Maintaining thyroid homeostasis during pregnancy is vital for fetal development. The few studies that have investigated associations between metal exposure and gestational thyroid function have yielded mixed findings. To evaluate the association of exposure to a mixture of toxic metals with thyroid parameters in 824 pregnant women from the Rhea birth cohort in Crete, Greece. Concentrations of three toxic metals [cadmium (Cd), antimony (Sb), lead (Pb)] and iodine were measured in urine using inductively coupled plasma mass spectrometry and thyroid hormones [Thyroid Stimulating Hormone (TSH), free thyroxine (fT4), and free triiodothyronine (fT3)] were measured in serum in early pregnancy. Associations of individual metals with thyroid parameters were assessed using adjusted regression models, while associations of the metal mixture with thyroid parameters were assessed using Bayesian Kernel Machine Regression (BKMR).Women with high (3rd tertile) concentrations of urinary Cd, Sb and Pb, respectively, had 13.3 % (95%CI: 2.0 %, 23.2 %), 12.5 % (95%CI: 1.8 %, 22.0 %) and 16.0 % (95%CI: 5.7 %, 25.2 %) lower TSH compared to women with low concentrations (2nd and 1st tertile). In addition, women with high urinary Cd had 2.2 % (95%CI: 0.0 %, 4.4 %) higher fT4 and 4.0 % (95%CI: −0.1 %, 8.1 %) higher fT3 levels, and women with high urinary Pb had 4 % (95%CI: 0.2 %, 8.0 %) higher fT3 levels compared to women with low exposure. The negative association of Cd with TSH persisted only when iodine sufficiency was unfavorable. BKMR attested that simultaneous exposure to toxic metals was associated with decreased TSH and increased fT3 and revealed a potential synergistic interaction of Cd and Pb in association with TSH. The present results suggest that exposure to toxic metals even at low levels can alter gestational thyroid homeostasis.

Children in urban environments are exposed to potential harmful elements (PHEs) through variable exposure media. Playing activities in outdoor playgrounds have been considered of high concern due to children's exposure to sand-bound PHEs through unintentional or intentional sand ingestion. Furthermore, the affinity of magnetic particles with dust-bound PHEs in playgrounds has been reported. In this study, playground sands (PG sands) from public playgrounds in the city of Thessaloniki, N. Greece were sampled and the levels, the contamination degree, oral bioaccessibility and exposure assessment of PHEs were evaluated. In addition, low-cost and fast magnetic measurements (i.e. mass specific magnetic susceptibility, χₗf) were explored as potential pollution and health risk proxies. Mineralogically, siliceous PG sands dominated, while morphologically angular magnetic particles and Fe-rich “spherules” of anthropogenic origin were revealed and verified by enhanced χₗf values. The average total elemental contents exhibited a descending order of Mn > Ba > Cr > Zn > Ni > Pb > Cu > Co > As > Sn > Bi > Cd, however only Cd, Bi, Pb, Cr, As and Zn were presented anthropogenically enhanced. Notable increase on PHEs levels and finer sand fractions were observed with continuous sand use. Anthropogenically derived elements (i.e. Cd and Pb with high Igₑₒ values) exhibited higher bioaccessible fractions in PG sands and considered easily soluble in gastric fluids through ingestion. However, increased risks were found for specific PHEs (especially Pb) only in a worst case exposure scenario of an intentional sand ingestion (pica disorder). Statistical analysis results revealed a linkage of anthropogenic components with sand-bound magnetic particles. Moreover, the recorded high affinity of Pb contents (in an enhanced magnetized sub-set of PG sands) and bioaccessible Cd fractions with χₗf provide a preliminary indication on the successful applicability of low-cost and fast magnetic measurements in high impacted playground environments.

Cryptosporidium and Giardia are important parasites due to their zoonotic potential and impact on human health, often causing waterborne outbreaks of disease. Detection of (oo)cysts in water matrices is challenging and few countries have legislated water monitoring for their presence. The aim of this study was to investigate the presence and origin of these parasites in different water sources in Northern Greece and identify interactions between biotic/abiotic factors in order to develop risk-assessment models. During a 2-year period, using a longitudinal, repeated sampling approach, 12 locations in 4 rivers, irrigation canals, and a water production company, were monitored for Cryptosporidium and Giardia, using standard methods. Furthermore, 254 faecal samples from animals were collected from 15 cattle and 12 sheep farms located near the water sampling points and screened for both parasites, in order to estimate their potential contribution to water contamination. River water samples were frequently contaminated with Cryptosporidium (47.1%) and Giardia (66.2%), with higher contamination rates during winter and spring. During a 5-month period, (oo)cysts were detected in drinking-water (<1/litre). Animals on all farms were infected by both parasites, with 16.7% of calves and 17.2% of lambs excreting Cryptosporidium oocysts and 41.3% of calves and 43.1% of lambs excreting Giardia cysts. The most prevalent species identified in both water and animal samples were C. parvum and G. duodenalis assemblage AII. The presence of G. duodenalis assemblage AII in drinking water and C. parvum IIaA15G2R1 in surface water highlights the potential risk of waterborne infection. No correlation was found between (oo)cyst counts and faecal-indicator bacteria. Machine-learning models that can predict contamination intensity with Cryptosporidium (75% accuracy) and Giardia (69% accuracy), combining biological, physicochemical and meteorological factors, were developed. Although these prediction accuracies may be insufficient for public health purposes, they could be useful for augmenting and informing risk-based sampling plans.

Lead concentrations and isotopic compositions of contaminated urban soils and house dusts from Athens, Greece, have been determined to identify possible sources of Pb contamination and examine relationships between these two environmental media. Different soil particle sizes (<2000 μm, <200 μm, <100 μm, <70 μm, <32 μm) and chemical fractions (total, EDTA-extractable and acetic acid-extractable (HAc)) were analyzed for their Pb content and isotopic composition. Metal(loid)s (Pb, Zn, Cu, As, Ni, Cr, Mn, Fe) are significantly enriched in the finest fraction. The Pb isotopic compositions were similar for the different soil particle size fractions and different chemical extractions. The HAc extraction proved to be a useful procedure for tracing anthropogenic Pb in urban soil. The range of 206Pb/207Pb ratios (1.140–1.180) in Athens soil suggests that the Pb content represents an accumulated mixture of Pb deposited from past vehicular emissions and local natural sources. The contribution of anthropogenic Pb to total soil Pb ranged from 36% to 95%. The Pb isotopic composition of vacuum house dusts (206Pb/207Pb = 1.1.38–1.167) from Athens residents is mostly comparable to that of urban soil suggesting that exterior soil particles are transferred into homes. As a result, anthropogenic Pb in house dust from Athens urban environment principally originated from soil particles containing Pb from automobile emissions (former use of leaded gasoline).

We tested seven contemporary agrochemicals as potential plant protectants against ozone phytotoxicity. In nine experiments, Bel-W3 tobacco plants were experienced weekly exposures to a) 80 nmol mol−1 of ozone-enriched or ozone-free air in controlled environment chambers, b) an urban air polluted area, and c) an agricultural-remote area. Ozone caused severe leaf injury, reduced chlorophylls' and total carotenoids' content, and negatively affected photosynthesis and stomatal conductance. Penconazole, (35% ± 8) hexaconazole (28% ± 5) and kresoxim-methyl (28% ± 15) showed higher plants’ protection (expressed as percentage; mean ± s.e.) against ozone, although the latter exhibited a high variability. Azoxystrobin (21% ± 15) showed lower protection efficacy and Benomyl (15% ± 9) even lower. Trifloxystrobin (7% ± 11) did not protect the plants at all. Acibenzolar-S-methyl + metalaxyl-M (Bion MX) (−6% ± 17) exhibited the higher variability and contrasting results: in some experiments it showed some protection while in others it intensified the ozone injury by causing phytotoxic symptoms on leaves, even in control plants.

This study presents the chemical composition of VOCs in air and gas discharges collected at Nisyros Island (Dodecanese Archipelago, Greece). The main goals are i) to discriminate between natural and anthropogenic VOC sources and ii) to evaluate their impact on local air quality. Up to 63 different VOCs were recognized and quantitatively determined in 6 fumaroles and 19 air samples collected in the Lakki caldera, where fumarolic emissions are located, and the outer ring of the island, including the Mandraki village and the main harbor. Air samples from the crater area show significant concentrations of alkanes, alkenes, cyclic, aromatics, and S- and O-bearing heterocycles directly deriving from the hydrothermal system, as well as secondary O-bearing compounds from oxidation of primary VOCs. At Mandraki village, C6H6/Σ(methylated aromatics) and Σ(linear)/Σ(branched) alkanes ratios <1 allow to distinguish an anthropogenic source related to emissions from outlet pipes of touristic and private boats and buses.

This study investigated if atmospheric ammonia (NH3) pollution around a sheep farm influences the photosynthetic performance of the lichens Evernia prunastri and Pseudevernia furfuracea. Thalli of both species were transplanted for up to 30 days in a semi-arid region (Crete, Greece), at sites with concentrations of atmospheric ammonia of ca. 60 μg/m3 (at a sheep farm), ca. 15 μg/m3 (60 m from the sheep farm) and ca. 2 μg/m3 (a remote area 5 km away). Lichen photosynthesis was analysed by the chlorophyll a fluorescence emission to identify targets of ammonia pollution. The results indicated that the photosystem II of the two lichens exposed to NH3 is susceptible to this pollutant in the gas-phase. The parameter PIABS, a global index of photosynthetic performance that combines in a single expression the three functional steps of the photosynthetic activity (light absorption, excitation energy trapping, and conversion of excitation energy to electron transport) was much more sensitive to NH3 than the FV/FM ratio, one of the most commonly used stress indicators.

Due to their small dimensions, airborne particles are able to penetrate through inhalation into many human organs, from the lungs to the cardiovascular system and the brain, which can threaten our health. This work establishes a novel approach of collecting quantitative data regarding the fraction, the composition and the size distribution of combustion-emitted particulate matter through the magnetic characterization and analysis of samples received by common air pollution monitoring. To this end, SQUID magnetometry measurements were carried out for samples from urban and suburban areas in Thessaloniki, the second largest city of Greece, taking into consideration the seasonal and weekly variation of airborne particles levels as determined by occurring traffic and meteorological conditions. The level of estimated magnetically-responding atmospheric particulate matter was at least 0.5 % wt. of the collected samples, mostly being present in the form of ultrafine particles with nuclei sizes of approximately 14 nm and their aggregates. The estimated quantities of magnetic particulate matter show maximum values during autumn months (0.8 % wt.) when increased commuting takes place, appearing higher in the city center by up to 50% than those in suburban areas. In combination with high-resolution transmission electron imaging and elemental analysis, it was found that Fe₃O₄ and similar ferrites, some of them attached to heavy metals (Co, Cr), are the dominant magnetic contributors arising from anthropogenic high-temperature processes, e.g. due to traffic emissions. Importantly, nasal cytologic samples collected from residents of both central and suburban areas showed same pattern in what concerns magnetic behavior, thus verifying the critical role of nanosized magnetic particles in the assessment of air pollution threats. Despite the inherent statistical limitations of our study, such findings also indicate the potential transmission of infectious pathogens by means of pollution-derived nanoparticles into the respiratory system of the human body.

Persistent organic pollutants (POPs), including Perfluoroalkyl substances (PFASs), enter into the marine ecosystem, raising questions on possible adverse effects caused to the health of marine organisms and especially of top predators. Thus, there is an urge to assess the occurrence and the tissue distribution of PFASs in apex predators. To this end, the current study examines concentrations and distribution of 15 PFASs among 85 samples of different tissues from 9 shark and ray species collected in Greece. The results showed a similar PFAS pattern among the different tissues, with long carbon chain PFASs being the most frequently detected compounds. PFTrDA was the most predominant compound in terms of concentration and frequency of detection, followed by PFUnDA and PFOS. PFTrDA concentrations ranged between < LOQ and 27.1 ng/g ww, while PFUnDA and PFOS levels ranged from <LOQ to 16.0 and < LOQ to 21.6 ng/g ww, respectively. Regarding their frequency of detection, PFTrDA and PFUnDA were detected in 98% and 91% of the samples, respectively, while PFOS was detected in 79%. ΣPFAS concentrations in each analysed tissue ranged from 0.3 to 85 ng/g ww, with the latter being detected in the liver of angular roughshark (Oxynotus centrina). On average, PFASs were found to be accumulated in tissues in the following order: gonads > heart > liver ≈ gills > muscle. Relative contribution (%) of individual compounds to ΣPFAS concentration varied among the different shark tissues, and also among the different shark species. No correlation between PFASs levels in tissues and sharks’ gender, length and geographical origin was observed.