This study presents evidence for microplastic contamination in two resident species of brachyuran crab from the Thames Estuary: the native shore crab, Carcinus maenas (Linneaus, 1758) and the invasive Chinese mitten crab, Eriocheir sinensis (H. Milne Edwards, 1853). The gills, gastric mill and intestine of 94 C. maenas and 41 E. sinensis were examined. Crabs were sampled periodically (ca. every three months) between December 2018 and October 2019. A total of 874 plastics were recovered, ranging 34 μm–34 mm in length. Overall, 71.3% and 100% of C. maenas and E. sinensis, respectively, contained at least one item (fibre, film, fragment or tangle of fibres) in the gill chamber, gastric mill or gastrointestinal tract. The most common items were fibres (78.5%) but in some cases, particularly in the gastric mill, these were aggregated into tangles (7.8%). Almost all E. sinensis contained tangles of fibres (95.1%), whereas, relatively few C. maenas contained similar tangles (10.6%).

Biodiesel is considered as a valuable and less toxic alternative to diesel. However, cellular and molecular effects of repeated exposure to biodiesel emissions from a recent engine equipped with a diesel particle filter (DPF) remain to be characterized. To gain insights about this point, the lung transcriptional signatures were analyzed for rats (n = 6 per group) exposed to filtered air, 30% rapeseed biodiesel (B30) blend or reference diesel (RF0), upstream and downstream a DPF, for 3 weeks (3 h/day, 5 days/week).Genomic analysis revealed a modest regulation of gene expression level (lower than a 2-fold) by both fuels and a higher number of genes regulated downstream the DPF than upstream, in response to either RF0 or to B30 exhaust emissions. The presence of DPF was found to notably impact the lung gene signature of rats exposed to B30. The number of genes regulated in common by both fuels was low, which is likely due to differences in concentrations of regulated pollutants in exhausts, notably for compound organic volatiles, polycyclic aromatic hydrocarbons, NO or NOx. Nevertheless, we have identified some pathways that were activated for both exhaust emissions, such as integrin-, IGF-1- and Rac-signaling pathways, likely reflecting the effects of gas phase products. By contrast, some canonical pathways relative to “oxidative phosphorylation” and “mitochondrial dysfunction” appear as specific to B30 exhaust emission; the repression of transcripts of mitochondrial respiratory chain in lung of rats exposed to B30 downstream of DPF supports the perturbation of mitochondria function.This study done with a recent diesel engine (compliant with the European IV emission standard) and commercially-available fuels reveals that the diesel blend composition and the presence of an after treatment system may modify lung gene signature of rats repeatedly exposed to exhaust emissions, however in a rather modest manner.

Light absorption by brown carbon (BrC) is dynamic due to atmospheric aging processes, leading to complex and poorly constrained effects on photochemistry and climate. In this study, a smog chamber was used to simulate the heterogeneous ozone (O₃) aging of soot particles. Twelve aging times and seven O₃ concentrations were set to investigate the effects of aging degree on BrC light absorption. The results showed that light absorption by BrC was enhanced after O₃ aging, but followed a non-monotonic trend with an initial increase and subsequent decrease. An aging time of 60 min and O₃ concentration of 1.2 ppm were optimal for enhancing BrC absorption, where the contribution of BrC to total absorption and the contribution of BrC relative to black carbon absorption at 370 nm of ozonized soot were 23.0 ± 1.8% and 30.0 ± 3.0%, respectively, much greater than those of fresh soot (8.1 ± 1.1% and 8.8 ± 1.3%, respectively). The absorption Ångström exponent (AAE) and delta C (ΔC) of ozonized soot at 60 min ranged from 1.18 ± 0.01 to 1.31 ± 0.03 and from 13.5 ± 7.0 to 24.3 ± 13.5 μg m⁻³, respectively, and were greater than those of fresh soot (1.12 ± 0.02 and 8.0 ± 0.8 μg m⁻³), but also showed non-monotonic trends, suggesting the formation of BrC during O₃ aging. Comparative results indicated that AAE might be a better BrC indicator for soot than ΔC. The non-monotonic trend was tentatively explained by changes in organic carbon, oxygenated functional groups and conjugated structures, as well as polycyclic aromatic hydrocarbon (PAH) degradation and oxygenated PAH formation. The relative intensities of oxidative formation and degradation of chromophores may determine BrC evolution during O₃ aging. This study will be useful for clarifying BrC evolution in the atmosphere and estimating its radiative forcing.

Trichloropropyl phosphate (TCPP) is a halogenated organophosphate ester that is widely used as flame retardants and plasticizers. In this study, gender-specific accumulation and responses in mussel Mytilus galloprovincialis to TCPP exposure were focused and highlighted. After TCPP (100 nmol L⁻¹) exposure for 42 days, male mussels showed similar average bioaccumulation (37.14 ± 6.09 nmol g⁻¹ fat weight (fw)) of TCPP with that in female mussels (32.28 ± 4.49 nmol g⁻¹ fw). Proteomic analysis identified 219 differentially expressed proteins (DEPs) between male and female mussels in control group. There were 52 and 54 DEPs induced by TCPP in male and female mussels, respectively. Interestingly, gender-specific DEPs included 37 and 41 DEPs induced by TCPP in male and female mussels, respectively. The proteomic differences between male and female mussels were related to protein synthesis and degradation, energy metabolism, and functions of cytoskeleton and motor proteins. TCPP influenced protein synthesis, energy metabolism, cytoskeleton functions, immunity, and reproduction in both male and female mussels. Protein-protein interaction (PPI) networks indicated that protein synthesis and energy metabolism were the main biological processes influenced by TCPP. However, DEPs involved in these processes and their interaction patterns were quite different between male and female mussels. Basically, twelve ribosome DEPs which directly or indirectly interacted were found in protein synthesis in TCPP-exposed male mussels, while only 3 ribosome DEPs (not interacted) in TCPP-exposed female mussels. In energy metabolism, only 4 DEPs (with the relatively simple interaction pattern) mainly resided in fatty acid metabolism, butanoate/propanoate metabolism and glucose metabolism were discovered in TCPP-exposed male mussels, and more DEPs (with multiple interactions) functioned in TCA cycle and pyruvate/glyoxylate/dicarboxylate metabolism were found in TCCP-exposed female mussels. Taken together, TCPP induced gender-specific toxicological effects in mussels, which may shed new lights on further understanding the toxicological mechanisms of TCPP in aquatic organisms.

As top-predators in marine ecosystems, seabirds are regarded as appropriate bioindicator species for a variety of contaminants. Mercury (Hg) is a global pollutant, which can biomagnify along marine and freshwater food webs. Therefore, mercury body burden in seabirds, such as gulls, will integrate information about pollution in the environment. In the Ebro Delta (NE Spain), legacy mercury pollution from a chlor-alkali industry located ca. 100 km upstream of the Ebro river mouth has been affecting the delta environment. We have analyzed a 15-year temporal series (2004–2019) of Hg in birds from a breeding colony of Audouin’s gull (Ichthyaetus audouinii) in the Ebro Delta to understand how fluctuations in Hg levels are coupled to human activities in the industrial area in the upstream region of the river. Stable isotopic signatures of C and N (δ¹³Cbᵤₗₖ and δ¹⁵Nbᵤₗₖ) are determined to characterize the trophic ecology of the species. Since only δ¹³Cbᵤₗₖ but not δ¹⁵Nbᵤₗₖ was associated with THg levels, we used compound-specific stable nitrogen isotope analysis of amino acids (AA-CSIA) to evaluate the causes of variation in δ¹⁵Nbᵤₗₖ to further investigate the idea of a decoupling of δ¹⁵Nbᵤₗₖ and THg over time. We found Audouin’s gull to be sensitive to Hg variations in the environment due to anthropogenic changes and to be a good indicator species for this contaminant in the Ebro Delta.

Rice intake is a major route of oral exposure to inorganic arsenic (iAs), a known human carcinogen. The recent risk assessment on iAs in rice conducted by the US Food & Drug Administration (FDA) didn’t propose an action level for iAs in rice mainly because of the relatively low consumption rate in the general US population. However, this decision may not be applicable to high rice-intake populations, such as the Chinese population.The objective of this study was to probabilistically characterize the exposure of iAs via rice intake in Chinese population with a focus on the urban population.With the consideration of bioaccessibility of iAs in rice, iAs exposure is mainly determined by rice intake rate and iAs concentration in rice. To estimate the daily rice consumption, a dietary survey consisting of 1873 subjects was conducted in three major Chinese cities (Beijing, Guangzhou, and Hangzhou). Speciated As concentration in rice was measured using 480 rice samples collected from markets in these three cities. Monte Carlo simulation approach was applied to distributionally estimate the average daily dose (ADD) of iAs through rice intake.The estimated distribution of daily iAs exposure of the study population has a mean of 10.5 μg/day with a 95th percentile interval from 0.1 to 75.3 μg/day. The estimated distribution of ADD has a mean of 0.179 μg/kg/day with a 95th percentile interval from 0.001 to 1.224 μg/kg/day. Greater level of iAs exposure (due to higher rice intake) was observed in males than females, and in summer than other seasons with lower temperature. Geographically, the ADD of iAs exposure from rice intake reduces from south to north.About 13% of the Chinese urban population are exposed to iAs via rice intake higher than the Reference Dose (RfD) level.

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.

The contributions of contaminant sources are difficult to resolve in the sediment record using concentration gradients and flux reconstruction alone. In this study, we demonstrate that source partitioning using lead isotopes provide complementary and unique information to concentration gradients to evaluate point-source releases, transport, and recovery of metal mining pollution in the environment. We analyzed eight sediment cores, collected within 24 km of two gold mines, for Pb stable isotopes, Pb concentration, and sediment chronology. Stable Pb isotope ratios (²⁰⁶Pb/²⁰⁷Pb, ²⁰⁸Pb/²⁰⁴Pb) of mining ore were different from those of background (pre-disturbance) sediment, allowing the use of a quantitative mixing model. As previously reported for some Arctic lakes, Pb isotope ratios indicated negligible aerosol inputs to sediment from regional or long-range pollution sources, possibly related to low annual precipitation. Maximum recorded Pb flux at each site reached up to 63 mg m⁻² yr⁻¹ in the period corresponding to early years of mining when pollution mitigation measures were at a minimum (1950s–1960s). The maximum contribution of mining-derived Pb to these fluxes declined with distance from the mines from 92 ± 8% to 8 ± 4% at the farthest site. Mining-derived Pb was still present at the sediment surface within 9 km of Giant Mine more than ten years after mine closure (5–26 km, 95% confidence interval) and model estimates suggest it could be present for another ∼50–100 years. These results highlight the persistence of Pb pollution in freshwater sediment and the usefulness of Pb stable isotopes to quantify spatial and temporal trends of contamination from mining pollution, particularly as concentrations approach background.

Persistent organic pollutants (POPs) are believed to alter metabolic homeostasis during fetal development, leading to childhood obesity. However, limited studies have explored how fetal chemical exposures relate to birth and infant weight outcomes in low-income Hispanic families at the highest risk of obesity. Therefore, we sought to determine associations between neonatal POPs exposure measured in newborn dried blood spots (DBS) and prenatal diet quality, birth weight, and overweight status at 18 months old. We conducted a case-control study nested within the Starting Early Program randomized controlled trial comparing POPs concentrations in infants with healthy weight (n = 46) and overweight status (n = 52) at age 18 months. Three categories of POPs, organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs) and perfluoroalkyl substances (PFASs) were measured in archived newborn DBS. We assessed correlations between prenatal diet quality and neonatal POPs concentrations. Multivariable regression analyses examined associations between POPs (dichotomized at the mean) and birth weight z-score and weight status at 18 months, controlling for confounders. Seven of eight chemicals had detectable levels in greater than 94% of the sample. Higher protein, sodium and refined grain intake during pregnancy were correlated with lower POPs in newborn DBS. We found that high concentrations of perfluorooctanesulfonate (unstandardized coefficient [B]: −0.62, 95% confidence interval [CI]: −0.96 to −0.29) and perfluorohexanesulfate (B: −0.65, 95% CI: −0.99 to −0.31) were related to lower birth weight z-scores compared to those with low concentrations. We did not find associations between PBDEs, OCPs, and the other PFASs with birth weight z-scores, or between any POPs and weight status at 18 months. In conclusion, two PFASs were associated with lower birth weight, an important indicator of child health and growth, although direct associations with infant overweight status were not found. Whether neonatal POPs exposures contribute to economic and ethnic disparities in early obesity remains unclear.

Rice (Oryza sativa) tends to accumulate elevated levels of arsenic (As) in grain, threatening food safety and human health. The rice rhizosphere has a micro-environment that differs markedly from the bulk soil. Yet, little is known about how this micro-environment influences the mobility of As in the rhizosphere. Using rhizoboxes with two rice cultivars (cv. Shenyou 957 and Yangdao 6) differing in their radial oxygen loss (ROL), we investigated the in situ transformation of As in the rhizosphere associated with changes in microbial communities and As-related functional genes. Contrary to expectation, dissolved (porewater) As concentrations within the rhizosphere increased by 1.3–2.4 fold compared to the bulk soil during the seedling stage, with the magnitude of this difference gradually decreasing over time. The increased As mobilization in the rhizosphere was associated with increased soluble Fe. This increasing trend was associated with the increased abundance of both Fe-reducing bacteria (FeRB) and As-related functional genes within the rhizosphere. Furthermore, bacterial 16S rRNA gene sequencing data showed that the abundances of Geobacter and Clostridium were 3.1 times and 12.4 times higher in the rhizosphere, respectively. The importance of FeRB was also suggested by the fact that dissolved As concentrations were highly correlated with dissolved Fe concentrations (r² = 0.83) and also with the relative abundance of genus Clostridium_sensu_stricto_10 (r² = 0.85). This study highlights that although the rice rhizosphere favors a more aerobic condition compared to the bulk soil, As is more mobilized in the rhizosphere, and that Geobacter and some species of Clostridium play a critical role in controlling As mobilization in the rhizosphere.