Fungal contamination, aflatoxigenic fungi and levels of aflatoxin B1 in spices marketed in the West Bank of Palestine

Ninety-seven spices of seven different types were collected from different retailers in the West Bank of Palestine and were analysed for fungal contamination, specifically aflatoxigenic Aspergillus spp. and Aflatoxin B1 (AFB1) levels. Aspergillus was found in 89% samples analysed. Ground red chilli had the highest average number of fungal colonies. In decreasing order, mixed spices (57%), cardamom (53%), red chilli (52%), chicken spices (50%), sumac (47%) and pepper (38%), were contaminated with Aspergillus species. Aspergillus niger and A. flavus were dominating Aspergillus species in 37% and 23% of food samples analysed, respectively. Of the 11 tested isolates, 82% were identified as aflatoxin-producers. AFB1 was detected in 40.2% of the samples analysed with a mean value of 2.09 ± 3.20 μg/kg. Red chilli powder followed by chicken spices and cardamom recorded the highest levels (6.98, 3.55 and 1.48 μg/kg, respectively). Twenty-two of the spices (23%), were above the European Union's maximum limit of 5 μg/kg.

RAPD assessment of in vivo induced genotoxicity of raw and treated wastewater to albino rat

Randomly amplified polymorphic DNA (RAPD) was applied to assess the potential genotoxicity of wastewater to albino rats. Cluster analysis using the Euclidean distance resulted in two clusters; one includes the control rats and the treated wastewater-injected rats (join at a distance of 0.57). The other one includes the rats injected with the raw wastewater (joins the first cluster at a distance of 0.6). Results confirm the ability of both raw and treated wastewater to in vivo induce genotoxic effects to rats. This demonstrates that the treatment process does not remove all mutagens found in raw wastewater completely. Consequently, the reuse of treated wastewater for irrigation poses health and environmental hazard. Therefore, we recommend genotoxicity testing be used to monitor the quality of wastewater effluents, in addition to the traditional tests used. Besides, hazardous chemicals from laboratories should be separated and treated differently. Finally, RAPD test is a reliable one that can be applied to evaluate in vivo genotoxic effects of chemicals.

Quality assessment of roof-harvested rainwater in the West Bank, Palestinian Authority

Rain harvesting is becoming more common in the Palestinian Territories as a result of drinking water scarcity. Although it might pose serious human health risk, this water is being consumed without treatment in many areas of the West Bank. The present study evaluates the physicochemical and microbial quality of harvested rainwater that is used as potable water in the West Bank. Samples from roof-harvested rainwater storage tanks (n = 42) were collected in summer (SS) 2006/winter (WS) 2007. Physicochemical parameters measured were: temperature, pH, electrical conductivity, salinity, total dissolved solids, turbidity, nitrate, copper and lead. With few exceptions, all these parameters were within WHO guideline values. All samples (100%) were found to contain coliforms and to be heavily contaminated with heterotrophic bacteria. About 67% of all samples were contaminated with fecal coliforms. Specific PCR technique confirmed the presence of five pathogenic microorganisms that can be ordered according to their prevalence as: Citrobacter (83%) > Acinetobacter (78%) > Aeromonas (52%) > Pseudomonas and Campylobacter (7%). Prevalence of microorganisms in SS was higher than in WS. Although the physicochemical quality of most harvested rainwater samples was in accordance with WHO guidelines for drinking water, stored rainwater was significantly contaminated with bacteria resulting in significant human health risk from infectious diseases.

Distribution of toxic metals in organs of local cattle, sheep, goat and poultry from the West Bank, Palestinian Authority

Graphite furnace atomic absorption spectrophotometry was used to measure the concentrations of Cu, Cd, Pb, and Zn in muscles and internal organs (liver, kidneys, heart, and lungs) of cattle, sheep goat and poultry sampled from local markets in the West Bank, Palestinian Authority. Mean levels of metals (dry weight basis) during this study were as follows: Cd: 0.34-0.57 microg/g, Pb: 0.2-4.7 microg/g, Cr: 0.44-3.62 microg/g and Cu: 1.03-217.9 microg/g. Muscles and internal organs of each species were found to have statistically different metal levels. Generally, livers and kidneys were found to have the highest levels of metals and muscles the lowest levels. When compared to each other, the four animal groups either did not show any significant differences or no clear trends. Compared to results reported in the literature, our results were comparable to or less than most of the studies reported from clean sites in different countries.

Evaluating wastewater-induced plant genotoxicity using randomly amplified polymorphic DNA

Wastewater often contains genotoxic substances that can resist different stages of the treatment process. In the present study, randomly amplified polymorphic DNA technology was applied to evaluate the genotoxic effects of wastewater (treated and raw) irrigation on oat plants (Avena sativa). RAPD profiles obtained showed that both treated and raw wastewater (RWW) were having genotoxic effects on oat plants. This was apparent by the appearance/disappearance of bands in the treatments compared with the control plants. From the 15 primers used, 186 bands were obtained with an average of 12.4 bands per primer. Irrigating plants with RWW caused 51 new bands to appear and 19 to disappear. Treated wastewater (TWW) caused only 16 new bands and the loss of 17 bands. This makes TWW less genotoxic than RWW. The Euclidean distances shown on the dendrogram, revealed the presence of two clusters according to dissimilarity values. One cluster contained the control plants and those irrigated with TWW, whereas the second contained the plants irrigated with RWW. Similarity indices calculated between the treatments and the control plants showed that the control and the plants irrigated with TWW had a similarity index of 0.87, the control and plants irrigated with RWW 0.73 and between the treatments 0.75.

Monitoring urban heavy metal pollution using the House Sparrow (Passer domesticus)

The House Sparrow (Passer domesticus) is one of the most successful birds in the urban environment, and has a global distribution. The present study aims to provide baseline data about metals in sparrows from urban environments in the West Bank and to investigate the possibility of using the House Sparrow to monitor metal pollution in urban environments. Concentrations of Cu, Cd, Pb and Zn were measured in different tissues and organs of male and female juvenile (1-4 weeks old) and adult House Sparrows from the West Bank. Tissues and organs had the following order of metal richness: liver > stomach > bone > lung, feathers > muscles > egg contents, brain > heart > egg shell. Significant correlation coefficients were observed for the concentrations of Cu, Pb, and Zn in the egg shell and for the egg contents. Male and female Sparrows showed no significant differences in their metal concentrations. Adult Sparrows collected from rural areas were found to have significantly less Cu, Pb, and Zn (but not Cd) concentrations than those from urban environments. In order to investigate metal accumulation with age, metal concentrations were plotted against age stage (egg, 1-, 2-, 3-, and 4-week-old juveniles and adults). Significant relationships were observed between age stage and Cu, Pb, and Zn concentrations. The results provide some evidence for the potential of the House Sparrow as a biomonitor for urban heavy metal pollution. However, further issues regarding metal physiological regulation and the correlations between metals in the environment and those in tissues of the House Sparrows have to be addressed before recommending this bird as a biomonitor for urban metal pollution.

Assessment of heavy metal contamination in roadside surface soil and vegetation from the West Bank

Concentrations of heavy metals (Pb, Cd, Cu, Zn, Fe, Mn, Ni, and Cr) were investigated in roadside surface soil and the common perennial herb inula (Inula viscosa L., Compositae). Samples were collected at different distances (0-200 m) perpendicular to a main road that connects two main cities in the West Bank. Average concentrations of metals in soil samples were: Pb, 87.4; Cd, 0.27; Cu, 60.4; Zn, 82.2; Fe, 15,700; Mn, 224; Ni, 18.9; and Cr, 42.4 microg x g(-1). In plant leaves, concentrations were: Pb, 7.25; Cd, 0.10; Cu, 10.6; Zn, 47.6; Fe, 730; Mn, 140; Ni, 4.87; and Cr, 7.03 microg x g(-1). Roadside contamination was obvious by the significant negative correlations between concentrations of metals in soil and plant samples and distance from road edge. Only cadmium concentrations in soil and plant samples were not associated with roadside pollution. Roadside contamination in plants and soil did not extend much beyond a 20 m distance from road. I. viscosa reflected roadside contamination better than soil and their metal concentrations showed much less fluctuations than those in soil samples. Washing plant leaves decreased Pb and Fe concentrations significantly, indicating a significant aerial deposition of both. I. viscosa can be considered as a good biomonitor for roadside metal pollution.

Dose-dependent effects of dietary Pb and Zn on feeding and growth rates of the landsnail Helix engaddensis

Dose-dependent effects of dietary lead and zinc on feeding and growth rates of adult Helix engaddensis snails were studied over a 1-month period followed by a 2-week recovery period. Snails were fed on an artificial diet containing the following lead or zinc concentrations= 0, 20, 100, 500, 2500, and 12,500 microg/g dry food. At the end of the 6 weeks, mortality rate among snails fed on Pb-contaminated diet was 18.3% (11/60) and the respective value for Zn-contaminated diet was 50% (30/60). Both metals significantly reduced growth and feeding rates. Snails were found to be sensitive to zinc but tolerant to lead. During the recovery period, snails fed on Zn-contaminated diet failed completely to feed or grow normally, whereas snails fed on Pb-contaminated diet showed signs of slow improvement in terms of feeding and growth rates. The NOEC and LOEC for lead were 100 and 500 microg/g (-1), respectively, while the respective concentrations for zinc were 20 and 100 microg/g (-1).

Concentrations of heavy metals in roadside soils, plants, and landsnails from the West Bank, Palestine

Concentrations of Cu, Cd, Pb and Zn were determined in roadside soil, plant and landsnail samples along Nablus-Ramallah main road in the West Bank. Average concentrations (microgram.g-1, dry weight) of the four metals in soil samples were, Cu: 23.8, Zn: 128.3, Cd: 0.45 and Pb: 149.9. These values were higher than those found in soil samples collected from control sites. Metals in roadside plant samples were within normal levels although plants from control sites were found to have slightly less metals. Different parts of a plant (roots, stem & leaves) were found to accumulate metals in different concentrations. The average concentration (microgram.g-1) of metals in different plant parts were: Cu: < 5.2, Cd: < 1.0, Pb: < 2.19 and Zn: < 5.18. Average concentrations (microgram.g-1) of metals in the three roadside snails were ranging between 121-132 for Cu, 18-27 for Cd, 21-24 for Pb and 43-69 for Zn. Snails were found to magnify Cd to serious levels (> 30-50 times higher than in plants and soils). Lead in snails was about 10 times higher than that in plant leaves and much less than that in roadside soils. Other metals in snails did not show abnormal concentrations.

Levels of trace metals and effect of body size on metal content of the landsnail Levantina hierosylima from the West Bank-Palestine

Levels of four trace metals (Cu, Zn, Cd and Pb) were determined in the landsnail Levantina hierosylima from four locations in the West Bank. Average concentration of the metals was 126.9, 42, 20.2 and 19.4 ppm for Cu, Zn, Pb and Cd, respectively. Significant differences in metal concentrations were observed between snails from the four sampling sites (Jerusalem, Abu-Dies, Qarawa, and Taibeh). Differences are most probably due to atmospheric fallout of metals from traffic roads and industrial facilities. Effect of snail size (weight and shell width) on metal content was investigated for the four metals. Plotting metal content against soft tissue weight resulted in significant relationships. Small snails were found to be richer in Zn, Cd and Pb than larger ones. Regression coefficients for the relationships were 0.75, 0.76 and 0.81 for Pb, Cd and Zn, respectively. Copper content was directly related to body weight (regression coefficient = 0.96) indicating that Cu concentration is independent of body weight. Plotting metal content against shell width indicated similar results but with less strong correlation coefficients. L. hierosylima is a promising bioindicator for metal pollution and further laboratory investigations are needed in order to know more about the uptake and release of metals by this organism.

Effects of dietary Cd and Cu on feeding and growth rates of the landsnail Helix engaddensis

Effects of dietary cadmium and copper on feeding and growth rates of adult Helix engaddensis snails were studied for a 1-month period. The concentrations of cadmium were 0, 50, 100, 200, 400, and 800 microg Cd/g dry food, while those of copper were 0, 4, 20, 100, 500, and 2500 microg Cu/g dry food. Both metals inhibited feeding and growth rates significantly after 1 week and 3 weeks of exposure to Cd and Cu, respectively. Inhibition caused by Cd was found to be irreversible, which indicates toxicity, while that of Cu was reversible, indicating starvation because snails identified and refused to consume contaminated food. After 4 weeks of exposure, the NOEC of Cd was 50 microg/g and the LOEC was 100 microg/g, while those for Cu were 20 and 100 microg/g, respectively. EC50,75,90,100 (growth and feeding) values were calculated, and indicated that H. engaddensis snails are suitable for short-term toxicity bioassays.