The adverse health effects associated with the inhalation and ingestion of naturally occurring radon gas produced during the uranium decay chain mean that there is a need to identify high-risk areas. This study detected radon-prone areas using a geographic information system (GIS)-based probabilistic and machine learning methods, including the frequency ratio (FR) model and a convolutional neural network (CNN). Ten influencing factors, namely elevation, slope, the topographic wetness index (TWI), valley depth, fault density, lithology, and the average soil copper (Cu), calcium oxide (Cao), ferric oxide (Fe₂O₃), and lead (Pb) concentrations, were analyzed. In total, 27 rock samples with high activity concentration index values were divided randomly into training and validation datasets (70:30 ratio) to train the models. Areas were categorized as very high, high, moderate, low, and very low radon areas. According to the models, approximately 40% of the study area was classified as very high or high risk. Finally, the radon potential maps were validated using the area under the receiver operating characteristic curve (AUC) analysis. This showed that the CNN algorithm was superior to the FR method; for the former, AUC values of 0.844 and 0.840 were obtained using the training and validation datasets, respectively. However, both algorithms had high predictive power. Slope, lithology, and TWI were the best predictors of radon-affected areas. These results provide new information regarding the spatial distribution of radon, and could inform the development of new residential areas. Radon screening is important to reduce public exposure to high levels of naturally occurring radiation.

This international scale study measured the prevalence of indoor microplastics (MPs) in deposited dust in 108 homes from 29 countries over a 1-month period. Dust borne MPs shape, colour, and length were determined using microscopy and the composition measured using μFTIR. Human health exposure and risk was assessed along with residential factors associated with MPs via a participant questionnaire. Samples were categorised according to each country's gross national income (GNI). Synthetic polymers dominated in low income (LI) (39%) and high income (HI) (46%) while natural fibres were the most prevalent in medium income (MI) (43%) countries. Composition and statistical analysis showed that the main sources of MPs and dust were predominantly from indoor sources. Across all GNI countries, greater vacuuming frequency was associated with lower MPs loading. High income country samples returned higher proportions of polyamides and polyester fibres, whereas in LI countries polyurethane was the most prominent MPs fibre. Exposure modelling showed infants (0–2 years) were exposed to the highest MPs dose through inhalation (4.5 × 10⁻⁵ ± 3 × 10⁻⁵) and ingestion (3.24 × 10⁻² ± 3.14 × 10⁻²) mg/kg-Bw/day. Health risk analysis of constituent monomers of polymers indicates cancer incidence was estimated at 4.1–8.7 per million persons across age groups. This study's analysis showed socio-economic factors and age were dominant variables in determining dose and associated health outcomes of MPs in household dust.

This study focused on the impacts of aged aquaculture microplastics (MPs) on oysters (Crassostrea gigas). Adult oysters were exposed for two months to a cocktail of MPs representative of the contamination of the Pertuis Charentais area (Bay of Biscay, France) and issuing from oyster framing material. The MPs mixture included 28% of polyethylene, 40% of polypropylene and 32% of PVC (polyvinyl chloride). During the exposure, tissues were sampled for various analyzes (MP quantification, toxicity biomarkers). Although no effect on the growth of adult oysters was noted, the mortality rate of bivalves exposed to MPs (0.1 and 10 mg. L⁻¹ MP) increased significantly (respectively 13.3 and 23.3% of mortalities cumulative). On the one hand, the responses of biomarkers revealed impacts on oxidative stress, lipid peroxidation and environmental stress. At 56 days of exposure, significant increases were noted for Glutathione S-Transferase (GST, 10 mg. L⁻¹ MP), Malondialdehyde (MDA, 10 mg. L⁻¹ MP) and Laccase (LAC, 0.1 and 10 mg. L⁻¹ MP). No variations were observed for Superoxyde Dismutase (SOD). Besides, ingestion of MPs in oyster tissues and the presence in biodeposits was highlighted. In addition, in vitro fertilisations were performed to characterize MPs effects on the offspring. Swimming behavior, development and growth of D-larvae were analysed at 24-, 48- and 72-h after fertilisation. D-larvae, from exposed parents, demonstrated reduced locomotor activity. Developmental abnormalities and arrest as well as growth retardation were also noted. This study highlighted direct and intergenerational effects of MPs from aged plastic materials on Pacific oysters.

We examined ingestion and retention rates of microplastics (MPs) by two freshwater (Japanese medaka and zebrafish) and two marine fish species (Indian medaka and clown anemonefish) to determine their color preferences and gastrointestinal-tract retention times. In our ingestion experiments, clown anemonefish ingested the most MP particles, followed by zebrafish, and then Japanese and Indian medaka. Next, we investigated color preferences among five MP colors. Red, yellow, and green MP were ingested at higher rates than gray and blue MPs for all tested fish species. To test whether these differences truly reflect a recognition of and preference for certain colors based on color vision, we investigated the preferences of clown anemonefish for MP colors under light and dark conditions. Under dark conditions, ingestion of MP particles was reduced, and color preferences were not observed. Finally, we assessed gastrointestinal-tract retention times for all four fish species. Some individuals retained MP particles in their gastrointestinal tracts for over 24 h after ingestion. Our results show that fish rely on color vision to recognize and express preferences for certain MP colors. In addition, MP excretion times varied widely among individuals. Our results provide new insights into accidental MP ingestion by fishes.

Numerous toxicological studies have shown that ingestion of pesticides can induce physiological stress in breeding birds, with adverse consequences on egg laying parameters and offspring quality through parental effects. However, previous studies do not mimic current levels of pesticide residues in typical landscapes, and they do not consider potential cocktail effects of pesticides as they occur in the wild. Herein, we explored whether realistic pesticide exposure affected reproduction parameters and offspring condition through parental effects in Grey partridge. We fed 24 breeding pairs with either seeds from conventional agriculture crops treated with various pesticides during cropping, or organic grains without pesticide residues as controls. The conventional and organic grain diets mimicked food options potentially encountered by wild birds in the field. The results showed that ingesting low pesticide doses over a long period had consequences on reproduction and offspring quality without altering mortality in parents or chicks. Compared with organic pairs, conventional pairs yielded smaller chicks at hatching that had a lower body mass index at 24 days old. Additionally, these chicks displayed lower haematocrit when body mass index was higher. Therefore, ingestion of conventional grains by parents resulted in chronic exposure to pesticide residues, even at low doses, and this had detrimental consequences on offspring. These results demonstrate a sublethal effect of pesticide residues through parental effects. The consequences of parental exposure on chicks might partly explain the decline in wild Grey partridge populations, which raises questions for avian conservation and demography if current agrosystem approaches are continued.

Ingestion of microplastics by aquatic organisms is often harmful due to the dilution of their regular food with low-calorie microplastic particles, but can also be beneficial if nutritious biofilms are present on the microplastic surface. This begs the question: is ingestion of microplastic harmful or beneficial and can the net effect of the two mechanisms be quantified? Here, we quantified these harmful and beneficial effects on Daphnia magna, using dose-response tests with clean and biofouled microplastic respectively, and determined the trade-off between these counteracting effects. A population model was developed to calculate the isoclines for zero population growth, separating the regime where adverse food dilution dominated from that where the beneficial biofilm vector mechanism dominated. Our results show that the organisms grew better when exposed to biofouled microplastic compared to pristine microplastic. Very good model predictions (R2 = 0.868–0.991) of the effects of biofouled microplastic were obtained based on literature parameter values, with optimization required only for the two sub-model parameters driving the dose-effect relationships for pristine microplastic. These results contradict previous sudies were only pristine microplastic were used and demonstrate that the ruling paradigm of unambiguously adverse microplastic effects is not ecologically justifiable.

The number of published studies evaluating the effects of microplastics (MPs) in fish has increased in the last decade. However, of the available studies, few have explored the long-term effects of MPs on fish growth and reproduction and have resorted to MPs in the form of μm-sized beads/microspheres. In this study, 6-10 day-old post-hatch medaka (Oryzias latipes) fish were exposed to 50 (i.e. 1X) and 500 (i.e. 10X) μg of heterogeneously sized and irregularly shaped virgin polystyrene (PS) MP particles (200-μm range)/L for 150 days. These concentrations corresponded to respective daily mean values of 247 and 3087 particles/L administered through the diet. The PS MPs dietary exposure resulted in body burdens of 114 and 440 particles/g fish on day 50, and of 78 and 173 particles/g fish on day 100 since the respective exposures to the 1X and the 10X treatments started. The biometric analyses found no incidence of PS MPs ingestion on overall fish growth and development. The histological survey in the 10X group did not reveal alterations in gills or in the digestive tract. Mild alterations in other organs were seen and included increased fluid material in the peritoneal cavity, glomerular and tubular alterations in kidneys, and differences in the diameter of the thyroid follicles and thickness of the follicular epithelial cells. The initial days of the reproductive phase revealed MP-related differences in the number of gravid females, fecundity, and fertilization rates. Overall, these values reverted to normal rates throughout the succeeding days. No significant effects of PS MPs exposure were evidenced on offspring success. The 150-day PS MPs dietary exposure used in this study provided clues of histological effects and a reproduction delay. However, it did not seem to compromise overall growth/thriving and the ongoing reproduction.

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.

Plastics in the oceans can break up into smaller size and shape resembling prey or particles selected for ingestion by marine organisms. Plastic polymers may contain chemical additives and contaminants, including known endocrine disruptors that may be harmful for the marine organisms, in turn posing potential risks to marine ecosystems, biodiversity and food availability.This study assesses the presence of plastics in the contents of the gastrointestinal tract (GIT) of a commercial fish species, the Atlantic horse mackerel, Trachurus trachurus, sampled from two different fishing areas of central Mediterranean Sea. Adverse effect of plastics occurrence on T. Trachurus health were also assessed quantifying the liver expression of vitellogenin (VTG), a biomarker for endocrine disruption.A total of 92 specimens were collected and morphometric indices were analysed. A subgroup was examined for microplastics (MP < 1 mm) and macroplastics (MaP >1 cm) accumulation in the GIT and for VTG expression.Results indicated that specimens from the two locations are different in size and maturity but the ingestion of plastic is widespread, with microplastics (fragments and filaments) abundantly present in nearly all samples while macroplastics were found in the larger specimens, collected in one of the two locations. Spectroscopic analysis revealed that the most abundant polymers in MP fragments were polystyrene, polyethylene and polypropylene, whereas MP filaments were identified mainly as nylon 6, acrylic and polyester. MaP were composed mainly of weathered polyethylene or polypropylene.The expression of VTG was observed in the liver of 60% of all male specimens from both locations.The results of this study represent a first evidence that the ingestion of plastic pollution may alter endocrine system function in adult fish T. Trachurus and warrants further research.

Horse mackerel is a semi-pelagic species found in abundance in the Moroccan coasts and occupies the first ranks in the catches landed by the coastal fleet. In this study, we investigated the ingestion of Polyamide, Acrylic and Polystyrene by Atlantic horse mackerel, in the Moroccan Atlantic coastal area located between Larache (35°30′N) and Boujdour (26°30′N). The objective is to map the spatial distribution of horse Mackerel containing microplastics (MPs) in their stomachs and identify hot spot areas. We also aim to verify the most ingested polymer by this fish characterized by significant daily vertical migrations. The results show that the three studied polymers were detected in the stomach contents of more than 73% of studied fishes. The hot spot areas are located more in the northern part where urbanization and fishing activity are important. Polyamide, the densest polymer, is the most abundant (86% of cases), followed by acrylic. These two polymers were found in association in 47% of cases. No correlation between the presence of MPs in the stomach contents and the size of the individual fishes was noted. Interestingly, the group of mature specimens ingested more MPs than the immature group.