Air pollution, which includes particulate matter (PM), is classified in group 1 as a carcinogen to humans by the International Agency for Research in Cancer. Specifically, PM exposure has been associated with lung cancer in patients living in highly polluted cities. The precise mechanism by which PM is linked to cancer has not been completely described, and the genotoxicity induced by PM exposure plays a relevant role in cell damage. In this review, we aimed to analyze the types of DNA damage and alterations in DNA repair pathways induced by PM exposure, from both epidemiological and toxicological studies, to comprehend the contribution of PM exposure to carcinogenesis. Scientific evidence supports that PM exposure mainly causes oxidative stress by reactive oxygen species (ROS) and the formation of DNA adducts, specifically by polycyclic aromatic hydrocarbons (PAH). PM exposure also induces double-strand breaks (DSBs) and deregulates the expression of some proteins in DNA repair pathways, precisely, base and nucleotide excision repairs and homologous repair. Furthermore, specific polymorphisms of DNA repair genes could lead to an adverse response in subjects exposed to PM. Nevertheless, information about the effects of PM on DNA repair pathways is still limited, and it has not been possible to conclude which pathways are the most affected by exposure to PM or if DNA damage is repaired properly. Therefore, deepening the study of genotoxic damage and alterations of DNA repair pathways is needed for a more precise understanding of the carcinogenic mechanism of PM.

Microplastic (MP) has been detected ubiquitously in freshwater systems. Until now MP sampling, however, is predominantly based on short-term net or pumping and filtration systems which can only provide snapshots of MP abundance; especially in flowing water bodies. To improve representativeness in the determination of MP occurrences in these aquatic compartments, an integrative approach that covers larger water volumes for a longer period of time is required. In this regard, surface water supplied drinking water treatment plants (DWTPs) represent an opportunity. In DWTPs, suspended solids from thousands of cubic metres of raw water are continuously removed over several hours and enriched in coagulation/flocculation and filtration processes. Our hypothesis was that MP is also removed to a full extent, like suspended solids, and that an integrative approach for identification and quantification in raw water can be derived from the analysis of MP in the treatment sludge. To prove this hypothesis, treatment sludge from a riverside DWTP (Warnow river, North-Eastern Germany) was analysed for MP > 50 μm. A sample purification protocol overcoming potential matrix effects caused by coagulants and flocculants was developed and validated. MP was analysed using micro-Raman spectroscopy. MP occurrence determined for the Warnow river was compared with in situ reference sampling using an established pumping and filtration system at relatively stable flow conditions. As result, the number of MP particles derived from treatment sludge was extrapolated to 196 ± 42 m⁻³ for the Warnow river and is statistically insignificantly different from 233 ± 36 m⁻³ identified by conventional water sampling. In addition, the polymer distribution and particles shape indicated the validity of the integrative concept. Consequently, the determination of MP abundance for freshwater systems based on DWTP treatment sludge represents an adequate method to estimate MP concentrations in flowing waters in an integrative way.

Transformation products (TPs) of micropollutants contaminating our water resources have become an emerging issue due to the potential threats they pose to environmental and human health. This study investigated the transformation chemistry, toxicity, physicochemical properties and environmental behavior resulting from photocatalytic transformation of organic UV filters as model micropollutants. 3-Benzylidene camphor (3-BC), 4-hydroxybenzophenone (4-HB) and octocrylene (OC) were effectively degraded by UV-A/TiO₂ treatment, with TPs identified and characterized with high resolution mass spectrometry. Nitrated-TPs were observed to be formed in the presence of nitrite and nitrate for 3-BC and 4-HB, suggesting that the transformation process could be altered by components in the water matrix. Vibrio fischeri bioluminescence inhibition assay revealed an increase in toxicity of TPs derived from photocatalytic treatment, with quantitative structure-activity relationship model (ECOSAR) predicted an enhanced toxicity of individual TPs' after transformation. Assessment of physicochemical properties and environmental behavior suggested that TPs as compared to parent organic UV filters, may represent even greater hazards due to their increased water solubility, persistence and mobility – in addition to retaining the parent organic UV filter's toxicity. The results provide important information relevant to the potential risks for the selected organic UV filters, and their corresponding transformation products.

The annual production of sludges is significant all over the world, and large amounts of sludges have been improperly disposed by random dumping. The contaminants in these sludges may leak into the surrounding soils, surface and groundwater, or be blown into the atmosphere, thereby causing adverse effects to human health. In this study, the (anti-)androgenic activities in organic extracts of sludges produced from both industrial and domestic wastewater treatment plants (WWTPs) were examined using reporter gene assay based on MDA-kb2 cell lines and the potential (anti-)androgenic risks were assessed using hazard index (HI) based on bioassays. Twelve of the 18 samples exhibited androgen receptor (AR) antagonistic activities, with AR antagonistic equivalents ranging from 1.2 × 10² μg flutamide/g sludge to 1.8 × 10⁴ μg flutamide/g sludge; however, no AR agonistic activity was detected in any of the tested samples. These 12 sludges were all from chemical WWTPs; no sludges from domestic WWTPs displayed AR antagonistic activity. Aside from wastewater source, treatment scale and technology could also influence AR antagonistic potencies. The HI values of all the 12 sludges exceeded 1.0, and the highest HI value was above 3.0 × 10³ for children; this indicates that these sludges might cause adverse effects to human health and that children are at a greater risk than adults. The anti-androgenic potencies and risks of the subdivided fractions were also determined, and medium-polar and polar fractions were found to have relatively high detection rates and contribution rates to the AR antagonistic potencies and risks of the raw sample extracts.

Increasing concerns over bisphenol A (BPA) as an endocrine disrupting chemical (EDC) and its adverse effects on both humans and animals have led to the substitution by structural analogs, such as bisphenol F (BPF), in many application areas. Information regarding to the carry-over of this emerging chemical in farm animals is essential for legislation and risk assessment purposes. In this study, a large-scale number of animal experiments were designed to investigate the transfer of BPF from feed to eggs. One control and three experimental groups of laying hens (72 hens per group) were fed with basal diets and BPF-contaminated feed at concentration levels of 0.1, 0.5 and 2.5 mg kg⁻¹, respectively, for two weeks. The hens were then fed with BPF-free diets for a further four weeks. Eggs were collected daily, and separated into egg yolk and white for BPF analysis. The effects of different levels of BPF exposure on laying performance followed a non-monotonic dose-response curve, since low level BPF (0.1 mg kg⁻¹) exposure did increase the laying rate, mean egg weight and daily feed intake, while high level BPF (2.5 mg kg⁻¹) exposure showed a decreasing trend. BPF residues were detected in both egg yolks and whole eggs after two days of administration, and plateau phase was achieved within 9–18 days. There are clear linear dose-response relationships between the plateau BPF concentrations in feed and eggs. The residue of BPF was found mainly in egg yolks with conjugated form and depleted slowly (still detected 21 days after feeding the BPF-free diet of the high level group). Mean carry-over rate of 0.59% BPF from feed to eggs was obtained. Compared with the carry-over rates of PCBs and dioxins, BPF showed a relatively minor trend of bioaccumulation in eggs. To the best of our knowledge, this is the first report on the deposition, depletion, and bioaccumulation study of bisphenols in farm animals. The quantity of data can therefore be helpful in the frame of risk assessment, especially for a comprehensive estimation of consumer exposure to the residues of bisphenols.

Heavy metal pollution is becoming recurrent and threatens biota biosafety in many agricultural fields. Diverse solutions explore the application of amendments to enable remediation. Sulfur represents a nonmetallic chemical element that actively affects heavy metals phytoextraction, and promotes and alternatively mitigates soil functions. In this study, we conduct a meta-analysis to synthesize the current knowledge on the influence of sulfur amendments on plants heavy metals uptake from contaminated soil media. Random-effects model was used to summarize effect sizes from 524 data points extracted from 30 peer reviewed studies. The phytoextraction of cadmium, chromium and nickel were 1.6-, 3.3-, and 12.6-fold, respectively, higher when sulfur amendment was applied; while copper uptake was 0.3-fold lower. Irrespective of the sulfur type, heavy metal extraction increased with the raising sulfur stress. Individual organs showed significant differences of heavy metal uptake between sulfur applied and non-sulfur treatments, and combined organs did not. The heavy metals uptake in leaves and roots were higher in sulfur applied than non-sulfur applied treatments, while those in grain, husk, and stalks were lower. The heavy metals phytoextraction (response ratio) followed the order roots > leaves > stalk > grain > husk. Moreover, heavy metals uptake was 2-fold higher in the sulfur applied than the non-sulfur treatments under ideal (5.5–8) and alkaline conditions (8–14), and 0.2-fold lower under acidic pH (1–5.5). Cadmium, manganese and nickel, and chromium were the most extracted under sulfur application by Vicia sp., Sorghum sp. and Brassica sp., respectively; while chromium, manganese, and iron were the most uptake without sulfur amendments by Oryza sp., Zea sp. and Sorghum sp., respectively. Our study highlights that the influence of sulfur on heavy metal phytoextraction depends on the single or combined effects of sulfur stress intensity, sulfur compounds, plant organ, plant type, and soil pH condition.

Oxytetracycline (OTC) is a broad-spectrum antibiotic widely used in aquaculture, resulting in contamination of aquatic environments. In a previous study, we observed significant effects of OTC sublethal concentrations in zebrafish, its microbiome and the water bacterial community. Here we assessed the extent to which these effects are reversible after a recovery period. Zebrafish adults were exposed to OTC (10,000 μg/L) via water exposure. Effects were analyzed at 5 days (5 dE) and 2 months (2 mE) of exposure and recovery was assessed at 5 days (5dPE) and 1 month (1mPE) after exposure Impacts were observed in fish energetic reserves and in fish and water microbiomes structure, being significant even at 5 dE. At energetic reserves level, the effect in cellular energy allocation (CEA) was dependent on the exposure time: initially CEA increased while after 2 mE CEA decreased. At microbiome level, diversity was not affected but the richness of the water microbiome significantly decreased at 2 mE.Regarding the post-exposure period, at CEA level, organisms seem to recover. In water and gut microbiomes OTC effects were also attenuated after exposure ceases, indicating a recovery. Even so, the structure of water exposed community remained significantly different towards the control, while richness of this community significantly increased at 1mPE. During exposure the relative abundance of 11 and 16 genera was significantly affected in the gut and water microbiomes, respectively, though these numbers decreased to 4 and 8 genera in the post-exposure period. At functional level during exposure 12 and 13 pathways were predicted to be affected in zebrafish gut and water microbiomes respectively, while post-exposure few pathways remained significantly affected. Hence, our results suggest a recovery of the fish fitness as well as of the water and intestine microbiomes after exposure ceases. Even so, some of the effects caused by OTC remain significant after this recovery period.

Microplastics (MPs) are plastic fragments less than 5 mm, which may have adverse impacts on organisms. In this study, we investigated the impacts and mechanisms of polystyrene MPs (10 μm and 100 μm) and nanoplastics (NPs, 100 nm) with different concentrations (10 mg/kg and 100 mg/kg) in soil on the uptake of metal Cd and semi-metal As in earthworms, Eisenia fetida. MPs facilitated the accumulation of (semi-)metals via damaging the integrity of earthworm intestine, and earthworms accumulated more (semi-)metals in MP treatment groups than NP treatment groups, especially in group of 100 mg/kg of 10 μm MP with concentrations of 1.13 mg/kg and 32.7 mg/kg of Cd and As, respectively. Higher genotoxicity to earthworms was observed for MPs than NPs. Antioxidant enzymes activity and their mRNA gene relative expression levels indicated that MPs with high concentration induced severer damage to earthworms, thus resulting in the increased accumulation of (semi-)metals by earthworms. In addition, proteomic and metabolomic analysis revealed that MPs (100 ppm of 10 μm) disturbed the earthworm immune and metabolic systems, resulting in the highest accumulation of (semi-)metals in earthworms. This study clarifies the influence mechanisms of MPs with different sizes and levels on the accumulation of (semi-)metals by terrestrial invertebrates.

Chlorine-based compounds are typical persistent organic pollutants (POPs) that are widely generated in industrial production. This paper reports an effective and rapid pulsed laser irradiation technique for the dechlorination of hexachlorobenzene (HCB), a model pollutant, without additional catalysts or supports. The effects of the laser parameters, including the laser wavelength and power, on the dechlorination efficiency, were also investigated. The optimized results showed that a lower laser wavelength of 266 nm with 10 mJ/pulse power exhibited the highest dechlorination efficiency with 95% within 15 min. In addition, the laser beam effect was examined by designing the direct-pulsed laser single and multipath irradiation system. The results showed that improving the laser beam profile resulted in more than 95% dechlorination efficiency within 5 min. Thus, the dechlorination reaction proceeded much faster as the surface area that the laser beam came in contact with increased due to the multipath system than the single pathway. Gas chromatography identified benzene as the final product of HCB with pentachlorobenzene (PCB), tetrachlorobenzene (TeCB), trichlorobenzene (TCB), dichlorobenzene (DCB), and chlorobenzene (CB) as intermediate products. The mechanism of HCB dechlorination was explained by a comparison of theoretical calculations with the experimental results. The present study reports an advanced technique for the complete dechlorination of chlorobenzenes, which holds great application potential in environmental remediation.

In recent years, an extensive exposure to antibiotics from various sources has been demonstrated in China by the biomonitoring method, but the temporal trend remains little known. The study aim was to explore the temporal trend of exposure to antibiotics and associated health risk in children. A dynamic child cohort was established in Shanghai, East China between 2017 and 2020. A total of 684 school children aged 7-11 years were included, and 280 in 2017, 279 in 2018, 288 in 2019, and 287 in 2020 participated in annual surveys. Twenty-three typical antibiotics and three metabolites from five categories (four tetracyclines, five qinolones, six macrolides, eight sulfonamides, and three phenicols), bisphenol A (BPA), and monobutyl phthalate (MBP) were determined in urine. Logistic regression analysis with generalized estimating equations was conducted to investigate the associations between various variables and the detection frequency of antibiotics in urine. Seventeen antibiotics and three metabolites were found in 51.9% of all urine samples. Compared to 2017, the detection frequency in urine reduced 31.8% in 2020 for all antibiotics (58.2% vs 39.7%) and reduced 36.8%–55.8% for tetracyclines (11.4% vs 7.0%), qinolones (34.3% vs 21.3%), macrolides (8.6% vs 3.8%), sulfonamides (16.4% vs 8.7%), and phenicols (19.3% vs 12.2%). After accounting for personal characteristics, food consumption, and urinary BPA and MBP, a decreasing temporal trend of detection frequencies was observed from 2017 to 2020 for most antibiotics. Urinary concentration, estimated daily intake, and acceptable daily intake-based health risk of antibiotics showed a temporal trend similar to detection frequency. There was an extensive exposure to antibiotics in children. However, a decreasing temporal trend occurred for the exposure during the period from 2017 to 2020. The trend was likely to be caused by decreased antibiotic use and/or decreased residues in food and/or drinking water.