferred temperature ranged between 32 and 36 °C but no significant correlation was found between its density and the temperature. Considering the high density and long activity period of P. papatasi, the area of Marrakech should be regarded as a potential focus for L. major. This suggests the need for a continuously surveillance to prevent risk of zoonotic cutaneous leishmaniasis.

Toxic and essential trace metals in muscle, liver and kidney of bovines from a polluted area of Morocco

Toxic and essential trace metals were measured in muscle, bone, liver and kidney of bovine grazing on the municipal wastewater spreading field of Marrakech City (Morocco). Bovines were found to be seriously contaminated by toxic metals, especially cadmium, and levels were higher in liver and kidney, specific target organs for metal bioaccumulation. The high cadmium content seemed to contribute to a reduction in zinc and copper levels. The arithmetic mean concentrations of zinc, copper and cadmium in liver and kidney, were respectively: 126, 112 and 5.1 μg/g in liver; 89, 33 and 10.3 μg/g in kidney.

Pumping behaviour and filtration rate of the freshwater mussel Potomida littoralis as a tool for rapid detection of water contamination

In order to evaluate the ability of the freshwater bivalve Potomida littoralis for use as a biodetector of aquatic pollution, the short-term effects of some pollutants (metals, antifouling product and effluents) on pumping activity of this mussel were studied qualitatively (pumping behaviour) and quantitatively (filtration rate). The method of the flow sensing at the exhalent siphon showed that the normal activity of P. littoralis was characterized by a continuous pattern of pumping with occasional and brief interruptions. When exposed to toxic stress, the exhalent flow immediately shifted to an intermittent pattern with periods of pumping alternating with periods of pause that could last several minutes. The threshold concentrations of heavy metals/antifouling agent inducing this type of activity within 2 h were: 25 µ gl −1 for copper, 90 µ gl −1 for cadmium, 5 µ gl −1 for mercury, 3000 µ gl −1 for zinc and 700 µ gl −1 for the antifouling agent Mexel. Both the effluent samples of the urban wastewater of Marrakech city tested were found to be toxic. The filtration rate of control animals ranged from 0.91 to 1.72 l h −1 g −1 animal, while after 3 h exposure to Cu, Cd , Hg and the effluent E1 and E2, filtration rates were decreased by concentrations above the threshold levels set as toxic for the pumping activity. The sensitivity of P. littoralis to pollution and its usefulness as biodetector for rapid toxicity screening is discussed and a procedure for the detection of pollution in Moroccan freshwater is proposed.