Seawalls as a response to coastal erosion and flooding: a case study from Grande Comore,Comoros (West Indian Ocean)

Regional Environmental Change - Many coasts are eroding. In the Comoros, as in many other small island developing states (SIDS), communities frequently respond to coastal erosion by building...     

Occurrence of pesticides and polychlorinated biphenyls in water of the Nile river at the estuaries of Rosetta and Damiatta branches,north of delta,Egypt

Abstract

A study was conducted from summer 1995 to summer 1997 to assess the seasonal occurrence of pesticide residues and other organic contaminants, polychlorinated biphenyls (PCBs), in water at the estuaries of Rosetta and Damiatta branches of the Nile river. The results indicated that organochlorine compounds (OCs) including HCB, lindane, p,p‘‐DDE, p,p‘DDD, p,p‘‐DDT, aroclor 1254 and aroclor 1260 were present in all the water samples at concentration levels ranging between 0.195–0.240, 0.286–0.352, 0.035–0.067, 0.019–0.033, 0.024–0.031, 0.390–0.70 and 0.166–0.330 μg/l, respectively. The levels of these compounds were higher in water of Damiatta branch than those found in water of Rosetta branch. Aldrin, dieldrin and endrin were not detected in all water samples. Only 4 compounds from 36 organophosphorus insecticides, fungicides and s‐triazine herbicides tested were detected in water samples collected during summer and autumn seasons from Rosetta branch. The concentration levels of these detected compounds, dimethoate, malathion, captan, and ametryne, ranged from 0.011 to 0.340 μg/l, respectively. Similar compounds during the same seasons as found in water of Rosetta branch were also detected in water of Damiatta branch except ametryne. The levels of the detected compounds (dimethoate, malathion and captan) ranged between 0.030 and 0.330 μg/l. The levels of detected organophosphorus insecticides, fungicides and s‐triazine herbicides were in the order: dimethoate > malathion > captan > ametryne.     

Toxic effects of 2,4‐D herbicide on fish

Abstract

Acute and subacute 2,4‐D toxicity to carp (Cyprinus carpio L.) were investigated. Acute toxicity (LC‐ 50) was investigated in semi‐static test during a 24, 48, and 96‐ hours exposition. Subacute toxicity was investigated by exposing fish to different 2,4,‐D concentrations (150, 200, and 250 mg/L) for 14 days. Biochemical and morphological changes in certain organs and tissues were investigated.

LC‐ 50 values at 24 hours exposure was 310.0 mg/L, 295.0 mg/L for 48 hours, and 270.0 mg/L for 96 hours exposure.

Subacute toxicity tests show that 2,4‐D induce changes in the enzyme activities (AP, GOT, GPT) and morphological changes in the gills, liver and kidneys, but changes are of limited biological importance.     

Monitoring of effluent DOM biodegradation using fluorescence, UV and DOC measurements

The potential of effluent DOM to undergo microbial degradation was assessed in batch experiments. Effluent samples from Haifa wastewater treatment plant and Qishon reservoir (Greater Haifa wastewater reclamation complex, Israel) were incubated either with effluent or soil microorganisms for a period of 2-4 months and were characterized by dissolved organic carbon contents (DOC), UV(254) absorbance and by fluorescence excitation-emission matrices. Three main fluorescence peaks were identified that can be attributed to humic/fulvic components and "protein-like" structures. During biodegradation, specific fluorescences (F/DOC) of the three peaks were increased at various extents, suggesting selective degradation of non-fluorescing constituents. In some cases increase in the effluent fluorescence (F) was observed thus proposing (i) the formation of new fluorescing material associated with DOM biodegradation and/or (ii) degradation of certain organic components capable of quenching DOM fluorescence. Based on the ratio between fluorescence intensity and UV(254), different biodegradation dynamics for fluorescent DOM constituents as compared with other UV-absorbing molecules was delineated. Overall, about 50% of the total DOM was found to be readily degradable such that residual resistant DOC levels were between 8 and 10 mg l(-1). Enhanced levels of residual DOM in effluent-irrigated soils may contribute to the DOM pool capable of carrying pollutants to groundwater.     

Accelerating progress on salt iodisation in Sudan: time for action

This paper uses a public health approach to examine briefly: (a) the progress of universal salt iodisation (USI) in Sudan; (b) the roles of the main actors involved; and (c) the main issues around accelerating USI. The literature, especially that coming from the UN agencies, is analysed and experiences from the recently revitalised USI programme, and related relevant meetings, are distilled. In Sudan the prevalence of goitre is 22 per cent. It is assumed that productivity among the people affected is reduced by 5–25 per cent. Little apparent progress has been made with USI. The Government of Sudan, UN multilateral agencies, international consultative groups, bilateral agencies, global and national non-governmental organisations and, increasingly, the private sector must work together to find innovative approaches to increase awareness of the broader social, public health and nutritional contexts, and to advocate for increased national nd international funding.     

Total and Extractable Trace Elements in Lebanese River Sediments: Dry Season Data

Years of political instability have left Lebanon with significant gaps in environmental knowledge. This paper reports new results for trace metals in bed sediments of the river Nahr-lbrahim. The drainage basin of the river Nahr-lbrahim is largely floored by karstified limestone. Metal pollution is operative within the catchment. The objectives of this study were first to identify possible sources of metals (geological and/or anthropogenic) and then to characterise the chemical partitioning of the metals in the sediments. Bed load sediments were sampled at five locations along a 13km stretch from the river mouth, during the dry season. Samples were collected on two dates, dried and then sieved into three mechanical fractions. We report total Fe, Cu, Pb and Zn contents of the <75m sediment fraction for the dry season and interpret the results in terms of geology and point and non-point discharges to the river. Total metal contents were derived from summing the concentrations of metals in the chemical fractions of the sediments. A sequential chemical extraction procedure was applied to the <75m fraction and the data showed that, except for Fe, the carbonate fraction had the largest role in metal sediment deposition.     

Fatality risk assessment and modeling of drivers responsibility for causing traffic accidents in Dubai

Introduction: This paper examines crash and safety statistics from the Emirate of Dubai in an attempt to identify factors responsible for making this population at greater risk of crashes compared to other countries. Problem: In developing countries such as the United Arab Emirates (U.A.E.), motor-vehicle-related mortalities frequently exceed those of the industrialized nations of North America and Europe. Method: Fatality and injury data used in the analysis mainly come from Dubai Emirate police reports and from other relevant international sources. Groups of the population are identified according to associated risk and exposure factors. Influence and strength of the most common risk factors are quantified using relative risk, the Lorenz curve, and the Gini index. Further analysis employed logit modeling, and possible predictors available in Dubai police reports, to estimate probability and odds ratios associated with drivers that are deemed responsible for causing traffic accidents. Results: Traffic fatality risk was found to be higher in Dubai, compared to some developed nations, and to vary considerably between different classes of road users and groups of the resident population. The likelihood of a driver causing an accident is considerably higher for those driving goods vehicles, but it is also associated with other factors. Impact: Results provide epidemiological inferences about traffic mortality and morbidity, and suggest priorities and appropriate measures for intervention, targeting resident population.     

Functional wildlife parks: The views of Kenyan children who live with them

This study reports on Kenyan school children's ideas about wildlife parks in their country. A comparison is made between the responses of school children in primary school, before they receive any science education, and those of secondary school pupils at the end of the secondary cycle. The findings show little difference between the two groups of students in terms of their ideas about wildlife parks. This has serious implications for science and environmental education in Kenya. Parks are understood by these pupils in terms of real life issues, as derived from social consequences. The children's ideas are all based on the role that parks play in society, but the function of parks to support biodiversity conservation does not seem to be important to the students. While it is satisfying to note that the school children have a good understanding of parks in their social context, it is essential to address fully the scientific and ecological role of parks in order that biodiversity becomes more valued in our society.     

Biodegradability of chitin- and chitosan-containing films in soil environment

The biodegradation of polyethylene-chitin (PE-chitin) and polyethylene-chitosan (PE-chitosan) films, containing 10% by weight chitin or chitosan, by pure microbial cultures and in a soil environment was studied. Three soil-inhabited organsims,Serratia marcescens, Pseudomonas aeruginosa, andBeauveria bassiana were able to utilize chitin and chitosan in prepared PE-chitin and PE-chitosan films after eight weeks of incubation at 25°C in a basal medium containing no source of carbon or nitrogen. In a soil environment, the biodegradation of those films was studied and compared with a commercial biodegradable film containing 6% by the weight of corn starch. In soil placed in the lab, 73.4% of the chitosan and 84.7% of the chitin in the films were degraded, while 46.5% of the starch in the commercial film was degraded after six months of incubation. In an open field, 100% of the chitin and 100% of the chitosan in the films were degraded, but only 85% of the starch in the commercial film was degraded after six months of incubation. The weight of controls, (polyethylene films), remained mainly stable during the incubation period. Both PE-chitin and PE-chitosan films degraded at a higher rate than the commercial starch-based film in a soil environment indicating the potential use of chitin-based films for the manufacturing of biodegradable packaging materials.     

Examination of personality traits and social problem-solving skills of individuals whose driving licenses have been confiscated due to drunk driving

Objective: Drunk driving is one of the major behavioral issues connected with problematic alcohol consumption. The objective of this study was to evaluate the relationship between personality traits and social problem-solving skills of individuals who drive while intoxicated.

Method: One hundred forty-four individuals apprehended twice while driving drunk and sent to a driver behavior training program (9 females and 135 males) participated in our study. The Eysenck Personality Questionnaire Revised–Abbreviated (EPQ-RA) composed of 4 subscales (Extroversion, Neuroticism, Psychoticism, and Lying) and the Social Problem Solving Inventory (SPSI) composed of 7 subscales (Cognitive, Emotion, Behavior, Problem Definition and Formulation, Creating Solution Options, Solution Implementation and Verification, and Decision Making) were used to evaluate the participants.

Results: A positive relationship was found between the Extroversion subscale of the EPQ-RA and the Cognition subscale (P <.01), Emotion subscale (P <.01), Behavior subscale (P <.01), Generation of Alternatives subscale (P <.01), Decision Making subscale (P <.05), and Solution Implementation and Verification subscale (P <.01). For individuals who repeated intoxicated driving, all subscales of the EPQ-RA (Extroversion, Lying, Neuroticism, and Psychoticism subscales) explained 12% of the scores of the Cognition subscale and 16.2% (P <.001) of the Emotion subscale of the SPSI. There was no significant relationship between the first and second incident alcohol blood levels (P >.05).

Conclusion: Drinking and driving behaviors appear to be negative or maladaptive behaviors closely related to personality traits and may represent an effort to avoid negative emotions. Evaluation of negative emotions may have an important place in training programs intended to change drunk driving behavior.