Toxicologie environnementale et analytique

The biochemical oxygen demand (BOD5) constitutes an important water property for assessing the organic loads of wastewaters. This study on BOD5 values of commonly occurring wastewaters of Morris County, USA was taken up to develop a basic understanding about the quantum of organic loads in these wastewaters which is the basic requisite for developing any wastewater management strategy. The study showed that the BOD5 values of the wastewaters depended on the sources of the wastes. Among the three kinds of wastewater studied, industrial waters showed the highest BOD5 load while pharmaceutical wastewaters showed the lowest values. However, in spite of showing comparatively lower BOD5 loads, it was suggested that the management of pharmaceutical and hospital wastewaters should be dealt with special care owing to the possible occurrence of some harmful components in such wastewaters. Considerable seasonal variations in BOD5 values in these wastewaters indicated that this behavior should also be taken into account for making an effective wastewater reclamation program.

Honey bees (Apis mellifera) contribute an estimated $200 billion annually to the global economy, primarily through crop pollination. Despite their importance, the number of managed honey bee colonies continues to decline. Recent surveys have shown that colony losses are attributed in great part to problems associated with the ectoparasitic mite Varroa destructor, and with issues related to poor queen quality (particularly premature queen replacement), which often result in decreased colony productivity and increased risk of mortality. We aimed to investigate how sublethal exposure to beekeeper-applied miticides affects honey bees at both the individual (queen) and colony levels. We did so by comparing the growth (comb built, brood produced, food stored, and worker population), queen supersedure rates, and winter survival probabilities of colonies that were headed by queens that were raised in either miticide-laden or miticide-free beeswax cups then housed in hives that were either treated with miticides or left untreated. Contrary to our prediction, we found that treated colonies headed by queens raised in miticide-laden beeswax built significantly more worker and drone comb, and stored more food, than any other colony treatment. We did not, however, observe any other significant effect of colony treatment on the amount of brood production, worker population size, queen supersedure rate, or colony winter survival. Thus, we failed to observe a direct negative effect of miticide exposure at the colony level. More studies are needed to further test the potentially detrimental synergistic effects of in-hive miticides on honey bee health at the colony level.

This research work investigates the possibility of improving the phytoextraction of Cd by the application of citric acid. For this purpose, plants were grown in hydroponics under controlled conditions. Addition of 1, 5, 10 and 20 mg/L, Cd2+ significantly decreased the plant growth and biomass, and increased proline contents. The effects were dose dependent with obvious effects at higher Cd2+ concentration of 20 mg/L. Application of 5mM citric acid (CA) significantly depressed Cd2+ uptake and its accumulation in plant roots and shoots. CA alleviated Cd2+ toxicity by reducing oxidative stress. Application of CA also enhanced the antioxidant enzymes activity alone and under Cd stress. The results showed that Cd2+ accumulated more in roots than the shoots and application of citric acid depressed Cd2+ uptake at all concentrations. Jute mallow (Corchorus olitorius) proved to be an effective accumulator for cadmium, however, neither concentration of citric acid showed advantages for phytoextraction of cadmium. The results showed that jute mallow is a potential plant for phytoextraction of Cd without the use of CA as enhancer.

An experiment was carried out at the screen house of the college of environmental resources management at the Federal University of Agriculture Abeokuta, Ogun state to determine water use of three vegetable: Amaranthus, Corchorus and Celosia. The experiment was laid out in a completely randomized design (CRD) and was replicated three times with a control. 50 cl of water was applied to the crops at a day interval. Data collected were analyzed making use of ANOVA and statistical analysis system was used to compare the means of the crops planted as a sole of each crop planted and the test was also used to formulate two hypotheses. The result showed that there were no significant differences between the water uses of each vegetable while there were significant differences between the crop coefficients of each vegetable. Based on the experiment carried out, it was observed that the celosia, amaranthus and corchorus needed the same amount of water for their growth. Therefore it is recommended that farmers that practice rainfed agriculture during dry season when there will be or no rain make sure that sufficient water is been supply to the three vegetable crops for rapid growth and optimum yield

The aim of the present work is to study the effect of different sterilization methods on the biodegradation of biomedical polypropylene (PP) under the same biotic conditions. Three different sterilization techniques; γ-irradiation, steam sterilization and UV-irradiation were used to compare the effect of different sterilization methods on the biodegradability of PP. Neat and sterilized samples were incubated in compost and fungal culture environments. The changes in functional groups, mechanical properties, surface morphology and intrinsic viscosity in polymer were characterized by FT-IR spectroscopy, Instron, SEM and viscometric measurements, respectively. It was observed that the biodegradation of γ-sterilized samples in composting and microbial culture environments was higher than UVirradiated samples, while UV-irradiated more than steam-sterilized and neat samples. The results showed that the radio and photo-oxidative pretreatment directly enhanced the biodegradability of PP as the increase in fungal growth rate and weight loss during composting was found. The biodegradation rate of PP at the same biotic conditions mainly depends on the rate of degradation that initially occurred during sterilization. Overall, this study demonstrated that the biodegradation of sterilized PP in biotic conditions significantly depends on the nature of sterilization method.

Photocatalytic degradation is an important method to mediate organic pollution in the environment. This article reports Ag-modified SnO2@TiO2 core-shell composite photocatalysts prepared via a hydrothermal method. The composite materials were characterized by X-ray diffraction, transmission electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetry, X-ray photoelectron spectrometry, and UV-vis diffuse reflectance spectroscopy. The Ag modification and core structure in the composite enhanced the photocatalytic activity and stability of TiO2 for Rhodamine B degradation under visible light irradiation. The composite modified in 0.15 M AgNO3 showed an optimal level of photocatalytic activity, as it degraded 99.14% of Rhodamine B in 60 min while pure TiO2 only degraded 45.7% during the same time.

Nearshore vertebrate predators such as marine mammals and otters are apex predators, and as such, act both as drivers of the ecosystems in which they live and as sentinels of environmental health. As apex predators, these wild animals at the top of the food chain often bioaccumalate persistent organic pollutants (termed POPs) widespread throughout the environment. Organochlorines are a type of POP that tends to be lipophilic and hydrophobic which accumulate in the fatty tissues of marine mammals and other vertebrate predators over time. There has been growing concern about these POPs in the marine environment and within wildlife, as they can potentially cause health problems. Since the 1950s there have been 81,000 papers published on organochlorines in nearshore predators and potential negative effects to the environment, wildlife and humans. Here, we review organochlorines reported in the tissues of marine mammals and other nearshore vertebrate predators since 1995. We focus on five organochlorines that have been studied the most within nearshore vertebrate predators: 2,2-bis-(p-chlorophenyl)-1,1,1-trichloroethane or dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), toxaphene, and polychlorinated naphthalnese (PCNs).

Excessive and continuous use of organophosphorus insecticides as well as malathion has led to the contamination of ecosystems in several rejoins of the world. For its degradation in the ecosystems usage of the microbes has been proved to be the effective method for controlling ecosystems pollution. Biodegradation of pesticides by using microbes have more advantages over the conventional methods. In the present investigation therefore attempts have been made to make use of white rot fungus Pleurotus ostreatus for malathion degradation. Malathion rest quantity at 5, 15 and 25 days was 40.5, 22.6 and 11.8 (μg/100 mL) with degradation % 19.0, 54.8 and 76.4 respectively at initial concentration (50 μg/100 mL). Lignin peroxidase, manganese peroxidase, and laccase production was stimulated with the presence of malathion. At 25 μg/100 mL malathion, productivity of lignin peroxidase, manganese peroxidase, and laccase was 0.51, 0.57 and 4.30 U/ml respectively compared with the control (growth medium without malathion). At low concentrations of malathion (25 and 50 μg) P. ostreatus productivity of these enzymes was more, but at high concentration of malathion the productivity was less than control. Addition of lignin compound induced the productivity of ligninolytic enzymes and therefore the biodegradation of malathion was increased. GC/MS analysis revealed the presence of many products as a result of malathion biodegradation including diethyl mercaptosuccinate, methy l,2-(Dimethoxyphosphoryl)-2-(1,2,3- thiadiazol-4-yl) acetate, 3,4-dihydrothienyl (3,4,b)-5-carboxythiophene, Butanedioic acid, 2,2'-Thiodisuccinic acid; 1,1-Dimethyltetradecyl hydrosulfide and Disulfide, di-tert-dodecyl.

Multiwalled carbon nanotubes (MWCNTs) are among the nanomaterials earmarked for water purification, yet they have been reported to cause toxicity in fresh water species. This study was conducted to investigate the histopathological and physiological effects of MWCNTs in freshwater fish (Poecilia reticulata). Literature reports that physicochemical properties of MWCNTs could be linked to their toxicological effects, hence the MWCNTs used in this study were characterized prior to (for physical and chemical properties) and during testing (for chemical interactions). Fourier transmission infra-red spectroscopy (FT-IR) revealed additional functional groups in oxidized multiwalled carbon nanotubes (o-MWCNTs) that were absent in the pristine multiwalled carbon nanotubes (p-MWCNTs). Transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) also revealed amorphous carbon and residual Fe catalyst only in p-MWCNTs. The fish were exposed for 96 h in suspensions of p-MWCNTs and o-MWCNTs prepared by sonicating in moderately hard reconstituted water to test toxicity. Zeta potential measurements revealed an impartation of a negative charge onto MWCNT surfaces by HA, whilst hydrodynamic size measurements revealed aggregation/ disaggregation occurring alternately over the 96-h exposure time. Apart from only fish hyperactivity, no mortality was observed for 96-h acute tests for up to 300 mg/L MWCNT concentration. Histopathology revealed that MWCNTs aggregates were deposited mainly in the gut where they caused inflammation, hemorrhaging and oedema which were characterized by fragmented fibrin. Cell lyses also occurred in o-MWCNT exposed fish as evidenced by nuclei clusters among o-MWCNT aggregates. Statistical analysis by 2-way ANOVA followed by Bonferroni posttests showed that significant (p<0.05) reactive oxygen species (ROS) was induced as indicated by depleted antioxidant capacity (TCA), superoxide dismutase (SOD), lipid peroxidase (MDA) and protein carbonyl (PC) content between 3.25 and 15.0 mg/L of MWCNTs. These effects were attributed to the MWCNTs’ physicochemical properties as predetermined by functionalization (acid oxidation). The obtained results indicate that indeed MWCNTs cause toxic effects in freshwater fish, and although depuration was evident, there is a risk of MWCNT trophic transfer to fish eaters.

Coastal Land use Change has become an important component in current strategies for managing coastal resources and monitoring its environmental changes. This study examines the Landuse conversion and improper aquaculture activities in the coastal region of Nagapattinam SE coast of India. The brackish water aquaculture practices started very extensively since year 2000 onwards where fertile agriculture land, Mudflat areas, swampy land have been converted for the aquaculture ponds. Using temporal satellite data of Landsat ETM+PAN 1999, IRS P6 LISS IV 2007, Lands at OLI 2014 the changes that have been estimated. The results indicate that, the agricultural activity has been on the decrease these years. In addition, the data also suggest that the agricultural lands are decreasing due to increasing brackish water aquaculture activities, mud land, swampy land and waterlogged areas have been converted during last decade. Water quality index indicating in terms of index numbers, offers a useful representation of overall quality of water for public or for any intended use as well as in the pollution abatement programmes and in water quality management. Water quality index was calculated based on the basis of various physical chemical parameters like pH, Electrical conductivity, total dissolved solids, nitrate, calcium, sulfate, magnesium, fluoride, total hardness, sodium, chloride, carbonate and bicarbonate. Groundwater quality results clearly indicate that almost entire PWD selected Controlled well of Nagapattinam Taluk groundwater unsuitable for drinking purpose. It is also observed that the pollution load is relatively pre monsoon season. Average values for the seasons are taken into account the study area slightly alkaline. Chloride is the most important parameter in assessing the water quality. Since 2002 (19.49-excellent water quality) Tirumarugal only suitable for drinking purpose and other areas not suitable for the Period of (1998-2007). Result shows the change that has been occurred during 15 years of period mud land and swampy land, waterlogged areas totally converted to aquaculture activities.

In the present study, water quality of groundwater has been assessed in terms of water quality index (WQI) in Ballia district of Uttar Pradesh. Data of 12 groundwater samples each of hand pump and bore well was taken for computing the Water Quality Index using eleven parameters viz. pH, Total Dissolved Solids, Turbidity, Total Hardness, Arsenic, Fluoride, Chloride, Nitrate, Iron, Sulphate and Dissolved Oxygen. The WQI results show that the overall water quality class is ‘fair’ and water needs treatment

In consideration to the various impacts of charcoal and sawdust burning especially in the indoor fires in the developing countries. A charcoal-based and sawdust composite solid fuel has been developed to immensely reduce gaseous emissions, and as well minimize pollution from these sources. The formulations were made using clay (kaolinite) solution (1:2 of clay: water), sawdust and solid pulverized charcoal. Different mounts of the charcoal and sawdust were mixed with a fixed known amount of clay solution and a total of six formulations were made. 200 μm sieve, 500 ml beaker and pdt-crowcon gasman single-trace gas (CO) analyzers were all used in the solution formulation and emission analysis. The results show that the fuel-types which were produced from a mixture of the solid fuels and clay solution yield its minimum emission for a formulation of 1:1 of fuel (charcoal or sawdust): clay solution (1:2 of clay: water) by mass fraction. The results show a consistent pattern of emission reduction exhibited by the composite charcoal based fuels. The combustion of sawdust and its formulations follow a trend which is approximately equivalent to that of charcoal but with a higher release of emission. This higher release of emission from sawdust- based composite fuels show that sawdust is a better burner than charcoal. The addition of the clay content significantly contributes in channeling the routes of release of some of the compounds in the fuels to accompany the ash residue rather than as gaseous emissions. Therefore, the advantages include among others high gaseous emission reduction.

Background: The plant Henna (Lawsonia inermis, family Lythraceae) is a naturally grown or cultivated plant allover Africa and Asia. Marketed Henna is a natural powdered material derived from dried and crushed leaves of the plant. Henna is very popular in many parts of Egypt as it is part of the culture and traditions, and it recently became very popular in touristic areas as Sharm El Sheikh-Egypt being used as a tattooing agent. This makes detection of heavy metal content and, other toxic ingredients in Henna marketed in Egypt of crucial importance.

Objective: To investigate heavy metal content and, other toxic ingredients as para-phenylenediamine (PPD) in Black Henna marketed in Egypt.

Methods: Fifteen Black Henna samples were collected randomly from Sharm El Sheikh-Egypt market and, analyzed for metal content by atomic absorption spectrophotometry (ICP-MS) after microwave acid digestion, also the presence of PPD in henna samples was determined qualitatively and quantitatively using High Performance Liquid Chromatography (HPLC).

Results: PPD was detected in all the black henna samples at concentrations ranging between 1.75% and 32.1%, which is higher than that recommended for hair dyes. The mean concentration of some studied metals as Aluminium, Lead, copper, nickel, and zinc were higher than permissible levels for cosmetics in some of the studied samples.

Conclusion: In conclusion, PPD is a common ingredient in black henna dye in the developing world. Physicians must be aware of the potential toxicity of this chemical and of the clinical signs of systemic poisoning. High concentration of some metals as Aluminium, lead, copper, nickel, and zinc might be encountered in some Henna products. Considering popular use of henna, the hazardous cumulative effects of prolonged exposure to low concentrations of such metals, especially in children, cannot be ruled out. Further studies are recommended.

Introduction: Accelerated water quality change due to industrial pollution is one of the major environmental concerns throughout the world. In Ethiopia, Pollution of surface water is largely a problem due to rapid urbanization and industrialization. The main objective of this study was to determine the pollution profile of Modjo River throughout study sites.

Methods: A cross-sectional study was conducted to assess water pollution along Modjo River. Ten sampling sites were selected based on wastewater discharge, accessibility and pollution feasibility of river water. The sampling frequency was for two rounds composite sample taken from Modjo River. The chemical parameters were determined in the laboratory by using standard instrumental method AAS and UV-VIS.

Results: Temperature, Electrical conductivity, Turbidity and PH were within the acceptable limit of surface water standard. Ammonia Nitrogen (NH3-N), BOD, Phosphorous, Nitrate Nitrogen (NO3-N) was all above acceptable limit except for BOD and Ammonia Nitrogen in station 1 within acceptable limit. TDS above standard limit in Stations 5, 6, 7, 8, 10 were above acceptable limit. COD of station 2, 3, 4, 8, 9 and above the acceptable limit. For chromium stations 3, 6, 8, 9 and 10 above acceptable limit of surface water standards.

Conclusion and recommendations: The study result found that there was change on the physico-chemical parameters from upstream to downstream areas, which indicates an introduction of pollution load from industrial wastewater. It is recommended that National Environmental Quality Standard (NEQS) should be strictly enforced on all industries to install facilities and treat wastewater effectively.

Produced water (PW) discharged into the Mediterranean basin is a mixture of organic and inorganic materials of high toxicity and risk to the marine environment. This PW had a high water mineralization and significant amounts of suspended matter (SM). The detected levels of heavy metals, especially Ag+, Ba2+ and Pb2+ cations, were not negligible. The values of chemical oxygen demand (COD 735 mg/L) and total organic carbon (TOC 93.83 mg/L), which were very high, confirmed the presence of large concentrations of polycyclic aromatic hydrocarbons (PAHs) which were identified by infrared analysis. The total concentration of polycyclic aromatic hydrocarbons (PAHtot) in the PW sample was about 3.243 g/L. This can be treated by flotation in a very acidic medium at pH=2, in the presence of a neutral collector (Tween 80) at 0.5%, with an optimum cleaning efficiency of 93.67%, without necessarily generating the production of polluted sludge, in about 20 min, optimum time of flotation found. A study of flotation kinetics based on PAHtot recovery was carried out. It showed that the process followed Higuchi model. At the end of the treatment, all effluents were corrected from the acidic pH to the neutral pH, before to be discharged into the sea.

The toxicities of commercial detergent (Ariel; Linear Alkylbenzene Sulfonate), a household cleaning agent was investigated on some enzymatic and protein activities of juvenile African mud catfish (Clarias gariepinus). Fishes were exposed to lethal and sub-lethal concentrations of detergent for 21 days in a renewal bioassay procedure. The median lethal concentrations (LC50) were derived using Finney probit method while protein and enzymatic activities were determined using Biuret and Randox methods respectively. The LC50 values for 96 hours acute bioassay test was 0.11 g/l. Detergent exposed fish showed significant increase (p ≤ 0.05) in serum AST (109.00 ± 3.79 to 111.00 ± 3.80); liver globulin at 0.008 g/l (2.47 ± 0.03) and 0.013 g/l (2.57 ± 0.03). Significant decrease was recorded in liver AST, (ALP and creatinine 137 ± 4.67 to 151 ± 2.52; 80.67 ± 0.88 to 86.67 ± 3.67 and 0.27 ± 0.07 to 0.60 ± 0.00 respectively across all sub- lethal concentrations. The enzymes and proteins from serum, liver and heart tissues of fish have shown vividly that detergent is capable of inducing adverse effects and impacting on the health of fish. Therefore, the presence of detergent in aquatic ecosystem could be dangerous to fish and subsequently human health.