Toxicología ambiental y analítica

Unraveling the complexities associated with the relative differences in contaminant concentrations between the sexes of mature fish may provide insights into important behavioral and physiological differences between the sexes of not just fish but higher vertebrates as well. Whole-fish polychlorinated biphenyl (PCB) concentrations were determined in 25 mature female white suckers (Catostomus commersoni) and 26 mature male white suckers caught during their spawning run in the Kewaunee River, a tributary to Lake Michigan. Total length and weight were measured for each fish, and age of each fish was estimated from thin-sectioned otoliths. PCB concentration significantly increased with increasing total length, weight, and age. Consequently, three analysis of covariance (ANCOVA) models were fitted to the data to assess the effect of sex on white sucker PCB concentration. Based on model averaging, estimates of mean PCB concentrations in female and male white suckers were 185 and 219 ng/g, respectively. Thus, males were 18% greater in PCB concentration than females. We conclude that this difference between the sexes was most likely mainly driven by a higher rate of energy expenditure in males compared with females. Greater energy expenditure, owing to greater swimming activity and a higher resting metabolic rate, resulted in a higher rate of food consumption, which in turn led to a greater rate of PCB accumulation. Higher whole-fish PCB concentration in males compared with females has now been shown in nine different fish species. Our study represented the first documentation of this type of sex difference in a catostomid fish.

The ability of sandy soil to adsorb lead (Pb) to limit its dispersion in environmental compartments and its adverse effects on humans and ecological receptors depends on certain reaction parameters. The sandy soil has a low Pb retention capacity, but treatment of this soil with amendments such as bentonite, crabmeal and eggshells could significantly improve its ability to adsorb the Pb. To this end, various sorbent tests of Pb by sandy soils, soil amendments and soil+amendments have been carried out in a static mode in the laboratory. The adsorption parameters tested are: reaction time, volume/mass ratio, temperature, increasing Pb (II) concentrations, nature and type of amendment. Furthermore, it was under thermodynamic control and was endothermic in the case of an increase in adsorbed and exothermic Pb levels as they decreased. Moreover, the adsorption of Pb obeys the Langmuir model for the soil (R2=0.986), bentonite (R2=0.915) and crab meal (R2=0.790) and Freundlich for eggshells (R2=0.936). The adsorption of Pb as a function of the types and doses of amendment showed that the retention effect of Pb was very significant (p<0.0001) and that 2.5% of crab meal, compared to the minimum intakes of 10% bentonite and 20% eggshells were sufficient to adsorb the maximum Pb for soil treated with a single amendment. The application of two soil amendments showed that the amended soil adsorbed more Pb with the minimum Fe content compared to other amendments. These results show that crabmeal is an excellent biosolid for the retention of anthropogenic Pb. The desorption test demonstrates that Diethylene Triamine Pentacetic Acid (DTPA) extracted much higher amounts of freshly adsorbed Pb than those extracted with ammonium acetate. The amounts of Pb adsorbed were significantly correlated with the amounts of desorbed Pb. Adsorption and desorption are therefore important phenomena controlling the bioavailability of Pb in sandy soils.

The work determines the different lethal concentration of Moringa oleifera bark extract as a piscicide. The sourced fishes (250) were acclimatized for 14 days. The test plant fresh bark was pounded into a macerated sample and soaked with distilled water for 48 hrs to simulate local procedures. Ten Clarias gariepinus juveniles were placed in each of the experimental aquaria and different test concentrations of 0 ml, 10 ml, 20 ml, 40 ml, 80 ml, 160 ml, 320 ml and 640 ml/l of water were used. The 48-hrs bioassay was conducted to determine sub-lethal concentration (LC50) for C. gariepinus juvenile to aqueous extract of Moringa oleifera bark. The 24-hrs and 48-hrs of LC50 of M. oleifera applied to C. gariepinus juvenile were 121.89 ml/l and 110.92 ml/l, respectively. Physical reactions exhibited by the fish including erratic movement, air gulping, loss of reflex, discolouration and molting. Mortality increased with increasing concentration of aqueous extract of M. oleifera bark and time of exposure in C. gariepinus juveniles. Moreover, the acute (LC100) effect that killed all the fish within 24-hrs was discovered to be the highest concentration of 640 ml/l. This findings provide evidence of Moringa oleifera as botanical piscicide for partial fish harvesting.

Composting is used in the management as a method to recover organic wastes. It provides the environmental and health benefits by reducing the survival and spread of pathogens. The growth of urban population and economic activities has resulted in corresponding growth of solid waste in Robe town. However, the traditional approach to organic solid waste management in the town focuses on the end of line solutions that are capital intensive, and therefore costly. The main purpose of the current study was to assess the challenges and opportunities of composting organic solid wastes. The research used descriptive method with survey strategy. To draw the sample, both probability and nonprobability sampling method were used and the total sample sizes of 384 from the three selected kebeles were selected proportionally to their respective household numbers. Both qualitative and quantitative tools such as questionnaires, interview, field observation and photography were used to collect the required data. The data quality was measured in terms of validity, reliability and practicability. The data were analyzed using, SPSS and Microsoft Excel. The finding of the study revealed that, there is no proper composting of organic solid wastes in the town. The challenges that hold back the implementation of composting organic solid waste includes lack of awareness, lack of adequate space for composting, lack of support from government, policy frame work, institutional problem (lack of department of urban agriculture) and budget constraint. However, the opportunities are availability of huge amount of organic wastes, farmers engaged in urban agriculture, suitable environment for composting, huge demand for organic fertilizer and an increase in price of chemical fertilizer.

The objective of this study is to assess farmers’ awareness on the safely use of pesticides and field spraying practices that might potentially expose them to chemical hazards. The level of farmer's knowledge towards the negative effects of pesticides on the human health and environment was evaluated. A pilot survey was also carried out for assessing the potential residual levels of chlorpyrifos cypermethrin and lambda-cyhalthrin pesticides (which are commonly applied on the vegetable and fruit crops in the study area) in the feet, hands and face washing water of sprayers after application. The study was carried out among smallholder farmers of intensive vegetable and fruit production zones at northern delta, Egypt. Data was based on a random sample of 86 farmers using structured interviews and direct field observations. The obtained results showed that in spite of the farmers have good knowledge about the potential negative effects of pesticides on the human and for somewhat on the environment, lack of their following safety measures was dominant. All of the pesticide applicators investigated did not wear any protective clothing during spraying. Although they knew about the potential human health risks of pesticides, the precautionary measures taken against exposure were very rare. The study also found that there are no any farmer's obligations with the pre-harvest interval (PHI). No existence of agricultural extension in the study area. The results about exposure of the farmers to residues of chlorpyrifos cypermethrin and lambda-cyhalthrin pesticides level in the washing water of their feet, hands and face found that the feet washing was at higher residual levels and frequencies (11-131 μg, 80-100%) of these pesticides, for face (˂4.5 ng-125 μg, 0-100%) and for hands (1.3-78 μg, 80-100%). Using of high pressure motor machines was showed at high contribution for the workers contamination (12-131 μg) compared with the backpack manual sprayer (˂4.5 ng-114 μg). Washing water of the sprayer’s top clothes was found at about thousand times higher residue levels (1.5 × 103-102 × 103 μg) of the tested pesticides than those levels determined on the surface of the feet, hands and face of the farmers investigated. These findings might be referred to the wide spread distribution of the spray solution by the high pressure motor. Chlorpyrifos residues were detected at high levels and frequencies, while another two insecticides at lower values. This study suggested that great efforts to reduce potential health risks from chemicals should be implemented to improve farmer awareness against pesticides application and its hazards. Agricultural extension should be existed to play an effective and responsible role in these efforts. An improved approaches including integrated pest management (IPM) and, in general, good agricultural practices (GAPs) must be followed as a strategy for continued crops production with minimal risks of pesticides to the environment and human health.

The problem of getting quality water is increasing as untreated effluents are discharged into water bodies. The study aims at assessing the impact of various abattoirs wastewater on ground and surface water bodies in Abeokuta. Water samples were collected randomly in 9 different locations of Abeokuta (4 stream and 3 groundwater samples as well and 2 around abattoir vicinity as controls of surface and groundwater). All the samples were collected on the same day in the morning and were analysed for physical, chemical and microbiological load. The water quality parameters measured includes; Colour, Odour, pH, EC, Temperature, TDS, Cl2, DO, BOD, COD, TS, TSS, NO3, PO4, Heavy Metals (Pb, Zn, Cu, Cd, Fe), microbiological analysis. The parameters were analysed using standard procedures and the results were analysed using descriptive and inferential statistics. The ranges of the means values of all the parameters measured for pH, Temperature, Hardness, TDS, Cl2, NO3, PO4, BOD5, DO, COD, TS and TSS were 7.23-7.36, 27.3°C-28.0°C, 164- 323 mg/L, 102-518 mg/L, 20-70 mg/L, 0.005-0.706 mg/L, 0.212-0.850 mg/L, 0.570-7.400 mg/L, 1.0-6.8 mg/L, 72-504 mg/L, 0.260-0.520 mg/L, 15.4-16.1 mg/L and that of heavy metal were; 0.03-0.19 mg/L, 0.020-0.090 mg/L, 0.010-0.030 mg/L, 0.0-0.700 mg/L, 0.040-4.960 mg/L for Pb, Zn, Cu, Cd, Fe respectively while that of the Faecal Coliform was 100- 300 cfu/ml respectively. The results of the study revealed that all of the measured parameters show significant difference in their mean except Cl2, EC, PO4 TDS and Temperature. From the results, it was discovered that the concentration of Hardness, Pb, Cu, Pb, Zn, Cd, Fe and Faecal Coliform exceeded the permissible limits of both the WHO and FEPA standard for drinking and wastewater effluent. Pollution of ground and surface water through discharge of waste is an evidenced by the high concentrations of pollution indicators, nutrients and trace metals above the acceptable limits.

This work, aims to treat tannery wastewater sample to remove or reduce the pollutants load by using electrocoagulaion technique using an electrode of aluminum nanoparticles. The aluminum nanoparticles were synthesized using sol-gel method and characterized with XRD, TEM, SEM, EDX and FTIR. All the results show that these materials were in nano range. XRD pattern showed that the diameter of aluminum particles was around 14 nm and a peak at 2 theta 18 of aluminum hydroxide. TEM and SEM images of aluminum nanoparticles confirmed the XRD results. The EDX and FTIR indicate the presence of oxygen and hydroxyl ions accompanying the preparation of aluminum nanoparticles. The investigation of the tannery waste water showed high signs of pollution. The pH, turbidity, COD, TDS, chromium, sulphide, chloride and sulphate were 7, 13900 NTU, 10155 ppm, 462 ppm, 28950 ppm, 412 ppm, 6471.5 ppm and 5995 ppm respectively. All these values exceed the limits of the industrial effluent standards, except for the PH. In electrocoagulation treatment at 80 mA, 3 h and pH 7, succeeded to remove best 98.98%,90.6%,70.40%,99.9% and 88.3% of Turbidity, COD, TDS, Chromium and Sulphide respectively.

The gills, flesh, intestines and skins of fish from Onitsha segment of River were carefully, dissected from the fish samples. Water and sediment samples were equally collected from two sites for heavy metal determination using Atomic Absorption Spectrophotometer (AAS 220 FS). The highest concentration detectable was in the sediment sample followed by the concentrations in the fish samples. Iron concentration detected was highest followed by lead with antimony and cadmium mostly undetectable. Variations in the parameters determined were found to be statistically significant at p<0.05.

In situ investigation of the biodeteriorative microorganisms lived on the Sumela monastery stones were identified using Microbial Identification System (MIS) and SEM-EDS combined system energy dispersive spectrometric investigations. The results showed that wide variety micro/macro-organisms dwell on stones of the Sumela Monastery. Total 24 species and 10 genuses were determined on the deteriorated stone surfaces by microbial identification studies. The settled way of these organisms on stone surface were illustrated by SEM images. EDS analyses show that the major elements constituting the stones of the Sumela Monastery are silicon, aluminum, calcium, potassium, titanium, magnesium, zinc, sulfur, iron, sodium and niobium. Some of these elements could provide energy resources for the microorganisms by dissolving stone-surfaces of the Monastery. However, the biodeteriorative effect of micro/macroorganisms is more significant on stones of the Sumela Monastery, we see that the man is the most destructive agents on the historical building among all of the deteriorative factors.

The dynamic estuarine environment influences the sedimentary processes like physical and chemical characteristics of sediments. The dominant factor in sediment transport is the motion of water. The particles are moved by the current of water in the way of sliding, rolling, siltation and suspension. Texture a peculiar feature of the sediment which describes the nature of soil. In the water bodies, the textural characteristics reflect how long the sedimentary particles are affected by organic and inorganic contaminants. For the present study three different estuaries namely Kadinamkulam backwater, Veli Lake and Poonthura backwater around the Trivandrum city of Kerala were chosen as study sites. From each estuary three stations such as riverine zone, middle zone and bar mouth zone were fixed for collection of samples. Monthly collection of sediment for a period of one year from April-2014 to March 2015 was carried out. Regular analysis of texture was done and calculated the results. The observations from the present study showed that most of the months and in all the selected stations sandy soil dominates. The clayey and silty soil was reported in certain stations in specific seasons.

This study aims at the assessment of the impacts of artisanal refining of crude on soil and water quality in parts of Okrika and Ogu-Bolo areas of Rivers State, Nigeria. Standard sampling methods were used in the study. A total number of sixteen (16) sampling points were selected using random sampling techniques for the water points and soil samples within Ogu-Bolo and Okrika. Water and soil samples were analyzed in the laboratory using standard methods. The ArcGIS version 10.3, ENVI version 4.7, Surfer 10, SPSS 22 and Microsoft Enterprise were used for the interpretation. The Digital Elevation Model (DEM) was created from the elevation data obtained from Short Radar Thematic Mapper (SRTM) satellite image and contour extracted from the topographic map. The influence of the soil type, slope, flow accumulation and flow direction of the study area was used to delineate the level of contaminant plume. This was generated from the DEM using the ArcGIS 10.3 3-D analyst tool function. A water Quality index rating of 1 was measured in the study area which is an indication that the water is very bad. Also, the physio-chemical analysis on soil and water revealed poor water and soil. Water analysis showed high concentration of Fe and Zn which made the water in such area unsuitable for drinking. Also, the soil samples recorded high levels of crude content from 1 m, with concentration reducing with depth up to 3 m. A general contamination map of Okrika/Ogu-Bolo was modelled, indicating the contamination rating of total land mass of the study area, with 23.59 km (5.71%) rated very good, while 85.65 km (20.71%) were rated good. Also, 140.37 km (33.95%) had only showed moderate level of contamination while 112.56 km (27.22%) recorded bad level of contamination, with 51.29 km (12.40%) of the total land mass having very bad contamination record. Water quality assessment should be carried out regularly to determine any future pollution of the water. It is recommended that artisanal refining activities in the area should be discouraged to avoid further contamination in the area.

The main aim of this work is to optimize the environmental condition for best grafting by control the temperature and light of grafting conditions. To achieve that was study the effect of ambient temperatures (20, 23, 26 and 29°C), light intensity (0, 2500 and 5400 Lux) and type of tunnel (truss and flat) on stem diameter, shoot length, leaf area, shoot dry mass, grafted-take and energy consumption. The obtained results indicated that the average temperature was 20.45, 23.61, 27.01 and 29.71°C at 20, 23, 26 and 29°C ambient temperatures in truss tunnel, while, it was 20.61, 24.21, 27.53 and 30.09°C at 20, 23, 26 and 29°C ambient temperatures in flat tunnel. The stem diameter values were 4.626 and 4.476 mm in truss and flat tunnel under study with ambient temperature 20 to 29°C and light intensity 0 to 5400 Lux. The shoot length values were 8.254 and 8.131 cm in truss and flat tunnel under study with ambient temperature 20 to 29°C and light intensity 0 to 5400 Lux. The leaf area values were 56.074 and 53.214 cm2 in truss and flat tunnel under study with ambient temperature 20 to 29°C and light intensity 0 to 5400 Lux. The shoot dry mass values were 396.448 and 386.585 mg in truss and flat tunnel under study with ambient temperature 20 to 29°C and light intensity 0 to 5400 Lux. The grafted-take values were 84.525 and 78.460% in truss and flat tunnel under study with ambient temperature 20 to 29°C and light intensity 0 to 5400 Lux. The energy consumed decreased with increasing ambient temperature and decreasing light intensity.

Droughts, as complex climatic hazards, can threaten livelihoods, economies, and ecosystems in low-lying island states. In extreme cases, drought may cripple national development in these countries, and produce long-term impacts that hinder national efforts to achieve the United Nations’ sustainable development goals. This study addresses rainfall trends, the frequency of droughts, La Niña influences and the relationship between rainfall and Sea Surface Temperature (SST) in the small Pacific country of Tuvalu. The study follows this order of approach: (1) examine observed rainfall time series for four meteorological stations across Tuvalu; (2) decompose observed rainfall time series and develop detrended rainfall time series; (3) evaluate and identify rainfall trends, including drought frequency; (4) define drought in Tuvalu using box plots; (5) evaluate the seasonal cycle of rainfall; (6) identify La Niña years and (7) test the correlation between SST, an indicator of La Niña events, and rainfall. The findings of this study revealed that (1) de-trended rainfall time series show declining trends in all four rainfall stations over the period 1953-2012; (2) the frequency of drought ranges from three to fourteen years with a mean of nine years; (3) the occurrence of drought appears to follow the La Niña years; (4) boxplots provide an effective option for defining drought and, finally, (5) there is empirical support for a moderate to strong correlation between the de-trended values of SST and rainfall in the area of study.

This study investigated the presence of four pesticides (carbaryl, methomyl, carbofuran and chlorpyrifos) and two personal care products (PCPs) i.e., triclosan (TCS) and caffeine in River Kabul, upper River Indus and Kalpani stream receiving untreated wastewater from major towns in northern Pakistan. PCPs were also examined in domestic wastewater in Mardan district, Pakistan with untreated sewage disposal as common elsewhere in the country. Analysis were performed using liquid chromatography with a triple quadrupole tandem mass spectrometry (LC-MS/MS). All the target pesticides were detected in surface water bodies and in domestic sewage in various concentrations. Methomyl in River Kabul at maximum concentration of 8.3 μg/L was found above its reported LC50 for water fleas. PCPs level in sewage were comparable to other countries but in the absence of any treatment practice, environmental discharge to water bodies was higher by many orders of magnitude compared to treated effluent. Eco-toxicological risk assessment revealed a risk quotient (RQ) of >1 for methomyl, chlorpyrifos and carbofuran for water fleas and fish in River Kabul, River Indus and Kalpani stream and TCS for algae in Kalpani indicating a serious toxicity risk to aquatic organisms in these rivers.

A strain was able to use 2-picolinic acid (2-PA) as a sole source of carbon, nitrogen and energy under aerobic conditions was isolated in this paper. Based on 16S rRNA gene sequence analysis, this strain was identified as Comamonas sp. and named as ZD3. The effects of pH and initial concentrations of 2-PA on the degrading capacity of ZD3 were investigated. It was found that ZD3 degraded 2-PA effectively under a pH range of 5.0 to 9.0, in which 7.0 was proved to be the optimal value. When the initial concentration of 2-PA was 100, 200, 400, 600 and 800 mg/L, ZD3 completely degraded 2-PA within 10, 18, 22, 78 and 114 h, respectively. Zero order kinetic model expressed the degradation behavior of 2-PA by ZD3 well. It was observed that under the concentration range of 100 to 400 mg/L, the degradation rate constant increased with the increase in concentration and reached the maximum at 400 mg/L. However, under the concentration range of 600 to 800 mg/L, the degradation rate constant began to decrease, indicating an inhibitory effect. Moreover, ultraviolet scanning and high performance liquid chromatography ion trap timeof- flight mass spectrometry showed that during the degradation of 2-PA the first reaction was α hydroxylation so that 6-hydroxy picolinic acid (6-HPA) was produced.

Many dynamics and diurnal patterns impact upon the performance of effluent disposal areas. The timing of household water use and conveyance to a septic tank impacts on the available volume for application to an effluent disposal area. The timing and method of effluent application will impact on the performance of the effluent disposal area in assimilating nutrients and maintaining adequate infiltration rates. Rainfall patterns will impact on soil saturation at different times during the year; and threshold rainfall events may increase groundwater levels that will impact on the performance of the effluent disposal area. However, the dynamics and diurnal patterns comprising the “whole-of-on-site wastewater- system” are rarely discussed in the literature. This paper uses data obtained from a study of two allotments in a non-sewered subdivision at Salt Ash (NSW) to highlight these dynamics and diurnal patterns in order to improve the performance evaluation of on-site wastewater systems, in particular Mound systems. Results indicate that under existing septic tank-collection well design criteria the variability in average daily indoor water use and average diurnal water use patterns will impact on the temporal comparative performance of effluent disposal areas (Mound systems) at similar sites.

Water is the backbone of all life forms on earth. Water is an essentially important material on earth to both natural ecosystem and human development and for human use. Because of its clear importance, water is the most studied material on earth. Present study deals with physio-chemical analysis of industrial effluent collected from the Ahmedabad mega pipe line. Mega pipeline receives treated effluent of industrial cluster Vatva, Naroda, Odhav and Narol. Mega Pipeline from Naroda to Pirana has carrying capacity of 90 million litre per day (MLD). It is an outlet of Central Effluent Treatment Plant (CETP). Treated effluent is released into Sabarmati River. The study also documents total dissolved solids, calcium hardness, magnesium and Chemical Oxygen Demand exceeding permissible limits.

Bacterial strain DXZ9, which is able to degrade DDE, was isolated from the sludge of a pesticide factory. The sludge had been contaminated with DDT during an enrichment culture technique. The bacteria was identified as a Stenotrophomonas sp. The effects of various factors, such as pH, temperature and the concentration of the initial substrate on the degradation portion of DDE were investigated. The results showed that the DDE biodegradation proportion was 39.4% at the end of the 5th day, and the biodegradation proportion increased slightly and reached 41.9% at the end of the 10th day. Optimally, the pH, the concentration of the substrate, and the cultivation temperature were 7, 10 mg/l and 30°C, respectively, within 5 days and based on experimental optimization. DDT, the parent compound of DDE, could also be degraded by this bacterium; the biodegradation proportion of DDT was 55.0% and 57.6% at the end of the 5th and 10th days, respectively. The metabolites were analyzed by gas chromatography/mass spectrometry (GC/MS). DDT is dehydrochlorinated to DDE by bacterium DXZ9, and the metabolites of DDE were multipler undefined substances. These results indicate that DXZ9 has the ability to metabolize DDE and its parent compound, and it shows tremendous potential for use in field applications for the bioremediation of contaminated soil.