Area Of Crete Research Articles

The impact of nutrition on psycho-affective status in an older Cretan population: a cross-sectional study.

Cognitive and mood status influence both personal and social daily activities, with great impact on life quality, particularly among the elderly population. This cross-sectional study aimed to investigate the psycho-affective status concerning eating habits within an elderly population of the Chania area in Crete, Greece. Cognitive status was assessed in 101 elderly subjects through the Mini-Mental State Examination (MMSE), and mood was evaluated using the Hospital Anxiety and Depression Scale (HADS). Nutritional status was assessed using a validated food frequency questionnaire. Multivariable statistical analysis, after adjustment for age, marital status, education, and comorbidity, highlighted among males a positive association of the MMSE score with vegetable consumption (RR 1.18; 95%CI 1.03‒1.34) and a negative association with potato consumption (RR 0.83; 95%CI 0.72‒0.95). Conversely, among females, no statistically significant association was observed for any food. Further, among males, a protective effect on affective status was identified for chicken meat (RR 0.45; 95%CI 0.27‒0.77), fish (RR 0.41; 95%CI 0.21‒0.82), fruit (RR 0.70; 95%CI 0.52‒0.94), cereals (RR 0.67; 95%CI 0.53‒0.87), and cheese (RR 0.78; 95%CI 0.63‒0.97) consumption. Among females, the adjusted model showed a significant detrimental effect of vegetable consumption (RR 1.33; 95%CI 1.02‒1.73). A predominantly vegetable-based diet-with the notable exception of fruits and legumes-was associated with better cognitive status in males, albeit not in females. A higher intake of fruit, as well as fish, chicken meat, and cheese among males was associated with a better affective status, indicating that adequate protein supply may play a role in maintaining emotional balance.

A Study of Greek Graviera Cheese by NMR-Based Metabolomics.

Graviera is a very popular yellow hard cheese produced in mainland Greece and the Aegean islands, and in three PDO (protected denomination of origin) locations. Apart from geographic location, type of milk and production practices are also factors that affect cheese composition, and make this dairy product unique in taste and aroma. In this work, 1H nuclear magnetic resonance (NMR) spectroscopy in combination with chemometrics has been used to determine the metabolite profile (40 compounds) of graviera cheese produced in different geographic locations, with emphasis on cheeses produced on the island of Crete. Organic acids and amino acids were the main components quantified in the polar cheese fraction, while the fatty acid (FA) composition of the lipid fraction was also obtained. Analysis of variance (Anova) of the dataset showed that γ-aminobutyric acid (GABA), conjugated linoleic acids (CLA) and linoleic acid differentiate gravieras produced in different areas of Crete, and that the total amino acid content was higher in cheeses produced in eastern Crete. Targeted discriminant analysis models classified gravieras produced in mainland Greece, Cyclades and Crete based on differences in 1,2-diglycerides, sterols, GABA and FA composition. Targeted and untargeted orthogonal partial least squares discriminant analysis (OPLS-DA) models were capable of differentiating gravieras produced in the island of Crete and hold promise as the basis for the authentication of PDO graviera products.

Phytochemical Analysis of the Aerial Parts of Campanula pelviformis Lam. (Campanulaceae): Documenting the Dietary Value of a Local Endemic Plant of Crete (Greece) Traditionally Used as Wild Edible Green

Native wild edible greens usually include plants with widespread geographical ranges and represent a long tradition associated with well-documented health effects, especially in the frame of the Mediterranean diet. Although consuming local endemic and range-restricted plants as wild edible greens is rare, in some areas of Crete this is a long ethnobotanical tradition. The present study is focused on the phytochemical and nutritional element analyses of the edible parts of the wild-growing green Campanula pelviformis. To date, nine secondary metabolites have been isolated: lobetyolin (1), calaliukiuenoside (2), demethylsyrrigin (3), wahlenoside A (4), chlorogenic acid methyl (5) and butyl ester (6), nicotiflorin (7), rutin (8) and corchoionoside A (9). This first-time research on the phytochemical composition of this local endemic plant of Crete is a basic step in attempts to document its nutritional value, also allowing an exploration of its beneficial properties. The nutritional value of the Mediterranean diet owes much to the inclusion of native edible wild plants, which are abundant in mineral elements and bioactive compounds known to promote human health. Among these plants, the local Cretan endemic species C. pelviformis stands out as a rare and valuable source of wild edibles with traditional dietary significance in eastern Crete. This plant’s rich content of mineral elements and bioactive compounds makes it an intriguing subject for further research into the potential health benefits of wild plant consumption.

Mind the gap in data poor Natura 2000 sites and how to tackle them using Earth Observation and scientific diving surveys

Charismatic species drives decisions for the conservation of marine areas in the view of the coverage of the Natura 2000 sites in the European Union and other forms of Marine Protected Areas in Europe. However, when used solely, critical seascapes and habitats are systematically ignored and practically it can take decades to fulfill baseline needs on habitats distributions, habitats conservation status and species distributions and biodiversity assessments. Luckily, in the last decade, the use of new technologies in conjunction with scientific diving and budget friendly hydroacoustic tools and applications, has allowed to fill the gap in knowledge in such situations and seascapes. The current work demonstrates the use of Earth Observation and Science Dive to fill the gap of knowledge in a newly established Natura 2000 area in Crete, Greece, East Mediterranean, paving the road for replicable approaches in similar situations.

Vaccination Coverage and Associated Factors of COVID-19 Uptake in Adult Primary Health Care Users in Greece.

In our study, attitudes and perceptions of adult primary health care users regarding COVID-19 vaccination were evaluated. A single-center, cross-sectional study was conducted during a 1-year period (March 2021-March 2022) in a rural area in Crete, Greece. A sample of 626 self-reported questionnaires was collected at the end of the study period. Overall, 78% of respondents stated that they had received the COVID-19 vaccine. The reasons behind vaccine uptake were mainly personal beliefs and the desire to avoid professional constraints. The presence of diabetes type 2, fear of infection, and high perceived efficacy of vaccine previous flu vaccination, living with vulnerable persons, and the influence of scientific information were all significant predictors of COVID-19 vaccine uptake. On the contrary, unwillingness and/or uncertainty to be vaccinated was associated with fear of vaccine side effects, information insufficiency, media/internet information, older age, the presence of inflammatory arthritis, previous COVID-19 infection, the belief that infection confers much greater immunity than the vaccine, and attitudes against vaccinations in general were predictors against COVID-19 vaccination. In conclusion, taking into account all of the above predictors and particularly those regarding safety and vaccine effectiveness may guide future strategies appropriately tailored to specific characteristics and needs of different geographic populations.

The impact of seasonal influenza vaccination uptake on COVID-19 vaccination attitudes in a rural area in Greece.

Promoting vaccination for coronavirus disease 2019 (COVID-19), especially for high-risk groups such as the elderly and persons with comorbidities, is important for reducing the incidence of severe disease and death. Retrospective cross-sectional study of factors associated with COVID-19 vaccination, including previous influenza vaccination, among all persons who received medical services in a rural area in Crete, Greece, between October 2020-May 2021. Among 3129 participants, receipt of influenza vaccination in 2020-21 was strongly associated with COVID-19 vaccination, as was influenza vaccination in 2019-20, albeit to a lesser extent. In addition, persons older than 59years (with exception of those 90+years old) and those who lived closer to the hospital/health center, were more likely to vaccinate for COVID-19. Persons younger than 40years of age, females, persons with mental illness or neurologic disease, were also less likely to vaccinate for COVID-19 (all p<0.001). COVID-19 vaccination was more likely among those who were vaccinated for influenza before and during the pandemic. Access to healthcare services and specific comorbidities, were important influencers for vaccination, underlying the importance of tailored interventions to enforce vaccination in high-risk groups.

State anxiety and workplace harassment among nursing personnel

Introduction: According to Spielberger, state anxiety refers to “the subjective emotional state characterized by tension and nervousness as a result of the present situation.” Workplace harassment in the health sector is a real problem. Aim: The main aim of this study was to examine the existence of state anxiety and phenomena of workrelated harassment. Methodology: An investigation was carried out in the area of Crete between August 2017 and January 2018 in fourteen Health Centers, two Primary National Health Networks, four Emergency Department, eleven Intensive Care Units. The study involved 213 nurses. The Leymann Inventory of Psychological Terror and the State-Trait Anxiety Inventory (Unit 1, state anxiety) has been used. Results: The 45.5% of the total sample of the participants work in Intensive Care Units (ICU), the 24.9% in Emergency Departments (ED) and the 29.6% in Primary Care Units. The average age of the participants was 41.73 (±7.33). The reliability of State - Trait Anxiety Inventory (Unit 1, state anxiety) by Cronbach α was 0.895. The mean value of state anxiety was 40.82 for the total study sample. They were exposed to at least one mobbing behavior in the past 12 months, and for at least once a week, almost daily or daily and for at least 6 months the 11.3% of the total sample. Comparing the mean values οf the variable “structure” to the occurrence of state anxiety, the following results were obtained: ICU: state anxiety 41.74, ED: state anxiety 38.57. Primary Care: state anxiety 41.81. In particular, the higher values of state anxiety appear in the ED. There is α statistically significant result with state anxiety (Sig. (2-tailed) &gt; 0,05 between age, marital status, and educational level. Regarding the total years of working the nursing personnel in the present department and the gender, there is α statistically significant result (Sig. (2-tailed) &lt; 0,05) with state anxiety. From the total sample of the survey found that 24 people were exposed to at least one harassment behavior in the last 12 months and at least once a week and for at least 6 months. These 24 persons had a mean state anxiety of 47.50. Conclusions: The evaluation of the results shows that the nursing personnel of the total sample face state anxiety with mild intensity. Nurses who have been harassed have state anxiety with moderate intensity. It is necessary the education of nursing personnel in managing anxiety symptoms.

Estimation of the Required Bio-fuels Substituting Petroleum-based Fuels in Vehicles in the Island of Crete, Greece

The required bio-fuels for substituting petroleum-based fuels in vehicles in the island of Crete, Greece have been estimated. The quantities of gasoline and diesel oil currently used in vehicles in Crete as well as their GHG emissions have been calculated. The quantities of bio-ethanol and bio-diesel substituting 14% of them, according to the EU goal for 2030, have been evaluated. The necessary land area for cultivating energy crops producing the required bio-fuels has been also calculated. The total quantity of gasoline and diesel oil used in vehicles in 2020 in Crete has been estimated at 273,231 tons while their CO2 emissions at 886,702 tons. The bio-ethanol required for substituting 14% of the annual gasoline consumption has been calculated at 29,709 tons while the bio-diesel required for substituting 14% of the annual diesel oil consumption at 24,802 tons. The necessary land area cultivated with sugar beet producing the abovementioned quantity of bio-ethanol has been estimated at 7,427 ha while the necessary land area cultivated with rape seed producing the abovementioned quantity of bio-diesel has been estimated at 24,802 ha. The overall necessary land area, at 32,229 ha, corresponds at 3.81% of the total area in Crete. Energy crops have not been cultivated so far in Crete while the land availability is limited. It is proposed that apart from using bio-fuels in conventional vehicles equipped with ICEs different options for reducing GHG emissions in transportation, including the use of electric vehicles, should be considered in Crete.

Training nursing staff who have been victim of work labour harassment on the island of Crete in strengthen of their self-esteem with anonymous group psychotherapy through teleconferencing

Background: Professional self-esteem for nursing profession refers to the extent to which a person experiences its work as important while appreciating its performance as important. There is evidence that self-esteem is important for health. The majority of the victims of occupational harassment of nursing staff have a middle self – esteem. Purpose: This study tests the effectiveness of adding a fourteen weeks schema-focused Anonymous group psychotherapy via teleconference in victims of workplace harassment in nursing personnel in the island of Crete, Greece. Method: An investigation was carried out in the area of Crete between August 2017 and January 2018 in fourteen Health Centers, two Primary National Health Networks, four Emergency Department, eleven Intensive Care Units. The total sample of the present study was 213 nurses. This case–control study was carried out by α qualified psychologist. The participants were 14 nurses victims of workplace harassment assigned randomly to psychotherapy group and a control group to enhance of their self-esteem. Results: Statistically significant difference are presented in the psychotherapy group during a 14-week period for the scale of General Selfesteem (p-value = 0.002) measured with the Culture Free Self-Esteem Inventories. Conclusions: Anonymous group psychotherapy via teleconference is a safe and effective method for treating self - esteem in victims of workplace harassment. KEYWORDS: Anonymous group psychotherapy, Teleconference, Self-esteem, Nursing Personnel

Evaluation of the influence of olive mill waste on soils: the case study of disposal areas in Crete, Greece

It is well known that soils where olive mill wastes (OMWs) are disposed of eventually become overloaded with organic matter of unknown and insufficient quality as well as inorganic nutrients and polyphenols. In European Mediterranean countries, the disposal of OMW is considered to be a major environmental issue. An extensive study on the risks of soil quality caused by the disposal of OMW, in the framework of the LIFE PROSODOL Project (http://www.prosodol.gr), resulted in the definition of eight soil indicators. The indicators specifically for soils that contain OMW are pH, organic matter, electrical conductivity, total nitrogen, polyphenols, exchangeable potassium, available phosphorus, and available iron. To confirm the validity of this set of indicators, nine OMW disposal areas were randomly selected and studied in Rethymno, Crete, without any knowledge of their history, details of OMW production and disposal, or other activities in those areas. Soil samples were collected and analyzed for particle size distribution, pH, electrical conductivity, organic matter, carbonates, total N, available P, exchangeable cations (K, Ca, and Mg), polyphenols, boron, and available Mn, Fe, Cu, and Zn. The results indicated that all soil parameters were affected but in different directions and by different magnitudes. Changes were evaluated considering the number of ponds for which (a) changes in soil parameters were observed; (b) a parameter value was measured above the excessive threshold; and (c) the change in the parameter values was >100%. It was revealed that organic matter, nitrogen, polyphenols, potassium, phosphorus, and iron are the constituents for which all three evaluation factors yielded the highest values. Moreover, zinc could be also considered as a potential indicator although it is not included in the evaluated set of indicators. With regard to pH and electrical conductivity, although no substantial changes were observed in this study, they should always be included in a set of indicators as they are valuable in evaluating soil buffering capacity and salinization threat, respectively.

Use of Renewable Energy Sources for Energy Generation in Rural Areas in the Island of Crete, Greece

Use of renewable energies in rural areas in the island of Crete, Greece has been investigated. Crete has rich indigenous renewable energy resources which are currently utilized for covering part of its energy requirements. Various renewable energy technologies used for heat and electricity generation in the island have been examined. Solar energy, wind energy, hydro power, biomass, and low enthalpy geothermal energy are already used. The total installed electric power of renewable energies in Crete, located mostly in rural areas, is approximately at 30% of the total electric power installed. They currently generate more than 20% of the island’s annual electricity needs. More renewable energy applications are foreseen in the future in rural areas in Crete as soon as its electric grid will be interconnected with the country’s continental grid. New renewable energy technologies, which are not currently used, could generate in the future heat, cooling, electricity, and vehicle’s fuels in the island. Their use will have positive impacts including the promotion of energy investments, lower use of imported and polluting fossil fuels, de-carbonization of the island’s energy sector as well as creation of new local jobs. It is indicated that the rich renewable energy resources in Crete could provide almost all of its annual energy needs. This will result in Crete’s transformation to a low or zero carbon economy in accordance with EU targets for zero carbon emissions in the next decades complying with the global goal for climate change mitigation.

Automatic Coastline Extraction Using Edge Detection and Optimization Procedures

Coastal areas are quite fragile landscapes as they are among the most vulnerable to climate change and natural hazards. Coastline mapping and change detection are essential for safe navigation, resource management, environmental protection, and sustainable coastal development and planning. In this paper, we proposed a new methodology for the automatic extraction of coastline, using aerial images. This method is based on edge detection and active contours (snake method). Initially the noise of the image is reduced which is followed by an image segmentation. The output images are further processed to remove all small spatial objects and to concentrate on the spatial objects of interests. Then, the morphological operators are applied. We used aerial images taken from an aircraft and high-resolution satellite images from a coastal area in Crete, Greece, and we compared the results with geodetic measurements, to validate the methodology.

Assessing the Main Frequencies of Modern and Historical Buildings Using Ambient Noise Recordings: Case Studies in the Historical Cities of Crete (Greece)

Monitoring seismic structural response is an essential issue in earthquake risk assessments and mitigation studies for monumental buildings in order to undertake earthquake disaster management. This study aims at identifying the resonant frequency of soil and modern and historical buildings in three major municipalities of Crete (Heraklion, Chania, and Rethymno) using ambient noise recordings (microtremors) considering the importance of soil–structure interaction to seismic structural response, particularly for historical buildings and monumental structures. In this study, ambient noise recordings have been processed through Horizontal to Vertical Spectral Ratios (H/V) to preliminarily examine the main frequencies and to examine whether the building has its main frequency close to that of the soil in order to identify potential resonance phenomena. Numerous ambient noise recordings were recorded on the soil, in the basement, and at each n-floor of the buildings. The incorporation of local site conditions and soil-building resonance phenomena into the urban planning development of Crete regarding earthquake risk assessments is necessary. In this direction, microtremors can be used as an effective tool to support civil protection preparation and operational decision-making in terms of earthquake disaster, specifically in the area of Crete, which is characterized by high seismic activity and a high cultural monuments capacity.

An integrated method for assessing drought prone areas - Water efficiency practices for a climate resilient Mediterranean agriculture

This paper presents a new integrated GIS modeling method to assess drought vulnerability using multi-criteria analysis. The proposed methodology is an improvement over previous methods since it incorporates both dynamic and static factors that may affect water dynamics and contribute to water scarcity. These factors are: a) precipitation, b) evapotranspiration, c) soil water content, d) soil depth, e) artificial drainage, f) depth to water table, g) runoff accumulation, and h) saltwater intrusion zones. The above factors and their corresponding maps were fuzzified and spatially overlayed in order to obtain the final drought vulnerability map. The map depicts the spatial distribution of drought vulnerability represented by five classes ranging from very low to very high vulnerability. The proposed methodology was applied to the Greek island of Crete located in the Southeast Mediterranean region. The island of Crete is one of the most drought-prone areas in the region, while at the same time the island's economy relies strongly on agriculture and tourism. The derived results show that drought vulnerability is more severe in the eastern part of the island and that the coastal zones of the entire island are drought-prone areas. Also, according to the results, 19% of the island's area is characterized as “very highly vulnerable to drought”. This percentage varies significantly across the prefectures, with Rethymnon having the lowest vulnerability (2.8%), followed by the prefectures of Chania (6.3%), and Heraklion (17.3%), while the prefecture of Lassithi is the most vulnerable to drought (51.4%). The developed methodology was validated using historical data for drought affected areas in Crete, which is not always addressed in publications. Moreover, in this study, sustainable agricultural practices that ensure water efficiency especially in drought prone areas are proposed. These practices can be adopted by farmers to promote climate resilient agriculture in the Mediterranean region.

A GIS policy approach for assessing the effect of fertilizers on the quality of drinking and irrigation water and wellhead protection zones (Crete, Greece)

Fertilizers have undoubtedly contributed to the significant increase in yields worldwide and therefore to the considerable improvement of quality of life of man and animals. Today, attention is focussed on the risks imposed by agricultural fertilizers. These effects include the dissolution and transport of excess quantities of fertilizer major- and trace-elements to the groundwater that deteriorate the quality of drinking and irrigation water. In this study, a map for the Fertilizer Water Pollution Index (FWPI) was generated for assessing the impact of agricultural fertilizers on drinking and irrigation water quality. The proposed methodology was applied to one of the most intensively cultivated with tree crops area in Crete (Greece) where potential pollutant loads are derived exclusively from agricultural activities and groundwater is the main water source. In this region of 215 km2, groundwater sampling data from 235 wells were collected over a 15-year time period and analyzed for the presence of anionic (ΝΟ−3, PO−34) and cationic (K+1, Fe+2, Mn+2, Zn+2, Cu+2, B+3) fertilizer trace elements. These chemicals are the components of the primary fertilizers used in local tree crop production. Eight factors/maps were considered in order to estimate the spatial distribution of groundwater contamination for each fertilizer element. The eight factors combined were used to generate the Fertilizer Water Pollution Index (FWPI) map indicating the areas with drinking/irrigation water pollution due to the high groundwater contamination caused by excessive fertilizer use. Moreover, by taking into consideration the groundwater flow direction and seepage velocity, the pathway through which groundwater supply become polluted can be predicted. The groundwater quality results show that a small part of the study area, about 8 km2 (3.72%), is polluted or moderately polluted by the excessive use of fertilizers. Considering that in this area drinking water sources (wells) are located, this study highlights an analytic method for delineation wellhead protection zones. All these approaches were incorporated in a useful GIS decision support system that aids decision makers in the difficult task of protection groundwater resources.

Impact Assessment of a National Park Under the Auspices of Unesco

Crete features many protected areas of exceptional natural beauty that attract thousands of visitors every season. Many local enterprises count on that touristic activity to increase their revenues. One of the most important and well known protected areas of Crete is the Samaria National Park. It was established in 1962 and since then it has earned various international distinctions. The aim of this study is to quantify the economic effects of the visitations at the Samaria National Park, on the whole region of Chania and to identify the profile of the visitor.

Monitoring olive mills waste disposal areas in Crete using very high resolution satellite data

This paper evaluates the efficiency of different image analysis techniques applied to high resolution multispectral satellite data so as to identify olive oil waste disposal areas in the island of Crete where huge quantities of wastes are produced. For this purpose very high spatial resolution images including Pleiades, SPOT 6, QuickBird, WorldView-2 and GeoEye 1 have been exploited. The research included the application of the Normalised Difference Vegetation Index, Olive Oil Mill Waste Index as well as Principal Component Analysis. Moreover Intensity–Hue–Saturation transformation was carried out. Furthermore, unsupervised classification was performed for a variety of classes (5; 10 and 15) over the same area for two different periods. In addition, supervised linear constrained spectral un-mixing technique has been applied for the WorldView-2 image, to evaluate the potential use of sub-pixel analysis. Indeed, as it is demonstrated NDVI and OOMW indices may be used to enhance the exposure of disposal areas in high resolution satellite datasets, while the application of the PCA and HIS transformations seems to be able to further improve the results. Unsupervised classification techniques, with no ground truth data, can sufficiently work; however temporal changes of the disposal areas can affect the performance of the classifier. The use of spectral library was able to detect OOMW areas with a relatively high rate of success improving the results from the unsupervised classification. Finally, a COSMO-SkyMed radar image has been examined and fused with a hyperspectral EO-ALI image, indicating that such kind of datasets might be also explored for this purpose.

Delineation of Wellhead Protection Areas in Crete, Greece Using an Analytic Element Model

Groundwater is one of the main sources of drinking water in many regions and therefore investing in its protection is of paramount importance. A very important step in ensuring water of good quality is the delineation of well head protection areas (WHPAs), which is the focus of this research. The area of interest is the basin of the Keritis River, located near the city of Chania, Crete, Greece. The main contamination threats in the area are: i) olive oil industries ii) cemeteries and iii) urban waste from the towns located near or within the basin. The delineation of WHPAs in this work is performed using a more accurate method than a simple fixed radius around the well, which is currently common practice in Greece. A decision support modeling tool called Wellhead Analytical Element Model (WhAEM) was used for this purpose. WhAEM is a groundwater flow model designed to facilitate the delineation of capture zones and mapping well head protection, using the analytic element method. The unique hydrogeology of the modeled area (location of local heterogeneities, discontinuities, rivers, recharge, no-flow boundaries) is taken into account in order to prevent potentially harmful contaminants reaching the water supply. This process can be used as a management tool by water resources managers, stakeholders and public authorities in order to impose rational measures and potential restrictions in urban, agricultural and industrial activities developed in the area.

Urban Surface Temperature Time Series Estimation at the Local Scale by Spatial-Spectral Unmixing of Satellite Observations

The study of urban climate requires frequent and accurate monitoring of land surface temperature (LST), at the local scale. Since currently, no space-borne sensor provides frequent thermal infrared imagery at high spatial resolution, the scientific community has focused on synergistic methods for retrieving LST that can be suitable for urban studies. Synergistic methods that combine the spatial structure of visible and near-infrared observations with the more frequent, but low-resolution surface temperature patterns derived by thermal infrared imagery provide excellent means for obtaining frequent LST estimates at the local scale in cities. In this study, a new approach based on spatial-spectral unmixing techniques was developed for improving the spatial resolution of thermal infrared observations and the subsequent LST estimation. The method was applied to an urban area in Crete, Greece, for the time period of one year. The results were evaluated against independent high-resolution LST datasets and found to be very promising, with RMSE less than 2 K in all cases. The developed approach has therefore a high potential to be operationally used in the near future, exploiting the Copernicus Sentinel (2 and 3) observations, to provide high spatio-temporal resolution LST estimates in cities.

Long-term application of olive-mill wastewater affects soil chemical and microbial properties

Disposal of untreated olive-mill wastewater (OMW) is a major environmental problem in many Mediterranean countries. This study assessed the impact of OMW application on soil microbiological properties and explored the relationship to soil chemical properties during a 9-month, periodical soil-sampling campaign in a pilot study area in Crete, South Greece. Cases studied involved: direct application of OMW on soil; OMW disposal in active evaporation ponds; sites hosting evaporation ponds that have been inactive for the past 9 years; sites downstream of active evaporation ponds; and control soils, upstream of the waste-disposal ponds. Long-term OMW disposal on land affected the main soil chemical properties. Applicability of the results from the systematic monitoring was confirmed by results obtained in other OMW disposal sites around the pilot area. Soil microbial properties (microbial activity, microbial biomass carbon, and metabolic quotient) were considerably affected by OMW disposal. Moreover, seasonal changes of soil properties revealed short- and long-term residual effects due to OMW disposal. Significant correlations were observed among soil microbial characteristics and soil chemical properties, clearly indicating a close relationship between chemical properties and the transformation of microbial communities in soil after OMW land spreading. The determination of a key set of chemical and microbiological parameters that can be used as indicators for monitoring soil quality at olive-mill waste-disposal areas will verify the efficiency of the techniques used for the land disposal of OMW and will consequently promote their sustainable management.