Road traffic is one of the major sources of atmospheric particles in urban areas. Modelling the contribution of this source to urban pollution requires reliable estimates of emission factors possibly resolved in size. In this work, size-resolved particle emission factors (EFs) of the mixed vehicle fleet were measured in the urban area of Lecce (south-eastern Italy). The approach used is based on vertical fluxes measured with eddy-covariance, counting of vehicles, and estimation of footprints. Results show that the average EF in number (range 0.009–3 μm) was 2.2*10¹⁴ #/Veh km, being dominated by ultrafine particles (Dₚ < 0.25 μm) due to exhaust emissions. EF number size distribution decreases with particle size. A reduction of more than four orders of magnitude was observed at Dₚ ≅ 0.9 μm. EF mass size distribution reaches a maximum around Dₚ ≅ 0.3 μm then decreases until Dₚ ≅ 0.9 μm. For larger particles EF in mass increases for the influence of non-exhaust emissions. Average emission factor of PM₁ was 56 mg/Veh Km and that of PM₂.₅ was 63 mg/Veh Km. A comparison of measurements taken in 2010 and 2015 in the same area shows a decreasing trend of the average total EF in number of about 56%, likely as a consequence of the increased use of new generation vehicles following more restrictive limits for particle emissions.

The phenylpyrazole insecticide, fipronil, isused for the eradication of insects in agriculture, which also exposes various non-target groups such as birds and animals. Our aim was to assess the cardiac and pulmonary consequences of sub-acute administration of fipronil (¹∕₅ LD₅₀; 2.26 mg/kg) in the Japanese quail for fifteen days and to determine the tissue recovery over a period of 60 days. Fipronil exposure led to a significant decrease in the body weight of the treated birds. Its exposure also induced cardiac and pulmonary damage of varying degrees. Fipronil increased the lipid peroxide (LPO) and nitric oxide (NO) contents as well as indices of tissue injury in the serum of exposed birds. Furthermore, it decreased the antioxidant indices in both the organs. Most of these changes gradually reversed and the histological changes, particularly of the heart, reversed completely by day-60 of recovery. Furthermore, alterations in the mRNA gene expressions of Nuclear factor kappa B (NF-κB), Interleukin 6 (IL-6), and Tumor necrosis factor-alpha (TNF-α) were monitored by quantitative polymerase chain reaction (RT-PCR). In both the tissues, a significant up-regulation of the transcripts was recorded after fipronil administration, which was reversed during the recovery period in the heart tissue except for TNF-α, while the transcripts in the lung tissue declined non-significantly. This study showed that the exposure of Japanese quail to fipronil has a profound negative impact on heart and lung including oxidative injury and tissue inflammation. Fipronil can induce the activity of NF-κB inflammatory -signaling pathway that play a role in the associated tissue inflammation. Although most of the cardiac changes could be reversed after a recovery period of sixty days, the pulmonary changes did not reverse much.

The intensive use of Cu-based pesticides in agriculture could have an unintended impact on the ecosystems and human health via different exposure pathways. This paper presents the results of experiments involving colloidal stability, aggregation, and dissolution of Cu₂O commercial pesticide under various environmental conditions in view of ecological implications. The investigated pesticide contains ∼750 g kg⁻¹ Cu (75% weight of product), Cu₂O particles with sizes < 1 μm, and nominal size fraction of Cu₂O nanoparticles. The co-presence of Ca²⁺ (20 mM) and humic acid (HA, 15 mg L⁻¹) significantly modulates (p < 0.001) the colloidal stability and mobility of particles. The dissolution of Cu at pH 5.5 was about 85%, 90%, and 75% weight more than the dissolution of Cu at pH 7.0, pH 8.5, and pH 7.0 and pH 8.5 combined, respectively in all dispersions. However, increasing HA content from 0 to 15 mg L⁻¹ reduced the dissolution of Cu by 56%, 50%, and 40% weight at pH 5.5, 7.0, and 8.5, respectively. Thus, pH below 7.0 is a critical factor to control the dissolution and bioavailability of Cu that may pose ecotoxicity and environmental pollution, whereas pH above 7.0 and the presence of HA attenuate the pH effect. These findings provide insight into how the potential mobility and bioavailability of Cu is modulated by the water chemistry under various environmental scenarios and media.

This work explores the use of Raman micro-spectroscopy to determine sources of airborne particulate matter collected on PM₂.₅ air filters in Imperial Valley, California. The goal is to examine if nearby soil is a potential source of particles sampled on air filters deployed in an urbanized desert area during events of unusually high PM₂.₅ excursions. Particle specific composition information can be an indicator of potential origin. This can provide insights into the source of unexpectedly high proportion of large particles sampled on PM₂.₅ filters in the vicinity of Imperial Valley. The measured spectral correspondence between the filter and soil particles, in the size range of 2.5–10 μm, is consistent with windblown dust being a likely source of the larger (>2.5 μm) particles collected on the PM₂.₅ filters. Additionally, these particles were identified as components of commonly occurring crustal minerals in the vicinity of the sampling site, such as iron oxides, hydroxides, sulfides, titanium dioxides and aluminosilicates. A substantial portion of the analyzed filter particles displayed a strong broadband fluorescence signal, which is consistent with the presence of organic matter and has been recognized as a marker for soil related origin of the filter particles. Elemental carbon (soot) was found to be prevalent among the particles as well, suggesting the existence of combustion related sources. Comparison between a heavily loaded filter sample and a filter with a more typical, lower loading did not show any obvious difference in chemical compositions. In both cases the particles appeared to be of crustal origin with the prevalence of elemental carbon. The primary difference between these two filter samples appear to be their particle size distribution - the heavily loaded filter sample contained greater proportion of large particles (>2.5 μm), and was more consistent with spectral signature of soils analyzed from the region.

Although it is fairly well known that eggshells are the major source of Ca and other micronutrients for developing avian embryos, potential anatomical and/or ecological correlates explaining the variation in embryo-induced depletion of micronutrients from eggshells remain to be addressed. Using unhatched eggs at various developmental stages and post-hatched eggshells of wild and captive-bred birds of a large precocial species, the Capercaillie Tetrao urogallus, we explored two major questions. (i) Do egg size, regional eggshell thickness as well as levels of two major micronutrients (Ca and Mg) and eight trace elements (Cr, Cu, Mn, Fe, Co, Cd, Pb and Zn) measured in egg shells and contents vary with embryonic age within and between wild and captive-bred bird eggs? (ii) How the proportions of eggshell elements become depleted during the entire process of embryogenesis? The eggshells of wild Capercaillies were thinner at the equator and the sharp pole, and contained more Mg and Ca, while in their contents there was more Cu, Cd and Pb compared with captive birds. All ten metal concentrations measured in the egg contents increased (from 15% to 285% more) with the age of embryos. The concentrations of six elements measured in eggshells (Cu, Mn, Fe, Co, Cd and Zn) decreased consistently (from 15 to 70% less) during embryogenesis. This suggests the presence of these elements in the innermost decalcified shell layer and their further mobilization into the embryos/egg contents. Our results strongly imply that most trace elements present in the egg contents/developing embryos are mobilized from the eggshells. We highlight the fact that knowledge of the magnitude of embryogenesis-related functional changes in the physical (such as shell thickness) and chemical traits of the eggs and eggshells of oviparous vertebrates is fundamental for drawing correct inferences regarding the response of an individual to variable environmental conditions.

Fipronil, a broad-spectrum chiral insecticide, has been documented to induce significant neurotoxicity to nontarget aquatic species; however, whether its neurotoxicity behaves enantioselectively and what molecular mechanisms correspond to the neurotoxicity remain unanswered. To date, few investigations have focused on the genomic mechanisms responsible for the enantioselective toxicity of chiral pesticides. The epigenetic modifications, especially DNA methylation, caused by the pesticides are also blind spot of the research works. Video tracking showed that R-fipronil exhibited more intense neurotoxicity, as well as the induction of more severe anxiety-like behavior, such as boosted swimming speed and dysregulated photoperiodic locomotion, to embryonic and larval zebrafish compared with S-fipronil. The MeDIP-Seq analysis, combined with Gene Ontology and KEGG, revealed that R-fipronil disrupted five signaling pathways (MAPK, Calcium signaling, Neuroactive ligand-receptor interaction, Purine metabolism, and Endocytosis) to a greater extent than S-fipronil through the hypermethylation of several important neuro-related genes, whereas no significant alterations of global DNA methylation were observed on the two enantiomers. To summarize, our data indicated that the fipronil-conducted enantioselective neurotoxicity likely applied its enantioselectivity by the dysregulation of DNA methylation. Our study also provided novel epigenetic insights into the study of enantioselective biological effects and the relevant underlying mechanisms of chiral insecticide.

In recent years, the impact of Plant Protection Products (PPPs) on insect pollinator decline has stimulated significant amounts of research, as well as political and public interest. PPP residues have been found in various bee-related matrices, resulting in governmental bodies worldwide releasing guidance documents on methods for the assessment of the overall risk of PPPs to different bee species. An essential part of these risk assessments are PPP residues found in pollen and nectar, as they represent a key route of exposure. However, PPP residue values in these matrices exhibit large variations and are not available for many PPPs and crop species combinations, which results in inaccurate estimations and uncertainties in risk evaluation. Additionally, residue studies on pollen and nectar are expensive and practically challenging. An extrapolation between different cropping scenarios and PPPs is not yet justified, as the behaviour of PPPs in pollen and nectar is poorly understood. Therefore, this review aims to contribute to a better knowledge and understanding of the fate of PPP residues in pollen and nectar and to outline knowledge gaps and future research needs. The literature suggests that four primary factors, the crop type, the application method, the physicochemical properties of a compound and the environmental conditions have the greatest influence on PPP residues in pollen and nectar. However, these factors consist of many sub-factors and initial effects may be disguised by different sampling methodologies, impeding their exact characterisation. Moreover, knowledge about these factors is ambiguous and restricted to a few compounds and plant species. We propose that future research should concentrate on identifying relationships and common features amongst various PPP applications and crops, as well as an overall quantification of the described parameters; in order to enable a reliable estimation of PPP residues in pollen, nectar and other bee matrices.

Estrogenic endocrine disrupting chemicals (EDCs) are natural hormones, synthetic compounds or industrial chemicals that mimic estrogens due to their structural similarity with estrogen's functional moieties. They typically enter aquatic environments through wastewater treatment plant effluents or runoff from intensive livestock operations. Globally, most natural and synthetic estrogens in receiving aquatic environments are in the low ng/L range, while industrial chemicals (such as bisphenol A, nonylphenol and octylphenol) are present in the μg to low mg/L range. These environmental concentrations often exceed laboratory-based predicted no effect concentrations (PNECs) and have been evidenced to cause negative reproductive impacts on resident aquatic biota. In vertebrates, such as fish, a well-established indicator of estrogen-mediated endocrine disruption is overexpression of the egg yolk protein precursor vitellogenin (Vtg) in males. Although the vertebrate Vtg has high sensitivity and specificity to estrogens, and the molecular basis of its estrogen inducibility has been well studied, there is growing ethical concern over the use of vertebrate animals for contaminant monitoring. The potential utility of the invertebrate Vtg as a biomonitor for environmental estrogens has therefore gained increasing attention. Here we review evidence providing support that the molluscan Vtg holds promise as an invertebrate biomarker for exposure to estrogens. Unlike vertebrates, estrogen signalling in invertebrates remains largely unclarified and the classical genomic pathway only partially explains estrogen-mediated activation of Vtg. In light of this, in the latter part of this review, we summarise recent progress towards understanding the molecular mechanisms underlying the activation of the molluscan Vtg gene by estrogens and present a hypothetical model of the interplay between genomic and non-genomic pathways in the transcriptional regulation of the gene.

The presence of PM₂.₅ may affect the photodegradation of benzene in the natural atmosphere. On one hand, the photodegradation of benzene may be promoted with the increase in PM₂.₅ concentrations, owing to adsorption and catalysis effect of PM₂.₅ surface; On the other hand, PM₂.₅ can scatter or block ultraviolet light and lead to weakening the photochemical reactions in the atmospheric system. It is very difficult to prove which process is dominant in the real atmosphere due to the complexity of the atmosphere. Based on coupling detrended fluctuation analysis, the goal of this work is to reveal the role of PM₂.₅ in the photodegradation of benzene in real atmosphere over long time scales. The 9 years regular monitoring data from 2007 to 2016 in Puzi of Taiwan are analyzed. A new nonlinear parameter (PDB) is established to characterize the photodegradation degree of atmospheric benzene. Based on sliding window technique, the correlations between the temporal variation of PDB and PM₂.₅ are analyzed. The results show that there is a positive correlation between PDB and PM₂.₅ in daytime and little correlation between them in nighttime. It indicates that PM₂.₅ mainly plays the promoting effect on the photodegradation of atmospheric benzene. This is the first study to directly determine the role of PM₂.₅ in the photochemical behavior of atmospheric benzene based on long term field observation data. Moreover, the results suggest that the regional transport of PM₂.₅ could seriously affect the geochemistry cycle of some VOCs. This research provides a new analysis method to directly quantify the effect of PM₂.₅ on the photodegradation of VOCs in the real atmosphere. It is helpful for evaluating the role of PM₂.₅ in the complex photochemical system.

This study characterized spatio-temporal variations in the concentration of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds in the vicinity of gas and compressed natural gas (CNG) stations in Tehran, Iran. Health risk assessment (HRA) was computed using Monte Carlo simulations (MCS) for evaluating inhalation lifetime cancer risk (LTCR), the hazard quotient (HQ), and sensitivity analysis (SA) for BTEX exposure in different age groups (birth to <81) and as a function of distance (0–250 m) from the center of the stations. For all monitoring stations, the average values of benzene, toluene, ethylbenzene, and xylene in winter were 466.09 ± 132.25, 873.13 ± 233.51, 493.05 ± 141.22, and 910.57 ± 145.40 μg m⁻³, respectively. The mean wintertime ratios of T/B for the 12 stations ranged from 1.69 to 2.04. Furthermore, there was no significant relationship between the concentration of BTEX with either the specific month or distance from the center of stations (p > 0.05). Factors promoting BTEX formation in the study region were fuel evaporation and gas/CNG station emissions. The LTCRs for the target compounds in the winter for different age groups and distances from the center of stations was limited to 2.11 × 10⁻⁴ to 1.82 × 10⁻³ and 2.30 × 10⁻⁴ to 2.01 × 10⁻³, respectively, which exceeded proposed values by U.S. EPA. Moreover, the HQs for BTEX for three age groups and distances were limited to between 2.89 × 10⁻⁵ and 9.33 × 10⁻², which were lower than the acceptable limit (HQs < 1). The results of this work are applicable to similar areas that are heavily populated with vehicular traffic. This study motivates a closer look at mitigation strategies to limit the health effects of carcinogenic emissions such as benzene and ethylbenzene from gas/CNG stations.