The effects of microplastics pollution on the marine ecosystem have aroused attention. Copepod grazing stimulates dimethylsulfide (DMS) release from dimethylsulfoniopropionate (DMSP) in phytoplankton, but the effect of microplastics exposure on DMS and DMSP production during copepod feeding has not yet been revealed. Here, we investigated the effects of polyethylene (PE) and polyamide-nylon 6 (PA 6) microplastics on ecotoxicity and DMS/DMSP production in the copepod Tigriopus japonicus. The microplastics had detrimental effects on feeding, egestion, reproduction, survival, and DMS and DMSP production in T. japonicus and presented significant dose-response relationships. The 24 h-EC50 for ingestion rates (IRs) of female T. japonicus exposed to PE and PA 6 were 57.6 and 58.9 mg L⁻¹, respectively. In comparison, the body size of the copepods was not significantly affected by the microplastics during one generation of culture. Ingesting fluorescently labeled microplastics confirmed that microplastics were ingested by T. japonicus and adhered to the organs of the body surface. T. japonicus grazing promoted DMS release originating from degradation of DMSP in algal cells. Grazing-activated DMS production decreased because of reduced IR in the presence of microplastics. These results provide new insight into the biogeochemical cycle of sulfur during feeding in copepods exposed to microplastics.

The Deepwater Horizon (DWH) oil spill caused an estimated 100,000 bird mortalities. However, mortality estimates are often based on the number of visibly oiled birds and likely underestimate the true damage to avian populations as they do not include toxic effects from crude oil ingestion. Elevated susceptibility to disease has been postulated to be a significant barrier to recovery for birds that have ingested crude oil. Effective defense against pathogens involves integration of physiological and behavioral traits, which are regulated in-part by cytokine signaling pathways. In this study, we tested whether crude oil ingestion altered behavioral and physiological aspects of disease defense in birds. To do so, we used artificially weathered Mississippi Canyon 242 crude oil to orally dose zebra finches (Taeniopygia guttata) with 3.3 mL/kg or 10 mL/kg of crude oil or a control (peanut oil) for 14 days. We measured expression of cytokines (interleukin [IL]-1β, IL-6, IL-10) and proinflammatory pathways (NF-κB, COX-2) in the intestine, liver, and spleen (tissues that exhibit pathology in oil-exposed birds). We also measured heterophil:lymphocyte (H:L) ratio and complement system activity, and video-recorded birds to analyze sickness behavior. Finches that ingested crude oil exhibited tissue-specific changes in cytokine mRNA expression. Proinflammatory cytokine expression decreased in the intestine but increased in the liver and spleen. Birds exposed to crude oil had lower H:L ratios compared to the control on day 14, but there were no differences in complement activity among treatments. Additionally, birds exposed to 10 mL/kg crude oil had reduced activity, indicative of sickness behavior. Our results suggest cytokines play a role in mediating physiological and behavioral responses to crude oil ingestion. Although most avian population damage assessments focus on mortality caused by external oiling, crude oil ingestion may also indirectly affect survival by altering physiological and behavioral traits important for disease defense.

Fumonisins (FBs) are mycotoxins that are widely distributed in crops and feed, and ingestion of FBs -contaminated crops is harmful to animal health. Furthermore, it is unknown if Fumonisins B1 (FB1) can cause intestinal toxicity. To investigate FB1-induced intestinal toxicity, mice were treated with 0 or 5 mg/kg FB1 by gavage administration for 42 days. Histopathology indicated that FB1 exposure caused proliferation of intestinal epithelial cells, intestinal villi and epithelial layer shedding, intestinal gland atrophy, and necrosis. Notably, FB1 interfered with nuclear xenobiotic receptors (NXR) homeostasis by regulating the level of aryl hydrocarbon receptor (AHR), constitutive androstane receptor (CAR), pregnane X receptor (PXR) and downstream target genes (CYP450s). Moreover, abnormal expression of inflammatory cytokines (IL-1β, IL-2, IL-4, IL-10, and TNF-α) indicated the occurrence of inflammation. The present study provides new insights regarding the mechanism of FB1-induced intestinal toxicity through activating the NXR system and by triggering inflammatory responses in the intestinal tract in mice.

This study provided a comprehensive characterization on ingestion of different typologies of microplastics in several fish and invertebrate species from the Adriatic Sea, considered as a preferential area of plastic accumulation in the Mediterranean. Almost 500 organisms were sampled in the three sectors of Northern, Central and Southern Adriatic, testing the hypothesis that area of collection, habitat and feeding strategy might influence the occurrence of plastic particles in biota. In this study, the overall characterization considered separately plastic microparticles (MPs) from textile microfibers (MFs) which also included natural and semi-synthetic ones. Ingestion of MPs was a widespread phenomenon, but their number (typically 1 or 2) did not reveal any significant relationship with biometric values, geographical areas or ecological features of the species. Conversely, the frequency of ingestion, ranging from 13 to 35% of organisms containing MPs, appeared a more reliable index to highlight such differences, revealing higher values in species from Central and Southern basins compared to the Northern one, as well as in benthopelagic compared to benthic or pelagic organisms. Geographical differences also occurred in terms of size and typology of ingested particles, suggesting the importance of local river runoffs and surface currents dynamics. Textile microfibers (MFs) were also abundant in Adriatic food webs occurring in all the analyzed species with average numbers (3–10) and frequencies (40–70%) higher than those reported for MPs; further, an elevated percentage of MFs (>80%) was of natural or semi-synthetic origin.Overall, this study provided general insights toward the harmonization of a common biomonitoring strategy, as in the context of MSFD, including the suggestion of a frequency-based index and of a multi-species approach to increase the ecological relevance of assessment, as well as the comparability between different areas and trophic webs.

Ingestion of anthropogenic litter has been well documented in marine vertebrates, but comparatively little is known about marine invertebrates. We report macrolitter ingestion by the sandy anemone Bunodactis reynaudi at Muizenberg beach in False Bay, South Africa. Monthly surveys from May 2015 to August 2019 collected 491 ingested litter items (9.4 ± 14.9 items·month⁻¹, 39.8 ± 71.5 g·month⁻¹), of which >99% were plastic. The number of ingested items was correlated with the abundance of stranded items and ingestion peaked in autumn when seasonal rains washed more litter into the bay. Most ingested litter was clear (39%), white (16%) and black/purple (15%). Comparison with environmental litter showed selection for flexible plastics, particularly bags/packets and food packaging. Experimental feeding trials found that B. reynaudi selected for pieces of HDPE bag suspended in seawater for 2–20 days, suggesting that biofilms enhance the palatability of flexible plastics. Studies are needed to assess the possible impacts of plastic ingestion on B. reynaudi. While only a small proportion of the population currently ingest litter, ingestion might become more common if environmental litter loads increase. This might negatively affect the anemone’s ability to respond to other environmental changes such as increasing levels of heavy metal pollution.

In this study, samples of soil and particulate matter obtained from the highly industrialized region of Ostrava, Czech Republic, are used for the toxicity evaluation of the selected metal(loid)s (Cd, Cr, Cu, Ni, Pb, Zn, As). We investigated the samples from sites supposedly affected the most by the local pollution sources using mineralogical techniques (XRD, SEM/EDS) to understand the solid speciation of the contaminants as the crucial factor affecting their release. Although the bulk composition was defined by common silicates and oxides that are rather resistant to leaching, the presence of tiny Ni, Pb, and/or Zn sulfate-like droplets indicated a potential increase of the solubility of these metals. In vitro tests simulating gastric and lung fluids were used to assess the exposure risk for humans, as well as metal(loid) bioaccessibility. Based on the results, the potential risk for the observed age group (3-year-old children) could be recognized, particularly in the cases of As, Pb and Cd for both oral and inhalation exposure. Arsenic exhibits high bioaccessibility (7.13–79.7%, with the median values of 10.6 and 15.6 for SGL and SLF, respectively), high daily intake (1.4- to 8.5-fold higher than the tolerable daily intake) and high concentrations in atmospheric PM₁₀ (2.5 times the tolerable concentration in air). In contrast, Ni exceeded tolerable concentrations in the atmosphere up to 20-fold, but its bioaccessibility remained relatively low (0.1–22%), and Ni did not pose a major threat to human health. Cadmium, Pb and As originating from industrial activities and domestic heating have been suggested to be the most important pollutants (tolerable daily intake was exceeded by up to 74-, 34- and 8-fold for Cd, Pb and As, respectively).

Contamination by potentially toxic elements (PTEs) in children’s toys and jewelry is an ongoing problem where PTEs can become bioavailable especially via oral pathway (ingestion as a whole or of parts, and mouthing) and may cause adverse health effects for children. In the present review, legislation updates from the last decade in the United States (U.S.), Canada, and the European Union (E.U.) on PTEs in toys and jewelry are presented. Then, a literature review mostly covering the last decade on the total concentration, bioavailability, children’s exposure, and bioaccessibility of PTEs in toys and jewelry is provided. The U.S. and Canadian legislations mainly focus on lead (Pb) and cadmium (Cd) total/soluble concentration limits to prevent exposure and have received several updates within the last decade, extending particularly the covered span of children’s products. It seems that the introduction, subsequent enforcement, and update of regulations in developed countries have shifted the problem towards developing countries. In terms of categories, metallic toys and children’s jewelry still have the most severe PTE contamination and the presence of Pb and Cd in these articles is an ongoing issue. Some studies suggest that color can be used as an indicator for the potential presence of PTEs (linked to chemicals such as lead chromate, cadmium sulfide) but the evidence is not always clear. Another concern is vintage/second-hand toys and jewelry as those items might have been produced before the legislation was present. As total and bioaccessible concentrations of PTEs in toys and jewelry do not always correlate, approaches considering bioaccessibility (e.g. of the E.U.) are more scientifically appropriate and help with better estimation of risk from exposure. Studies on toy and jewelry contamination using in vitro bioaccessibility techniques has become more common, however, there is still no in vitro test specifically designed and validated for toys and jewelry.

In the last decade many studies have described the ingestion of plastic in marine animals. While most studies were dedicated to understanding the pre-ingestion processes involving decision-making foraging choices based on visual and olfactory cues of animals, our knowledge in the post-ingestion consequences remains limited. Here we proposed a theoretical complementary view of post-ingestion consequences, attempting to connect plastic ingestion with plastic-induced satiety. We analyzed data of plastic ingestion and dietary information of 223 immature green turtles (Chelonia mydas) from tropical Brazilian reefs in order to understand the impacts of plastic ingestion on foraging behavior. Generalized linear mixing models and permutational analysis of variance suggested that plastic accumulations in esophagus, stomach and intestine differed in their impact on green turtle’s food intake. At the initial stages of plastic ingestion, where the plastic still in the stomach, an increase in food intake was observed. The accumulation of plastic in the gastrointestinal tract can reduce food intake likely leading to plastic-induced satiety. Our results also suggest that higher amounts of plastics in the gastrointestinal tract may led to underweight and emaciated turtles. We hope that adopting and refining our proposed framework will help to clarify the post-ingestion consequences of plastic ingestion in wildlife.

Plastic marine debris hyper-concentrates hydrophobic contaminants such as polycyclic aromatic hydrocarbons (PAHs) and can transfer these sorbed contaminants to biota following ingestion. PAHs are known to induce cardiotoxicity and visual toxicity at sublethal doses. Juvenile White seabass (Atractoscion nobilis) fish were fed environmentally relevant concentrations of either virgin polystyrene or benzo(a)pyrene (BaP)-sorbed polystyrene for 5 days and were monitored for changes in phototactic response, swimming behavior, and hepatic cytochrome p450 1A (CYP1A) enzyme activity. No significant differences in the monitored endpoints were recorded in fish that ingested either polystyrene or BaP-sorbed polystyrene relative to control fish following the short-term exposure. However, fish exposed to 252 μg/L BaP alone as a positive control had significantly elevated CYP1A enzyme activity (p = 0.046) and impaired phototactic response (p = 0.020), though no altered swimming behavior was observed (p = 0.843) relative to control fish. These results demonstrate that pelagic fish ingesting environmentally relevant concentrations of BaP-sorbed polystyrene for a short, 5-day duration do not demonstrate measurable changes in vision, swimming activity, nor CYP1A activity. High variability within enzyme activity and behavioral responses suggest that lack of significant effects may be due to low sample size.

Road dust samples from industrial, urban, and tourist areas of the international tourist city of Guilin, China, were collected to study the concentration, spatial distribution, pollution level, and health risk of potentially toxic elements (PTEs) using an array-based risk assessment model from the United States Environmental Protection Agency. The geoaccumulation index (Igₑₒ), ecological risk index, and spatial interpolation were used to investigate the road dust pollution level. The results indicated that apart from Ni and Al, the concentration of all the heavy metals (Pb, Zn, Ni, Cu, Cr, Cd, Fe, Mn, and As) were markedly higher than the corresponding background values in the three functional areas. Based on the Igₑₒ, the study area had an uncontaminated to moderate pollution level, and the industrial area was slightly more polluted and posed a greater ecological risk than the urban and tourist areas. Comparatively, Pb, Zn, and Cu exhibited higher pollution levels in the three functional sites. Hotspots of PTEs were more concentrated in urban and industrial areas than in tourist areas. Furthermore, the health risk model revealed significant non-carcinogenic risks to children from As in urban, industrial, and tourist areas as the hazard quotients (1.64, 2.04, and 1.42, respectively) exceeded the threshold standard of 1.00. The carcinogenic risk via ingestion (RIᵢₙg) illustrated significant risks to children from Cr, As, and Ni because the RIᵢₙg values were considerably higher than the threshold standard (1.00E-6 to 1.00E-4) in the three functional areas. However, no cancer risk was observed from the dermal and inhalation pathways.