Fluorescence spectroscopy is an optical spectroscopic method that has been applied for the assessment of environmental quality extensively during the last 20 years. Most of the earlier works have used conventional light sources in spectrofluorometers to assess quality. Many recent works have used laser sources of light for the same purpose. The improvement of the energy sources and of the higher resolution spectrometers has led to a tremendous increase in applications. The motivation for the present review study is the increasing use of laser sources in environmental applications. The review is divided in two parts. The fundamental principles of fluorescence spectroscopy are described in the first part. The environmental applications are described in the second part.

Wetlands are of great importance for providing the appropriate conditions for the diversity of species and inhabitants living in these ecosystems and for a wide range of public goods and services (fresh water, air filtering, recreational and tourism opportunities). However, despite their importance, wetlands are continuously degraded due to various human activities at an alarming rate worldwide. In the context of this study and considering the rational management of wetlands and the inevitable impact of climate change, a wetland, spatiotemporal monitoring system is proposed, implemented in the karst wetland of Almyros Stream (Heraklion, Crete, Greece). The implementation of this system is based on robust techniques from the allied fields of chemistry, earth and ecology assisted by GIS techniques. Our results indicate that this Mediterranean karst wetland of great ecological importance is under pressure because of pollution, climate change and land change. This argument is supported by (a) the high concentrations of water photosynthetic pigments and nutrients at certain times of the year, both provided by chemical analysis and partially verified by geophysical monitoring (spectral induced polarization) and (b) the high values of soil magnetic susceptibility at sites close to human infrastructures that is an indicator of heavy metals concentrations.

Urban streams undergo significant ecological alterations due to urbanization, including hydrological changes, water contamination, and biodiversity loss. This research employs a combination of satellite and drone imagery alongside traditional chemical and geophysical methods, facilitating a multi-dimensional assessment of Almyros and Gazanos urban stream health in Heraklion (Crete, Greece). The satellite imagery, obtained from the Copernicus program, allows for monitoring land use and impervious surface density around the streams, while drone surveys capture high-resolution images and calculate various water quality indices. In addition, chemical analyses of water samples for pollutants, as well as geophysical measurements using spectral induced polarization (SIP) and electromagnetic scanning (GEM-2), provide insight into the integrity of aquatic and riparian ecosystems. The study reflects on the different types of anthropogenic pressure faced by these two ecosystems. Almyros stream exhibits signs of eutrophication, characterized by elevated levels of chlorophyll and the presence of algal blooms, possibly due to runoff from adjacent agricultural activities. Conversely, the Gazanos stream shows signs of pollution mostly related to urbanization. The findings emphasize that both streams are under increasing anthropogenic pressure, thus highlighting the importance of employing comprehensive methods for effective stream management and policy implementation. This study ultimately advocates for ongoing monitoring initiatives that embrace technological advancements to safeguard urban water ecosystems.

There is a wide variety of substances that are considered as emerging pollutants because their presence in waterbodies causes serious problems. Their presence in stormwater is also of great importance, but it is less studied. From the variety of emerging pollutants, we have selected to study nine substances in stormwater, six phthalate esters: dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, di-n-octyl phthalate and three pharmaceuticals: acetaminophen, caffeine and phenacetin. The reasons for the selection were the frequency in use, and the lack of data about their detection in stormwater in Greece and also in other countries. For this purpose, the samples were preconcentrated by solid-phase extraction. The analytes were identified and quantitatively determined by reversed-phase liquid-phase chromatography connected to a diode array detector. The detection limits were in the range from 0.20 to 2.09 μg/L while the recoveries were between 42% and 113%. The results showed that the most abundant pharmaceutical was phenacetin with concentrations from nd to 7.82 μg/L and the most abundant phthalate was dimethyl phthalate with concentrations from nd to 7.9 μg/L.

The present study deals with the fluorescent constituents of Almiros (or Almyros) River in Heraklion, Greece. Water samples have been pre-concentrated by the solid phase extraction (SPE) method and subjected to reversed phase high performance liquid chromatography (RP-HPLC) coupled with a fluorescence detector. Seasonal variations of organic matter were mainly observed while spatial variations were observed in a less extent. The samples from upstream points correspond to more fluorescence peaks and of higher intensity compared to the rest of the samples. Generally, the fluorescence intensity decreases towards downstream. Fluorescent intensities of peaks present an inversely proportional relation to the salinity. In concluding, fluorescence compounds may comprise a well indicator of the salinity fluctuations in well-developed karstification systems below sea level and open to the sea that present high mean flow rates with strong seasonal variability.